| 1. |
- Tapper, Sofie, 1989-, et al.
(author)
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A pilot study of essential tremor: cerebellar GABA+/Glx ratio is correlated with tremor severity
- 2020
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In: Cerebellum & ataxias. - : BioMed Central. - 2053-8871. ; 7
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Journal article (peer-reviewed)abstract
- Essential tremor is a common movement disorder with an unclear origin. Emerging evidence suggests the role of the cerebellum and the thalamus in tremor pathophysiology. We examined the two main neurotransmitters acting inhibitory (GABA+) and excitatory (Glx) respectively, in the thalamus and cerebellum, in patients diagnosed with severe essential tremor. Furthermore, we also investigated the relationship between determined neurotransmitter concentrations and tremor severity in the essential tremor patients.
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| 2. |
- Alonso, Fabiola, et al.
(author)
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Influence of Virchow-Robin spaces on the electric field distribution in subthalamic nucleus deep brain stimulation
- 2021
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In: Clinical neurology and neurosurgery. - : Elsevier. - 0303-8467 .- 1872-6968. ; 204
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Journal article (peer-reviewed)abstract
- Patient MRI from DBS implantations in the subthalamic nucleus (STN) were reviewed and it was found that around 10% had Virchow-Robin spaces (VRS). Patient-specific models were developed to evaluate changes in the electric field (EF) around DBS leads. The patients (n = 7) were implanted bilaterally either with the standard voltage-controlled lead 3389 or with the directional current-controlled lead 6180. The EF distribution was evaluated by comparing simulations using patient-specific models with homogeneous models without VRS. The EF, depicted with an isocontour of 0.2 V/mm, showed a deformation in the presence of the VRS around the DBS lead. For patient-specific models, the radial extension of the EF isocontours was enlarged regardless of the operating mode or the DBS lead used. The location of the VRS in relation to the active contact and the stimulation amplitude, determined the changes in the shape and extension of the EF. It is concluded that it is important to take the patients? brain anatomy into account as the high conductivity in VRS will alter the electric field if close to the DBS lead. This can be a cause of unexpected side effects.
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| 3. |
- Fytagoridis, Anders, et al.
(author)
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Funktionell neurokirurgi möjlig hjälp vid svåra neurogena tillstånd
- 2023
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In: Läkartidningen. - : Sveriges Läkarforbund. - 0023-7205 .- 1652-7518. ; 120
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Research review (peer-reviewed)abstract
- Funktionell neurokirurgi är ett samlingsnamn för en bred arsenal av neurokirurgiska metoder för att lindra besvär vid olika neurogena tillstånd. Syftet är genomgående att förbättra livskvalitet, och verksamheterna präglas av ett uttalat multidisciplinärt och tvärprofessionellt samarbete. Detta underlättar en god patientselektion, vilket är helt avgörande för att uppnå ett lyckat resultat. Med rätt urval och uppföljning erbjuder dessa ingrepp säker och effektiv lindring eller till och med bot för notoriskt svårbehandlade och ofta starkt funktionsnedsättande tillstånd.
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| 4. |
- Ginstman, Fredrik, et al.
(author)
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Altered levels of transthyretin in human cerebral microdialysate after subarachnoid haemorrhage using proteomics; a descriptive pilot study
- 2023
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In: Proteome Science. - : BMC. - 1477-5956. ; 21:1
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Journal article (peer-reviewed)abstract
- BackgroundSubarachnoid haemorrhage (SAH) is one of the most severe forms of stroke in which delayed cerebral ischemia is one of the major complications. Neurointensive care aims at preventing and treating such complications and identification of biomarkers of early signs of ischemia might therefore be helpful.MethodsWe aimed at describing proteome profile in cerebral microdialysate in four patients with aneurysmal SAH using two dimensional gel electrophoresis in combination with mass spectrometry in search for new biomarkers for delayed cerebral ischemia and to investigate if there were temporal fluctuations in those biomarkers over time after aneurysmal bleed.ResultsThe results showed transthyretin in nine different proteoforms (1001, 1102, 2101, 3101, 4101, 4102, 5001, 5101, 6101) in cerebral microdialysate samples from four patients having sustained SAH. Several proteoforms show highly differing levels and pooled analysis of all samples showed varying optical density related to time from aneurysmal bleed, indicating a temporal evolution.ConclusionsTransthyretin proteoforms have not earlier been shown in cerebral microdialysate after SAH and we describe differing levels based on proteoform as well as time from subarachnoid bleed. Transthyretin is well known to be synthetized in choroid plexus, whilst intraparenchymal synthesis remains controversial. The results need to be confirmed in larger studies in order to further describe transthyretin.
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| 5. |
- Göransson, Nathanael, et al.
(author)
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Postoperative Lead Movement after Deep Brain Stimulation Surgery and the Change of Stimulation Volume
- 2021
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In: Stereotactic and Functional Neurosurgery. - : S. Karger. - 1011-6125 .- 1423-0372. ; 99:3, s. 221-229
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Journal article (peer-reviewed)abstract
- Introduction: Lead movement after deep brain stimulation may occur and influence the affected volume of stimulation. The aim of the study was to investigate differences in lead position between the day after surgery and approximately 1 month postoperatively and also simulate the electric field (EF) around the active contacts in order to investigate the impact of displacement on affected volume. Methods: Twenty-three patients with movement disorders underwent deep brain stimulation surgery (37 leads). Computed tomography at the 2 time points were co-fused respectively with the stereotactic images in Surgiplan. The coordinates (x, y, and z) of the lead tips were compared between the 2 dates. Eleven of these patients were selected for the EF simulation in Comsol Multiphysics. Postoperative changes of EF spread in the tissue due to conductivity changes in perielectrode space and due to displacement were evaluated by calculating the coverage coefficient and the Sorensen-Dice coefficient. Results: There was a significant displacement (mean +/- SD) on the left lead: x (0.44 +/- 0.72, p < 0.01), y (0.64 +/- 0.54, p < 0.001), and z (0.62 +/- 0.71, p < 0.001). On the right lead, corresponding values were: x (-0.11 +/- 0.61, ns), y (0.71 +/- 0.54, p < 0.001), and z (0.49 +/- 0.81, p < 0.05). The anchoring technique was a statistically significant variable associated with displacement. No correlation was found between bilateral (n = 14) versus unilateral deep brain stimulation, gender (n = 17 male), age <60 years (n = 8), and calculated air volume. The simulated stimulation volume was reduced after 1 month because of the perielectrode space. When considering perielectrode space and displacement, the volumes calculated the day after surgery and approximately 1 month later were partly overlapped. Conclusion: The left lead tip displayed a tendency to move lateral, anterior, and inferior and the right a tendency to move anterior and inferior. The anchoring technique was associated to displacement. New brain territory was affected due to the displacement despite considering the reduced stimulated volume after 1 month. Postoperative changes in perielectrode space and small lead movements are reasons for delaying programming to 4 weeks following surgery.
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| 6. |
- Hermansen, Anna, et al.
(author)
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A more than 20-year follow-up of pain and disability after anterior cervical decompression and fusion surgery for degenerative disc disease and comparisons between two surgical techniques
- 2023
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In: BMC Musculoskeletal Disorders. - : BMC. - 1471-2474. ; 24:1
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Journal article (peer-reviewed)abstract
- BackgroundFollow-ups more than 20 years after neck surgery are extremely rare. No previous randomized studies have investigated differences in pain and disability more than 20 years after ACDF surgery using different techniques. The purpose of this study was to describe pain and functioning more than 20 years after anterior cervical decompression and fusion surgery, and to compare outcomes between the Cloward Procedure and the carbon fiber fusion cage (CIFC).MethodsThis study is a 20 to 24-year follow-up of a randomized controlled trial. Questionnaires were sent to 64 individuals, at least 20 years after ACDF due to cervical radiculopathy. Fifty individuals (mean age 69, 60% women, 55% CIFC) completed questionnaires. Mean time since surgery was 22.4 years (range 20,5-24). Primary outcomes were neck pain and neck disability index (NDI). Secondary outcomes were frequency and intensity of neck and arm pain, headache, dizziness, self-efficacy, health related quality of life or global outcome. Clinically relevant improvements were defined as 30 mm decrease in pain and a decrease in disability of 20 percentage units. Between-group differences over time were analyzed with mixed design ANOVA and relationships between main outcomes and psychosocial factors were analyzed by Spearman s rho.ResultsNeck pain and NDI score significantly improved over time (p < .001), with no group differences in primary or secondary outcomes. Eighty-eight per cent of participants experienced improvements or full recovery, 71% (pain) and 41% (NDI) had clinically relevant improvements. Pain and NDI were correlated with lower self-efficacy and quality of life.ConclusionThe results from this study do not support the idea that fusion technique affects long-term outcome of ACDF. Pain and disability improved substantially over time, irrespective of surgical technique. However, the majority of participants reported residual disability not to a negligible extent. Pain and disability were correlated to lower self-efficacy and quality of life.
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| 7. |
- Hermansen, Anna, et al.
(author)
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Dizziness and balance outcomes after two different postoperative rehabilitation approaches following neck surgery : analyses of a multicenter randomized controlled trial
- 2023
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In: Physiotherapy Theory and Practice. - Philadelphia, PA, United States : Taylor & Francis. - 0959-3985 .- 1532-5040. ; 39:4, s. 750-760
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Journal article (peer-reviewed)abstract
- Background Dizziness and balance problems are common symptoms in patients with cervical radiculopathy. Objective To evaluate the effect of neck surgery postoperatively combined with either structured rehabilitation or standard approach in patients with cervical radiculopathy and dizziness and/or balance problems, and investigate factors influencing dizziness and balance at 6-month follow-up.Methods Individuals (n = 149) with cervical radiculopathy and dizziness and/or balance problems were randomized preoperatively to structured postoperative rehabilitation or standard postoperative approach. Outcomes were intensity of dizziness and subjective balance, and clinical measures of balance.Results Self-reported measures improved at three months (p < 0.001 to p = .007) and the standing balance at six months (p = .008). No between-group differences. Baseline values, neck pain, and physical activity level explained 23-39% of the variance in 6-month outcomes for self-reported measures. Baseline values and physical activity level explained 71% of the variance in walking balance, and lower baseline scores were significantly associated with standing balance impairments (OR 0.876).Conclusion Patients improved significantly in dizziness and subjective balance intensity shortly after surgery, and in standing balance at 6 months, independent of postoperative rehabilitation. Neck pain, physical activity, and neck muscle function influenced dizziness and balance, although preoperative values and neck pain were of most importance for 6-month outcomes.
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| 8. |
- Johansson, Johannes, et al.
(author)
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Comparison between patient-specific deep brain stimulation simulations and commercial system SureTune3
- 2021
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In: Biomedical Engineering & Physics Express. - : IOP PUBLISHING LTD. - 2057-1976. ; 7:5
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Journal article (peer-reviewed)abstract
- Objective. Software to visualize estimated volume of tissue activated (VTA) in deep brain stimulation assuming a homogeneous tissue surrounding such as SureTune3 has recently become available for clinical use. The objective of this study is to compare SureTune3 with homogeneous and heterogeneous patient-specific finite element method (FEM) simulations of the VTA to elucidate how well they coincide in their estimates. Approach. FEM simulations of the VTA were performed in COMSOL Multiphysics and compared with VTA from SureTune3 with variation of voltage and current amplitude, pulse width, axon diameter, number of active contacts, and surrounding homogeneous grey or white matter. Patient-specific simulations with heterogeneous tissue were also performed. Main results. The VTAs corresponded well for voltage control in homogeneous tissue, though with the smallest VTAs being slightly larger in SureTune3 and the largest VTAs being slightly larger in the FEM simulations. In current control, FEM estimated larger VTAs in white matter and smaller VTAs in grey matter compared to SureTune3 as grey matter has higher electric conductivity than white matter and requires less voltage to reach the same current. The VTAs also corresponded well in the patient-specific cases except for one case with a cyst of highly conductive cerebrospinal fluid (CSF) near the active contacts. Significance. The VTA estimates without taking the surrounding tissue into account in SureTune3 are in good agreement with patient-specific FEM simulations when using voltage control in the absence of CSF-filled cyst. In current control or when CSF is present near the active contacts, the tissue characteristics are important for the VTA and needs consideration. Clinical. trial ethical approval: Local ethics committee at Linkoping University (2012/434-31).
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| 9. |
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| 10. |
- Lam, Kwun, et al.
(author)
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Larger pain extent is associated with greater pain intensity and disability but not with general health status or psychosocial features in patients with cervical radiculopathy
- 2021
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In: Medicine. - : Lippincott, Williams & Wilkins. - 0025-7974 .- 1536-5964. ; 100:8
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Journal article (peer-reviewed)abstract
- Pain as a result of cervical radiculopathy (CR) can be widespread, nondermatomal and individually specific, but the association between pain extent and other clinical features has never been explored. The objective of this study is to investigate whether pain extent relates to clinical variables including pain intensity in addition to health indicators including disability, general health, depression, somatic anxiety, coping strategies or self-efficacy. An observational cohort study was conducted. Participants were recruited from 4 hospital spinal centres in Sweden. Pain extent was quantified from the pain drawings of 190 individuals with cervical disc disease, verified with magnetic resonance imaging (MRI) and compatible with clinical findings (examined by a neurosurgeon), that show cervical nerve root compression. Pain extent was evaluated in relation to neck pain, arm pain, and headache intensity. Multiple linear regression analysis were then used to verify whether pain extent was associated with other health indicators including disability, health-related quality of life, depression, somatic anxiety, coping strategies and self-efficacy. Pain extent was directly related to neck, arm and headache pain intensity (all P < .01). Multiple linear regression revealed that pain extent was significantly associated only to the level of perceived disability (P < .01). Increased pain extent in people with CR is associated with higher headache, neck and arm pain intensity, and disability but not measures of general health, depression, somatic anxiety, coping strategies or self-efficacy.
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