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  • 1.
    Alfredson, Håkan
    et al.
    Umeå University, Faculty of Medicine, Surgical and Perioperative Sciences, Sports Medicine.
    Harstad, Herlof
    Haugen, Simen
    Ohberg, Lars
    Umeå University, Faculty of Medicine, Radiation Sciences, Diagnostic Radiology.
    Sclerosing polidocanol injections to treat chronic painful shoulder impingement syndrome-results of a two-centre collaborative pilot study.2006In: Knee Surg Sports Traumatol Arthrosc, ISSN 0942-2056, Vol. 14, no 12, 1321-6 p.Article in journal (Refereed)
  • 2.
    Alfredson, Håkan
    et al.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Sports Medicine.
    Masci, Lorenzo
    Öhberg, Lars
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    Partial midportion Achilles tendon ruptures: new sonographic findings helpful for diagnosis.2011In: British Journal of Sports Medicine, ISSN 0306-3674, E-ISSN 1473-0480, Vol. 45, no 5, 429-432 p.Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Partial Achilles tendon ruptures are not always easy to diagnose. A history including a sudden onset of pain, and/or relative weakness in plantar flexion force, are indicators. The most loaded side of the Achilles tendon is the dorsal side (skin side). OBJECTIVE: To evaluate the ultrasound (US) and Doppler (CD) findings in patients with a suspected partial rupture in the Achilles tendon. Material and METHODS: Seventeen patients (16 men and 1 woman) with a mean age of 36 years (range 23-71) were examined clinically and by US+CD because of midportion Achilles tendon pain. There was an acute onset in 14/17 patients, and all had painful weakness during tendon loading activity. RESULTS: In all patients the US examination showed a partial Achilles tendon rupture, presented as a disrupted dorsal (skin side) tendon line and an irregular tendon structure mainly located in the dorsal and mid-tendon. The size of the rupture varied from 1/3 to 2/3 of the tendon thickness. In the dorsal part of the tendon, corresponding to the region with disrupted tendon line and irregular structure, CD examination showed high blood flow-most often of a longitudinal character. Six of the patients were surgically treated, and macroscopical examination verified the ultrasound findings, showing disruption on the dorsal side, and a partial rupture in the dorsal and mid- tendon. CONCLUSIONS: Ultrasound and Doppler examination can be helpful tools to diagnose partial midportion Achilles tendon ruptures. The characteristic findings of a disrupted dorsal tendon line, and high blood flow in the structurally abnormal dorsal tendon, indicate a partial rupture.

  • 3.
    Alfredson, Håkan
    et al.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Sports Medicine.
    Ohberg, Lars
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    Increased intratendinous vascularity in the early period after sclerosing injection treatment in Achilles tendinosis: a healing response?2006In: Knee Surg Sports Traumatol Arthrosc, ISSN 0942-2056, Vol. 14, no 4, 399-401 p.Article in journal (Refereed)
  • 4.
    Alfredson, Håkan
    et al.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Sports Medicine.
    Pietilä, Tom
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Sports Medicine.
    Öhberg, Lars
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    Lorentzon, Ronny
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    Achilles tendinosis and calf muscle strength: the effect of short-term immobilization after surgical treatment1998In: American Journal of Sports Medicine, ISSN 0363-5465, E-ISSN 1552-3365, Vol. 26, no 2, 166-71 p.Article in journal (Refereed)
    Abstract [en]

    We prospectively studied calf muscle strength in 7 men and 4 women (mean age, 40.9 +/- 10.1 years) who had surgical treatment for chronic Achilles tendinosis. Surgery was followed by immobilization in a weightbearing below-the-knee plaster cast for 2 weeks followed by a stepwise increasing strength training program. Strength measurements (peak torque and total work) were done preoperatively (Week 0) and at 16, 26, and 52 weeks postoperatively. We measured isokinetic concentric plantar flexion strength at 90 and 225 deg/sec and eccentric flexion strength at 90 deg/sec on both the injured and noninjured sides. Preoperatively, concentric and eccentric strength were significantly lower on the injured side at 90 and 225 deg/sec. Postoperatively, concentric peak torque on the injured side decreased significantly between Weeks 0 and 16 and increased significantly between Weeks 26 and 52 at 90 deg/sec but was significantly lower than that on the noninjured side at all periods and at both velocities. The eccentric strength was significantly lower on the injured side at Week 26 but increased significantly until at Week 52 no significant differences between the sides could be demonstrated. It seems, therefore, that the recovery in concentric and eccentric calf muscle strength after surgery for Achilles tendinosis is slow. We saw no obvious advantages in recovery of muscle strength with a short immobilization time (2 weeks) versus a longer (6 weeks) period used in a previous study.

  • 5.
    Alfredson, Håkan
    et al.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences.
    Willberg, Lotta
    Öhberg, Lars
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    Forsgren, Sture
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Anatomy.
    Ultrasound and doppler-guided artthroscopic shaving for the treatment of patellar tendinopathy/jumper´s knee: biological background and description of method2011In: Anterior knee pain and patellar instability / [ed] Sanchis-Alfonso, Vicente, London: Springer London, 2011, 367-371 p.Chapter in book (Refereed)
    Abstract [en]

    Treatment with ultrasound and Doppler-guided arthroscopic shaving of the region with vessels and nerves outside the dorsal tendon has shown promising clinical results in patients with proximal patellar tendinopathy/Jumper´s knee. The results concerning only a limited patient material has been published in a scientific paper. Results on larger materials are under evaluation for later publication. Proper understanding of the ultrasound and Doppler findings, to enable for a precise and minimal arthroscopic shaving procedure on the dorsal side of the tendon, are cornerstones using this new type of treatment.

  • 6.
    Alfredson, Håkan
    et al.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Sports Medicine.
    Öhberg, Lars
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    Neovascularisation in chronic painful patellar tendinosis - promising results after sclerosing neovessels outside the tendon challenge the need for surgery2005In: Knee Surg Sports Traumatol Arthrosc, ISSN 0942-2056, Vol. 13, no 2, 74-80 p.Article in journal (Refereed)
  • 7.
    Alfredson, Håkan
    et al.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Sports Medicine.
    Öhberg, Lars
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    Sclerosing injections to areas of neo-vascularisation reduce pain in chronic Achilles tendinopathy: a double-blind randomised controlled trial2005In: Knee Surgery, Sports Traumatology, Arthroscopy, ISSN 0942-2056, E-ISSN 1433-7347, Vol. 13, no 4, 338-344 p.Article in journal (Refereed)
  • 8.
    Alfredson, Håkan
    et al.
    Umeå University, Faculty of Medicine, Surgical and Perioperative Sciences, Sports Medicine.
    Öhberg, Lars
    Umeå University, Faculty of Medicine, Radiation Sciences, Diagnostic Radiology.
    Zeisig, Ewa
    Umeå University, Faculty of Medicine, Surgical and Perioperative Sciences, Sports Medicine.
    Lorentzon, Ronny
    Umeå University, Faculty of Medicine, Surgical and Perioperative Sciences, Sports Medicine.
    Treatment of midportion Achilles tendinosis: similar clinical results with US and CD-guided surgery outside the tendon and sclerosing polidocanol injections.2007In: Knee Surg Sports Traumatol Arthrosc, ISSN 0942-2056, Vol. 15, no 12, 1504-1509 p.Article in journal (Refereed)
  • 9.
    Alkstedt, Karl
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    Respiratory gated PET/CT in lung cancer, a comparison with static PET/CT2012Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
  • 10.
    Ambarki, Khalid
    et al.
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Hallberg, Per
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Jóhannesson, Gauti
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Ophthalmology.
    Lindén, Christina
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Ophthalmology.
    Zarrinkoob, Laleh
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Wåhlin, Anders
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics. Umeå University, Faculty of Medicine, Umeå Centre for Functional Brain Imaging (UFBI).
    Birgander, Richard
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    Malm, Jan
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Eklund, Anders
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Blood flow of ophthalmic artery in healthy individuals determined by phase-contrast magnetic resonance imaging2013In: Investigative Ophthalmology and Visual Science, ISSN 0146-0404, Vol. 54, no 4, 2738-2745 p.Article in journal (Refereed)
    Abstract [en]

    PURPOSE: Recent development of magnetic resonance imaging (MRI) offers new possibilities to assess ocular blood flow. This prospective study evaluates the feasibility of phase-contrast MRI (PCMRI) to measure flow rate in the ophthalmic artery (OA) and establish reference values in healthy young (HY) and elderly (HE) subjects.

    METHODS: Fifty HY subjects (28 females, 21-30 years of age) and 44 HE (23 females, 64-80 years of age) were scanned on a 3-Tesla MR system. The PCMRI sequence had a spatial resolution of 0.35 mm per pixel, with the measurement plan placed perpendicularly to the OA. Mean flow rate (Qmean), resistive index (RI), and arterial volume pulsatility of OA (ΔVmax) were measured from the flow rate curve. Accuracy of PCMRI measures was investigated using a vessel-phantom mimicking the diameter and the flow rate range of the human OA.

    RESULTS: Flow rate could be assessed in 97% of the OAs. Phantom investigations showed good agreement between the reference and PCMRI measurements with an error of <7%. No statistical difference was found in Qmean between HY and HE individuals (HY: mean ± SD = 10.37 ± 4.45 mL/min; HE: 10.81 ± 5.15 mL/min, P = 0.655). The mean of ΔVmax (HY: 18.70 ± 7.24 μL; HE: 26.27 ± 12.59 μL, P < 0.001) and RI (HY: 0.62 ± 0.08; HE: 0.67 ± 0.1, P = 0.012) were significantly different between HY and HE.

    CONCLUSIONS: This study demonstrated that the flow rate of OA can be quantified using PCMRI. There was an age difference in the pulsatility parameters; however, the mean flow rate appeared independent of age. The primary difference in flow curves between HE and HY was in the relaxation phase of the systolic peak.

  • 11.
    Ambarki, Khalid
    et al.
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Israelsson, Hanna
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Neurology.
    Wåhlin, Anders
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Birgander, Richard
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    Eklund, Anders
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Malm, Jan
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Neurology.
    Brain ventricular size in healthy elderly: comparison between evans index and volume measurement.2010In: Neurosurgery, ISSN 0148-396X, E-ISSN 1524-4040, Vol. 67, no 1, 94-99 p.Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: A precise definition of ventricular enlargement is important in the diagnosis of hydrocephalus as well as in assessing central atrophy. The Evans index (EI), a linear ratio between the maximal frontal horn width and the cranium diameter, has been extensively used as an indirect marker of ventricular volume (VV). With modern imaging techniques, brain volume can be directly measured. OBJECTIVE: To determine reference values of intracranial volumes in healthy elderly individuals and to correlate volumes with the EI. METHODS: Magnetic resonance imaging (3 T) was performed in 46 healthy white elderly subjects (mean age +/- standard deviation, 71 +/- 6 years) and in 20 patients (74 +/- 7 years) with large ventricles according to visual inspection. VV, relative VV (RVV), and EI were assessed. Ventricular dilation was defined using VV and EI by a value above the 95th percentile range for healthy elderly individuals. RESULTS: In healthy elderly subjects, we found VV = 37 +/- 18 mL, RVV = 2.47 +/- 1.17%, and EI = 0.281 +/- 0.027. Including the patients, there was a strong correlation between EI and VV (R = 0.94) as well as between EI and RVV (R = 0.95). However, because of a wide 95% prediction interval (VV: +/-45 mL; RVV: +/- 2.54%), EI did not give a sufficiently good estimate of VV and RVV. CONCLUSION: VV (or RVV) and the EI reflect different properties. The exclusive use of EI in clinical studies as a marker of enlarged ventricles should be questioned. We suggest that the definition of dilated ventricles in white elderly individuals be defined as VV >77 mL or RVV >4.96 %. Future studies should compare intracranial volumes with clinical characteristics and prognosis.

  • 12.
    Ambarki, Khalid
    et al.
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics. Umeå University, Faculty of Science and Technology, Centre for Biomedical Engineering and Physics (CMTF).
    Lindqvist, Tomas
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology. Umeå University, Faculty of Science and Technology, Centre for Biomedical Engineering and Physics (CMTF).
    Wåhlin, Anders
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics. Umeå University, Faculty of Science and Technology, Centre for Biomedical Engineering and Physics (CMTF).
    Petterson, E
    Warntjes, JBM
    Birgander, Richard
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    Malm, Jan
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Eklund, Anders
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics. Umeå University, Faculty of Science and Technology, Centre for Biomedical Engineering and Physics (CMTF).
    Evaluation of automatic measurement of the intracranial volume based on quantitative MR imaging2012In: American Journal of Neuroradiology, ISSN 0195-6108, E-ISSN 1936-959X, Vol. 33, no 10, 1951-1956 p.Article in journal (Refereed)
    Abstract [en]

    BACKGROUND AND PURPOSE: Brain size is commonly described in relation to ICV, whereby accurate assessment of this quantity is fundamental. Recently, an optimized MR sequence (QRAPMASTER) was developed for simultaneous quantification of T1, T2, and proton density. ICV can be measured automatically within minutes from QRAPMASTER outputs and a dedicated software, SyMRI. Automatic estimations of ICV were evaluated against the manual segmentation.

    MATERIALS AND METHODS: In 19 healthy subjects, manual segmentation of ICV was performed by 2 neuroradiologists (Obs1, Obs2) by using QBrain software and conventional T2-weighted images. The automatic segmentation from the QRAPMASTER output was performed by using SyMRI. Manual corrections of the automatic segmentation were performed (corrected-automatic) by Obs1 and Obs2, who were blinded from each other. Finally, the repeatability of the automatic method was evaluated in 6 additional healthy subjects, each having 6 repeated QRAPMASTER scans. The time required to measure ICV was recorded.

    RESULTS: No significant difference was found between reference and automatic (and corrected-automatic) ICV (P > .25). The mean difference between the reference and automatic measurement was -4.84 ± 19.57 mL (or 0.31 ± 1.35%). Mean differences between the reference and the corrected-automatic measurements were -0.47 ± 17.95 mL (-0.01 ± 1.24%) and -1.26 ± 17.68 mL (-0.06 ± 1.22%) for Obs1 and Obs2, respectively. The repeatability errors of the automatic and the corrected-automatic method were <1%. The automatic method required 1 minute 11 seconds (SD = 12 seconds) of processing. Adding manual corrections required another 1 minute 32 seconds (SD = 38 seconds).

    CONCLUSIONS: Automatic and corrected-automatic quantification of ICV showed good agreement with the reference method. SyMRI software provided a fast and reproducible measure of ICV.

  • 13.
    Ambarki, Khalid
    et al.
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Wåhlin, Anders
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Birgander, Richard
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    Eklund, Anders
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Malm, Jan
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    MR imaging of brain volumes: evaluation of a fully automatic software2011In: American Journal of Neuroradiology, ISSN 0195-6108, E-ISSN 1936-959X, Vol. 32, no 2, 408-412 p.Article in journal (Refereed)
    Abstract [en]

    BACKGROUND AND PURPOSE: Automatic assessment of brain volumes is needed in researchand clinical practice. Manual tracing is still the criterionstandard but is time-consuming. It is important to validatethe automatic tools to avoid the problems of clinical studiesdrawing conclusions on the basis of brain volumes estimatedwith methodologic errors. The objective of this study was toevaluate a new commercially available fully automatic softwarefor MR imaging of brain volume assessment. Automatic and expertmanual brain volumes were compared.

    MATERIALS AND METHODS: MR imaging (3T, axial T2 and FLAIR) was performed in 41 healthyelderly volunteers (mean age, 70 ± 6 years) and 20 patientswith hydrocephalus (mean age, 73 ± 7 years). The softwareQBrain was used to manually and automatically measure the followingbrain volumes: ICV, BTV, VV, and WMHV. The manual method hasbeen previously validated and was used as the reference. Agreementbetween the manual and automatic methods was evaluated by usinglinear regression and Bland-Altman plots.

    RESULTS: There were significant differences between the automatic andmanual methods regarding all volumes. The mean differences wereICV = 49 ± 93 mL (mean ± 2SD, n = 61), BTV = 11± 70 mL, VV = –6 ± 10 mL, and WMHV = 2.4± 9 mL. The automatic calculations of brain volumes tookapproximately 2 minutes per investigation.

    CONCLUSIONS: The automatic tool is promising and provides rapid assessmentof brain volumes. However, the software needs improvement beforeit is incorporated into research or daily use. Manual segmentationremains the reference method.

  • 14.
    Andersson, Jonas
    et al.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Karpe, Fredrik
    NIHR Oxford Biomedical Research Centre, Churchill Hospital, Oxford, UK.
    Sjöström, Lars-Göran
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Riklund, Katrine
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    Söderberg, Stefan
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Cardiology.
    Olsson, Tommy
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Association of adipose tissue blood flow with fat depot sizes and adipokines in women2012In: International Journal of Obesity, ISSN 0307-0565, E-ISSN 1476-5497, Vol. 36, no 6, 783-789 p.Article in journal (Refereed)
    Abstract [en]

    Objective: To explore possible associations between adipose tissue (AT) blood flow (ATBF), AT depot sizes and adipocyte-derived hormones (adipokines) in women.

    Subjects: In all, 43 healthy women were divided into four groups: normal-weight (n=11) and obese (n=11) pre-menopausal women and normal-weight (n=10) and obese (n=11) post-menopausal women.

    Methods: Fasting levels of adipokines were obtained, and a single-slice computed tomography scan at the level of L4-L5 was used to estimate fat depot sizes. ATBF was assessed by xenon washout while in a fasting state and after oral glucose load. We also measured glucose, insulin and non-esterified fatty acids.

    Results: Total, subcutaneous and visceral AT areas strongly correlated with ATBF (all P<0.001). Circulating leptin levels strongly and inversely correlated with ATBF (P=0.001), but this association did not remain after adjustment for body mass index. Adiponectin was not associated with blood flow.

    Conclusion: ATBF is closely linked to subcutaneous and visceral AT size. Further analyses are needed to determine possible mediators of this association, including mechanistic studies to assess a putative role for leptin as a significant modulator of blood flow. International Journal of Obesity advance online publication, 26 July 2011; doi:10.1038/ijo.2011.152.

  • 15.
    Andersson, Linus
    et al.
    Umeå University, Faculty of Social Sciences, Department of Psychology.
    Claesson, Anna-Sara
    Umeå University, Faculty of Social Sciences, Department of Psychology.
    Nyberg, Lars
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Physiology. Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    Stenberg, Berndt
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Dermatology and Venerology.
    Nordin, Steven
    Umeå University, Faculty of Social Sciences, Department of Psychology.
    Brain responses to olfactory and trigeminal exposure in idiopathic environmental illness (IEI) attributed to smells: An fMRI study2014In: Journal of Psychosomatic Research, ISSN 0022-3999, E-ISSN 1879-1360, Vol. 77, no 5, 401-408 p.Article in journal (Refereed)
    Abstract [en]

    OBJECTIVE: Idiopathic environmental intolerance (IEI) to smells is a prevalent medically unexplained illness. Sufferers attribute severe symptoms to low doses of non-toxic chemicals. Despite the label, IEI is not characterized by acute chemical senses. Theoretical models suggest that sensitized responses in the limbic system of the brain constitute an important mechanism behind the symptoms. The aim was to investigate whether and how brain reactions to low-levels of olfactory and trigeminal stimuli differ in individuals with and without IEI. METHODS: Brain responses to intranasally delivered isoamyl acetate and carbon dioxide were assessed in 25 women with IEI and 26 non-ill controls using functional magnetic resonance imaging. RESULTS: The IEI group had higher blood-oxygenated-level-dependent (BOLD) signal than controls in the thalamus and a number of, mainly, parietal areas, and lower BOLD signal in the superior frontal gyrus. The IEI group did not rate the exposures as more intense than the control group did, and there were no BOLD signal differences between groups in the piriform cortex or olfactory regions of the orbitofrontal cortex. CONCLUSIONS: The IEI reactions were not characterized by hyper-responsiveness in sensory areas. The results can be interpreted as a limbic hyperreactivity and speculatively as an inability to inhibit salient extemal stimuli.

  • 16.
    Andersson, Ronny
    et al.
    Umeå University, Faculty of Medicine, Radiation Sciences, Oncology.
    Hofer, Åke
    Umeå University, Faculty of Medicine, Public Health and Clinical Medicine, Dermatology and Venerology.
    Riklund-Åhlström, Katrine
    Umeå University, Faculty of Medicine, Radiation Sciences, Diagnostic Radiology.
    Henriksson, Roger
    Umeå University, Faculty of Medicine, Radiation Sciences, Oncology.
    Effects of interferon-[alpha], verapamil and dacarbazine in the treatment of advanced malignant melanoma2003In: Melanoma research, ISSN 0960-8931, Vol. 13, no 1, 87-91 p.Article in journal (Refereed)
    Abstract [en]

    Treatment of patients with metastatic melanoma with either dacarbazine (DTIC) or interferon-[alpha] (IFN[alpha]) as single drugs, or in combination, results in a response rate of approximately 15–20%. This study evaluated the activity and toxicity following treatment with a combination of DTIC, IFN[alpha]2b and verapamil (VPL). Thirty patients with disseminated metastatic melanoma received DTIC 250 mg/m2 on days 1–5 of a 4 week schedule, IFN[alpha]2b 3 MIU on days 1–5 each week, and VPL 80 mg three times a day throughout the cycle, until either disease progression or serious toxicity was observed. Among the 28 evaluable patients, there were four complete responses (CRs), five partial responses (PRs) and eight patients with stable disease (SD). The overall response rate (CR + PR) was 32%. Two patients with a CR were long-term survivors (45 and 34 months) and a third is still in complete remission after 49 months. The fourth CR patient relapsed and died with progressive brain metastases after 8 months. Among the eight patients with SD, one survived for 22 months and another for 34 months. Despite one toxic death, these results suggest that this treatment regimen is well tolerated and seems to be more effective than DTIC alone in a subset of patients. A controlled randomized study would be required to determine the value of adding VPL and IFN[alpha]2b to DTIC.

  • 17. Arheden, Håkan
    et al.
    Aspelin, Peter
    Bajc, Marika
    Damm, Sabine
    Flodmark, Olof
    Friberg, Peter
    Gustafsson, Lars
    Holtås, Stig
    Modin, Agnes
    Riklund, Katrine
    Umeå University, Faculty of Medicine, Radiation Sciences, Diagnostic Radiology.
    Rydh, Anders
    Umeå University, Faculty of Medicine, Radiation Sciences, Diagnostic Radiology.
    Functional imaging medicine: a new specialty with great prospects2006In: Läkartidningen, ISSN 0023-7205, Vol. 103, no 39, 2883-2884 p.Article in journal (Refereed)
  • 18.
    Arnerlöv, Conny
    et al.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Surgery.
    Söderström, Minette
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Surgery.
    Öhberg, Lars
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    Mobile kidney pain provocation ultrasonography before surgery for symptomatic mobile kidney: A prospective study of 43 consecutive patients2016In: Scandinavian journal of urology, ISSN 2168-1805, E-ISSN 2168-1813, Vol. 50, no 1, 61-64 p.Article in journal (Refereed)
    Abstract [en]

    OBJECTIVE: The aim of this study was to evaluate whether mobile kidney pain provocation ultrasonography together with intravenous pyelography in supine and standing positions and a full medical history can confirm the diagnosis of the clinical condition of symptomatic mobile kidney and aid the selection of patients for surgical treatment.

    MATERIALS AND METHODS: In a consecutive study, 43 patients with the clinical picture of symptomatic mobile kidney, a positive mobile kidney pain provocation ultrasonography and a renal descent of at least 2 lumbar vertebral heights on intravenous pyelography in the standing position, were operated on with nephropexy. Patients' pain relief after nephropexy was evaluated by clinical follow-up, a questionnaire and visual analogue scale (VAS) scoring.

    RESULTS: Reduction of pain after nephropexy was associated with a significant decrease in VAS scoring from a median of 8 (range 4-10) preoperatively to a median of 0 (range 0-7) postoperatively (p < 0.001). Thirty-four patients (79%) were cured of their pain and seven patients (16%) experienced substantial relief from their pain symptoms. In two patients (5%) the symptoms were unchanged.

    CONCLUSION: The results indicate that mobile kidney pain provocation ultrasonography and intravenous pyelography in supine and standing positions can verify the diagnosis of symptomatic mobile kidney and aid the selection of patients who will benefit from nephropexy.

  • 19.
    Asklund, Thomas
    et al.
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Oncology.
    Henriksson, Roger
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Oncology.
    Axelsson, Jan
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Oncology.
    Bergström, Åsa
    Kasper, Maria
    Ögren, Margareta
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    Toftgård, Rune
    Riklund, Katrine Åhlström
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    Early and persisting response to vismodegib in a patient with bone metastasizing medulloblastoma2013In: Acta Oncologica, ISSN 0284-186X, E-ISSN 1651-226X, Vol. 52, no 4, 862-865 p.Article in journal (Refereed)
  • 20.
    Asklund, Thomas
    et al.
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Oncology.
    Sandström, Maria
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Oncology.
    Shahidi, Saeed
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Riklund, Katrine
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    Henriksson, Roger
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Oncology.
    Durable stabilization of three chordoma cases by bevacizumab and erlotinib2014In: Acta Oncologica, ISSN 0284-186X, E-ISSN 1651-226X, Vol. 53, no 7, 980-984 p.Article in journal (Refereed)
  • 21.
    Backman, Lars
    et al.
    Aging Research Center, Karolinska Institute and University of Stockholm, Stockholm,.
    Nyberg, Lars
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology. Umeå University, Faculty of Medicine, Umeå Centre for Functional Brain Imaging (UFBI). Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB).
    Dopamine and training-related working-memory improvement2013In: Neuroscience and Biobehavioral Reviews, ISSN 0149-7634, E-ISSN 1873-7528, Vol. 37, no 9, 2209-2219 p.Article, review/survey (Refereed)
    Abstract [en]

    Converging evidence indicates that the neurotransmitter dopamine (DA) is implicated in working-memory (WM) functioning and that WM is trainable. We review recent work suggesting that DA is critically involved in the ability to benefit from WM interventions. Functional MRI studies reveal increased striatal BOLD activity following certain forms of WM interventions, such as updating training. Increased striatal BOLD activity has also been linked to transfer of learning to non-trained WM tasks, suggesting a neural signature of transfer. The striatal BOLD signal is partly determined by DA activity. Consistent with this assertion, PET research demonstrates increased striatal DA release during updating of information in WM after training. Genetic studies indicate larger increases in WM performance post training for those who carry advantageous alleles of DA-relevant genes. These patterns of results corroborate the role of DA in WM improvement. Future research avenues include: (a) neuromodulatory correlates of transfer; (b) the potential of WM training to enhance DA release in older adults; (c) comparisons among different WM processes (i.e., updating, switching, inhibition) regarding regional patterns of training-related DA release; and (d) gene-gene interactions in relation to training-related WM gains.

  • 22. Bailey, D. L.
    et al.
    Pichler, B. J.
    Gueckel, B.
    Barthel, H.
    Beer, A. J.
    Botnar, R.
    Gillies, R.
    Goh, V.
    Gotthardt, M.
    Hicks, R. J.
    Lanzenberger, R.
    la Fougere, C.
    Lentschig, M.
    Nekolla, S. G.
    Niederdraenk, T.
    Nikolaou, K.
    Nuyts, J.
    Olego, D.
    Åhlstrom Riklund, Katrine
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    Signore, A.
    Schaefers, M.
    Sossi, V.
    Suminski, M.
    Veit-Haibach, P.
    Umutlu, L.
    Wissmeyer, M.
    Beyer, T.
    Combined PET/MRI: from Status Quo to Status Go. Summary Report of the Fifth International Workshop on PET/MR Imaging; February 15-19, 2016; Tubingen, Germany2016In: Molecular Imaging and Biology, ISSN 1536-1632, E-ISSN 1860-2002, Vol. 18, no 5, 637-650 p.Article in journal (Refereed)
    Abstract [en]

    This article provides a collaborative perspective of the discussions and conclusions from the fifth international workshop of combined positron emission tomorgraphy (PET)/magnetic resonance imaging (MRI) that was held in Tubingen, Germany, from February 15 to 19, 2016. Specifically, we summarise the second part of the workshop made up of invited presentations from active researchers in the field of PET/MRI and associated fields augmented by round table discussions and dialogue boards with specific topics. This year, this included practical advice as to possible approaches to moving PET/MRI into clinical routine, the use of PET/MRI in brain receptor imaging, in assessing cardiovascular diseases, cancer, infection, and inflammatory diseases. To address perceived challenges still remaining to innovatively integrate PET and MRI system technologies, a dedicated round table session brought together key representatives from industry and academia who were engaged with either the conceptualisation or early adoption of hybrid PET/MRI systems. Discussions during the workshop highlighted that emerging unique applications of PET/MRI such as the ability to provide multi-parametric quantitative and visual information which will enable not only overall disease detection but also disease characterisation would eventually be regarded as compelling arguments for the adoption of PET/MR. However, as indicated by previous workshops, evidence in favour of this observation is only growing slowly, mainly due to the ongoing inability to pool data cohorts from independent trials as well as different systems and sites. The participants emphasised that moving from status quo to status go entails the need to adopt standardised imaging procedures and the readiness to act together prospectively across multiple PET/MRI sites and vendors.

  • 23.
    Bergdahl, Jan
    et al.
    Umeå University, Faculty of Social Sciences, Department of Psychology.
    Larsson, Anne
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Nilsson, Lars-Göran
    Riklund Åhlström, Katrine
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    Nyberg, Lars
    Umeå University, Faculty of Social Sciences, Department of Psychology. Umeå University, Faculty of Medicine, Umeå Centre for Functional Brain Imaging (UFBI).
    Treatment of chronic stress in employees: subjective, cognitive and neural correlates2005In: Scandinavian Journal of Psychology, ISSN 0036-5564, E-ISSN 1467-9450, Vol. 46, no 5, 395-402 p.Article in journal (Refereed)
    Abstract [en]

    This study reports the effect of an affect-focused intervention program, the Affect School, on stress, psychological symptoms, cognitive functioning and neural activity. Fifty employees in social service and education, with high levels of chronic stress, were randomly divided into a treatment (N= 27) and control (N= 23) group. Complete sets of data were available in 20 participants in the treatment group and 17 in the control group. The Perceived Stress Questionnaire assessed stress and the Symptom Check List-90 psychological symptoms before and after treatment. Episodic-memory functioning under focused and divided attention conditions was also assessed. Prior and after the Affect School, seven participants in the treatment group were studied with functional magnetic resonance imaging (fMRI) during episodic memory processing. After the Affect School there was a reduction in stress and psychological symptoms for the treatment group but not in the control group. The controls showed a reduction in episodic memory functioning whereas the performance of the treatment group remained intact. The fMRI scanning indicated a qualitative change in the neural network subserving episodic memory. These preliminary results suggest that the Affect School is effective on individuals with high stress.

  • 24. Bergdahl, Maud
    et al.
    Bergdahl, Jan
    Umeå University, Faculty of Social Sciences, Department of Psychology.
    Nyberg, Lars
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB). Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    Nilsson, Lars-Göran
    Psykologiska institutionen, Stockholms universitet.
    Difference in apolipoprotein E type 4 allele (APOE e4) amongdentate and edentulous subjects2008In: Gerodontology, ISSN 0734-0664, E-ISSN 1741-2358, Vol. 25, no 3, 179-186 p.Article in journal (Refereed)
    Abstract [en]

    Objectives: To evaluate the frequency of apolipoprotein (APOE) alleles and determine whether APOE type 4 allele (e4) was associated with edentulousness even when certain factors were controlled.Background: The APOE are important in lipid homeostasis, and APOE e4 has been found in many diseases and to have a negative impact on longevity. Tooth loss is more common in ill aged subjects with low income and education.Materials and methods: In a population-based study involving 1860 subjects between 35 and 85 years 1321 dentate (mean age = 54; 54% women, 46% men) and 539 edentulous (mean age = 72; 62% women, 38% men) subjects were studied. Logistic regression was performed with dentate/edentulous as dependent variables and years of education, socio-economic status, social network, stress level, handicap from birth, 23 various diseases and APOE e4 as covariates. Thereafter, APOE e4 frequencies were studied in 342 dentateand 336 edentulous subjects 50–85 years of age. The subjects were matched with regard to age, gender, years of education, living condition, stress level, handicap from birth and 23 various diseases.Results: APOE allele frequency in the total group was e2 = 7.8%, e3 = 76.4% and e4 = 15.8%. Age, living condition, years of education and APOE e4 were significant covariates in edentulous subjects (p £ 0.001).APOE e4 in the matched groups revealed significant differences between the dentate group and the edentulous group (v2 = 5.68; p = 0.017). There was no group effect (F(29,648) = 0.849; p < 0.696; Wilks’ lambda = 0.963). In the dentate group, the frequencies of APOE were: e2 = 8.8%, e3 = 77.9% ande4 = 13.3%. Corresponding frequencies of APOE in the edentulous group were: e2 = 6.6%, e3 = 75.4% and e4 = 18.0%.Conclusion: Despite matching both groups with regard to different background factors, the edentulous group had a higher frequency of APOE e4 than the dentate group. Thus, genetic factors might contribute to greater risk in developing complex oral diseases leading to tooth loss or just be an indication that the subjects in our study carrying APOE e4 are more fragile.

  • 25. Bergdahl, Maud
    et al.
    Habib, Reza
    Bergdahl, Jan
    Umeå University, Faculty of Social Sciences, Department of Psychology.
    Nyberg, Lars
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology. Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB).
    Nilsson, Lars-Göran
    Natural teeth and cognitive function in humans2007In: Scandinavian Journal of Psychology, ISSN 0036-5564, E-ISSN 1467-9450, Vol. 48, no 6, 557-565 p.Article in journal (Refereed)
    Abstract [en]

    A number of neurobiological, psychological and social factors may account for cognitive impairment. In animal studies a relation between dental status and cognitive performance has been found. It is unclear whether such a relation exists for humans. In a first step we compared the performance of 1,351 participants (53% women, 47% men; age M = 54.0) with natural teeth to 487 edentulous participants (59% women, 41% men; age M = 71.3) on 12 cognitive tests. The natural teeth group had a lower mean age, fewer women, more years of education, higher mini-mental state (MMSE), and performed significantly higher on several cognitive tests. In a subsequent analysis, the cognitive performance of a subset of the participants (50–85 years) was examined. In this analysis, 211 had natural dentition and 188 were edentulous. The groups were matched for gender, age, social variables, diseases, stress and MMSE. The cognitive disadvantage of the edentulous group was still apparent. The results suggest that functional natural teeth relate to relatively preserved cognitive functioning in older age.

  • 26.
    Berglin, Eva
    et al.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Reumatology.
    Lorentzon, Ronnie
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Sports Medicine.
    Nordmark, L
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    Nilsson-Sojka, Birgitta
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Clinical Immunology.
    Rantapää Dahlqvist, Solbritt
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Reumatology.
    Predictors of radiological progression and changes in hand bone density in early rheumatoid arthritis2003In: Rheumatology, ISSN 1462-0324, E-ISSN 1462-0332, Vol. 42, no 2, 268-275 p.Article in journal (Refereed)
    Abstract [en]

    OBJECTIVE: To identify predictors for radiological and functional outcome and bone loss in the hands in early rheumatoid arthritis (RA) during the first 2 yr of disease and to study the relationship between these variables.

    METHODS: An inception cohort of consecutively recruited patients was examined at baseline and after 12 and 24 months using X-rays of hands and feet, clinical [28-joint count, Health Assessment Questionnaire (HAQ), global visual analogue scale (VAS), grip strength] and laboratory (erythrocyte sedimentation rate, C-reactive protein, markers of bone formation and resorption) measurements and dual-energy X-ray absorptiometry measurements of the hands.

    RESULTS: Joint destruction increased significantly during the study, with the Larsen score at baseline as the strongest predictor. Radiological progression and bone loss over 24 months were significantly retarded in patients responding to therapy. The effects of the shared epitope and initial high inflammatory activity on radiological progression were overridden by the therapeutic response. Radiological progression correlated significantly with bone loss. Global VAS, Larsen score and HAQ at inclusion significantly predicted change in HAQ over time.

    CONCLUSIONS: Radiological progression and bone loss were retarded by early therapeutic response. Bone loss was related to radiological progression.

  • 27. Berglund, Johan
    et al.
    Skorpil, Mikael
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    Multi-scale graph-cut algorithm for efficient water-fat separation2017In: Magnetic Resonance in Medicine, ISSN 0740-3194, E-ISSN 1522-2594, Vol. 78, no 3, 941-949 p.Article in journal (Refereed)
    Abstract [en]

    PURPOSE: To improve the accuracy and robustness to noise in water-fat separation by unifying the multiscale and graph cut based approaches to B0 -correction.

    METHODS: A previously proposed water-fat separation algorithm that corrects for B0 field inhomogeneity in 3D by a single quadratic pseudo-Boolean optimization (QPBO) graph cut was incorporated into a multi-scale framework, where field map solutions are propagated from coarse to fine scales for voxels that are not resolved by the graph cut. The accuracy of the single-scale and multi-scale QPBO algorithms was evaluated against benchmark reference datasets. The robustness to noise was evaluated by adding noise to the input data prior to water-fat separation.

    RESULTS: Both algorithms achieved the highest accuracy when compared with seven previously published methods, while computation times were acceptable for implementation in clinical routine. The multi-scale algorithm was more robust to noise than the single-scale algorithm, while causing only a small increase (+10%) of the reconstruction time.

    CONCLUSION: The proposed 3D multi-scale QPBO algorithm offers accurate water-fat separation, robustness to noise, and fast reconstruction. The software implementation is freely available to the research community. Magn Reson Med, 2016. © 2016 International Society for Magnetic Resonance in Medicine.

  • 28. Bergouignan, Loretxu
    et al.
    Nyberg, Lars
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB). Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    Ehrsson, H. Henrik
    Out-of-body-induced hippocampal amnesia2014In: Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424, E-ISSN 1091-6490, Vol. 111, no 12, 4421-4426 p.Article in journal (Refereed)
    Abstract [en]

    Theoretical models have suggested an association between the ongoing experience of the world from the perspective of one's own body and hippocampus-based episodic memory. This link has been supported by clinical reports of long-term episodic memory impairments in psychiatric conditions with dissociative symptoms, in which individuals feel detached from themselves as if having an out-of-body experience. Here, we introduce an experimental approach to examine the necessary role of perceiving the world from the perspective of one's own body for the successful episodic encoding of real-life events. While participants were involved in a social interaction, an out-of-body illusion was elicited, in which the sense of bodily self was displaced from the real body to the other end of the testing room. This condition was compared with a well-matched in-body illusion condition, in which the sense of bodily self was colocalized with the real body. In separate recall sessions, performed similar to 1 wk later, we assessed the participants' episodic memory of these events. The results revealed an episodic recollection deficit for events encoded out-of-body compared with in-body. Functional magnetic resonance imaging indicated that this impairment was specifically associated with activity changes in the posterior hippocampus. Collectively, these findings show that efficient hippocampus-based episodic-memory encoding requires a first-person perspective of the natural spatial relationship between the body and the world. Our observations have important implications for theoretical models of episodic memory, neurocognitive models of self, embodied cognition, and clinical research into memory deficits in psychiatric disorders.

  • 29.
    Bitar, Robert
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    The prevalence and clinical features of SWEDD in the NYPUM study -a retrospective analysis2016Independent thesis Basic level (professional degree), 20 credits / 30 HE creditsStudent thesis
  • 30. Blomberg, Frida
    et al.
    Brulin, Christine
    Umeå University, Faculty of Medicine, Department of Nursing.
    Andertun, Regina
    Rydh, Anders
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    Patients' perception of quality of care in a radiology department: a medical-physical approach2010In: Journal of Radiology Nursing, ISSN 1546-0843, Vol. 29, no 1, 10-17 p.Article in journal (Refereed)
    Abstract [en]

    The aim of our cross-sectional study was to identify patients' perception of quality of care (QoC), and further to evaluate the relation between QoC and demographic factors in patients who have been subject to a radiology examination or a radiology treatment. Good QoC is the primary aim of the public medical and health service, with the aim of same quality for the whole population. Few scientific studies have been carried out within radiology with the aim of investigating differences between varying demographic factors and patient's perceptions of QoC. The radiology department's version of the Quality from the Patient's Perspective questionnaire (QPP) was used for data collection. Six hundred and ninty-eight patients participated in the study. Low estimation of the QoC was associated with dissatisfaction with telephone contact, long waiting time, neither easy nor hard waiting time experience, not receiving an invitation in time, and age 56 to 75 years. Female patient responses for estimated QoC were higher, as were those from patients with less formal education. Our study shows that factors inducing dissatisfaction concerning QoC, above all long waiting times, can be tolerated if radiology personnel provide good routines for information. Telephone contact, and adequate, timely information, is especially important. The results of this study demonstrate that several factors play a role in a patient's perception of QoC in a radiology department. The further research on patient-focused quality improvement is needed to improve patient's perception of quality care in the radiology department.

  • 31.
    Boraxbekk, Carl-Johan
    et al.
    Umeå University, Faculty of Social Sciences, Centre for Demographic and Ageing Research (CEDAR).
    Lundquist, Anders
    Umeå University, Faculty of Social Sciences, Umeå School of Business and Economics (USBE), Statistics.
    Nordin, Annelie
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Psychiatry.
    Nyberg, Lars
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Physiology. Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    Nilsson, Lars-Göran
    Aging Research Center, Karolinska Institutet.
    Adolfsson, Rolf
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Psychiatry.
    Free Recall Episodic Memory Performance Predicts Dementia 10 Years Prior to Clinical Diagnosis: Findings from the Betula Longitudinal Study2015In: Dementia and geriatric cognitive disorders extra, E-ISSN 1664-5464, Vol. 5, no 2, 191-202 p.Article in journal (Refereed)
    Abstract [en]

    Background/Aims: Early dementia diagnosis is a considerable challenge. The present study examined the predictive value of cognitive performance for a future clinical diagnosis of late-onset Alzheimer's disease or vascular dementia in a random population sample. Methods: Cognitive performance was retrospectively compared between three groups of participants from the Betula longitudinal cohort. Group 1 developed dementia 11-22 years after baseline testing (n = 111) and group 2 after 1-10 years (n = 280); group 3 showed no deterioration towards dementia during the study period (n = 2,855). Multinomial logistic regression analysis was used to investigate the predictive value of tests reflecting episodic memory performance, semantic memory performance, visuospatial ability, and prospective memory performance. Results: Age-and education-corrected performance on two free recall episodic memory tests significantly predicted dementia 10 years prior to clinical diagnosis. Free recall performance also predicted dementia 11-22 years prior to diagnosis when controlling for education, but not when age was added to the model. Conclusion: The present results support the suggestion that two free recall-based tests of episodic memory function may be useful for detecting individuals at risk of developing dementia 10 years prior to clinical diagnosis.

  • 32.
    Boraxbekk, Carl-Johan
    et al.
    Umeå University, Faculty of Social Sciences, Centre for Demographic and Ageing Research (CEDAR). Umeå University, Faculty of Medicine, Umeå Centre for Functional Brain Imaging (UFBI).
    Salami, Alireza
    Umeå University, Faculty of Medicine, Umeå Centre for Functional Brain Imaging (UFBI). Aging Research Center (ARC), Karolinska Institute, Stockholm, Sweden.
    Wåhlin, Anders
    Umeå University, Faculty of Medicine, Umeå Centre for Functional Brain Imaging (UFBI). Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Nyberg, Lars
    Umeå University, Faculty of Medicine, Umeå Centre for Functional Brain Imaging (UFBI). Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Physiology. Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    Physical activity over a decade modifies age-related decline in perfusion, gray matter volume, and functional connectivity of the posterior default mode network: a multimodal approach2016In: NeuroImage, ISSN 1053-8119, E-ISSN 1095-9572, Vol. 131, 133-141 p.Article in journal (Refereed)
    Abstract [en]

    One step toward healthy brain aging may be to entertain a physically active lifestyle. Studies investigating physical activity effects on brain integrity have, however, mainly been based on single brain markers, and few used a multimodal imaging approach. In the present study, we used cohort data from the Betula study to examine the relationships between scores reflecting current and accumulated physical activity and brain health. More specifically, we first examined if physical activity scores modulated negative effects of age on seven resting state networks previously identified by Salami, Pudas, and Nyberg (2014). The results revealed that one of the most age-sensitive RSN was positively altered by physical activity, namely, the posterior default-mode network involving the posterior cingulate cortex (PCC). Second, within this physical activity-sensitive RSN, we further analyzed the association between physical activity and gray matter (GM) volumes, white matter integrity, and cerebral perfusion using linear regression models. Regions within the identified DMN displayed larger GM volumes and stronger perfusion in relation to both current and 10-years accumulated scores of physical activity. No associations of physical activity and white matter integrity were observed. Collectively, our findings demonstrate strengthened PCC–cortical connectivity within the DMN, larger PCC GM volume, and higher PCC perfusion as a function of physical activity. In turn, these findings may provide insights into the mechanisms of how long-term regular exercise can contribute to healthy brain aging.

  • 33.
    Borota, L
    et al.
    Umeå University, Faculty of Medicine, Radiation Sciences, Diagnostic Radiology.
    Jonasson, P
    Umeå University, Faculty of Medicine, Radiation Sciences, Diagnostic Radiology.
    Basilar and bilateral carotid dolichoectasia with spontaneous dissection of C2 segment of the internal carotid artery.2006In: AJNR Am J Neuroradiol, ISSN 0195-6108, Vol. 27, no 6, 1241-1244 p.Article in journal (Refereed)
  • 34.
    Borota, Ljubisa
    et al.
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    Jonasson, Per
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    Agolli, Armend
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Orthopaedics.
    Spontaneous resorption of intradural lumbar disc fragments2008In: The spine journal, ISSN 1529-9430, E-ISSN 1878-1632, Vol. 8, no 2, 397-403 p.Article in journal (Refereed)
    Abstract [en]

    Background context: Intradural disc herniation is relatively rare complication of the spinal degenerative process that occurs most frequently in the lumbar part of the spine. Both myelographic and magnetic resonance features of this entity have been described, and the mechanism of intradural herniation has already been proposed and generally accepted. In this article, we present a case of spontaneous resorption of an intradural, fragmented intervertebral disc. Spontaneous resorption of intradural disc fragments has not been previously reported.

    Purpose: To discuss a possible mechanism of spontaneous resorption of the subdural disc fragments.

    Study design: Case report and literature review.

    Methods: Radiological follow-up of a 46-year-old man with the intradural herniation of disc fragments.

    Conclusion: The reaction generated by the meninges might lead to the complete resorption of intrathecally localized disc fragments.

  • 35. Brolin, Gustav
    et al.
    Edenbrandt, Lars
    Granerus, Goeran
    Olsson, Anna
    Afzelius, David
    Gustafsson, Agneta
    Jonsson, Cathrine
    Hagerman, Jessica
    Johansson, Lena
    Riklund, Katrine
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology. EQUALIS AB, Uppsala, Sweden.
    Ljungberg, Michael
    The accuracy of quantitative parameters in Tc-99m-MAG3 dynamic renography: a national audit based on virtual image data2016In: Clinical Physiology and Functional Imaging, ISSN 1475-0961, E-ISSN 1475-097X, Vol. 36, no 2, 146-154 p.Article in journal (Refereed)
    Abstract [en]

    Assessment of image analysis methods and computer software used in Tc-99m-MAG3 dynamic renography is important to ensure reliable study results and ultimately the best possible care for patients. In this work, we present a national multicentre study of the quantification accuracy in Tc-99m-MAG3 renography, utilizing virtual dynamic scintigraphic data obtained by Monte Carlo-simulated scintillation camera imaging of digital phantoms with time-varying activity distributions. Three digital phantom studies were distributed to the participating departments, and quantitative evaluation was performed with standard clinical software according to local routines. The differential renal function (DRF) and time to maximum renal activity (T-max) were reported by 21 of the 28 Swedish departments performing Tc-99m-MAG3 studies as of 2012. The reported DRF estimates showed a significantly lower precision for the phantom with impaired renal uptake than for the phantom with normal uptake. The T-max estimates showed a similar trend, but the difference was only significant for the right kidney. There was a significant bias in the measured DRF for all phantoms caused by different positions of the left and right kidney in the anterior-posterior direction. In conclusion, this study shows that virtual scintigraphic studies are applicable for quality assurance and that there is a considerable uncertainty associated with standard quantitative parameters in dynamic Tc-99m-MAG3 renography, especially for patients with impaired renal function.

  • 36.
    Brändström, Helge
    et al.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Sundelin, Anna
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Hoseason, Daniela
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Sundström, Nina
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Birgander, Richard
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    Johansson, Göran
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Winsö, Ola
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Koskinen, Lars-Owe
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Haney, Michael
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Risk for intracranial pressure increase related to enclosed air in post-craniotomy patients during air ambulance transport: a retrospective cohort study with simulation2017In: Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine, ISSN 1757-7241, E-ISSN 1757-7241, Vol. 25, 50Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Post-craniotomy intracranial air can be present in patients scheduled for air ambulance transport to their home hospital. We aimed to assess risk for in-flight intracranial pressure (ICP) increases related to observed intracranial air volumes, hypothetical sea level pre-transport ICP, and different potential flight levels and cabin pressures. METHODS: A cohort of consecutive subdural hematoma evacuation patients from one University Medical Centre was assessed with post-operative intracranial air volume measurements by computed tomography. Intracranial pressure changes related to estimated intracranial air volume effects of changing atmospheric pressure (simulating flight and cabin pressure changes up to 8000 ft) were simulated using an established model for intracranial pressure and volume relations. RESULTS: Approximately one third of the cohort had post-operative intracranial air. Of these, approximately one third had intracranial air volumes less than 11 ml. The simulation estimated that the expected changes in intracranial pressure during 'flight' would not result in intracranial hypertension. For intracranial air volumes above 11 ml, the simulation suggested that it was possible that intracranial hypertension could develop 'inflight' related to cabin pressure drop. Depending on the pre-flight intracranial pressure and air volume, this could occur quite early during the assent phase in the flight profile. DISCUSSION: These findings support the idea that there should be radiographic verification of the presence or absence of intracranial air after craniotomy for patients planned for long distance air transport. CONCLUSIONS: Very small amounts of air are clinically inconsequential. Otherwise, air transport with maintained ground-level cabin pressure should be a priority for these patients.

  • 37.
    Burzynska, A Z
    et al.
    Max Planck Institute for Human Development, Berlin.
    Preuschhof, C
    Max Planck Institute for Human Development, Berlin.
    Bäckman, L
    Max Planck Institute for Human Development, Berlin, Karolinska Institute.
    Nyberg, Lars
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Physiology. Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    Li, S-C
    Max Planck Institute for Human Development, Berlin.
    Lindenberger, U
    Max Planck Institute for Human Development, Berlin, .
    Heekeren, H R
    Max Planck Institute for Human Development, Berlin, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig.
    Age-related differences in white matter microstructure: region-specific patterns of diffusivity.2010In: NeuroImage, ISSN 1053-8119, E-ISSN 1095-9572, Vol. 49, no 3, 2104-2112 p.Article in journal (Refereed)
    Abstract [en]

    We collected MRI diffusion tensor imaging data from 80 younger (20-32 years) and 63 older (60-71 years) healthy adults. Tract-based spatial statistics (TBSS) analysis revealed that white matter integrity, as indicated by decreased fractional anisotropy (FA), was disrupted in numerous structures in older compared to younger adults. These regions displayed five distinct region-specific patterns of age-related differences in other diffusivity properties: (1) increases in both radial and mean diffusivity; (2) increases in radial diffusivity; (3) no differences in parameters other than FA; (4) a decrease in axial and an increase in radial diffusivity; and (5) a decrease in axial and mean diffusivity. These patterns suggest different biological underpinnings of age-related decline in FA, such as demyelination, Wallerian degeneration, gliosis, and severe fiber loss, and may represent stages in a cascade of age-related degeneration in white matter microstructure. This first simultaneous description of age-related differences in FA, mean, axial, and radial diffusivity requires histological and functional validation as well as analyses of intermediate age groups and longitudinal samples.

  • 38.
    Bäckman, Lars
    et al.
    Aging Research Center, Karolinska Institute, Stockholm, Sweden.
    Nyberg, Lars
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology. Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB).
    Soveri, Anna
    Department of Psychology and Logopedics, Åbo Akademi University, Turku, Finland.
    Johansson, Jarkko
    Turku PET Center, University of Turku, Turku, Finland.
    Andersson, Micael
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB).
    Dahlin, Erika
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB).
    Neely, Anna S
    Umeå University, Faculty of Social Sciences, Department of Psychology.
    Virta, Jere
    Turku PET Center, University of Turku, Turku, Finland.
    Laine, Matti
    Department of Psychology and Logopedics, Åbo Akademi University, Turku, Finland.
    Rinne, Juha O
    Turku PET Center, University of Turku, Turku, Finland.
    Effects of working-memory training on striatal dopamine release2011In: Science, ISSN 0036-8075, Vol. 333, no 6043, 718- p.Article in journal (Refereed)
    Abstract [en]

    Updating of working memory has been associated with striato-frontal brain regions and phasic dopaminergic neurotransmission. We assessed raclopride binding to striatal dopamine (DA) D2 receptors during a letter-updating task and a control condition before and after 5 weeks of updating training. Results showed that updating affected DA activity before training and that training further increased striatal DA release during updating. These findings highlight the pivotal role of transient neural processes associated with D2 receptor activity in working memory.

  • 39.
    Carlsson, Daniel
    et al.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine.
    Wahlström, Jens
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine.
    Burström, Lage
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine.
    Hagberg, Mats
    Avd för samhällsmedicin och folkhälsa vid Institutionen för medicin, Göteborgs universitet.
    Lundström, Ronnie
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology. Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Pettersson, Hans
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine.
    Nilsson, Tohr
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine.
    Can sensation of cold hands predict Raynaud’s phenomenon or paresthesia?: a 21-year follow-upManuscript (preprint) (Other academic)
    Abstract [en]

    Background Raynaud’s phenomenon (white fingers) and neurosensory symptoms are common after hand-arm vibration exposure. Knowledge regarding early signs of a vibration injury are needed.

    Aim To investigate the risk of developing Raynaud’s phenomenon and paresthesia in relation to sensation of cold hands in a cohort of male employees at an engineering plant.

    Methods We followed a cohort of 241 male manual and office workers at an engineering plant for 21 years. At baseline and each follow-up, sensation of cold, Raynaud's phenomenon and paresthesia in the hands were assessed with questionnaires and vibration exposure was measured. Risk estimates were calculated with Univariate and multiple logistic regression analyses. The analyses were adjusted for vibration exposure and tobacco usage.

    Results During the study period, 21 individuals developed Raynaud’s phenomenon and 43 developed paresthesia. When adjusting the risk of developing Raynaud's phenomenon for vibration exposure and tobacco use, the odds ratios were between 6.0 and 6.3 (95% CI 2.2-17.0), depending upon the measure for vibration exposure used in the analysis. No increased risk for paresthesia in relation to a sensation of cold hands was observed.

    Conclusions A sensation of cold hands is a risk factor for Raynaud´s phenomenon. At the individual level, reporting a sensation of cold hands does not appear to be useful information to rule in, or rule out, future development of Raynaud’s phenomenon given a weak to moderate predictive value. For paresthesia, the sensation of cold is not a risk factor and there is no predictive value at the individual level.

  • 40.
    Chermenina, Maria
    et al.
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Histology and Cell Biology.
    Schouten, P
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Histology and Cell Biology.
    Nevalainen, Nina
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    Johansson, F
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Histology and Cell Biology.
    Orädd, Greger
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology. Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB).
    Strömberg, Ingrid
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Histology and Cell Biology.
    GDNF is important for striatal organization and maintenance of dopamine neurons grown in the presence of the striatum2014In: Neuroscience, ISSN 0306-4522, E-ISSN 1873-7544, Vol. 270, 1-11 p.Article in journal (Refereed)
    Abstract [en]

    Glial cell-derived neurotrophic factor (GDNF) exerts neuroprotective and neurorestorative effects on neurons and GDNF plays a significant role in maintenance of the dopamine neurons utilizing grafting to create a nigrostriatal microcircuit of Gdnf knockout (Gdnf(-/-)) tissue. To further evaluate the role of GDNF on organization of the nigrostriatal system, single or double grafts of ventral mesencephalon (VM) and lateral ganglionic eminence (LGE) with mismatches in Gdnf genotypes were performed. The survival of single grafts was monitored utilizing magnetic resonance imaging (MRI) and cell survival and graft organization were evaluated with immunohistochemistry. The results revealed that the size of VM single grafts did not change over time independent of genotype, while the size of the LGE transplants was significantly reduced already at 2weeks postgrafting when lacking GDNF. Lack of GDNF did not significantly affect the survival of tyrosine hydroxylase (TH)-positive neurons in single VM grafts. However, the survival of TH-positive neurons was significantly reduced in VM derived from Gdnf(+/+) when co-grafted with LGE from the Gdnf(-/-) tissue. In contrast, lack of GDNF in the VM portion of co-grafts had no effect on the survival of TH-positive neurons when co-grafted with LGE from Gdnf(+/+) mice. The TH-positive innervation of co-grafts was sparse when the striatal co-grafts were derived from the Gdnf(-/-) tissue while dense and patchy when innervating LGE producing GDNF. The TH-positive innervation overlapped with the organization of dopamine and cyclic AMP-regulated phosphoprotein-relative molecular mass 32,000 (DARPP-32)-positive neurons, that was disorganized in LGE lacking GDNF production. In conclusion, GDNF is important for a proper striatal organization and for survival of TH-positive neurons in the presence of the striatal tissue.

  • 41.
    Dahlin, Erika
    et al.
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB).
    Bäckman, Lars
    Aging Research Center, Karolinska institutet,Stockholm.
    Stigsdotter Neely, Anna
    Umeå University, Faculty of Social Sciences, Department of Psychology.
    Nyberg, Lars
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB). Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    Training of the executive component of working memory: subcortial areas mediate transfer effects2009In: Restorative Neurology and Neuroscience, ISSN 0922-6028, Vol. 27, no 5, 405-419 p.Article in journal (Refereed)
    Abstract [en]

    Purpose: Several recent studies show that training can improve working memory (WM) performance. In this review, many issues related to WM training, such as neural basis, transfer effects, and age-related changes are addressed.

    Method: We focus on our own studies investigating training on tasks taxing the executive updating function and discuss our findings in relation to results from other studies investigating training of the executive component of WM.

    Results: The review confirms positive behavioral effects of training on working memory. The most common neural pattern following training is fronto-parietal activity decreases. Increases in sub-cortical areas are also frequently reported after training, and we suggest that such increases indicate changes in the underlying skill following training. Transfer effects are in general difficult to demonstrate. Some studies show that older adults increase their performance after WM training. However, transfer effects are small or nonexistent in old age.

    Conclusions: The main finding in this review is that sub-cortical areas seem to have a critical role in mediating transfer effects to untrained tasks after at least some forms of working memory training (such as updating).

  • 42.
    Dahlin, Erika
    et al.
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB).
    Nyberg, Lars
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB). Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    Bäckman, Lars
    Stigsdotter Neely, Anna
    Umeå University, Faculty of Social Sciences, Department of Psychology.
    Plasticity of executive functioning in young and older adults: immediative training gains, transfer, and long-term maintenance2008In: Psychology and Aging, ISSN 0882-7974, E-ISSN 1939-1498, Vol. 23, no 4, 720-730 p.Article in journal (Refereed)
    Abstract [en]

    The authors investigated immediate training gains, transfer effects, and 18-month maintenance after 5 weeks of computer-based training in updating of information in working memory in young and older subjects. Trained young and older adults improved significantly more than controls on the criterion task (letter memory), and these gains were maintained 18 months later. Transfer effects were in general limited and restricted to the young participants, who showed transfer to an untrained task that required updating (3-back). The findings demonstrate substantial and durable plasticity of executive functioning across adulthood and old age, although there appear to be age-related constraints in the ability to generalize the acquired updating skill.

  • 43.
    Dahlin, Erika
    et al.
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB). Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    Stigsdotter-Neely, Anna
    Umeå University, Faculty of Social Sciences, Department of Psychology.
    Larsson, Anne
    Umeå University, Faculty of Medicine, Umeå Centre for Functional Brain Imaging (UFBI). Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Bäckman, Lars
    Aging Research Center, Karolinska Institute, 11330 Stockholm, Sweden.
    Nyberg, Lars
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology. Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB).
    Transfer of learning after updating training mediated by the striatum2008In: Science, ISSN 0036-8075, Vol. 320, no 5882, 1510-1512 p.Article in journal (Refereed)
    Abstract [en]

    Process-specific training can improve performance on untrained tasks, but the magnitude of gain is variable and often there is no transfer at all. We demonstrate transfer to a 3-back test of working memory after 5 weeks of training in updating. The transfer effect was based on a joint training-related activity increase for the criterion (letter memory) and transfer tasks in a striatal region that also was recruited pretraining. No transfer was observed to a task that did not engage updating and striatal regions, and age-related striatal changes imposed constraints on transfer. These findings indicate that transfer can occur if the criterion and transfer tasks engage specific overlapping processing components and brain regions.

  • 44.
    de Almeida, F. J. Mota
    et al.
    Department of Endodontics, Tandvårdens Kompetenscentrum, Norrbottens County Counci, Luleå; Department of Oral-and-Maxillofacial Radiology, Odontologiska fakulteten, Malmö University, Malmö, Sweden.
    Knutsson, K.
    Department of Oral-and-Maxillofacial Radiology, Odontologiska fakulteten, Malmö University, Malmö, Sweden.
    Flygare, Lennart
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    The impact of cone beam computed tomography on the choice of endodontic diagnosis2015In: International Endodontic Journal, ISSN 0143-2885, E-ISSN 1365-2591, Vol. 48, no 6, 564-572 p.Article in journal (Refereed)
    Abstract [en]

    Aim To determine whether the outcome of cone beam computed tomography (CBCT) examinations performed in accordance with the European Commission guidelines in a clinical setting has an impact on choosing diagnoses in endodontics. Methodology A prospective observational study was conducted. Fifty-three consecutive patients (81 teeth) from two different endodontic specialist clinics in Sweden were followed. After performing a thorough clinical examination (based on the history, clinical findings, and diagnostic tests such as intra-oral radiography), the examiner wrote down a preliminary diagnosis before CBCT examination. After the CBCT examination, a new diagnosis was made by the same examiner. Both the pre- and the post-CBCT examination diagnoses were plotted according to patients and teeth. The CBCT examinations were performed using similar equipment and protocols that were standardized amongst the clinics. Results The diagnoses were changed for at least one tooth in 22 patients (41%); overall, the diagnoses were changed for 28 teeth (35%). Conclusion CBCT has a substantial impact on diagnostic thinking in endodontics when used in accordance with the European Commission guidelines.

  • 45. de Boer, Lieke
    et al.
    Axelsson, Jan
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology. Umeå University, Faculty of Medicine, Umeå Centre for Functional Brain Imaging (UFBI).
    Riklund, Katrine
    Umeå University, Faculty of Medicine, Umeå Centre for Functional Brain Imaging (UFBI). Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    Nyberg, Lars
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology. Umeå University, Faculty of Medicine, Umeå Centre for Functional Brain Imaging (UFBI). Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB).
    Dayan, Peter
    Backman, Lars
    Guitart-Masip, Marc
    Attenuation of dopamine-modulated prefrontal value signals underlies probabilistic reward learning deficits in old age2017In: eLIFE, E-ISSN 2050-084X, Vol. 6, e2642Article in journal (Refereed)
    Abstract [en]

    Probabilistic reward learning is characterised by individual differences that become acute in aging. This may be due to age-related dopamine (DA) decline affecting neural processing in striatum, prefrontal cortex, or both. We examined this by administering a probabilistic reward learning task to younger and older adults, and combining computational modelling of behaviour, fMRI and PET measurements of DA D1 availability. We found that anticipatory value signals in ventromedial prefrontal cortex (vmPFC) were attenuated in older adults. The strength of this signal predicted performance beyond age and was modulated by D1 availability in nucleus accumbens. These results uncover that a value-anticipation mechanism in vmPFC declines in aging, and that this mechanism is associated with DA D1 receptor availability.

  • 46.
    de Flon, Pierre
    et al.
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Gunnarsson, Martin
    Laurell, Katarina
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Soderstrom, Lars
    Birgander, Richard
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    Lindqvist, Thomas
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    Krauss, Wolfgang
    Dring, Ann
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Bergman, Joakim
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Sundström, Peter
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Svenningsson, Anders
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience. Department of Clinical Sciences, Danderyd Hospital, Karolinska Institutet, Stockholm, Sweden.
    Reduced inflammation in relapsing-remitting multiple sclerosis after therapy switch to rituximab2016In: Neurology, ISSN 0028-3878, E-ISSN 1526-632X, Vol. 87, no 2, 141-147 p.Article in journal (Refereed)
    Abstract [en]

    Objective: To describe the effects of switching treatment from ongoing first-line injectable therapies to rituximab on inflammatory activity measured by MRI and levels of CSF neurofilament light chain (CSF-NFL) in a cohort of patients with clinically stable relapsing-remitting multiple sclerosis (RRMS).

    Method: Seventy-five patients with clinically stable RRMS treated with the first-line injectables interferon-β (IFN-β) and glatiramer acetate (GA) at 3 Swedish centers were switched to rituximab in this open-label phase II multicenter study. After a run-in period of 3 months, 2 IV doses of 1,000 mg rituximab were given 2 weeks apart followed by repeated clinical assessment, MRI, and CSF-NFL for 24 months.

    Results: The mean cumulated number of gadolinium-enhancing lesions per patient at months 3 and 6 after treatment shift to rituximab was reduced compared to the run-in period (0.028 vs 0.36, p = 0.029). During the first year after treatment shift, the mean number of new or enlarged T2 lesions per patient was reduced (0.01 vs 0.28, p = 0.004) and mean CSF-NFL levels were reduced by 21% (p = 0.01).

    Conclusions: For patients with RRMS, a treatment switch from IFN or GA to rituximab is associated with reduced inflammatory activity measured by MRI and CSF-NFL.

    Classification of evidence: This study provides Class IV evidence that rituximab has an equal or superior effect in reducing inflammatory activity in RRMS measured by MRI and CSF-NFL compared to first-line injectables during the first year after treatment shift.

  • 47.
    de Frias, Cindy M
    et al.
    Stockholm University.
    Marklund, Petter
    Stockholm University, Stockholm Brain Institute.
    Eriksson, Elias
    Göteborg University.
    Larsson, Anne
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Öman, Lena
    Umeå University.
    Annerbrink, Kristina
    Göteborg University.
    Bäckman, Lars
    Karolinska Institute.
    Nilsson, Lars-Göran
    Stockholm University.
    Nyberg, Lars
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology. Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Physiology.
    Influence of COMT gene polymorphism on fMRI-assessed sustained and transient activity during a working memory task.2010In: Journal of cognitive neuroscience, ISSN 0898-929X, E-ISSN 1530-8898, Vol. 22, no 7, 1614-1622 p.Article in journal (Refereed)
    Abstract [en]

    The catechol O-methyltransferase (COMT) gene--encoding an enzyme that is essential for the degradation of dopamine (DA) in prefrontal cortex (PFC)--contains a single nucleotide polymorphism (val/met) important for cognition. According to the tonic-phasic hypothesis, individuals carrying the low-enzyme-activity allele (met) are characterized by enhanced tonic DA activity in PFC, promoting sustained cognitive representations in working memory. Val carriers have reduced tonic but enhanced phasic dopaminergic activity in subcortical regions, enhancing cognitive flexibility. We tested the tonic-phasic DA hypothesis by dissociating sustained and transient brain activity during performance on a 2-back working memory test using mixed blocked/event-related functional magnetic resonance imaging. Participants were men recruited from a random sample of the population (the Betula study) and consisted of 11 met/met and 11 val/val carriers aged 50 to 65 years, matched on age, education, and cognitive performance. There were no differences in 2-back performance between genotype groups. Met carriers displayed a greater transient medial temporal lobe response in the updating phase of working memory, whereas val carriers showed a greater sustained PFC activation in the maintenance phase. These results support the tonic-phasic theory of DA function in elucidating the specific phenotypic influence of the COMT val(158)met polymorphism on different components of working memory.

  • 48.
    Ek, Jesper
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    Effects of age-related brain white matter hyperintensities on cognition2016Independent thesis Basic level (professional degree), 20 credits / 30 HE creditsStudent thesis
  • 49.
    Ekman, Urban
    et al.
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology. Umeå University, Faculty of Medicine, Umeå Centre for Functional Brain Imaging (UFBI). Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Physiology. Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Eriksson, Johan
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Physiology. Umeå University, Faculty of Medicine, Umeå Centre for Functional Brain Imaging (UFBI).
    Forsgren, Lars
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Domellöf, Magdalena
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Elgh, Eva
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Psychiatry.
    Lundquist, Anders
    Umeå University, Faculty of Medicine, Umeå Centre for Functional Brain Imaging (UFBI). Umeå University, Faculty of Social Sciences, Umeå School of Business and Economics (USBE), Statistics.
    Nyberg, Lars
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Physiology. Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology. Umeå University, Faculty of Medicine, Umeå Centre for Functional Brain Imaging (UFBI).
    Longitudinal changes in task-evoked brain responses in Parkinson's disease patients with and without mild cognitive impairment2014In: Frontiers in Neuroscience, ISSN 1662-4548, E-ISSN 1662-453X, Vol. 8, 207Article in journal (Refereed)
    Abstract [en]

    Cognitive deficits are common in Parkinson's disease. Previous cross-sectional research has demonstrated a link between cognitive impairments and fronto-striatal dopaminergic dysmodulation. However, longitudinal studies that link disease progression with altered task-evoked brain activity are lacking. Therefore, our objective was to longitudinally evaluate working-memory related brain activity changes in Parkinson's disease patients with and without mild cognitive impairment (MCI). Patients were recruited within a longitudinal cohort study of incident patients with idiopathic parkinsonism. We longitudinally (at baseline examination and at 12-months follow-up) compared 28 patients with Parkinson's disease without MCI with 11 patients with Parkinson's disease and MCI. Functional MRI blood oxygen level dependent signal was measured during a verbal two-back working-memory task. Patients with MCI under-recruited bilateral medial prefrontal cortex at both time-points (main effect of group: p < 0.001, uncorrected). Critically, a significant group-by-time interaction effect (p < 0.001, uncorrected) was found in the right fusiform gyrus, indicating that working-memory related activity decreased for patients with Parkinson's disease and MCI between baseline and follow-up, while patients without MCI were stable across time-points. The functional connectivity between right fusiform gyrus and bilateral caudate nucleus was stronger for patients without MCI relative to patients with MCI. Our findings support the view that deficits in working-memory updating are related to persistent fronto-striatal under-recruitments in patients with early phase Parkinson's disease and MCI. The longitudinal evolution of MCI in Parkinson's disease translates into additional task-evoked posterior cortical changes.

  • 50.
    Ekman, Urban
    et al.
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Physiology. Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology. Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience. Umeå University, Faculty of Medicine, Umeå Centre for Functional Brain Imaging (UFBI).
    Eriksson, Johan
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Physiology. Umeå University, Faculty of Medicine, Umeå Centre for Functional Brain Imaging (UFBI).
    Forsgren, Lars
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Jakobson Mo, Susanna
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology.
    Riklund, Katrine
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology. Umeå University, Faculty of Medicine, Umeå Centre for Functional Brain Imaging (UFBI).
    Nyberg, Lars
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Physiology. Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology. Umeå University, Faculty of Medicine, Umeå Centre for Functional Brain Imaging (UFBI).
    Functional brain activity and presynaptic dopamine uptake in patients with Parkinson's disease and mild cognitive impairment: a cross-sectional study2012In: Lancet Neurology, ISSN 1474-4422, E-ISSN 1474-4465, Vol. 11, no 8, 679-687 p.Article in journal (Refereed)
    Abstract [en]

    Background: Many patients with Parkinson's disease have mild cognitive impairment (MCI). Deficits in executive functions and working memory suggest dysfunctional frontostriatal brain circuitry. We aimed to assess brain responses during a working memory task in a cohort of newly diagnosed drug-naive patients with Parkinson's disease with and without MCI.

    Methods: Participants were recruited within a prospective cohort study of incident patients with idiopathic parkinsonism, including Parkinson's disease. Between Jan 1, 2004, and April 30, 2009, all physicians in the Umea catchment area were requested to refer all individuals with suspected parkinsonism to the Department of Neurology at lima University. Included patients fulfilled the UK Parkinson's Disease Society Brain Bank clinical diagnostic criteria for Parkinson's disease. Control individuals were matched on the basis of age and sex with the first 50 patients included in the study. Participants who scored 1.5 SDs or more below the population mean on at least two cognitive measures were diagnosed with MCI. The primary outcome measures were functional MRI blood-oxygen-level-dependent signal and SPECT presynaptic uptake. Functional MRI was done during a verbal two-back working memory task. Presynaptic dopamine SPECT was done to assess presynaptic striatal dopaminergic system integrity. Event-related transient analyses of functional MRI data were done for the whole brain and for frontostriatal regions of interest, and semi-quantitative SPECT analyses were done for striatal regions of interest.

    Findings: Compared with controls (n=24), patients with Parkinson's disease (n=77) had under-recruitment in an extensive brain network including bilateral striatal and frontal regions (p<0.001). Within the Parkinson's disease group, patients with Parkinson's disease and MCI (n=30) had additional under-recruitment in the right dorsal caudate nucleus (p=0.005) and the bilateral anterior cingulate cortex (p<0.001) compared with patients with Parkinson's disease without MCI (n=26). In patients with Parkinson's disease and MCI, SPECT uptake in the right caudate was lower than in patients with Parkinson's disease without MCI (p=0.008) and correlated with striatal functional MRI blood-oxygen-level-dependent signal (r=0.32, p=0.031).

    Interpretation: These altered brain responses in patients with Parkinson's disease and MCI suggest that cognitive impairment is linked to frontostriatal dysfunction.

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