umu.sePublications
Change search
Link to record
Permanent link

Direct link
BETA
Sundström, Nina
Alternative names
Publications (10 of 26) Show all publications
Wijayatunga, P. & Sundström, N. (2019). Discriminative Prediction of Adverse Events for Optimized Therapies Following Traumatic Brain Injury. In: : . Paper presented at 31st Swedish AI Society Workshop 2019, June 18–19, 2019, Umeå, Sweden. Umeå, Article ID 3.
Open this publication in new window or tab >>Discriminative Prediction of Adverse Events for Optimized Therapies Following Traumatic Brain Injury
2019 (English)Conference paper, Published paper (Refereed)
Abstract [en]

Traumatic brain injury (TBI) causes temporary or perma- nent alteration in brain functions. At intensive care units, TBI patients are usually multimodally monitored, thus rendering large volumes of data on many physiological variables. For the physician, these data are difficult to interpret due to their complexity, speed and volume. Thus, computa- tional aids are recommended, e.g., for predicting patient’s clinical status in near future. In this article, we describe a probabilistic model that can be used for aiding physician’s decision making process in TBI patient care in real time. Our model tries to capture time varying patterns of patient’s clinical information. The model is built by using a discrimi- native model learning framework so that it can predict adverse clinical events with a higher level of accuracy. That is, our model is built so that prediction of certain desired events are given more attention than that of the other less important ones. This can be achieved by estimating model parameters in such a way, for e.g. using a cost function, when a suitable model structure has been selected, that again can be done dis- criminatively. However, such estimation procedures have no closed form solutions, so numerical optimization methods are used.

Place, publisher, year, edition, pages
Umeå: , 2019
Keywords
Dependence, Accuracy, Clinical, Real time
National Category
Probability Theory and Statistics
Research subject
Statistics
Identifiers
urn:nbn:se:umu:diva-160522 (URN)
Conference
31st Swedish AI Society Workshop 2019, June 18–19, 2019, Umeå, Sweden
Available from: 2019-06-19 Created: 2019-06-19 Last updated: 2019-06-20Bibliographically approved
Öhberg, F., Bäcklund, T., Sundström, N. & Grip, H. (2019). Portable Sensors Add Reliable Kinematic Measures to the Assessment of Upper Extremity Function. Sensors, 19(5), Article ID 1241.
Open this publication in new window or tab >>Portable Sensors Add Reliable Kinematic Measures to the Assessment of Upper Extremity Function
2019 (English)In: Sensors, ISSN 1424-8220, E-ISSN 1424-8220, Vol. 19, no 5, article id 1241Article in journal (Refereed) Published
Abstract [en]

Ordinal scales with low resolution are used to assess arm function in clinic. These scales may be improved by adding objective kinematic measures. The aim was to analyze within-subject, inter-rater and overall reliability (i.e., including within-subject and inter-rater reliability) and check the system's validity of kinematic measures from inertial sensors for two such protocols on one person. Twenty healthy volunteers repeatedly performed two tasks, finger-to-nose and drinking, during two test sessions with two different raters. Five inertial sensors, on the forearms, upper arms and xiphoid process were used. Comparisons against an optical camera system evaluated the measurement validity. Cycle time, range of motion (ROM) in shoulder and elbow were calculated. Bland-Altman plots and linear mixed models including the generalizability (G) coefficient evaluated the reliability of the measures. Within-subject reliability was good to excellent in both tests (G = 0.80-0.97) and may serve as a baseline when assessing upper extremities in future patient groups. Overall reliability was acceptable to excellent (G = 0.77-0.94) for all parameters except elbow axial rotation in finger-to-nose task and both elbow axial rotation and flexion/extension in drinking task, mainly due to poor inter-rater reliability in these parameters. The low to good reliability for elbow ROM probably relates to high within-subject variability. The sensors provided good to excellent measures of cycle time and shoulder ROM in non-disabled individuals and thus have the potential to improve today's assessment of arm function.

Place, publisher, year, edition, pages
MDPI, 2019
Keywords
inter-rater reliability, inertial sensor, kinematics, upper limb, arm function
National Category
Physiotherapy
Identifiers
urn:nbn:se:umu:diva-158105 (URN)10.3390/s19051241 (DOI)000462540400260 ()30870999 (PubMedID)
Available from: 2019-04-12 Created: 2019-04-12 Last updated: 2019-04-12Bibliographically approved
Koskinen, L.-O. D., Sundström, N., Hägglund, L., Eklund, A. & Olivecrona, M. (2019). Prostacyclin Affects the Relation Between Brain Interstitial Glycerol and Cerebrovascular Pressure Reactivity in Severe Traumatic Brain Injury. Neurocritical Care, 31(3), 494-500
Open this publication in new window or tab >>Prostacyclin Affects the Relation Between Brain Interstitial Glycerol and Cerebrovascular Pressure Reactivity in Severe Traumatic Brain Injury
Show others...
2019 (English)In: Neurocritical Care, ISSN 1541-6933, E-ISSN 1556-0961, Vol. 31, no 3, p. 494-500Article in journal (Refereed) Published
Abstract [en]

Background: Cerebral injury may alter the autoregulation of cerebral blood flow. One index for describing cerebrovascular state is the pressure reactivity (PR). Little is known of whether PR is associated with measures of brain metabolism and indicators of ischemia and cell damage. The aim of this investigation was to explore whether increased interstitial levels of glycerol, a marker of cell membrane damage, are associated with PR, and if prostacyclin, a membrane stabilizer and regulator of the microcirculation, may affect this association in a beneficial way.

Materials and Methods: Patients suffering severe traumatic brain injury (sTBI) were treated according to an intracranial pressure (ICP)-targeted therapy based on the Lund concept and randomized to an add-on treatment with prostacyclin or placebo. Inclusion criteria were verified blunt head trauma, Glasgow Coma Score <= 8, age 15-70 years, and a first measured cerebral perfusion pressure of >= 10 mmHg. Multimodal monitoring was applied. A brain microdialysis catheter was placed on the worst affected side, close to the penumbra zone. Mean (glycerol(mean)) and maximal glycerol (glycerol(max)) during the 96-h sampling period were calculated. The mean PR was calculated as the ICP/mean arterial pressure (MAP) regression coefficient based on hourly mean ICP and MAP during the first 96 h.

Results: Of the 48 included patients, 45 had valid glycerol and PR measurements available. PR was higher in the placebo group as compared to the prostacyclin group (p = 0.0164). There was a positive correlation between PR and the glycerol(mean) (rho = 0.503, p = 0.01) and glycerol(max) (rho = 0.490, p = 0.015) levels in the placebo group only.

Conclusions: PR is correlated to the glycerol level in patients suffering from sTBI, a relationship that is not seen in the group treated with prostacyclin. Glycerol has been associated with membrane degradation and may support glycerol as a biomarker for vascular endothelial breakdown. Such a breakdown may impair the regulation of cerebrovascular PR.

Place, publisher, year, edition, pages
Springer-Verlag New York, 2019
Keywords
Traumatic brain injury, Pressure reactivity, Autoregulation, Glycerol, Cerebral microdialysis, Prostacyclin
National Category
Anesthesiology and Intensive Care
Identifiers
urn:nbn:se:umu:diva-167070 (URN)10.1007/s12028-019-00741-4 (DOI)000501700900007 ()31123992 (PubMedID)
Available from: 2020-01-13 Created: 2020-01-13 Last updated: 2020-01-13Bibliographically approved
Andrén, K., Wikkelsö, C., Sundström, N., Agerskov, S., Israelsson, H., Laurell, K., . . . Tullberg, M. (2018). Long-term effects of complications and vascular comorbidity in idiopathic normal pressure hydrocephalus: a quality registry study. Journal of Neurology, 265(1), 178-186
Open this publication in new window or tab >>Long-term effects of complications and vascular comorbidity in idiopathic normal pressure hydrocephalus: a quality registry study
Show others...
2018 (English)In: Journal of Neurology, ISSN 0340-5354, E-ISSN 1432-1459, Vol. 265, no 1, p. 178-186Article in journal (Refereed) Published
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.

Place, publisher, year, edition, pages
Springer, 2018
Keywords
hydrocephalus, normal pressure, dementia, gait, complications, concomitant disease, risk factors, registries
National Category
Neurology
Identifiers
urn:nbn:se:umu:diva-144413 (URN)10.1007/s00415-017-8680-z (DOI)000419777000023 ()29188384 (PubMedID)
Available from: 2018-02-09 Created: 2018-02-09 Last updated: 2019-11-25Bibliographically approved
Sundström, N., Lagebrant, M., Eklund, A., Koskinen, L.-O. D. & Malm, J. (2018). Subdural hematomas in 1846 patients with shunted idiopathic normal pressure hydrocephalus: treatment and long-term survival. Journal of Neurosurgery, 129(3), 797-804
Open this publication in new window or tab >>Subdural hematomas in 1846 patients with shunted idiopathic normal pressure hydrocephalus: treatment and long-term survival
Show others...
2018 (English)In: Journal of Neurosurgery, ISSN 0022-3085, E-ISSN 1933-0693, Vol. 129, no 3, p. 797-804Article in journal (Refereed) Published
Abstract [en]

OBJECTIVE Subdural hematoma (SDH) is the most common serious adverse event in patients with shunts. Adjustable shunts are used with increasing frequency and make it possible to noninvasively treat postoperative SDH. The objective of this study was to describe the prevalence and treatment preferences of SDHs, based on fixed or adjustable shunt valves, in a national cohort of patients with shunted idiopathic normal pressure hydrocephalus (iNPH), as well as to evaluate the effect of SDH and treatment on long-term survival.

METHODS Patients with iNPH who received a CSF shunt in Sweden from 2004 to 2015 were included in a prospective quality registry (n = 1846) and followed regarding SDH, its treatment, and mortality. The treatment of SDH was categorized into surgery, opening pressure adjustments, or no treatment.

RESULTS During the study period, the proportion of adjustable shunts increased from 75% to 95%. Ten percent (n = 184) of the patients developed an SDH. In 103 patients, treatment was solely opening pressure adjustment. Surgical treatment was used in 66 cases (36%), and 15 (8%) received no treatment. In patients with fixed shunt valves, 90% (n = 17) of SDHs were treated surgically compared with 30% (n = 49) in patients with adjustable shunts (p < 0.001). There was no difference in long-term patient survival between the SDH and non-SDH groups or between different treatments.

CONCLUSIONS SDH remains a common complication after shunt surgery, but adjustable shunts reduced the need for surgical interventions. SDH and treatment did not significantly affect survival in this patient group, thus the noninvasive treatment offered by adjustable shunts considerably reduces the level of severity for this common adverse event.

Place, publisher, year, edition, pages
American Association of Neurological Surgeons, 2018
Keywords
NPR = National Population Registry, SDH = subdural hematoma, SHDR = Swedish Hospital Discharge Registry, SHQR = Swedish Hydrocephalus Quality Register, cerebrospinal fluid shunt, complications, hydrocephalus, iNPH = idiopathic normal pressure hydrocephalus, normal pressure, subdural hematoma, survival, treatment
National Category
Neurology
Identifiers
urn:nbn:se:umu:diva-142422 (URN)10.3171/2017.5.JNS17481 (DOI)000443287000026 ()29076787 (PubMedID)
Available from: 2017-11-30 Created: 2017-11-30 Last updated: 2018-09-14Bibliographically approved
Koskinen, L.-O. D., Sundström, N., Hägglund, L., Eklund, A. & Olivecrona, M. (2018). The relation between brain interstitial clycerol and pressure reactivity in TBI is prostacyclin dependent. Paper presented at 3rd Joint Symposium of the International-and-National-Neurotrauma-Societies-and-AANS/CNS-Section on Neurotrauma and Critical Care, AUG 11-16, 2018, Toronto, CANADA. Journal of Neurotrauma, 35(16), A185-A185
Open this publication in new window or tab >>The relation between brain interstitial clycerol and pressure reactivity in TBI is prostacyclin dependent
Show others...
2018 (English)In: Journal of Neurotrauma, ISSN 0897-7151, E-ISSN 1557-9042, Vol. 35, no 16, p. A185-A185Article in journal, Meeting abstract (Other academic) Published
Place, publisher, year, edition, pages
Mary Ann Liebert, 2018
Keywords
biomarker, intracranial pressure, neurocritical care
National Category
Neurology
Identifiers
urn:nbn:se:umu:diva-151558 (URN)000441527400497 ()
Conference
3rd Joint Symposium of the International-and-National-Neurotrauma-Societies-and-AANS/CNS-Section on Neurotrauma and Critical Care, AUG 11-16, 2018, Toronto, CANADA
Note

Meeting Abstract: PS2.04.10

Available from: 2018-09-10 Created: 2018-09-10 Last updated: 2018-09-10Bibliographically approved
Holmlund, P., Eklund, A., Koskinen, L.-O. D., Johansson, E., Sundström, N., Malm, J. & Qvarlander, S. (2018). Venous collapse regulates intracranial pressure in upright body positions. American Journal of Physiology. Regulatory Integrative and Comparative Physiology, 314(3), R377-R385
Open this publication in new window or tab >>Venous collapse regulates intracranial pressure in upright body positions
Show others...
2018 (English)In: American Journal of Physiology. Regulatory Integrative and Comparative Physiology, ISSN 0363-6119, E-ISSN 1522-1490, Vol. 314, no 3, p. R377-R385Article in journal (Refereed) Published
Abstract [en]

Recent interest in intracranial pressure (ICP) in the upright posture has revealed that the mechanisms regulating postural changes in ICP are not fully understood. We have suggested an explanatory model where the postural changes in ICP depend on well-established hydrostatic effects in the venous system and where these effects are interrupted by collapse of the internal jugular veins (IJVs) in more upright positions. The aim of this study was to investigate this relationship by simultaneous invasive measurements of ICP, venous pressure and IJV collapse in healthy volunteers. ICP (monitored via the lumbar route), central venous pressure (PICC-line) and IJV cross-sectional area (ultrasound) were measured in 11 healthy volunteers (47±10 years) in seven positions, from supine to sitting (0°-69°). Venous pressure and anatomical distances were used to predict ICP in accordance with the explanatory model, and IJV area was used to assess IJV collapse. The hypothesis was tested by comparing measured ICP to predicted ICP. Our model accurately described the general behavior of the observed postural ICP changes (mean difference: -0.03±2.7 mmHg). No difference was found between predicted and measured ICP for any tilt-angle (p-values: 0.65 - 0.94). The results support the hypothesis that postural ICP changes are governed by hydrostatic effects in the venous system and IJV collapse. This improved understanding of the postural ICP regulation may have important implications for the development of better treatments for neurological and neurosurgical conditions affecting ICP.

Place, publisher, year, edition, pages
American Physiological Society, 2018
Keywords
Intracranial pressure, healthy volunteers, hydrocephalus, posture, venous pressure
National Category
Neurology
Identifiers
urn:nbn:se:umu:diva-142424 (URN)10.1152/ajpregu.00291.2017 (DOI)000426326500006 ()29118021 (PubMedID)
Available from: 2017-11-30 Created: 2017-11-30 Last updated: 2019-03-06Bibliographically approved
Sundström, N., Malm, J., Laurell, K., Lundin, F., Kahlon, B., Cesarini, K. G., . . . Wikkelsö, C. (2017). Incidence and outcome of surgery for adult hydrocephalus patients in Sweden. British Journal of Neurosurgery, 31(1), 21-27
Open this publication in new window or tab >>Incidence and outcome of surgery for adult hydrocephalus patients in Sweden
Show others...
2017 (English)In: British Journal of Neurosurgery, ISSN 0268-8697, E-ISSN 1360-046X, Vol. 31, no 1, p. 21-27Article in journal (Refereed) Published
Abstract [en]

OBJECT: To present population-based and age related incidence of surgery and clinical outcome for adult patients operated for hydrocephalus, registered in the Swedish Hydrocephalus Quality Registry (SHQR).

METHODS: All patients registered in SHQR during 2004-2011 were included. Data on age, gender, type of hydrocephalus and type of surgery were extracted as well as three months outcome for patients with idiopathic normal pressure hydrocephalus (iNPH).

RESULTS: The material consisted of 2360 patients, 1229 men and 1131 women, age 63.8 ± 14.4 years (mean ± standard deviation (SD)). The mean total incidence of surgery was 5.1 ± 0.9 surgeries/100,000/year; 4.7 ± 0.9 shunt surgeries and 0.4 ± 0.1 endoscopic third ventriculostomies. For iNPH, secondary communicating hydrocephalus and obstructive hydrocephalus, the incidence of surgery was 2.2 ± 0.8, 1.9 ± 0.3 and 0.8 ± 0.1/100,000/year, respectively. During 2004-2011, the incidence of surgery increased in total (p = .044), especially in age groups 70-79 years and ≥80 years (p = .012 and p = .031). After surgery, 253 of 652 iNPH patients (38.8%) improved at least one step on the modified Rankin scale (mRS). Number needed to treat was 3.0 for improving one patient from unfavourable (mRS 3-5) to favourable (mRS 0-2). The mean score of a modified iNPH scale increased from 54 ± 23 preoperatively to 63 ± 25 postoperatively (p < .0001, n = 704), and 58% improved. No significant regional differences in incidence, surgical techniques or outcome were found.

CONCLUSIONS: Incidence of hydrocephalus surgery increased significantly during 2004-2011, specifically in elderly patients. Surgical treatment of iNPH markedly improved functional independence, but the improvement rate was low compared to recent single- and multicentre studies. Thus, the potential for surgical improvement is likely lower than generally reported when treating patients as part of everyday clinical care.

National Category
Neurology Surgery
Identifiers
urn:nbn:se:umu:diva-131130 (URN)10.1080/02688697.2016.1229749 (DOI)000394397400006 ()27619731 (PubMedID)
Available from: 2017-02-06 Created: 2017-02-06 Last updated: 2018-06-09Bibliographically approved
Brändström, H., Sundelin, A., Hoseason, D., Sundström, N., Birgander, R., Johansson, G., . . . Haney, M. (2017). Risk for intracranial pressure increase related to enclosed air in post-craniotomy patients during air ambulance transport: a retrospective cohort study with simulation. Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine, 25, Article ID 50.
Open this publication in new window or tab >>Risk for intracranial pressure increase related to enclosed air in post-craniotomy patients during air ambulance transport: a retrospective cohort study with simulation
Show others...
2017 (English)In: Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine, ISSN 1757-7241, E-ISSN 1757-7241, Vol. 25, article id 50Article in journal (Refereed) Published
Abstract [en]

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

Place, publisher, year, edition, pages
BioMed Central, 2017
Keywords
Air ambulance, Intracranial pressure, Pneumocephalus
National Category
Anesthesiology and Intensive Care Neurosciences Surgery Radiology, Nuclear Medicine and Medical Imaging
Identifiers
urn:nbn:se:umu:diva-134974 (URN)10.1186/s13049-017-0394-9 (DOI)000401225800001 ()28499454 (PubMedID)
Available from: 2017-05-15 Created: 2017-05-15 Last updated: 2018-06-09Bibliographically approved
Bäcklund, T., Frankel, J., Israelsson, H., Malm, J. & Sundström, N. (2017). Trunk sway in idiopathic normal pressure hydrocephalus: quantitative assessment in clinical practice. Gait & Posture, 62-70, Article ID 54.
Open this publication in new window or tab >>Trunk sway in idiopathic normal pressure hydrocephalus: quantitative assessment in clinical practice
Show others...
2017 (English)In: Gait & Posture, ISSN 0966-6362, E-ISSN 1879-2219, p. 62-70, article id 54Article in journal (Refereed) Published
Abstract [en]

Background: In diagnosis and treatment of patients with idiopathic normal pressure hydrocephalus (iNPH), there is need for clinically applicable, quantitative assessment of balance and gait. Using a body worn gyroscopic system, the aim of this study was to assess postural stability of iNPH patients in standing, walking and during sensory deprivation before and after cerebrospinal fluid (CSF) drainage and surgery. A comparison was performed between healthy elderly (HE) and patients with various types of hydrocephalus (ventriculomegaly (VM)).

Methods: Trunk sway was measured in 31 iNPH patients, 22 VM patients and 58 HE. Measurements were performed at baseline in all subjects, after CSF drainage in both patient groups and after shunt surgery in the iNPH group.

Results: Preoperatively, the iNPH patients had significantly higher trunk sway compared to HE, specifically for the standing tasks (p < 0.001). Compared to VM, iNPH patients had significantly lower sway velocity during gait in three of four cases on firm support (p < 0.05). Sway velocity improved after CSF drainage and in forward-backward direction after surgery (p < 0.01). Compared to HE both patient groups demonstrated less reliance on visual input to maintain stable posture.

Conclusions: INPH patients had reduced postural stability compared to HE, particularly during standing, and for differentiation between iNPH and VM patients sway velocity during gait is a promising parameter. A reversible reduction of visual incorporation during standing was also seen. Thus, the gyroscopic system quantitatively assessed postural deficits in iNPH, making it a potentially useful tool for aiding in future diagnoses, choices of treatment and clinical follow-up. 

Place, publisher, year, edition, pages
Elsevier, 2017
Keywords
Idiopathic normal pressure hydrocephalus, Trunk sway, Balance, Gait, Gyroscope
National Category
Biomedical Laboratory Science/Technology
Identifiers
urn:nbn:se:umu:diva-138239 (URN)10.1016/j.gaitpost.2017.02.017 (DOI)000405044400011 ()28259041 (PubMedID)
Available from: 2017-08-16 Created: 2017-08-16 Last updated: 2018-06-09Bibliographically approved
Organisations

Search in DiVA

Show all publications