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  • 1.
    Abdollahi, Nyayesh
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Modifierad constraint-induced movement therapy förbättrar livskvalitet hos unga stroke-patienter2015Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
  • 2. Abel, Olubunmi
    et al.
    Powell, John F.
    Andersen, Peter M.
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Al-Chalabi, Ammar
    ALSoD: A user-friendly online bioinformatics tool for amyotrophic lateral sclerosis genetics2012In: Human Mutation, ISSN 1059-7794, E-ISSN 1098-1004, Vol. 33, no 9, p. 1345-1351Article in journal (Refereed)
    Abstract [en]

    Amyotrophic lateral sclerosis (ALS) is the commonest adult onset motor neuron disease, with a peak age of onset in the seventh decade. With advances in genetic technology, there is an enormous increase in the volume of genetic data produced, and a corresponding need for storage, analysis, and interpretation, particularly as our understanding of the relationships between genotype and phenotype mature. Here, we present a system to enable this in the form of the ALS Online Database (ALSoD at http://alsod.iop.kcl.ac.uk), a freely available database that has been transformed from a single gene storage facility recording mutations in the SOD1 gene to a multigene ALS bioinformatics repository and analytical instrument combining genotype, phenotype, and geographical information with associated analysis tools. These include a comparison tool to evaluate genes side by side or jointly with user configurable features, a pathogenicity prediction tool using a combination of computational approaches to distinguish variants with nonfunctional characteristics from disease-associated mutations with more dangerous consequences, and a credibility tool to enable ALS researchers to objectively assess the evidence for gene causation in ALS. Furthermore, integration of external tools, systems for feedback, annotation by users, and two-way links to collaborators hosting complementary databases further enhance the functionality of ALSoD. Hum Mutat 33:1345-1351, 2012. (c) 2012 Wiley Periodicals, Inc.

  • 3. Abel, Olubunmi
    et al.
    Powell, John F
    Andersen, Peter M
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Al-Chalabi, Ammar
    Credibility analysis of putative disease-causing genes using bioinformatics2013In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 8, no 6, p. e64899-Article in journal (Refereed)
    Abstract [en]

    Background: Genetic studies are challenging in many complex diseases, particularly those with limited diagnostic certainty, low prevalence or of old age. The result is that genes may be reported as disease-causing with varying levels of evidence, and in some cases, the data may be so limited as to be indistinguishable from chance findings. When there are large numbers of such genes, an objective method for ranking the evidence is useful. Using the neurodegenerative and complex disease amyotrophic lateral sclerosis (ALS) as a model, and the disease-specific database ALSoD, the objective is to develop a method using publicly available data to generate a credibility score for putative disease-causing genes.

    Methods: Genes with at least one publication suggesting involvement in adult onset familial ALS were collated following an exhaustive literature search. SQL was used to generate a score by extracting information from the publications and combined with a pathogenicity analysis using bioinformatics tools. The resulting score allowed us to rank genes in order of credibility. To validate the method, we compared the objective ranking with a rank generated by ALS genetics experts. Spearman's Rho was used to compare rankings generated by the different methods.

    Results: The automated method ranked ALS genes in the following order: SOD1, TARDBP, FUS, ANG, SPG11, NEFH, OPTN, ALS2, SETX, FIG4, VAPB, DCTN1, TAF15, VCP, DAO. This compared very well to the ranking of ALS genetics experts, with Spearman's Rho of 0.69 (P = 0.009).

    Conclusion: We have presented an automated method for scoring the level of evidence for a gene being disease-causing. In developing the method we have used the model disease ALS, but it could equally be applied to any disease in which there is genotypic uncertainty.

  • 4. Abosch, Aviva
    et al.
    Timmermann, Lars
    Bartley, Sylvia
    Rietkerk, Hans Guido
    Whiting, Donald
    Connolly, Patrick J.
    Lanctin, David
    Hariz, Marwan I.
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    An International Survey of Deep Brain Stimulation Procedural Steps2013In: Stereotactic and Functional Neurosurgery, ISSN 1011-6125, E-ISSN 1423-0372, Vol. 91, no 1, p. 1-11Article, review/survey (Refereed)
    Abstract [en]

    Background: Deep brain stimulation (DBS) surgery is standard of care for the treatment of certain movement disorders.

    Objective: We sought to characterize the spectrum of steps performed in DBS surgery, at centers around the world where this surgery is performed.

    Methods: We identified the main steps in DBS surgery workflow and grouped these 19 steps into 3 phases (preoperative, operative, and postoperative). A survey tool, informed by a pilot survey, was administered internationally by trained study personnel at high- and low-volume DBS centers. Procedural components, duration, and surgeon motivational factors were assessed. Cluster analysis was used to identify procedural and behavioral clusters.

    Results: One hundred eighty-five procedure workflow surveys (143 DBS centers) and 65 online surveys of surgeon motivational drivers were completed (45% response rate). Significant heterogeneity in technique, operative time, and surgeon motivational drivers was reported across centers.

    Conclusions: We provide a description of the procedural steps involved in DBS surgery and the duration of these steps, based on an international survey. These data will enable individual surgeons and centers to examine their own experience relative to colleagues at other centers and in other countries. Such information could also be useful in comparing efficiencies and identifying workflow obstacles between different hospital environments.

  • 5.
    af Bjerkén, Sara
    et al.
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB). Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Stenmark Persson, Rasmus
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience. Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB).
    Barkander, Anna
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB).
    Karalija, Nina
    Umeå University, Faculty of Medicine, Umeå Centre for Functional Brain Imaging (UFBI). Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Pelegrina-Hidalgo, Noelia
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB).
    Gerhardt, Greg A
    Virel, Ana
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB).
    Strömberg, Ingrid
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB).
    Noradrenaline is crucial for the substantia nigra dopaminergic cell maintenance2019In: Neurochemistry International, ISSN 0197-0186, E-ISSN 1872-9754, Vol. 131, article id 104551Article in journal (Refereed)
    Abstract [en]

    In Parkinson's disease, degeneration of substantia nigra dopaminergic neurons is accompanied by damage on other neuronal systems. A severe denervation is for example seen in the locus coerulean noradrenergic system. Little is known about the relation between noradrenergic and dopaminergic degeneration, and the effects of noradrenergic denervation on the function of the dopaminergic neurons of substantia nigra are not fully understood. In this study, N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine (DSP4) was injected in rats, whereafter behavior, striatal KCl-evoked dopamine and glutamate releases, and immunohistochemistry were monitored at 3 days, 3 months, and 6 months. Quantification of dopamine-beta-hydroxylase-immunoreactive nerve fiber density in the cortex revealed a tendency towards nerve fiber regeneration at 6 months. To sustain a stable noradrenergic denervation throughout the experimental timeline, the animals in the 6-month time point received an additional DSP4 injection (2 months after the first injection). Behavioral examinations utilizing rotarod revealed that DSP4 reduced the time spent on the rotarod at 3 but not at 6 months. KCl-evoked dopamine release was significantly increased at 3 days and 3 months, while the concentrations were normalized at 6 months. DSP4 treatment prolonged both time for onset and reuptake of dopamine release over time. The dopamine degeneration was confirmed by unbiased stereology, demonstrating significant loss of tyrosine hydroxylase-immunoreactive neurons in the substantia nigra. Furthermore, striatal glutamate release was decreased after DSP4. In regards of neuroinflammation, reactive microglia were found over the substantia nigra after DSP4 treatment. In conclusion, long-term noradrenergic denervation reduces the number of dopaminergic neurons in the substantia nigra and affects the functionality of the nigrostriatal system. Thus, locus coeruleus is important for maintenance of nigral dopaminergic neurons.

  • 6.
    Ahlberg, Carolina
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Event related cortical desynchronization during motor imagery in spinal cord injury patients Can electroencephalographically-recorded mu waves command a wheelchair?2018Independent thesis Basic level (professional degree), 20 credits / 30 HE creditsStudent thesis
  • 7.
    Akimoto, Chizuru
    et al.
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience.
    Forsgren, Lars
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Linder, Jan
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Birve, Anna
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Backlund, Irene
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience.
    Andersson, Jörgen
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Nilsson, Ann-Charloth
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Alstermark, Helena
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Andersen, Peter M
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    No GGGGCC-hexanucleotide repeat expansion in C9ORF72 in parkinsonism patients in Sweden2013In: Amyotrophic Lateral Sclerosis and Frontotemporal Degeneration, ISSN 2167-8421, Vol. 14, no 1, p. 26-29Article in journal (Refereed)
    Abstract [en]

    An intronic GGGGCC-hexanucleotide repeat expansion in C9ORF72 was recently identified as a major cause of amyotrophic lateral sclerosis and frontotemporal dementia. Some amyotrophic lateral sclerosis patients have signs of parkinsonism, and many parkinsonism patients develop dementia. In this study we examined if the hexanucleotide repeat expansion was present in parkinsonism patients, to clarify if there could be a relationship between the repeat expansion and disease. We studied the size of the hexanucleotide repeat expansion in a well defined population-based cohort of 135 Parkinson's disease patients and 39 patients with atypical parkinsonism and compared with 645 Swedish control subjects. We found no correlation between Parkinson's disease or atypical parkinsonism and the size of the GGGGCC repeat expansion in C9ORF72. In conclusion, this GGGGCC-repeat expansion in C9ORF72 is not a cause of parkinsonism in the Swedish population.

  • 8.
    Akimoto, Chizuru
    et al.
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Volk, Alexander E.
    van Blitterswijk, Marka
    Van den Broeck, Marleen
    Leblond, Claire S.
    Lumbroso, Serge
    Camu, William
    Neitzel, Birgit
    Onodera, Osamu
    van Rheenen, Wouter
    Pinto, Susana
    Weber, Markus
    Smith, Bradley
    Proven, Melanie
    Talbot, Kevin
    Keagle, Pamela
    Chesi, Alessandra
    Ratti, Antonia
    van der Zee, Julie
    Alstermark, Helena
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Birve, Anna
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Calini, Daniela
    Nordin, Angelica
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Tradowsky, Daniela C.
    Just, Walter
    Daoud, Hussein
    Angerbauer, Sabrina
    DeJesus-Hernandez, Mariely
    Konno, Takuya
    Lloyd-Jani, Anjali
    de Carvalho, Mamede
    Mouzat, Kevin
    Landers, John E.
    Veldink, Jan H.
    Silani, Vincenzo
    Gitler, Aaron D.
    Shaw, Christopher E.
    Rouleau, Guy A.
    van den Berg, Leonard H.
    Van Broeckhoven, Christine
    Rademakers, Rosa
    Andersen, Peter M.
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Kubisch, Christian
    A blinded international study on the reliability of genetic testing for GGGGCC-repeat expansions in C9orf72 reveals marked differences in results among 14 laboratories2014In: Journal of Medical Genetics, ISSN 0022-2593, E-ISSN 1468-6244, Vol. 51, no 6, p. 419-424Article in journal (Refereed)
    Abstract [en]

    Background The GGGGCC-repeat expansion in C9orf72 is the most frequent mutation found in patients with amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Most of the studies on C9orf72 have relied on repeat-primed PCR (RP-PCR) methods for detection of the expansions. To investigate the inherent limitations of this technique, we compared methods and results of 14 laboratories. Methods The 14 laboratories genotyped DNA from 78 individuals (diagnosed with ALS or FTD) in a blinded fashion. Eleven laboratories used a combination of amplicon-length analysis and RP-PCR, whereas three laboratories used RP-PCR alone; Southern blotting techniques were used as a reference. Results Using PCR-based techniques, 5 of the 14 laboratories got results in full accordance with the Southern blotting results. Only 50 of the 78 DNA samples got the same genotype result in all 14 laboratories. There was a high degree of false positive and false negative results, and at least one sample could not be genotyped at all in 9 of the 14 laboratories. The mean sensitivity of a combination of amplicon-length analysis and RP-PCR was 95.0% (73.9-100%), and the mean specificity was 98.0% (87.5-100%). Overall, a sensitivity and specificity of more than 95% was observed in only seven laboratories. Conclusions Because of the wide range seen in genotyping results, we recommend using a combination of amplicon-length analysis and RP-PCR as a minimum in a research setting. We propose that Southern blotting techniques should be the gold standard, and be made obligatory in a clinical diagnostic setting.

  • 9. Akram, Harith
    et al.
    Dayal, Viswas
    Mahlknecht, Philipp
    Georgiev, Dejan
    Hyam, Jonathan
    Foltynie, Thomas
    Limousin, Patricia
    De Vita, Enrico
    Jahanshahi, Marjan
    Ashburner, John
    Behrens, Tim
    Hariz, Marwan
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience. Unit of Functional Neurosurgery, Sobell Department of Motor Neuroscience and Movement Disorders, UCL Institute of Neurology, London, UK.
    Zrinzo, Ludvic
    Connectivity derived thalamic segmentation in deep brain stimulation for tremor2018In: NeuroImage: Clinical, ISSN 0353-8842, E-ISSN 2213-1582, Vol. 18, p. 130-142Article in journal (Refereed)
    Abstract [en]

    The ventral intermediate nucleus (VIM) of the thalamus is an established surgical target for stereotactic ablation and deep brain stimulation (DBS) in the treatment of tremor in Parkinson's disease (PD) and essential tremor (ET). It is centrally placed on a cerebello-thalamo-cortical network connecting the primary motor cortex, to the dentate nucleus of the contralateral cerebellum through the dentato-rubro-thalamic tract (DRT). The VIM is not readily visible on conventional MR imaging, so identifying the surgical target traditionally involved indirect targeting that relies on atlas-defined coordinates. Unfortunately, this approach does not fully account for individual variability and requires surgery to be performed with the patient awake to allow for intraoperative targeting confirmation. The aim of this study is to identify the VIM and the DRT using probabilistic tractography in patients that will undergo thalamic DBS for tremor. Four male patients with tremor dominant PD and five patients (three female) with ET underwent high angular resolution diffusion imaging (HARDI) (128 diffusion directions, 1.5 mm isotropic voxels and b value = 1500) preoperatively. Patients received VIM-DBS using an MR image guided and MR image verified approach with indirect targeting. Postoperatively, using parallel Graphical Processing Unit (GPU) processing, thalamic areas with the highest diffusion connectivity to the primary motor area (M1), supplementary motor area (SMA), primary sensory area (S1) and contralateral dentate nucleus were identified. Additionally, volume of tissue activation (VTA) corresponding to active DBS contacts were modelled. Response to treatment was defined as 40% reduction in the total Fahn-Tolosa-Martin Tremor Rating Score (FTMTRS) with DBS-ON, one year from surgery. Three out of nine patients had a suboptimal, long-term response to treatment. The segmented thalamic areas corresponded well to anatomically known counterparts in the ventrolateral (VL) and ventroposterior (VP) thalamus. The dentate-thalamic area, lay within the M1-thalamic area in a ventral and lateral location. Streamlines corresponding to the DRT connected M1 to the contralateral dentate nucleus via the dentate-thalamic area, clearly crossing the midline in the mesencephalon. Good response was seen when the active contact VTA was in the thalamic area with highest connectivity to the contralateral dentate nucleus. Non-responders had active contact VTAs outside the dentate-thalamic area. We conclude that probabilistic tractography techniques can be used to segment the VL and VP thalamus based on cortical and cerebellar connectivity. The thalamic area, best representing the VIM, is connected to the contralateral dentate cerebellar nucleus. Connectivity based segmentation of the VIM can be achieved in individual patients in a clinically feasible timescale, using HARDI and high performance computing with parallel GPU processing. This same technique can map out the DRT tract with clear mesencephalic crossing.

  • 10. Akram, Harith
    et al.
    Hariz, Marwan
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Zrinzo, Ludvic
    Connectivity derived thalamic segmentation: Separating myth from reality2019In: NeuroImage: Clinical, ISSN 0353-8842, E-ISSN 2213-1582, Vol. 22, article id UNSP 101758Article in journal (Refereed)
  • 11. Akram, Harith
    et al.
    Limousin, Patricia
    Hyam, Jonathan
    Hariz, Marwan I.
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience. Unit of Functional Neurosurgery, Sobell Department of Motor Neuroscience and Movement Disorders, UCL Institute of Neurology, University College London.
    Zrinzo, Ludvic
    Aim for the Suprasternal Notch: Technical Note to Avoid Bowstringing after Deep Brain Stimulation2015In: Stereotactic and Functional Neurosurgery, ISSN 1011-6125, E-ISSN 1423-0372, Vol. 93, no 4, p. 227-230Article in journal (Refereed)
    Abstract [en]

    Background: Bowstringing may occur when excessive fibrosis develops around extension cables in the neck after deep brain stimulation (DBS) surgery. Though the occurrence of this phenomenon is rare, we have noted that it tends to cause maximal discomfort when the cables cross superficially over the convexity of the clavicle. We hypothesise that bowstringing may be avoided by directing the extension cables towards the suprasternal notch. Methods: When connecting DBS leads to an infraclavicular pectoral implantable pulse generator (IPG), tunnelling is directed towards the suprasternal I notch, before being directed laterally towards the IPG pocket. In previously operated patients with established fibrosis, the fibrous tunnel is opened and excised as far cranially as possible, allowing medial rerouting of cables. Using this approach, we reviewed our series of patients who underwent DBS surgery over 10 years. Results: In 429 patients, 7 patients (2%) with cables tunnelled over the convexity of the clavicle complaining of bowstringing underwent cable exploration and rerouting. This eliminated bowstringing and provided better cosmetic results. When the cable trajectory was initially directed towards the suprasternal notch, no bowstringing was observed. Conclusion:The tunnelling trajectory appears to influence postoperative incidence of fibrosis associated with DBS cables. Modifying the surgical technique may reduce the incidence of this troublesome adverse event. (C) 2015 S.Karger AG, Basel

  • 12. Akram, Harith
    et al.
    Sotiropoulos, Stamatios N.
    Jbabdi, Saad
    Georgiev, Dejan
    Mahlknecht, Philipp
    Hyam, Jonathan
    Foltynie, Thomas
    Limousin, Patricia
    De Vita, Enrico
    Jahanshahi, Marjan
    Hariz, Marwan
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience. Unit of Functional Neurosurgery, Sobell Department of Motor Neuroscience and Movement Disorders, UCL Institute of Neurology, Queen Square, London, WC1N 3BG, UK.
    Ashburner, John
    Behrens, Tim
    Zrinzo, Ludvic
    Subthalamic deep brain stimulation sweet spots and hyperdirect cortical connectivity in Parkinson's disease2017In: NeuroImage, ISSN 1053-8119, E-ISSN 1095-9572, Vol. 158, p. 332-345Article in journal (Refereed)
    Abstract [en]

    Objectives: Firstly, to identify subthalamic region stimulation clusters that predict maximum improvement in rigidity, bradykinesia and tremor, or emergence of side-effects; and secondly, to map-out the cortical fingerprint, mediated by the hyperdirect pathways which predict maximum efficacy.

    Methods: High angular resolution diffusion imaging in twenty patients with advanced Parkinson's disease was acquired prior to bilateral subthalamic nucleus deep brain stimulation. All contacts were screened one-year from surgery for efficacy and side-effects at different amplitudes. Voxel-based statistical analysis of volumes of tissue activated models was used to identify significant treatment clusters. Probabilistic tractography was employed to identify cortical connectivity patterns associated with treatment efficacy.

    Results: All patients responded well to treatment (46% mean improvement off medication UPDRS-III [p < 0.0001]) without significant adverse events. Cluster corresponding to maximum improvement in tremor was in the posterior, superior and lateral portion of the nucleus. Clusters corresponding to improvement in bradykinesia and rigidity were nearer the superior border in a further medial and posterior location. The rigidity cluster extended beyond the superior border to the area of the zona incerta and Forel-H-2 field. When the clusters where averaged, the coordinates of the area with maximum overall efficacy was X = -10(-9.5), Y = -3(-1) and Z = -7(-3) in MNI(AC-PC) space. Cortical connectivity to primary motor area was predictive of higher improvement in tremor; whilst that to supplementary motor area was predictive of improvement in bradykinesia and rigidity; and connectivity to prefrontal cortex was predictive of improvement in rigidity.

    Interpretation: These findings support the presence of overlapping stimulation sites within the subthalamic nucleus and its superior border, with different cortical connectivity patterns, associated with maximum improvement in tremor, rigidity and bradykinesia.

  • 13. Akram, Harith
    et al.
    Wu, Chengyuan
    Hyam, Jonathan
    Foltynie, Thomas
    Limousin, Patricia
    De Vita, Enrico
    Yousry, Tarek
    Jahanshahi, Marjan
    Hariz, Marwan
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience. Unit of Functional Neurosurgery, Sobell Department of Motor Neuroscience and Movement Disorders, UCL Institute of Neurology, Queen Square, London, UK.
    Behrens, Timothy
    Ashburner, John
    Zrinzo, Ludvic
    L-Dopa Responsiveness Is Associated With Distinctive Connectivity Patterns in Advanced Parkinson's Disease2017In: Movement Disorders, ISSN 0885-3185, E-ISSN 1531-8257, Vol. 32, no 6, p. 874-883Article in journal (Refereed)
    Abstract [en]

    Background: Neuronal loss and dopamine depletion alter motor signal processing between cortical motor areas, basal ganglia, and the thalamus, resulting in the motor manifestations of Parkinson's disease. Dopamine replacement therapy can reverse these manifestations with varying degrees of improvement. Methods: To evaluate functional connectivity in patients with advanced Parkinson's disease and changes in functional connectivity in relation to the degree of response to L-dopa, 19 patients with advanced Parkinson's disease underwent resting-state functional magnetic resonance imaging in the on-medication state. Scans were obtained on a 3-Tesla scanner in 3x3x2.5mm(3) voxels. Seed-based bivariate regression analyses were carried out with atlas-defined basal ganglia regions as seeds, to explore relationships between functional connectivity and improvement in the motor section of the UPDRS-III following an L-dopa challenge. False discovery rate-corrected P was set at < 0.05 for a 2-tailed t test. Results: A greater improvement in UPDRS-III scores following L-dopa administration was characterized by higher resting-state functional connectivity between the prefrontal cortex and the striatum (P=0.001) and lower resting-state functional connectivity between the pallidum (P=0.001), subthalamic nucleus (P=0.003), and the paracentral lobule (supplementary motor area, mesial primary motor, and primary sensory areas). Conclusions: Our findings show characteristic basal ganglia resting-state functional connectivity patterns associated with different degrees of L-dopa responsiveness in patients with advanced Parkinson's disease. L-Dopa exerts a graduated influence on remapping connectivity in distinct motor control networks, potentially explaining some of the variance in treatment response.

  • 14. Al Nimer, Faiez
    et al.
    Elliott, Christina
    Bergman, Joakim
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Khademi, Mohsen
    Dring, Ann M
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Aeinehband, Shahin
    Bergenheim, Tommy
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Christensen, Jeppe Romme
    Sellebjerg, Finn
    Svenningsson, Anders
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Linington, Christopher
    Olsson, Tomas
    Piehl, Fredrik
    Lipocalin-2 is increased in progressive multiple sclerosis and inhibits remyelination2016In: Neurology: Neuroimmunology and neuroinflammation, ISSN 0948-6259, E-ISSN 2332-7812, Vol. 3, no 1, article id e191Article in journal (Refereed)
    Abstract [en]

    Objective: We aimed to examine the regulation of lipocalin-2 (LCN2) in multiple sclerosis (MS) and its potential functional relevance with regard to myelination and neurodegeneration. Methods: We determined LCN2 levels in 3 different studies: (1) in CSF and plasma from a case-control study comparing patients with MS (n = 147) with controls (n = 50) and patients with relapsing-remitting MS (n = 75) with patients with progressive MS (n = 72); (2) in CSF and brain tissue microdialysates from a case series of 7 patients with progressive MS; and (3) in CSF at baseline and 60 weeks after natalizumab treatment in a cohort study of 17 patients with progressive MS. Correlation to neurofilament light, a marker of neuroaxonal injury, was tested. The effect of LCN2 on myelination and neurodegeneration was studied in a rat in vitro neuroglial cell coculture model. Results: Intrathecal production of LCN2 was increased predominantly in patients with progressive MS (p < 0.005 vs relapsing-remitting MS) and displayed a positive correlation to neurofilament light (p = 0.005). Levels of LCN2 in brain microdialysates were severalfold higher than in the CSF, suggesting local production in progressive MS. Treatment with natalizumab in progressive MS reduced LCN2 levels an average of 13% (p < 0.0001). LCN2 was found to inhibit remyelination in a dose-dependent manner in vitro. Conclusions: LCN2 production is predominantly increased in progressive MS. Although this moderate increase does not support the use of LCN2 as a biomarker, the correlation to neurofilament light and the inhibitory effect on remyelination suggest that LCN2 might contribute to neurodegeneration through myelination-dependent pathways.

  • 15. Al Nimer, Faiez
    et al.
    Thelin, Eric
    Nystrom, Harriet
    Dring, Ann M.
    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.
    Piehl, Fredrik
    Nelson, David W.
    Bellander, Bo-Michael
    Comparative Assessment of the Prognostic Value of Biomarkers in Traumatic Brain Injury Reveals an Independent Role for Serum Levels of Neurofilament Light2015In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 10, no 7, article id e0132177Article in journal (Refereed)
    Abstract [en]

    Traumatic brain injury (TBI) is a common cause of death and disability, worldwide. Early determination of injury severity is essential to improve care. Neurofilament light (NF-L) has been introduced as a marker of neuroaxonal injury in neuroinflammatory/-degenerative diseases. In this study we determined the predictive power of serum (s-) and cerebrospinal fluid (CSF-) NF-L levels towards outcome, and explored their potential correlation to diffuse axonal injury (DAI). A total of 182 patients suffering from TBI admitted to the neurointensive care unit at a level 1 trauma center were included. S-NF-L levels were acquired, together with S100B and neuron-specific enolase (NSE). CSF-NF-L was measured in a subcohort (n = 84) with ventriculostomies. Clinical and neuro-radiological parameters, including computerized tomography (CT) and magnetic resonance imaging, were included in the analyses. Outcome was assessed 6 to 12 months after injury using the Glasgow Outcome Score (1-5). In univariate proportional odds analyses mean s-NF-L, -S100B and -NSE levels presented a pseudo-R-2 Nagelkerke of 0.062, 0.214 and 0.074 in correlation to outcome, respectively. In a multivariate analysis, in addition to a model including core parameters (pseudo-R-2 0.33 towards outcome; Age, Glasgow Coma Scale, pupil response, Stockholm CT score, abbreviated injury severity score, S100B), S-NF-L yielded an extra 0.023 pseudo-R-2 and a significantly better model (p = 0.006) No correlation between DAI or CT assessed-intracranial damage and NF-L was found. Our study thus demonstrates that SNF-L correlates to TBI outcome, even if used in models with S100B, indicating an independent contribution to the prediction, perhaps by reflecting different pathophysiological processes, not possible to monitor using conventional neuroradiology. Although we did not find a predictive value of NF-L for DAI, this cannot be completely excluded. We suggest further

  • 16. Al-Chalabi, Ammar
    et al.
    Andersen, Peter M.
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Chandran, Siddharthan
    Chio, Adriano
    Corcia, Philippe
    Couratier, Philippe
    Danielsson, Olof
    de Carvalho, Mamede
    Desnuelle, Claude
    Grehl, Torsten
    Grosskreutz, Julian
    Holmøy, Trygve
    Ingre, Caroline
    Karlsborg, Merete
    Kleveland, Grethe
    Christoph Koch, Jan
    Koritnik, Blaz
    KuzmaKozakiewicz, Magdalena
    Laaksovirta, Hannu
    Ludolph, Albert
    McDermott, Christopher
    Meyer, Thomas
    Ropero, Bernardo Mitre
    Pardina, Jesus Mora
    Nygren, Ingela
    Petri, Susanne
    Povedano Panades, Mónica
    Salachas, Francois
    Shaw, Pamela
    Silani, Vincenzo
    Staaf, Gert
    Svenstrup, Kirsten
    Talbot, Kevin
    Tysnes, Ole-Bjørn
    Van Damme, Philip
    van der Kooi, Anneke
    Weber, Markus
    Weydt, Patrick
    Wolf, Joachim
    Hardiman, Orla
    van den Berg, Leonard H.
    July 2017 ENCALS statement on edaravone2017In: Amyotrophic Lateral Sclerosis and Frontotemporal Degeneration, ISSN 2167-8421, E-ISSN 2167-9223, Vol. 18, no 7-8, p. 471-474Article in journal (Other academic)
  • 17. Alping, P.
    et al.
    Svenningsson, A.
    Clinical Science Danderyd´s Hospital, Karolinska Institutet, Stockholm.
    Salzer, Jonatan
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Burman, J.
    Dahle, C.
    Fink, K.
    Hillert, J.
    Lycke, J.
    Landtblom, A. -M
    Martin, C.
    Nilsson, P.
    Walentin, F.
    Olsson, T.
    Frisell, T.
    Piehl, F.
    Rituximab in multiple sclerosis: data from the swedish MS registry2016In: Multiple Sclerosis Journal, ISSN 1352-4585, E-ISSN 1477-0970, Vol. 22, p. 49-49Article in journal (Refereed)
  • 18. Alping, Peter
    et al.
    Frisell, Thomas
    Novakova, Lenka
    Islam-Jakobsson, Protik
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Salzer, Jonatan
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Björck, Anna
    Axelsson, Markus
    Malmeström, Clas
    Fink, Katharina
    Lycke, Jan
    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.
    Piehl, Fredrik
    Rituximab versus Fingolimod after Natalizumab in Multiple Sclerosis Patients2016In: Annals of Neurology, ISSN 0364-5134, E-ISSN 1531-8249, Vol. 79, no 6, p. 950-958Article in journal (Refereed)
    Abstract [en]

    Objective: Many JC virus antibody-positive relapsing-remitting multiple sclerosis (RRMS) patients who are stable on natalizumab switch to other therapies to avoid progressive multifocal leukoencephalopathy.

    Methods: We compared outcomes for all RRMS patients switching from natalizumab due to JC virus antibody positivity at 3 Swedish multiple sclerosis centers with different preferential use of rituximab and fingolimod (Stockholm, n = 156, fingolimod 51%; Gothenburg, n = 64, fingolimod 88%; Umea, n = 36, fingolimod 19%), yielding a total cohort of N = 256 (fingolimod 55%).

    Results: Within 1.5 years of cessation of natalizumab, 1.8% (rituximab) and 17.6% (fingolimod) of patients experienced a clinical relapse (hazard ratio for rituximab = 0.10, 95% confidence interval [CI] = 0.02-0.43). The hazard ratio (favoring rituximab) for adverse events (5.3% vs 21.1%) and treatment discontinuation (1.8% vs 28.2%) were 0.25 (95% CI = 0.10-0.59) and 0.07 (95% CI = 0.02-0.30), respectively. Furthermore, contrast-enhancing lesions were found in 1.4% (rituximab) versus 24.2% (fingolimod) of magnetic resonance imaging examinations (odds ratio = 0.05, 95% CI = 0.00-0.22). Differences remained when adjusting for possible confounders (age, sex, disability status, time on natalizumab, washout time, follow-up time, and study center).

    Interpretation: Our findings suggest an improved effectiveness and tolerability of rituximab compared with fingolimod in stable RRMS patients who switch from natalizumab due to JC virus antibody positivity. Although residual confounding factors cannot be ruled out, the shared reason for switching from natalizumab and the preferential use of either rituximab or fingolimod in 2 of the centers mitigates these concerns.

  • 19.
    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, E-ISSN 1552-5783, Vol. 54, no 4, p. 2738-2745Article 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.

  • 20.
    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, p. 1951-1956Article 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.

  • 21.
    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, p. 408-412Article 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.

  • 22.
    Ambarki, Khalid
    et al.
    Umeå University, Faculty of Medicine, Department of Radiation Sciences. 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. Umeå University, Faculty of Medicine, Umeå Centre for Functional Brain Imaging (UFBI).
    Zarrinkoob, Laleh
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Wirestam, R.
    Petr, J.
    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. Umeå University, Faculty of Science and Technology, Centre for Biomedical Engineering and Physics (CMTF). Umeå University, Faculty of Medicine, Umeå Centre for Functional Brain Imaging (UFBI).
    Accuracy of Parenchymal Cerebral Blood Flow Measurements Using Pseudocontinuous Arterial Spin-Labeling in Healthy Volunteers2015In: American Journal of Neuroradiology, ISSN 0195-6108, E-ISSN 1936-959X, Vol. 36, no 10, p. 1816-1821Article in journal (Refereed)
    Abstract [en]

    BACKGROUND AND PURPOSE: The arterial spin-labeling method for CBF assessment is widely available, but its accuracy is not fully established. We investigated the accuracy of a whole-brain arterial spin-labeling technique for assessing the mean parenchymal CBF and the effect of aging in healthy volunteers. Phase-contrast MR imaging was used as the reference method. MATERIALS AND METHODS: Ninety-two healthy volunteers were included: 49 young (age range, 20-30 years) and 43 elderly (age range, 65-80 years). Arterial spin-labeling parenchymal CBF values were averaged over the whole brain to quantify the mean pCBF(ASL) value. Total. CBF was assessed with phase-contrast MR imaging as the sum of flows in the internal carotid and vertebral arteries, and subsequent division by brain volume returned the pCBF(PCMRI) value. Accuracy was considered as good as that of the reference method if the systematic difference was less than 5 mL/min/100 g of brain tissue and if the 95% confidence intervals were equal to or better than +/- 10 mL/min/100 g. RESULTS: pCBF(ASL) correlated to pCBF(PCMRI) (r = 0.73; P < .001). Significant differences were observed between the pCBF(ASL) and pCBF(PCMRI) values in the young (P = .001) and the elderly (P < .001) volunteers. The systematic differences (mean 2 standard deviations) were -4 +/- 14 mL/min/100 g in the young subjects and 6 +/- 12 mL/min/100 g in the elderly subjects. Young subjects showed higher values than the elderly subjects for pCBF(PCMRI) (young, 57 +/- 8 mL/min/100 g; elderly, 54 +/- 7 mL/min/100 g; P = .05) and pCBF(ASL) (young, 61 +/- 10 mL/min/100 g; elderly, 48 +/- 10 mL/min/100 g; P < .001). CONCLUSIONS: The limits of agreement were too wide for the arterial spin-labeling method to be considered satisfactorily accurate, whereas the systematic overestimation in the young subjects and underestimation in the elderly subjects were close to acceptable. The age-related decrease in parenchymal CBF was augmented in arterial spin-labeling compared with phase-contrast MR imaging.

  • 23.
    Andersen, Peter M.
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    ALS and FTD: two sides of the same coin?2013In: Lancet Neurology, ISSN 1474-4422, E-ISSN 1474-4465, Vol. 12, no 10, p. 937-938Article in journal (Other academic)
  • 24.
    Andersen, Peter M.
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Is all ALS genetic?2017In: Neurology, ISSN 0028-3878, E-ISSN 1526-632X, Vol. 89, no 3, p. 220-221Article in journal (Other academic)
  • 25.
    Andersen, Peter M
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Mutation in C9orf72 changes the boundaries of ALS and FTD2012In: Lancet Neurology, ISSN 1474-4422, E-ISSN 1474-4465, Vol. 11, no 3, p. 205-207Article in journal (Refereed)
  • 26.
    Andersen, Peter M.
    et al.
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Hempel, Maja
    Santer, René
    Nordström, Ulrika
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Tsiakas, Konstantinos
    Johannsen, Jessika
    Volk, Alexander E.
    Bierhals, Tatjana
    Zetterström, Per
    Umeå University, Faculty of Medicine, Department of Medical Biosciences.
    Marklund, Stefan L.
    Umeå University, Faculty of Medicine, Department of Medical Biosciences.
    Phenotype in an Infant with SOD1 Homozygous Truncating Mutation2019In: New England Journal of Medicine, ISSN 0028-4793, E-ISSN 1533-4406, Vol. 381, no 5, p. 486-488Article in journal (Refereed)
  • 27.
    Andersen, Peter M.
    et al.
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Kuzma-Kozakiewicz, Magdalena
    Keller, Jürgen
    Aho-Oezhan, Helena E. A.
    Ciecwierska, Katarzyna
    Szejko, Natalia
    Vázquez, Cynthia
    Böhm, Sarah
    Badura-Lotter, Gisela
    Meyer, Thomas
    Petri, Susanne
    Linse, Katharina
    Hermann, Andreas
    Semb, Olof
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Professionell Development.
    Stenberg, Erica
    Nackberg, Simona
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Professionell Development.
    Dorst, Johannes
    Uttner, Ingo
    Häggström, Ann-Cristin
    Ludolph, Albert C.
    Lulé, Dorothée
    Therapeutic decisions in ALS patients: cross-cultural differences and clinical implications2018In: Journal of Neurology, ISSN 0340-5354, E-ISSN 1432-1459, Vol. 265, no 7, p. 1600-1606Article in journal (Refereed)
    Abstract [en]

    Objective: Quantitative analysis of decision-making on therapeutic options in different sociocultural context in amyotrophic lateral sclerosis (ALS).

    Methods: ALS patients (n = 244) were consecutively recruited in Germany (n = 83), Poland (n = 83), and Sweden (n = 78) in a prospective cross-cultural study (www.NEEDSinALS.com). They were interviewed on preferences for therapeutic techniques including invasive (IV) and non-invasive ventilation (NIV), as well as percutaneous endoscopic gastrostomy (PEG) and on hypothetical termination of these using quantitative questions. Using standardized questionnaires, religiousness, personal values, quality of life, and depressiveness were assessed.

    Results: NIV was most frequently used in Germany and PEG in Sweden. Swedish patients were most liberal on initiation and termination of PEG, NIV and IV. Polish patients were mostly undecided and were least likely to consider discontinuing supportive management. Current use was partly associated with age, gender and state of physical function; also, financial support explained some variance. Future preferences on therapeutic options from the patient’s perspective were also closely associated with cultural factors. The more oriented towards traditional and conservative values, the less likely patients were to decide for invasive therapeutic devices (IV, PEG), the least likely to have ideations to discontinue any device and the more likely to have an undecided attitude.

    Conclusions: Current use of therapeutic options is determined by medical condition in analogy to clinical guidelines. For future considerations, other factors such as cultural background are crucial, yielding hurdles to be regarded in the implementation of advanced directives in a multicultural environment.

  • 28.
    Andersson, Johanna
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Prevalence of idiopathic normal pressure hydrocephalus. A pilot study in Jämtland.2015Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
  • 29.
    Andersson, Jörgen
    et al.
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Rosell, M.
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience.
    Kockum, Karin
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Söderström, Lars
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience.
    Laurell, Katarina
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Challenges in diagnosing normal pressure hydrocephalus: evaluation of the diagnostic guidelines2017In: eNeurologicalSci, ISSN 2405-6502, Vol. 7, p. 27-31Article in journal (Refereed)
    Abstract [en]

    Purpose: To evaluate the present diagnostic guidelines of idiopathic normal pressure hydrocephalus (iNPH) in a sample from the general population.

    Methods: A total of 168 individuals (93 females, 75 males), mean age 75 years (range 66-92) with and without symptoms of iNPH underwent a CT-scan of the brain, a neurological examination with assessment of the triad symptoms, i.e. gait disturbances, memory impairment and urgency incontinence. The participants were then diagnosed as "unlikely", "possible" and "probable" iNPH according to the American-European and the Japanese guidelines, respectively. Separately, a senior consultant in neurology diagnosed each patient based on the overall clinical picture.

    Results: Obtaining a diagnosis of "probable iNPH" was three times more likely according to the American-European guidelines (n = 35) compared to the Japanese guidelines (n = 11) or the neurologist (n = 11). The concordance was highest (Kappa = 0.69) between the Japanese guidelines and the neurologist.

    Conclusions: Considerable discrepancies were found when diagnosing iNPH according to two international guidelines and a neurologist, respectively. The Japanese guidelines, which include a minimum of two triad symptoms, were most concordant with the neurologist. As a step towards widely accepted, standardized diagnostic criteria, we suggest a revision of the current guidelines, preferably into one common diagnostic system.

  • 30.
    Andersson, Kennet
    et al.
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Manchester, I. R.
    Laurell, Katarina
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Cesarini, K. Giuliana
    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).
    Measurement of CSF dynamics with oscillating pressure infusion2013In: Acta Neurologica Scandinavica, ISSN 0001-6314, E-ISSN 1600-0404, Vol. 128, no 1, p. 17-23Article in journal (Refereed)
    Abstract [en]

    Introduction Infusion tests are used to diagnose and select patients with idiopathic normal pressure hydrocephalus (INPH) for shunt surgery. The test characterizes cerebrospinal fluid dynamics and estimates parameters of the cerebrospinal fluid system, the pressure-volume index (PVI) and the outflow conductance (Cout). The Oscillating Pressure Infusion (OPI) method was developed to improve the test and reduce the investigation time. The aim of this study was to evaluate the new OPI method by comparing it with an established reference method. Methods Forty-seven patients (age 71.2 +/- 8.9years) with communicating hydrocephalus underwent a preoperative lumbar infusion investigation with two consecutive infusion protocols, reference (42min) and new (20min), that is, 94 infusion tests in total. The OPI method estimated Cout and PVI simultaneously. A real-time analysis of reliability was applied to investigate the possibility of infusion time reduction. Results The difference in Cout between the methods was 1.2 +/- 1.8l/s/kPa (Rout=-0.8 +/- 3.5mmHg/ml/min), P<0.05, n=47. With the reliability analysis, the preset 20min of active infusion could have been even further reduced for 19 patients to between 10 and 19min. PVI was estimated to 16.1 +/- 6.9ml, n=47. Conclusions The novel Oscillating Pressure Infusion method produced real-time estimates of Cout including estimates of reliability that was in good agreement with the reference method and allows for a reduced and individualized investigation time.

  • 31.
    Andersson, Kennet
    et al.
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Sundström, Nina
    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.
    Eklund, Anders
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Effect of resting pressure on the estimate of cerebrospinal fluid outflow conductance2011In: Fluids and barriers of the CNS, ISSN 2045-8118, Vol. 8, no 1, p. 15-Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: A lumbar infusion test is commonly used as a predictive test for patients with normal pressure hydrocephalus and for evaluation of cerebrospinal fluid (CSF) shunt function. Different infusion protocols can be used to estimate the outflow conductance (Cout) or its reciprocal the outflow resistance, (Rout) with or without using the baseline resting pressure, Pr. Both from a basic physiological research and a clinical perspective, it is important to understand the limitations of the model on which infusion tests are based. By estimating Cout using two different analyses, with or without Pr, the limitations could be explored. The aim of this study was to compare the Cout estimates, and investigate what effect Pr had on the results.

    METHODS: Sixty-three patients that underwent a constant pressure infusion protocol as part of their preoperative evaluation for normal pressure hydrocephalus, were included (age 70.3+/-10.8 years (mean +/-SD). The analysis was performed without (Cexcl Pr) and with (Cincl Pr) Pr. The estimates were compared using Bland-Altman plots and paired sample t-tests (p<0.05 considered significant).

    RESULTS: Mean Cout for the 63 patients was: Cexcl Pr = 7.0+/-4.0 (mean +/-SD) ul/(s kPa) and Cincl Pr = 9.1+/-4.3 ul/(s kPa) and Rout was 19.0+/-9.2 and 17.7+/-11.3 mmHg/ml/min, respectively. There was a positive correlation between methods (r=0.79, n=63, p<0.01). The difference, DeltaCout, -2.1+/-2.7 ul/(s kPa) between methods was significant (p<0.01) and DeltaRout was 1.2 +/- 8.8 mmHg/ml/min). The Bland-Altman plot visualized that the variation around the mean difference was similar all through the range of measured values and there was no correlation between DeltaCout and Cout.

    CONCLUSIONS: The difference between Cout estimates, obtained from analyses with or without Pr, needs to be taken into consideration when comparing results from studies using different infusion test protocols. The study suggests variation in CSF formation rate, variation in venous pressure or a pressure dependent Cout as possible causes for the deviation from the CSF absorption model seen in some patients.

  • 32.
    Andersson, Nina
    et al.
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Grip, Helena
    Umeå University, Faculty of Medicine, Department of Community Medicine and Rehabilitation, Physiotherapy.
    Lindvall, Peter
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Koskinen, Lars-Owe D
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Brändström, Helge
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    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.
    Air transport of patients with intracranial air: computer model of pressure effects2003In: Aviation, Space and Environmental Medicine, ISSN 0095-6562, E-ISSN 1943-4448, Vol. 74, no 2, p. 138-144Article in journal (Refereed)
  • 33.
    Andersson, Oskar
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    White matter lesions in Parkinson's disease: aspects on comorbidity and motor subtypes.2016Independent thesis Basic level (professional degree), 20 credits / 30 HE creditsStudent thesis
  • 34.
    Andersén, Peter
    et al.
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Bäckström, Torbjörn
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Obstetrics and Gynaecology.
    Dahlquist, Gisela
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Paediatrics.
    Damber, Jan-Erik
    Engström-Laurent, Anna
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Gustafson, Yngve
    Umeå University, Faculty of Medicine, Department of Community Medicine and Rehabilitation, Geriatric Medicine.
    Hjemdahl, Paul
    Korsgren, Olle
    Olsson, Håkan
    Wiberg, Mikael
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Hand Surgery.
    Widmark, Anders
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Oncology.
    Svensk medicinsk forskning behöver inte mer styrning2014In: Läkartidningen, ISSN 0023-7205, E-ISSN 1652-7518, Vol. 111, no 22-23, p. 980-981Article in journal (Other (popular science, discussion, etc.))
  • 35. Andreae, Laura C
    et al.
    Peukert, Daniela
    Lumsden, Andrew
    Gilthorpe, Jonathan
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Analysis of Lrrn1 expression and its relationship to neuromeric boundaries during chick neural development2007In: Neural Development, ISSN 1749-8104, Vol. 2, no 22, p. 1-16Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: The Drosophila leucine-rich repeat proteins Tartan (TRN) and Capricious (CAPS) mediate cell affinity differences during compartition of the wing imaginal disc. This study aims to identify and characterize the expression of a chick orthologue of TRN/CAPS and examine its potential function in relation to compartment boundaries in the vertebrate central nervous system.

    RESULTS: We identified a complementary DNA clone encoding Leucine-rich repeat neuronal 1 (Lrrn1), a single-pass transmembrane protein with 12 extracellular leucine-rich repeats most closely related to TRN/CAPS. Lrrn1 is dynamically expressed during chick development, being initially localized to the neural plate and tube, where it is restricted to the ventricular layer. It becomes downregulated in boundaries following their formation. In the mid-diencephalon, Lrrn1 expression prefigures the position of the anterior boundary of the zona limitans intrathalamica (ZLI). It becomes progressively downregulated from the presumptive ZLI just before the onset of expression of the signalling molecule Sonic hedgehog (Shh) within the ZLI. In the hindbrain, downregulation at rhombomere boundaries correlates with the emergence of specialized boundary cell populations, in which it is subsequently reactivated. Immunocolocalization studies confirm that Lrrn1 protein is endocytosed from the plasma membrane and is a component of the endosomal system, being concentrated within the early endosomal compartment.

    CONCLUSION: Chick Lrrn1 is expressed in ventricular layer neuroepithelial cells and is downregulated at boundary regions, where neurogenesis is known to be delayed, or inhibited. The timing of Lrrn1 downregulation correlates closely with the activation of signaling molecule expression at these boundaries. This expression is consistent with the emergence of secondary organizer properties at boundaries and its endosomal localisation suggests that Lrrn1 may regulate the subcellular localisation of specific components of signalling or cell-cell recognition pathways in neuroepithelial cells.

  • 36.
    Andrén, Kerstin
    et al.
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Wikkelsö, Carsten
    Sundström, Nina
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Agerskov, Simon
    Israelsson, Hanna
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience.
    Laurell, Katarina
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience.
    Hellström, Per
    Tullberg, Mats
    Long-term effects of complications and vascular comorbidity in idiopathic normal pressure hydrocephalus: a quality registry study2018In: Journal of Neurology, ISSN 0340-5354, E-ISSN 1432-1459, Vol. 265, no 1, p. 178-186Article in journal (Refereed)
    Abstract [en]

    Background: There is little knowledge about the factors influencing the long-term outcome after surgery for idiopathic normal pressure hydrocephalus (iNPH).

    Objective: To evaluate the effects of reoperation due to complications and of vascular comorbidity (hypertension, diabetes, stroke and heart disease) on the outcome in iNPH patients, 2–6 years after shunt surgery.

    Methods: We included 979 patients from the Swedish Hydrocephalus Quality Registry (SHQR), operated on for iNPH during 2004–2011. The patients were followed yearly by mailed questionnaires, including a self-assessed modified Rankin Scale (smRS) and a subjective comparison between their present and their preoperative health condition. The replies were grouped according to the length of follow-up after surgery. Data on clinical evaluations, vascular comorbidity, and reoperations were extracted from the SHQR.

    Results: On the smRS, 40% (38–41) of the patients were improved 2–6 years after surgery and around 60% reported their general health condition to be better than preoperatively. Reoperation did not influence the outcome after 2–6 years. The presence of vascular comorbidity had no negative impact on the outcome after 2–6 years, assessed as improvement on the smRS or subjective improvement of the health condition, except after 6 years when patients with hypertension and a history of stroke showed a less favorable development on the smRS.

    Conclusion: This registry-based study shows no negative impact of complications and only minor effects of vascular comorbidity on the long-term outcome in iNPH.

  • 37. Aparicio, S
    et al.
    Morrison, A
    Gould, A
    Gilthorpe, Jonathan
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Chaudhuri, C
    Rigby, P
    Krumlauf, R
    Brenner, S
    Detecting conserved regulatory elements with the model genome of the Japanese puffer fish, Fugu rubripes.1995In: Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424, E-ISSN 1091-6490, Vol. 92, no 5, p. 1684-1688Article in journal (Refereed)
    Abstract [en]

    Comparative vertebrate genome sequencing offers a powerful method for detecting conserved regulatory sequences. We propose that the compact genome of the teleost Fugu rubripes is well suited for this purpose. The evolutionary distance of teleosts from other vertebrates offers the maximum stringency for such evolutionary comparisons. To illustrate the comparative genome approach for F. rubripes, we use sequence comparisons between mouse and Fugu Hoxb-4 noncoding regions to identify conserved sequence blocks. We have used two approaches to test the function of these conserved blocks. In the first, homologous sequences were deleted from a mouse enhancer, resulting in a tissue-specific loss of activity when assayed in transgenic mice. In the second approach, Fugu DNA sequences showing homology to mouse sequences were tested for enhancer activity in transgenic mice. This strategy identified a neural element that mediates a subset of Hoxb-4 expression that is conserved between mammals and teleosts. The comparison of noncoding vertebrate sequences with those of Fugu, coupled to a transgenic bioassay, represents a general approach suitable for many genome projects.

  • 38.
    Asklund, Thomas
    et al.
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Oncology.
    Kvarnbrink, Samuel
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Oncology.
    Holmlund, Camilla
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Oncology.
    Wibom, Carl
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Oncology.
    Bergenheim, Tommy
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Henriksson, Roger
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Oncology.
    Hedman, Håkan
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Oncology.
    Synergistic killing of Glioblastoma Stem-like cells by Bortezomib and HDAC Inhibitors2012In: Anticancer Research, ISSN 0250-7005, E-ISSN 1791-7530, Vol. 32, no 7 ; Special Issue, p. 2407-2413Article in journal (Refereed)
    Abstract [en]

    Background: The malignant brain tumour glioblastoma is a devastating disease that remains a therapeutic challenge. Materials and Methods: Effects of combinations of the US Food and Drug Administation (FDA) approved proteasome inhibitor bortezomib and the histone deacetylase (HDAC) inhibitors vorinostat, valproic acid and sodium phenylbutyrate were studied on primary glioblastoma stem cell lines and conventional glioblastoma cell lines. Cell survival, proliferation and death were analyzed by fluorometric microculture cytotoxicity assay (FMCA), propidium iodide labeling and flow cytometry, and cell cloning through limiting dilution and live-cell bright-field microscopy. Results: Bortezomib and the HDAC inhibitors showed synergistic cell killing at clinically relevant drug concentrations, while the conventional cell lines cultured in serum-containing medium were relatively resistant to the same treatments. Conclusion: These findings of synergistic glioblastoma stem cell killing by bortezomib and three different FDA-approved HDAC inhibitors confirm and expand previous observations on co-operative effects between these classes of drugs.

  • 39.
    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, p. 980-984Article in journal (Refereed)
  • 40.
    Asplund, Pär
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Percutaneous Balloon Compression for the Treatment of Trigeminal Neuralgia2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Background. Trigeminal neuralgia (TN) is a paroxysmal unilateral facial pain condition. That it is rather rare is of little comfort to those who are affected, as TN is often described as one of the worst pains known to mankind. Advanced age and multiple sclerosis (MS) are risk factors for developing TN. The first line of treatment is medical, primarily with carbamazepine. When medical treatment fails, as it does in many patients, there are several surgical options. One of the minimally invasive options, suitable for patients with comorbidity, is percutaneous balloon compression (PBC). Despite its introduction in the early 1980s, PBC is arguably the least well studied of the minimally invasive procedures for the treatment of TN.

    Aims. The aim of this thesis was to evaluate the efficacy of PBC, both overall and in MS-TN patients specifically. Further, it intended to identify and evaluate pre- and intraoperative parameters associated with the efficacy of PBC. It also investigated changes in sensory function after PBC, and identified side effects and complications associated with PBC. Finally, it sought to evaluate how efficacy, side effects and complications differed between PBC and another minimally invasive technique; percutaneous retrogasserian glycerol rhizotomy (PRGR).

    Methods. Cohorts of patients treated with PBC in Umeå and Stockholm, and with PRGR in Umeå, were followed retrospectively. Data from an existing database was combined with data from medical records, radiographs and telephone interviews.

    Results. After PBC, 90 % of the patients were completely pain free without medication for TN. The median time to recurrence of pain was 28 months. In patients with concurrent MS, the initial success rate was 67 % and the median time to recurrence was 8 months. In patients without MS, who had not previously been treated surgically, the initial success rate was 91 % and the median time to recurrence was 48 months. The procedure could, however, be repeated with good results. A good compression, indicated by a pear-shaped balloon as seen on intraoperative lateral radiograph, was crucial to achieve good pain relief. Postoperative hypoesthesia was present in the majority of patients, but after 3-6 months, sensibility was partly or fully normalized in most patients. Severe complications were rare, but included transient cardiac arrest, meningitis and dysesthesia. The side effects profile was favorable to that of percutaneous retrogasserian glycerol rhizotomy, in that the latter produced more cases of dysesthesia and decreased corneal sensibility. The efficacy of the two treatments were, however, not significantly different.

    Conclusions. PBC is an effective and relatively safe treatment option for patients with TN refractory to medical treatment. It deserves its place among the standard treatments for TN, and could be considered for those patients eligible for surgery for which open surgery is a less suitable option.

     

  • 41.
    Asplund, Pär
    et al.
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Blomstedt, Patric
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Bergenheim, A. Tommy
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Percutaneous Balloon Compression vs Percutaneous Retrogasserian Glycerol Rhizotomy for the Primary Treatment of Trigeminal Neuralgia2016In: Neurosurgery, ISSN 0148-396X, E-ISSN 1524-4040, Vol. 78, no 3, p. 421-428Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Despite >30 years of clinical use, the literature is still sparse when it comes to comparisons between percutaneous balloon compression (PBC) and percutaneous retrogasserian glycerol rhizolysis (PRGR) as treatments for trigeminal neuralgia.

    OBJECTIVE: To perform a retrospective cohort comparison between PBC and PRGR with regard to therapeutic effect, side effects, and complications.

    METHODS: Medical records and follow-up data from 124 primary PRGRs performed from 1986 to 2000 and 82 primary PBCs performed from 2000 to 2013 were reviewed. All patients had undergone clinical sensory testing and assessment of sensory thresholds. Analyses were performed to compare duration of pain relief, frequency of sensory disturbances, and side effects.

    RESULTS: Median duration of pain relief was 21 months after PRGR and 20 months after PBC. Both methods carried a high risk of hypesthesia/hypalgesia (P < .001) that was partly reversed with time. Decreased corneal sensibility was common after PRGR (P < .001) but not after PBC. Dysesthesia was more common after PRGR (23%) compared after PBC (4%; P < .001). Other side effects were noted but uncommon.

    CONCLUSION: PBC and PRGR are both effective as primary surgical treatment of trigeminal neuralgia. Both carry a risk of postoperative hypesthesia, but in this series, the side effect profile favored PBC. Furthermore, PBC is technically less challenging, whereas PRGR requires fewer resources. Between these 2 techniques, we propose PBC as the primary surgical technique for percutaneous treatment of trigeminal neuralgia on the basis of its lower incidence of dysesthesia, corneal hypesthesia, and technical failures.

    ABBREVIATIONS: MS, multiple sclerosisPBC, percutaneous balloon compressionPRGR, percutaneous retrogasserian glycerol rhizotomyTN, trigeminal neuralgiaThis is an open-access article distributed under the terms of the Creative Commons Attribution-Noncommercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work, provided it is properly cited. The work cannot be changed in any way or used commercially.

  • 42.
    Asplund, Pär
    et al.
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Linderoth, Bengt
    Bergenheim, A Tommy
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Neurosurgery.
    The predictive power of balloon shape and change of sensory functions on outcome of percutaneous balloon compression for trigeminal neuralgia2010In: Journal of Neurosurgery, ISSN 0022-3085, E-ISSN 1933-0693, Vol. 113, no 3, p. 498-507Article in journal (Refereed)
    Abstract [en]

    The authors have demonstrated that using a pear-shaped balloon when performing percutaneous balloon compression for trigeminal neuralgia results in longer pain relief than non-pear-shaped balloons. Other surgical parameters seemed less important with respect to pain relief. Balloon compression also, in many cases, results in hypesthesia.

  • 43.
    Asplund, Pär
    et al.
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Linderoth, Bengt
    Lind, Göran
    Winter, Jaleh
    Bergenheim, A. Tommy
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    One hundred eleven Percutaneous Balloon Compressions for Trigeminal Neuralgia in a Cohort of 66 Patients with Multiple Sclerosis2019In: Operative neurosurgery, ISSN 2332-4252Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Trigeminal neuralgia associated with multiple sclerosis (MS-TN) is comparatively rare and larger series of percutaneous balloon compression (PBC) in such cases are few in the literature.

    OBJECTIVE: To evaluate the results after PBC for MS-TN with regards to therapeutic effect, side effects, and complications.

    METHODS: One hundred eleven procedures with PBC performed in 66 cases of MS-TN were analyzed. Therapeutic effect was measured as postoperative time to pain recurrence without medication. All complications were compiled and the sensory function was evaluated in a subgroup of cases.

    RESULTS: The initial pain free rate was 67% and the median time to pain recurrence was 8 mo. Thirty-six patients were treated with PBC only, and among them, the results were worse if treated 3 to 4 times before, compared to first treatment (P = .009-.034). Patients who had several PBCs had worse results already after the first surgery (P < .001). A significant number of patients had impaired sensation to light touch directly after surgery, which was normalized at the late follow-up. Sensimetric testing showed raised thresholds for perception and pain directly after surgery (P = .004-.03), but these were also normalized at the late follow-up.

    CONCLUSION: PBC is a treatment that can be effective for many patients with MS-TN. Repeated previous surgeries is a risk factor for an unsatisfactory outcome. However, the patients with multiple surgeries had less satisfactory results already at the first procedure, indicating that a therapy resistant disease can be predicted after the first two PBCs. Postoperative sensory deficits were common but not lasting.

  • 44. Auer-Grumbach, Michaela
    et al.
    Bennett, D. L. H.
    Andersen, Peter
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Harms, M. B.
    Reilly, M. M.
    Weishaupt, J.
    Strom, T. M.
    Walther, T.
    Scherer, S. S.
    Zuchner, S.
    Martini, R.
    Senderek, J.
    Rare coding variants in the mme gene, encoding the metalloprotease neprilysin, are linked to late-onset axonal neuropathies2016In: Journal of the peripheral nervous system, ISSN 1085-9489, E-ISSN 1529-8027, Vol. 21, no 3, p. 235-235Article in journal (Other academic)
  • 45. Auer-Grumbach, Michaela
    et al.
    Toegel, Stefan
    Schabhuettl, Maria
    Weinmann, Daniela
    Chiari, Catharina
    Bennett, David L. H.
    Beetz, Christian
    Klein, Dennis
    Andersen, Peter M.
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Boehme, Ilka
    Fink-Puches, Regina
    Gonzalez, Michael
    Harms, Matthew B.
    Motley, William
    Reilly, Mary M.
    Renner, Wilfried
    Rudnik-Schoeneborn, Sabine
    Schlotter-Weigel, Beate
    Themistocleous, Andreas C.
    Weishaupt, Jochen H.
    Ludolph, Albert C.
    Wieland, Thomas
    Tao, Feifei
    Abreu, Lisa
    Windhager, Reinhard
    Zitzelsberger, Manuela
    Strom, Tim M.
    Walther, Thomas
    Scherer, Steven S.
    Zuchner, Stephan
    Martini, Rudolf
    Senderek, Jan
    Rare Variants in MME, Encoding Metalloprotease Neprilysin, Are Linked to Late-Onset Autosomal-Dominant Axonal Polyneuropathies2016In: American Journal of Human Genetics, ISSN 0002-9297, E-ISSN 1537-6605, Vol. 99, no 3, p. 607-623Article in journal (Refereed)
    Abstract [en]

    Axonal polyneuropathies are a frequent cause of progressive disability in the elderly. Common etiologies comprise diabetes mellitus, paraproteinaemia, and inflammatory disorders, but often the underlying causes remain elusive. Late-onset axonal Charcot-Marie-Tooth neuropathy (CMT2) is an autosomal-dominantly inherited condition that manifests in the second half of life and is genetically largely unexplained. We assumed age-dependent penetrance of mutations in a so far unknown gene causing late-onset CMT2. We screened 51 index case subjects with late-onset CMT2 for mutations by whole-exome (WES) and Sanger sequencing and subsequently queried WES repositories for further case subjects carrying mutations in the identified candidate gene. We studied nerve pathology and tissue levels and function of the abnormal protein in order to explore consequences of the mutations. Altogether, we observed heterozygous rare loss-of-function and missense mutations in MME encoding the metalloprotease neprilysin in 19 index case subjects diagnosed with axonal polyneuropathies or neurodegenerative conditions involving the peripheral nervous system. MME mutations segregated in an autosomal-dominant fashion with age-related incomplete penetrance and some affected individuals were isolated case subjects. We also found that MME mutations resulted in strongly decreased tissue availability of neprilysin and impaired enzymatic activity. Although neprilysin is known to degrade beta-amyloid, we observed no increased amyloid deposition or increased incidence of dementia in individuals with MME mutations. Detection of MME mutations is expected to increase the diagnostic yield in late-onset polyneuropathies, and it will be tempting to explore whether substances that can elevate neprilysin activity could be a rational option for treatment.

  • 46. Augestad, Ingrid Lovise
    et al.
    Nyman, Axel Karl Gottfrid
    Costa, Alex Ignatius
    Barnett, Susan Carol
    Sandvig, Axel
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Haberg, Asta Kristine
    Sandvig, Ioanna
    Effects of Neural Stem Cell and Olfactory Ensheathing Cell Co-transplants on Tissue Remodelling After Transient Focal Cerebral Ischemia in the Adult Rat2017In: Neurochemical Research, ISSN 0364-3190, E-ISSN 1573-6903, Vol. 42, no 6, p. 1599-1609Article in journal (Refereed)
    Abstract [en]

    Effective transplant-mediated repair of ischemic brain lesions entails extensive tissue remodeling, especially in the ischemic core. Neural stem cells (NSCs) are promising reparative candidates for stroke induced lesions, however, their survival and integration with the host-tissue post-transplantation is poor. In this study, we address this challenge by testing whether co-grafting of NSCs with olfactory ensheathing cells (OECs), a special type of glia with proven neuroprotective, immunomodulatory, and angiogenic effects, can promote graft survival and host tissue remodelling. Transient focal cerebral ischemia was induced in adult rats by a 60-min middle cerebral artery occlusion (MCAo) followed by reperfusion. Ischemic lesions were verified by neurological testing and magnetic resonance imaging. Transplantation into the globus pallidus of NSCs alone or in combination with OECs was performed at two weeks post-MCAo, followed by histological analyses at three weeks post-transplantation. We found evidence of extensive vascular remodelling in the ischemic core as well as evidence of NSC motility away from the graft and into the infarct border in severely lesioned animals co-grafted with OECs. These findings support a possible role of OECs as part of an in situ tissue engineering paradigm for transplant mediated repair of ischemic brain lesions.

  • 47.
    Awad, Amar
    et al.
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB).
    Blomstedt, Patric
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Westling, Göran
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB).
    Eriksson, Johan
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB).
    Functional imaging of Essential Tremor treated with Deep Brain Stimulation In the caudal Zona incerta2017Conference paper (Refereed)
  • 48. Axelsson, Markus
    et al.
    Malmeström, Clas
    Gunnarsson, Martin
    Zetterberg, Henrik
    Sundström, Peter
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Lycke, Jan
    Svenningsson, Anders
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Immunosuppressive therapy reduces axonal damage in progressive multiple sclerosis2013In: Multiple Sclerosis, ISSN 1352-4585, E-ISSN 1477-0970, Vol. 19, no 11, Supplement: S, p. 543-543Article in journal (Other academic)
  • 49. Axelsson, Markus
    et al.
    Malmeström, Clas
    Gunnarsson, Martin
    Zetterberg, Henrik
    Sundström, Peter
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Lycke, Jan
    Svenningsson, Anders
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Immunosuppressive therapy reduces axonal damage in progressive multiple sclerosis2014In: Multiple Sclerosis, ISSN 1352-4585, E-ISSN 1477-0970, Vol. 20, no 1, p. 43-50Article in journal (Refereed)
    Abstract [en]

    Background: In progressive multiple sclerosis (PMS), disease-modifying therapies have not been shown to reduce disability progression. Objective: The impact from immunosuppressive therapy in PMS was explored by analyzing cerebrospinal fluid (CSF) biomarkers of axonal damage (neurofilament light protein, NFL), astrogliosis (glial fibrillary acidic protein, GFAP), and B-cell regulation (CXCL13). Methods: CSF was obtained from 35 patients with PMS before and after 12-24 months of mitoxantrone (n=30) or rituximab (n=5) treatment, and from 14 age-matched healthy control subjects. The levels of NFL, GFAP, and CXCL13 were determined by immunoassays. Results: The mean NFL level decreased by 51% (1781 ng/l, SD 2018 vs. 874 ng/l, SD 694, p=0.007), the mean CXCL13 reduction was 55% (9.71 pg/ml, SD 16.08, vs. 4.37 pg/ml, SD 1.94, p=0.008), while GFAP levels remained unaffected. Subgroup analysis showed that the NFL reduction was confined to previously untreated patients (n=20) and patients with Gd-enhancing lesions on magnetic resonance imaging (n=12) prior to study baseline. Conclusions: Our data imply that 12-24 months of immunosuppressive therapy reduces axonal damage in PMS, particularly in patients with ongoing disease activity. Determination of NFL levels in CSF is a potential surrogate marker for treatment efficacy and as endpoint in phase II trials of MS.

  • 50. Aziz, Tipu Z.
    et al.
    Hariz, Marwan
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience. UCL Institute of Neurology, Unit of Functional Neurosurgery, London, England.
    To sleep or not to sleep during deep brain stimulation surgery for Parkinson disease?2017In: Neurology, ISSN 0028-3878, E-ISSN 1526-632X, Vol. 89, no 19, p. 1938-1939Article in journal (Other academic)
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