| 1. |
- Fytagoridis, Anders, et al.
(författare)
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Surgical Replacement of Implantable Pulse Generator in Deep Brain Stimulation : Adverse Events and Risk Factors in a Multicenter Cohort
- 2016
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Ingår i: Stereotactic and Functional Neurosurgery. - : S. Karger AG. - 1011-6125 .- 1423-0372. ; 94:4, s. 235-239
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Tidskriftsartikel (refereegranskat)abstract
- Background: Deep brain stimulation (DBS) is a growing treatment modality, and most DBS systems require replacement of the implantable pulse generator (IPG) every few years. The literature regarding the potential impact of adverse events of IPG replacement on the longevity of DBS treatments is rather scarce. Objective: To investigate the incidence of adverse events, including postoperative infections, associated with IPG replacements in a multicenter cohort. Methods: The medical records of 808 patients from one Australian and five Swedish DBS centers with a total of 1,293 IPG replacements were audited. A logistic regression model was used to ascertain the influence of possible predictors on the incidence of adverse events. Results: The overall incidence of major infections was 2.3% per procedure, 3.7% per patient and 1.7% per replaced IPG. For 28 of 30 patients this resulted in partial or complete DBS system removal. There was an increased risk of infection for males (OR 3.6, p = 0.026), and the risk of infection increased with the number of prior IPG replacements (OR 1.6, p < 0.005). Conclusions: The risk of postoperative infection with DBS IPG replacement increases with the number of previous procedures. There is a need to reduce the frequency of IPG replacements.
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| 2. |
- Rejmstad, Peter, et al.
(författare)
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Oxygen saturation estimation in brain tissue using diffuse reflectance spectroscopy along stereotactic trajectories
- 2017
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Ingår i: Optics Express. - : Optical Society of America. - 1094-4087. ; 25:7, s. 8192-8201
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Tidskriftsartikel (refereegranskat)abstract
- Diffuse reflectance spectroscopy (DRS) can be used to estimate oxygen saturation (SO2) of hemoglobin and blood fraction (fB) in brain tissue. The aim of the study was to investigate the SO2 and fB in different positions along deep brain stimulation (DBS) trajectories and in specific target regions using DRS and a novel algorithm. DRS measurements were done at 166 well-defined anatomical positions in relation to stereotactic DBS-implantation along 20 trajectories toward 4 DBS targets (STN, Vim, GPi and Zi). The measurements were dived into groups (gray, white and light gray matter) related to anatomical position, and DBS targets, before comparison and statistical analysis. The median SO2 in gray, white and light gray matter were 52%, 24% and 20%, respectively. Median fB in gray matter (3.9%) was different from values in white (1.0%, p < 0.05) and light gray (0.9%, p < 0.001) matter. No significant difference in median SO2 and fB was found between DBS target regions. The novel algorithm allows for quick and reliable estimation of SO2 and fB in human brain tissue.
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| 3. |
- Tapper, Sofie, 1989-, et al.
(författare)
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A pilot study of essential tremor: cerebellar GABA+/Glx ratio is correlated with tremor severity
- 2020
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Ingår i: Cerebellum & ataxias. - : BioMed Central. - 2053-8871. ; 7
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Tidskriftsartikel (refereegranskat)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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| 4. |
- Tapper, Sofie, 1989-
(författare)
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Neurotransmitter Imaging of the Human Brain : Detecting γ-Aminobutyric Acid (GABA) Using Magnetic Resonance Spectroscopy
- 2019
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Introduction: In this thesis, MEGA-edited Magnetic Resonance Spectroscopy (MRS) has been used for the purpose of non-invasive detection of !- aminobutyric acid (GABA) within the brain. GABA is the main inhibitory neurotransmitter in the human central nervous system, and glutamate is the corresponding main excitatory neurotransmitter. A balance between GABA and glutamate is crucial for healthy neurotransmission within the brain, and regional altered concentrations have been linked to certain neurological disorders. However, it is challenging to measure GABA, and special editing approaches are needed in order to allow reliable quantification. In addition, the GABA measurement is further complicated due to disturbances such as movements during the acquisition that may lead to artifacts in the resulting spectrum. This thesis can be divided into two sections, where the first section focuses on three clinical applications (narcolepsy, irritable bowel syndrome (IBS), and essential tremor (ET)), which were all investigated using MEGA-edited single- voxel spectroscopy (SVS). The second section focuses on method development, where two statistical retrospective approaches were investigated for the purpose of improving MEGA-edited data. In addition, a new MRS imaging (MRSI) pulse sequence with the purpose of GABA detection using a high spatial resolution, short acquisition time, and full brain coverage was also investigated.Materials and Methods: In total, 164 participants were included and 272 MRS measurements were performed with the voxel placed in the medial prefrontal cortex (mPFC, 136), thalamus (32), and cerebellum (104) using two different but “identical” MR systems. Nineteen narcolepsy patients and 21 matched healthy controls performed an fMRI working memory task using a simultaneous EEG followed by an mPFC GABA-edited MRS measurement. Sixty-four IBS patients and 32 matched healthy controls underwent an mPFC GABA-edited MRS measurement followed by resting state fMRI. In addition, psychological symptoms were assessed using questionnaires. Ten ET patients and six matched healthy controls underwent four GABA-edited MRS measurements with the voxels placed in the thalamus and cerebellum. In this study, the symptom severity was investigated using the essential tremor rating scale (ETRS). All clinical MRS datasets were analyzed using conventional methods for post-processing and quantification. Furthermore, 12 volunteers were recruited for the purpose of investigating statistical retrospective approaches for artifact detection and elimination of MRS data. Each participant underwent three reference measurements and three measurements with induced head movements conducted according to a movement paradigm. Order statistic filtering (OSF) and jackknife correlation (JKC) were investigated as regards to the elimination of artifact-influenced spectra and reliability of the resulting concentrations. Finally, phantom measurements were performed for the purpose of investigating MEGA-edited MRSI.Results: In narcolepsy, a trend-level association was observed between the mPFC MRS concentrations and increased deactivation within the default mode network during the working memory task. A significantly higher mPFC GABA+ concentration was observed in IBS patients with a high severity of comorbid anxiety. In ET, a positive correlation was observed between cerebellar GABA+/Glx ratios and tremor severity. Moreover, movements during the measurement decreased the concentration estimates due to signal loss in the spectra. Both OSF and JKC resulted in trend-level improvement of the signal- intense metabolites in spectrum when artifacts were present in the data, while performing equally as well as conventional analysis methodology when no intentional movements were present in the data. Finally, using the fast MEGA- edited multi-voxel sequence developed for a conventional clinical scanner, our phantom measurements showed that GABA was detectable using a 1:45 min acquisition time and an MRSI voxel size of 1 mL.Discussion: Several challenges such as time constraints, large voxel sizes, and protocol design were encountered when performing SVS MEGA-PRESS in the clinical research settings. In addition, artifacts in the MRS data originating for example, from motions, negatively impacted the resulting averaged spectra, which was evident in both data from clinical populations and healthy controls. In the presence of artifacts in the data, both OSF and JKC improved the SVS MEGA-edited spectra. In addition, the implemented JKC method can be used not only for artifact detection, but also as a generally applicable retrospective technique for the quality control of a dataset, or as an indication of whether a shift in voxel placement occurred during the measurement. Using the MEGA-edited MRSI pulse sequence, there are many technical challenges, including detrimental effects from eddy currents, spurious echoes, and field inhomogeneities. Even though there are many technical challenges when using MEGA-edited MRSI, an optimized version of the MRSI sequence would be extremely valuable in clinical research applications where high spatial resolution and short acquisition times are highly desired.Conclusions: OSF and JKC improved the metabolite quantification when artifacts were present in the data, and JKC was preferable. Although there are many technical challenges, MEGA-edited MRSI with full brain coverage in combination with a minimal voxel size for the purpose of GABA detection, would be extremely useful in clinical research applications where disorders such as narcolepsy, IBS, or ET, are investigated.
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| 5. |
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| 6. |
- Wårdell, Karin, et al.
(författare)
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High-Resolution Laser Doppler Measurements of Microcirculation in the Deep Brain Structures : A Method for Potential Vessel Tracking.
- 2016
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Ingår i: Stereotactic and Functional Neurosurgery. - : S. Karger. - 1011-6125 .- 1423-0372. ; 94:1, s. 1-9
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Laser Doppler flowmetry (LDF) can be used to measure cerebral microcirculation in relation to stereotactic deep brain stimulation (DBS) implantations.OBJECTIVE: To investigate the microcirculation and total light intensity (TLI) corresponding to tissue grayness in DBS target regions with high-resolution LDF recordings, and to define a resolution which enables detection of small vessels.METHODS: Stereotactic LDF measurements were made prior to DBS implantation with 0.5-mm steps in the vicinity to 4 deep brain targets (STN, GPi, Vim, Zi) along 20 trajectories. The Mann-Whitney U test was used to compare the microcirculation and TLI between targets, and the measurement resolution (0.5 vs. 1 mm). The numbers of high blood flow spots along the trajectories were calculated.RESULTS: There was a significant difference (p < 0.05) in microcirculation between the targets. High blood flow spots were present at 15 out of 510 positions, 7 along Vim and GPi trajectories, respectively. There was no statistical difference between resolutions even though both local blood flow and TLI peaks could appear at 0.5-mm steps.CONCLUSIONS: LDF can be used for online tracking of critical regions presenting blood flow and TLI peaks, possibly relating to vessel structures and thin laminas along stereotactic trajectories.
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| 7. |
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| 8. |
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| 9. |
- Alonso, Fabiola, 1980-, et al.
(författare)
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Influence of Virchow-Robin spaces in the Electric Field Distribution in Subthalamic Nucleus Deep Brain Stimulation
- 2019
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Konferensbidrag (refereegranskat)abstract
- Objectives: Previous investigations have shown the appearance of cysts i.e. Virchow-Robin spaces (VR) in the basal ganglia and their relationship with parkinsonian symptoms [1-3]. Simulations [4]using the finite element method (FEM) suggests that VR affects the electric field around deep brain stimulation (DBS) electrodes. The aim of the study was to evaluate how the electric field is modified by the presence of cysts in the STN. Methods: The effect of cysts on the electric field around the DBS lead placed in the STN was evaluated using FEM. 3D patient-specific brain models were built with COMSOL 5.2 (COMSOL AB, Sweden) and an in-house developed software [5] to convert a T2 weighted MRI of Parkinsonian patients (ethics approval no: 2012/434-3) into electrical conductivity matrix readable by FEM software. VR was classified as CSF [6]assigning a high electrical conductivity (2.0 S/m). The stimulation amplitudes were set to the clinically programmed values. Depending on the lead used, the stimulation was set to voltage control (3389) or current control (6180, ring mode). The coordinates corresponding to the lowest (first) electrode and the third higher up in the lead, taken from the postoperative CT electrode artefact, were used to localize the leads in the brain model [7]. The electric field was visualized with a 0.2V/mm isosurface. Results: Simulations showed that the electric field distribution is affected by the cysts. The higher conductivity at these regions in the vicinity of the electrode redistributes the electric field pushing it away from the cyst. The same effect occurs regardless of the operating mode or the lead design as long as the directional lead is configured in ring mode. Conclusions: The use of patient-specific models has shown the importance of considering nuances of the patients’ anatomy in the STN. This information can be used to determine the stimulation parameter and to support the analysis of side effects induced by the stimulation. The potential advantage of directional leads can also be assessed by including in the model patient-specific data.
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| 10. |
- Alonso, Fabiola, et al.
(författare)
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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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Ingår i: Clinical neurology and neurosurgery. - : Elsevier. - 0303-8467 .- 1872-6968. ; 204
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Tidskriftsartikel (refereegranskat)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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| 11. |
- Alonso, Fabiola, et al.
(författare)
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Investigation into Deep Brain Stimulation Lead Designs : A Patient-Specific Simulation Study
- 2016
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Ingår i: Brain Sciences. - : MDPI. - 2076-3425. ; 6:3, s. 1-16
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Tidskriftsartikel (refereegranskat)abstract
- New deep brain stimulation (DBS) electrode designs offer operation in voltage and current mode and capability to steer the electric field (EF). The aim of the study was to compare the EF distributions of four DBS leads at equivalent amplitudes (3 V and 3.4 mA). Finite element method (FEM) simulations (n = 38) around cylindrical contacts (leads 3389, 6148) or equivalent contact configurations (leads 6180, SureStim1) were performed using homogeneous and patient-specific (heterogeneous) brain tissue models. Steering effects of 6180 and SureStim1 were compared with symmetric stimulation fields. To make relative comparisons between simulations, an EF isolevel of 0.2 V/mm was chosen based on neuron model simulations (n = 832) applied before EF visualization and comparisons. The simulations show that the EF distribution is largely influenced by the heterogeneity of the tissue, and the operating mode. Equivalent contact configurations result in similar EF distributions. In steering configurations, larger EF volumes were achieved in current mode using equivalent amplitudes. The methodology was demonstrated in a patient-specific simulation around the zona incerta and a “virtual” ventral intermediate nucleus target. In conclusion, lead design differences are enhanced when using patient-specific tissue models and current stimulation mode.
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| 12. |
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| 13. |
- Antonsson, Johan, et al.
(författare)
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Diffuse reflectance spectroscopy measurements for tissue type discrimination during deep brain stimulation
- 2008
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Ingår i: Journal of neural engineering. - : IOP Publishing. - 1741-2560 .- 1741-2552. ; 5:2, s. 185-190
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Tidskriftsartikel (refereegranskat)abstract
- Diffuse reflectance spectroscopy as a method for improving intracerebral guidance during functional neurosurgery has been investigated. An optical probe was developed for measurements during stereotactic and functional neurosurgery in man. The aim of the study was to investigate the spectral differences between white and grey matter and between white matter and functional targets. Diffuse reflectance spectroscopy measurements in ten patients were recorded at incremental steps towards and in three different functional targets (STN, GPi and Zi). The recorded spectra along the trajectory were sorted into white or grey matter, based on preoperative MRI images or the recorded spectral shape and intensity. The difference between tissue types was calculated as a quotient. Significant intensity differences between white and grey matter were found to be at least 14% (p < 0.05) and 20% (p < 0.0001) for MRI and spectral-sorted data respectively. The reflectance difference between white matter and the functional targets of GPi was higher than for STN and Zi. The results indicate that diffuse reflectance spectroscopy has a potential to be developed to a suitable complement to other intracerebral guidance methods.
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| 14. |
- Bobinski, L, et al.
(författare)
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Leptomeningeal cyst due to vacuum extraction delivery in a twin infant
- 2007
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Ingår i: Acta Neurochirurgica. - : Springer Science and Business Media LLC. - 0001-6268 .- 0942-0940. ; 149:3, s. 319-323
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Tidskriftsartikel (refereegranskat)abstract
- A rare case of a leptomeningeal cyst is reported in a twin male neonate delivered using a vacuum extractor, who presented a huge, non-pulsating, oedematous mass overlying the frontal fontanelle after birth. The mass was initially diagnosed as a cephalo haematoma. Ultrasonography indicated intracranial bleeding and a subsequent CT scan revealed an intraparenchymal bleeding above the left frontal horn, combined with a thin, left-sided, subdural haematoma and subarachnoid haemorrhage in the left Sylvian fissure. Apart from a bulging soft and round formation (2 × 2 × 3 cm) next to the anterior fontanel growing since birth, the neurological development of the infant was normal. MRI examination at the age of 7 months revealed that it consisted of a cystic mass (leptomeningeal cyst) connected to the left frontal horn, stretching right through the brain and also penetrating the dura mater. No signs of the perinatal haematomas were observed at this time. Surgical treatment, with fenestration of the cyst into the frontal horn and a watertight duraplasty with a periosteal flap and thrombin glue covered by small bone chips, was performed at 9 months of age. Due to a residual skull bone defect a second cranioplasty with autologous skull bone was performed three and half years later. During a follow-up period of 12 years the neurological and psychological development of the boy has been indistinguishable to that of his twin brother, indicating the satisfactory outcome of the treatment. © 2007 Springer-Verlag.
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| 15. |
- Boström, Sverre, 1948-, et al.
(författare)
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A new scaled microgauge for use in neurosurgery
- 2005
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Ingår i: Acta Neurochirurgica. - : Springer Science and Business Media LLC. - 0001-6268 .- 0942-0940. ; 147:12, s. 1281-1282
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Tidskriftsartikel (refereegranskat)abstract
- A new scaled microgauge is described for measuring anatomical structures during microsurgery. The instrument has a tip marked in millimetres, which can be positioned in any desired angle enabling measurement in confined areas. © Springer-Verlag 2005.
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| 16. |
- Boström, Sverre, et al.
(författare)
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Improved brain protection at decompressive craniectomy - a new method using Palacoso (R) R-40 (methylmethacrylate)
- 2005
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Ingår i: Acta Neurochirurgica. - : Springer Science and Business Media LLC. - 0001-6268 .- 0942-0940. ; 147:3, s. 279-281
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Tidskriftsartikel (refereegranskat)abstract
- A new method is described for protecting the brain after decompressive craniectomy in which a temporary methylmethacrylate flap is formed, somewhat larger than the original bone flap, thus gaining "extra" volume for the oedematous brain in which to expand. The present procedure was developed as a pan of ordinary clinical practice particularly in response to demands from the NICU staff and our colleagues at other clinics who were responsible for the care of the patient in the post NICU period. They made us keenly aware that these patients frequently lack optimal co-ordination and balance and therefore run an increased risk of trauma to the unprotected brain when failing. This prompted us to develop a method for brain protection after decompressive craniectomy aiding in the care and rehabilitation until the final installation of the patient's own bone flap can be performed.
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| 17. |
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| 18. |
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| 19. |
- Diczfalusy, Elin, et al.
(författare)
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A model for simulation and patient-specific visualization of the tissue volume of influence during brain microdialysis
- 2011
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Ingår i: Medical and Biological Engineering and Computing. - : Springer Publishing Company. - 0140-0118 .- 1741-0444. ; 49:12, s. 1459-1469
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Tidskriftsartikel (refereegranskat)abstract
- Microdialysis can be used in parallel to deep brain stimulation (DBS) to relate biochemical changes to the clinical outcome. The aim of the study was to use the finite element method to predict the tissue volume of influence (TVI(max)) and its cross-sectional radius (r (TVImax)) when using brain microdialysis, and visualize the TVI(max) in relation to patient anatomy. An equation based on Fick's law was used to simulate the TVI(max). Factorial design and regression analysis were used to investigate the impact of the diffusion coefficient, tortuosity and loss rate on the r (TVImax). A calf brain tissue experiment was performed to further evaluate these parameters. The model was implemented with pre-(MRI) and post-(CT) operative patient images for simulation of the TVI(max) for four patients undergoing microdialysis in parallel to DBS. Using physiologically relevant parameter values, the r (TVImax) for analytes with a diffusion coefficient D = 7.5 × 10(-6) cm(2)/s was estimated to 0.85 ± 0.25 mm. The simulations showed agreement with experimental data. Due to an implanted gold thread, the catheter positions were visible in the post-operative images. The TVI(max) was visualized for each catheter. The biochemical changes could thereby be related to their anatomical origin, facilitating interpretation of results.
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| 20. |
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| 21. |
- Diczfalusy, Elin, et al.
(författare)
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Simulations and visualizations for interpretation of brain microdialysis data during deep brain stimulation
- 2012
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Ingår i: IEEE Engineering in Medicine and Biology Society (EMBC), 2012. - : IEEE. - 9781424441198 - 9781424441204 - 9781457717871 ; , s. 6438-6441
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Konferensbidrag (refereegranskat)abstract
- Microdialysis of the basal ganglia was used in parallel to deep brain stimulation (DBS) for patients with Parkinson’s disease. The aim of this study was to patientspecifically simulate and visualize the maximum tissue volume of influence (TVImax) for each microdialysis catheter and the electric field generated around each DBS electrode. The finite element method (FEM) was used for the simulations. The method allowed mapping of the anatomical origin of the microdialysis data and the electric stimulation for each patient. It was seen that the sampling and stimulation targets differed among the patients, and the results will therefore be used in the future interpretation of the biochemical data.
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| 22. |
- Dizdar (Dizdar Segrell), Nil, et al.
(författare)
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Letter: Untitled
- 2013
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Ingår i: Journal of Neuroscience Methods. - : Elsevier. - 0165-0270 .- 1872-678X. ; 212:2, s. 363-363
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Tidskriftsartikel (refereegranskat)abstract
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| 23. |
- Fytagoridis, Anders, et al.
(författare)
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Funktionell neurokirurgi möjlig hjälp vid svåra neurogena tillstånd
- 2023
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Ingår i: Läkartidningen. - : Sveriges Läkarforbund. - 0023-7205 .- 1652-7518. ; 120
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Forskningsöversikt (refereegranskat)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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| 24. |
- Ginstman, Fredrik, et al.
(författare)
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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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Ingår i: Proteome Science. - : BMC. - 1477-5956. ; 21:1
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Tidskriftsartikel (refereegranskat)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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| 25. |
- Göransson, Nathanael, et al.
(författare)
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Postoperative lead movement after deep brain stimulation surgery and changes of stimulation area
- 2017
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- IntroductionLead movement after deep brain stimulation (DBS) may occur and influence the area of stimulation. The cause of the displacement is not fully understood. The aim of the study was to investigate differences in lead position between the day after surgery and approximately one month postoperatively and also simulate the electric field (EF) around the active contacts.Methods23 patients with movement disorders underwent DBS surgery (37 leads). CT at the two time points were co-fused respectively with the stereotactic images in Surgiplan. The coordinates (x, y, z) of the lead tips were compared between the two dates (paired t-test). 8 of these patients were selected for the EF simulation in Comsol Multiphysics.ResultsThere was a significant discrepancy (mean ± s.d.) on the left lead: x (0.44 ± 0.72, p < 0.01), y (0.64 ± 0.54, p < 0.001), z (0.62 ± 0.71, p < 0.001). On the right lead, corresponding values were: x (-0.11 ± 0.61, n.s.), y (0.71 ± 0.54, p < 0.001), z (0.49 ± 0.81, p < 0.05). No correlation was found between bilateral (n =14) vs. unilateral DBS, gender (n = 17 male) and age < 60 years (n = 8). The lead movement affected the EF spread (Fig. 1).ConclusionThe left lead tip displayed a tendency to move lateral, anterior and inferior and the right a tendency to move anterior and inferior. Lead movement after DBS can be a factor to consider before starting the stimulation. The differences in the area of stimulation might affect clinical outcome.
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| 26. |
- Göransson, Nathanael, et al.
(författare)
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Postoperative Lead Movement after Deep Brain Stimulation Surgery and the Change of Stimulation Volume
- 2021
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Ingår i: Stereotactic and Functional Neurosurgery. - : S. Karger. - 1011-6125 .- 1423-0372. ; 99:3, s. 221-229
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Tidskriftsartikel (refereegranskat)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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| 27. |
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| 28. |
- Hermansen, Anna, et al.
(författare)
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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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Ingår i: BMC Musculoskeletal Disorders. - : BMC. - 1471-2474. ; 24:1
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Tidskriftsartikel (refereegranskat)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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| 29. |
- Hermansen, Anna, et al.
(författare)
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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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Ingår i: Physiotherapy Theory and Practice. - Philadelphia, PA, United States : Taylor & Francis. - 0959-3985 .- 1532-5040. ; 39:4, s. 750-760
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Tidskriftsartikel (refereegranskat)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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| 30. |
- Johansson, Johannes, et al.
(författare)
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Comparison between patient-specific deep brain stimulation simulations and commercial system SureTune3
- 2021
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Ingår i: Biomedical Engineering & Physics Express. - : IOP PUBLISHING LTD. - 2057-1976. ; 7:5
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Tidskriftsartikel (refereegranskat)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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| 31. |
- Karlsson, Anette, et al.
(författare)
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An Investigation of Fat Infiltration of the Multifidus Muscle in Patients With Severe Neck Symptoms Associated With Chronic Whiplash-Associated Disorder
- 2016
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Ingår i: Journal of Orthopaedic and Sports Physical Therapy. - : Journal of Orthopaedic & Sports Physical Therapy (JOSPT). - 0190-6011 .- 1938-1344. ; 46:10, s. 886-893
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Tidskriftsartikel (refereegranskat)abstract
- STUDY DESIGN: Cross-sectional study. BACKGROUND: Findings of fat infiltration in cervical spine multifidus, as a sign of degenerative morphometric changes due to whiplash injury, need to be verified. OBJECTIVES: To develop a method using water/fat magnetic resonance imaging (MRI) to investigate fat infiltration and cross-sectional area of multifidus muscle in individuals with whiplash associated disorders (WADS) compared to healthy controls. METHODS: Fat infiltration and cross-sectional area in the multifidus muscles spanning the C4 to C7 segmental levels were investigated by manual segmentation using water/fat-separated MRI in 31 participants with WAD and 31 controls, matched for age and sex. RESULTS: Based on average values for data spanning C4 to C7, participants with severe disability related to WAD had 38% greater muscular fat infiltration compared to healthy controls (P = .03) and 45% greater fat infiltration compared to those with mild to moderate disability related to WAD (P = .02). There were no significant differences between those with mild to moderate disability and healthy controls. No significant differences between groups were found for multifidus cross-sectional area. Significant differences were observed for both cross-sectional area and fat infiltration between segmental levels. CONCLUSION: Participants with severe disability after a whiplash injury had higher fat infiltration in the multifidus compared to controls and to those with mild/moderate disability secondary to WAD. Earlier reported findings using T1-weighted MRI were reproduced using refined imaging technology. The results of the study also indicate a risk when segmenting single cross-sectional slices, as both cross-sectional area and fat infiltration differ between cervical levels.
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| 32. |
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| 33. |
- Lam, Kwun, et al.
(författare)
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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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Ingår i: Medicine. - : Lippincott, Williams & Wilkins. - 0025-7974 .- 1536-5964. ; 100:8
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Tidskriftsartikel (refereegranskat)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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| 34. |
- Liew, Bernard X. W., et al.
(författare)
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Clinical predictive modelling of post-surgical recovery in individuals with cervical radiculopathy : a machine learning approach
- 2020
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Ingår i: Scientific Reports. - : Nature Publishing Group. - 2045-2322. ; 10:1
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Tidskriftsartikel (refereegranskat)abstract
- Prognostic models play an important role in the clinical management of cervical radiculopathy (CR). No study has compared the performance of modern machine learning techniques, against more traditional stepwise regression techniques, when developing prognostic models in individuals with CR. We analysed a prospective cohort dataset of 201 individuals with CR. Four modelling techniques (stepwise regression, least absolute shrinkage and selection operator [LASSO], boosting, and multivariate adaptive regression splines [MuARS]) were each used to form a prognostic model for each of four outcomes obtained at a 12 month follow-up (disability-neck disability index [NDI]), quality of life (EQ5D), present neck pain intensity, and present arm pain intensity). For all four outcomes, the differences in mean performance between all four models were small (difference of NDI<1 point; EQ5D<0.1 point; neck and arm pain<2 points). Given that the predictive accuracy of all four modelling methods were clinically similar, the optimal modelling method may be selected based on the parsimony of predictors. Some of the most parsimonious models were achieved using MuARS, a non-linear technique. Modern machine learning methods may be used to probe relationships along different regions of the predictor space.
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| 35. |
- Liew, Bernard X W, et al.
(författare)
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Probing the mechanisms underpinning recovery in post-surgical patients with cervical radiculopathy using Bayesian networks
- 2020
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Ingår i: European Journal of Pain. - : John Wiley & Sons. - 1090-3801 .- 1532-2149. ; 24:5, s. 909-920
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Rehabilitation approaches should be based on an understanding of the mechanisms underpinning functional recovery. Yet, the mediators that drive an improvement in post-surgical pain-related disability in individuals with cervical radiculopathy (CR) are unknown. The aim of the present study is to use Bayesian networks (BN) to learn the probabilistic relationships between physical and psychological factors, and pain-related disability in CR.METHODS: We analysed a prospective cohort dataset of 201 post-surgical individuals with CR. In all, 15 variables were used to build a BN model: age, sex, neck muscle endurance, neck range of motion, neck proprioception, hand grip strength, self-efficacy, catastrophizing, depression, somatic perception, arm pain intensity, neck pain intensity and disability.RESULTS: A one point increase in a change of self-efficacy at 6 months was associated with a 0.09 point decrease in a change in disability at 12 months (t = -64.09, p < .001). Two pathways led to a change in disability: a direct path leading from a change in self-efficacy at 6 months to disability, and an indirect path which was mediated by neck and arm pain intensity changes at 6 and 12 months.CONCLUSIONS: This is the first study to apply BN modelling to understand the mechanisms of recovery in post-surgical individuals with CR. Improvements in pain-related disability was directly and indirectly driven by changes in self-efficacy levels. The present study provides potentially modifiable mediators that could be the target of future intervention trials. BN models could increase the precision of treatment and outcome assessment of individuals with CR.SIGNIFICANCE: Using Bayesian Network modelling, we found that changes in self-efficacy levels at 6-month post-surgery directly and indirectly influenced the change in disability in individuals with CR. A mechanistic understanding of recovery provides potentially modifiable mediators that could be the target of future intervention trials.
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| 36. |
- Lund, Nils, 1993-, et al.
(författare)
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Fatty infiltrate and neck muscle volume in individuals with chronic whiplash associated disorders compared to healthy controls - a cross sectional case-control study
- 2023
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Ingår i: BMC Musculoskeletal Disorders. - : BioMed Central (BMC). - 1471-2474. ; 24:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: The underlying pathophysiological mechanisms of chronic Whiplash Associated Disorders (WAD) are not fully understood. More knowledge of morphology is needed to better understand the disorder, improve diagnostics and treatments. The aim was to investigate dorsal neck muscle volume (MV) and muscle fat infiltration (MFI) in relation to self-reported neck disability among 30 participants with chronic WAD grade II-III compared to 30 matched healthy controls.Methods: MV and MFI at spinal segments C4 through C7 in both sexes with mild- to moderate chronic WAD (n = 20), severe chronic WAD (n = 10), and age- and sex matched healthy controls (n = 30) was compared. Muscles: trapezius, splenius, semispinalis capitis and semispinalis cervicis were segmented by a blinded assessor and analyzed.Results: Higher MFI was found in right trapezius (p = 0.007, Cohen's d = 0.9) among participants with severe chronic WAD compared to healthy controls. No other significant difference was found for MFI (p = 0.22-0.95) or MV (p = 0.20-0.76).ConclusionsThere are quantifiable changes in muscle composition of right trapezius on the side of dominant pain and/or symptoms, among participants with severe chronic WAD. No other statistically significant differences were shown for MFI or MV. These findings add knowledge of the association between MFI, muscle size and self-reported neck disability in chronic WAD.
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| 37. |
- Marco, Barbero, et al.
(författare)
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Determining the level of cervical radiculopathy : Agreement between visual inspection of pain drawings and magnetic resonance imaging
- 2023
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Ingår i: Pain Practice. - : Wiley. - 1530-7085 .- 1533-2500. ; 23:1, s. 32-40
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Tidskriftsartikel (refereegranskat)abstract
- Background and Aims Pain drawings are commonly used in the clinical assessment of people with cervical radiculopathy. This study aimed to assess (1) the agreement of clinical interpretation of pain drawings and MRI findings in identifying the affected level of cervical radiculopathy, (2) the agreement of these predictions based on the pain drawing among four clinicians from two different professions (i.e., physiotherapy and surgery) and (3) the topographical pain distribution of people presenting with cervical radiculopathy (C4-C7). Methods Ninety-eight pain drawings were obtained from a baseline assessment of participants in a randomized clinical trial, in which single-level cervical radiculopathy was determined using MRI. Four experienced clinicians independently rated each pain drawing, attributing the pain distribution to a single nerve root (C4-C7). A post hoc analysis was performed to assess agreement. Outcome measures Percentage agreement and kappa values were used to assess the level of agreement. Topographic pain frequency maps were created for each cervical radiculopathy level as determined by MRI. Results The radiculopathy level determined from the pain drawings showed poor overall agreement with MRI (mean = 35.7%, K = -0.007 to 0.139). The inter-clinician agreement ranged from fair to moderate (K = 0.212-0.446). Topographic frequency maps revealed that pain distributions were widespread and overlapped markedly between patients presenting with different levels cervical radiculopathy. Conclusion This study revealed a lack of agreement between the segmental level affected determined from the patients pain drawing and the affected level as identified on MRI. The large overlap of pain and non-dermatomal distribution of pain reported by patients likely contributed to this result.
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| 38. |
- Ng, Eunice, et al.
(författare)
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Factors Associated With Work Ability in Patients Undergoing Surgery for Cervical Radiculopathy
- 2015
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Ingår i: Spine. - : LIPPINCOTT WILLIAMS & WILKINS. - 0362-2436 .- 1528-1159. ; 40:16, s. 1270-1276
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Tidskriftsartikel (refereegranskat)abstract
- Study Design. Cross-sectional study. Objective. To investigate the factors associated with work ability in patients undergoing surgery for cervical radiculopathy. Summary of Background Data. Surgery is a common treatment of cervical radiculopathy in people of working age. However, few studies have investigated the impact on the work ability of these patients. Methods. Patients undergoing surgery for cervical radiculopathy (n = 201) were recruited from spine centers in Sweden to complete a battery of questionnaires and physical measures the day before surgery. The associations between various individual, psychological, and work-related factors and self-reported work ability were investigated by Spearman rank correlation coefficient, multivariate linear regression, and forward stepwise regression analyses. Factors that were significant (P < 0.05) in each statistical analysis were entered into the successive analysis to reveal the factors most related to work ability. Work ability was assessed using the Work Ability Index. Results. The mean Work Ability Index score was 28 (SD, 9.0). The forward stepwise regression analysis revealed 6 factors significantly associated with work ability, which explained 62% of the variance in the Work Ability Index. Factors highly correlated with greater work ability included greater self-efficacy in performing self-cares, lower physical load on the neck at work, greater self-reported chance of being able to work in 6 months time, greater use of active coping strategies, lower frequency of hand weakness, and higher health-related quality of life. Conclusion. Psychological, work-related and individual factors were significantly associated with work ability in patients undergoing surgery for cervical radiculopathy. High self-efficacy was most associated with greater work ability. Consideration of these factors by surgeons preoperatively may provide optimal return to work outcomes after surgery.
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| 39. |
- Nord, Maria, et al.
(författare)
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Levodopa Pharmacokinetics in Brain after Both Oral and Intravenous Levodopa in One Patient with Advanced Parkinson’s Disease
- 2017
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Ingår i: Advances in Parkinsons Disease. - : Scientific Research Publishing Inc. - 2169-9712 .- 2169-9720. ; 6:2, s. 52-66
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Tidskriftsartikel (refereegranskat)abstract
- Objective: One patient received oral levodopa during a study aiming for better understanding of the basal ganglia and of the mechanisms of deep brain stimulation of the subthalamic nucleus (STN DBS) with and without intravenous (IV) levodopa infusion in patients with Parkinson’s disease (PD). The results from oral and IV levodopa treatment are presented.Methods: Five patients with advanced PD were included in the original study. During planned STN DBS surgery microdialysis probes were implanted in the right putamen and in the right and left globus pallidus interna (Gpi). During the study, microdialysis was performed continuously and STN DBS, with and without IV levodopa infusion, was performed according to a specific protocol. After DBS surgery, but before STN DBS was started, one patient received oral levodopa/ benserazide and entacapone tablets out of protocol due to distressing parkinsonism.Results: The levodopa levels increased prompt in the central nervous system after the first PD medication intakes but declined after the last. Immediately the levodopa seemed to be metabolized to dopamine (DA) since the levels of DA correlated well with levodopa concentrations. Left STN DBS seemed to further increase DA levels in left Gpi while right STN DBS seemed to increase DA levels in the right putamen and right Gpi. There was no obvious effect on levodopa levels.Conclusions: The results indicate that PD patients still have capacity to metabolize levodopa to DA despite advanced disease with on-off symptoms and probably pronounced nigral degeneration. STN DBS seems to increase DA levels with a more pronounced effect on ipsilateral structures in striatum.
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| 40. |
- Nord, Maria, et al.
(författare)
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The Effect of Peripheral Enzyme Inhibitors on Levodopa Concentrations in Blood and CSF
- 2010
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Ingår i: Movement Disorders. - : John Wiley & Sons. - 0885-3185 .- 1531-8257. ; 25:3, s. 363-367
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Tidskriftsartikel (refereegranskat)abstract
- Levodopa combined with a dopa-decarboxylase inhibitor, such as carbidopa. shifts the metabolism to the COMT pathway. Adding the peripheral acting COMT inhibitor entacapone provides improvement for patients with PD suffering from motor fluctuations. We studied the effects of the enzyme inhibitors entacapone and carbidopa on the levodopa concentrations in CSF and in blood. Five PD patients with wearing-off underwent lumbar drainage and intravenous microdialysis. Samples were taken 12 h daily for 3 days. Day I; intravenous levodopa was given, day 2; additional oral entacapone 200 mg tid, day 3; additional oral entacapone 200 mg bid and carbidopa 25 mg bid. Levodopa in CSF and in dialysates was analysed. The AUC for levodopa increased both in blood and CSF when additional entacapone was given alone and in combination with carbidopa. The C-max of levodopa in both CSF and blood increased significantly. Additional entacapone to levodopa therapy gives an increase of C-max in CSF and in blood. The increase is more evident when entacapone is combined with carbidopa.
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| 41. |
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| 42. |
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| 43. |
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| 44. |
- Nordin, Teresa, 1987-, et al.
(författare)
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White matter tracing combined with electric field simulation – A patient-specific approach for deep brain stimulation
- 2019
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Ingår i: NeuroImage. - : Elsevier. - 2213-1582. ; 24, s. 1-11
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Tidskriftsartikel (refereegranskat)abstract
- ObjectiveDeep brain stimulation (DBS) in zona incerta (Zi) is used for symptom alleviation in essential tremor (ET). Zi is positioned along the dentato-rubro-thalamic tract (DRT). Electric field simulations with the finite element method (FEM) can be used for estimation of a volume where the stimulation affects the tissue by applying a fixed isolevel (VDBS). This work aims to develop a workflow for combined patient-specific electric field simulation and white matter tracing of the DRT, and to investigate the influence on the VDBS from different brain tissue models, lead design and stimulation modes. The novelty of this work lies in the combination of all these components.MethodPatients with ET were implanted in Zi (lead 3389, n = 3, voltage mode; directional lead 6172, n = 1, current mode). Probabilistic reconstruction from diffusion MRI (dMRI) of the DRT (n = 8) was computed with FSL Toolbox. Brain tissue models were created for each patient (two homogenous, one heterogenous isotropic, one heterogenous anisotropic) and the respective VDBS (n = 48) calculated from the Comsol Multiphysics FEM simulations. The DRT and VDBS were visualized with 3DSlicer and superimposed on the preoperative T2 MRI, and the common volumes calculated. Dice Coefficient (DC) and level of anisotropy were used to evaluate and compare the brain models.ResultCombined patient-specific tractography and electric field simulation was designed and evaluated, and all patients showed benefit from DBS. All VDBS overlapped the reconstructed DRT. Current stimulation showed prominent difference between the tissue models, where the homogenous grey matter deviated most (67 < DC < 69). Result from heterogenous isotropic and anisotropic models were similar (DC > 0.95), however the anisotropic model consistently generated larger volumes related to a greater extension of the electric field along the DBS lead. Independent of tissue model, the steering effect of the directional lead was evident and consistent.ConclusionA workflow for patient-specific electric field simulations in combination with reconstruction of DRT was successfully implemented. Accurate tissue classification is essential for electric field simulations, especially when using the current control stimulation. With an accurate targeting and tractography reconstruction, directional leads have the potential to tailor the electric field into the desired region.
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| 45. |
- Peolsson, Anneli, et al.
(författare)
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Morphology and composition of the ventral neck muscles in individuals with chronic whiplash related disorders compared to matched healthy controls : a cross-sectional case-control study
- 2022
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Ingår i: BMC Musculoskeletal Disorders. - : BioMed Central (BMC). - 1471-2474. ; 23:1
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Tidskriftsartikel (refereegranskat)abstract
- ObjectiveStudies of cross-sectional area (CSA) (morphology) and muscle fat infiltration (MFI) (composition) in ventral neck muscles is scarce in patients with chronic whiplash associated disorders (WAD), especially for men and those with severe WAD compared with matched healthy controls. The aim was to compare CSA and MFI of sternocleidomastoid (SCM), longus capitis (LCA) and longus colli (LCO) in patients with chronic right-sided dominant moderate (Neck Disability Index: NDI < 40) or severe WAD (NDI ≥ 40), compared to age- and sex-matched healthy controls.MethodsCross-sectional case–control study with blinded investigators. Thirty-one patients with chronic WAD (17 women and 14 men, mean age 40 years) (SD 12.6, range 20–62)) and 31 age- and sex-matched healthy controls underwent magnetic resonance imaging of ventral neck muscles segmental level C4.ResultsUnique to the severe group was a larger magnitude of MFI in right SCM (p = 0.02) compared with healthy controls. There was no significant difference between the groups with regards to the other muscles and measures.ConclusionsIndividuals with severe right-sided dominant WAD have a higher MFI in the right SCM compared to healthy controls. No other differences were found between the groups. The present study indicates that there are changes in the composition of muscles on the side of greatest pain.
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| 46. |
- Peolsson, Anneli, 1967-, et al.
(författare)
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Neurological outcomes after surgery and postoperative rehabilitation for cervical radiculopathy due to disc disease: a 2-year-follow-up of a randomized clinical trial
- 2023
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Ingår i: Scientific Reports. - : NATURE PORTFOLIO. - 2045-2322. ; 13:1
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Tidskriftsartikel (refereegranskat)abstract
- Reports on neurological outcomes in patients with cervical radiculopathy (CR) undergoing surgery and postoperative rehabilitation are important to inform prognosis. This 2-year-follow-up of a randomized clinical trial aimed to compare secondary neurological outcomes between structured postoperative rehabilitation and a standard approach after surgery for CR. A secondary aim was to increase knowledge about recovery of neurological impairments in relation to patient-reported neck disability. Neurological outcomes included assessment of sensibility, motor function, arm reflexes and the Spurling test. A total of 153 and 135 participants (>70% response rate) completed the clinical examination. Between-group differences, changes over time, and associations between persistent neurological impairments and the Neck Disability Index were investigated. No between-group differences were reported (p>0.07), and neurological impairments in sensibility, motor function, and a positive Spurling test decreased over time in both groups (p<0.04). Persistent impairments in sensibility and reflex arm were most frequent at follow-up, whereas, a persistent positive Spurling test, and impairments in motor function were associated with higher NDI score. Neurological outcomes improved over time in patients undergoing surgery for CR with no between-group differences., However, persistent neurological impairments were common, and associated with poorer outcome for patient-reported neck disability.Clinical registration: clinicaltrial.gov NCT01547611, 08/03/2012, Title: Outcome of physiotherapy after surgery for cervical disc disease: a prospective multi-centre trial.
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| 47. |
- Peolsson, Anneli, et al.
(författare)
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Outcome of physiotherapy after surgery for cervical disc disease: a prospective randomised multi-centre trial
- 2014
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Ingår i: BMC Musculoskeletal Disorders. - : Springer Science and Business Media LLC. - 1471-2474. ; 15
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Tidskriftsartikel (refereegranskat)abstract
- Background: Many patients with cervical disc disease require leave from work, due to long-lasting, complex symptoms, including chronic pain and reduced levels of physical and psychological function. Surgery on a few segmental levels might be expected to resolve disc-specific pain and reduce neurological deficits, but not the non-specific neck pain and the frequent illness. No study has investigated whether post-surgery physiotherapy might improve the outcome of surgery. The main purpose of this study was to evaluate whether a well-structured rehabilitation programme might add benefit to the customary post-surgical treatment for cervical disc disease, with respect to function, disability, work capability, and cost effectiveness. Methods/Design: This study was designed as a prospective, randomised, controlled, multi-centre study. An independent, blinded investigator will compare two alternatives of rehabilitation. We will include 200 patients of working age, with cervical disc disease confirmed by clinical findings and symptoms of cervical nerve root compression. After providing informed consent, study participants will be randomised to one of two alternative physiotherapy regimes; (A) customary treatment (information and advice on a specialist clinic); or (B) customary treatment plus active physiotherapy. Physiotherapy will follow a standardised, structured programme of neck-specific exercises combined with a behavioural approach. All patients will be evaluated both clinically and subjectively (with questionnaires) before surgery and at 6 weeks, 3 months, 6 months, 12 months, and 24 months after surgery. The main outcome variable will be neck-specific disability. Cost-effectiveness will also be calculated. Discussion: We anticipate that the results of this study will provide evidence to support physiotherapeutic rehabilitation applied after surgery for cervical radiculopathy due to cervical disc disease.
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| 48. |
- Peolsson, Anneli, et al.
(författare)
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Pathophysiology behind prolonged whiplash associated disorders : study protocol for an experimental study
- 2019
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Ingår i: BMC Musculoskeletal Disorders. - : BMC. - 1471-2474. ; 20
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundThere is insufficient knowledge of pathophysiological parameters to understand the mechanism behind prolonged whiplash associated disorders (WAD), and it is not known whether or not changes can be restored by rehabilitation. The aims of the projects are to investigate imaging and molecular biomarkers, cervical kinaesthesia, postural sway and the association with pain, disability and other outcomes in individuals with longstanding WAD, before and after a neck-specific exercise intervention. Another aim is to compare individuals with WAD with healthy controls.MethodsParticipants are a sub-group (n=30) of individuals recruited from an ongoing randomized controlled study (RCT). Measurements in this experimental prospective study will be carried out at baseline (before intervention) and at a three month follow-up (end of physiotherapy intervention), and will include muscle structure and inflammation using magnetic resonance imaging (MRI), brain structure and function related to pain using functional MRI (fMRI), muscle function using ultrasonography, biomarkers using samples of blood and saliva, cervical kinaesthesia using the butterfly test and static balance test using an iPhone app. Association with other measures (self-reported and clinical measures) obtained in the RCT (e.g. background data, pain, disability, satisfaction with care, work ability, quality of life) may be investigated. Healthy volunteers matched for age and gender will be recruited as controls (n=30).DiscussionThe study results may contribute to the development of improved diagnostics and improved rehabilitation methods for WAD.Trial registrationClinicaltrial.gov Protocol ID: NCT03664934, initial release 09/11/2018.
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| 49. |
- Peolsson, Anneli, et al.
(författare)
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Postoperative structured rehabilitation in patients undergoing surgery for cervical radiculopathy: a 2-year follow-up of a randomized controlled trial
- 2019
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Ingår i: Journal of Neurosurgery. - : AMER ASSOC NEUROLOGICAL SURGEONS. - 1547-5654 .- 1547-5646. ; 31:1, s. 60-69
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE Information about postoperative rehabilitation for cervical radiculopathy (CR) is scarce. The aim of this study was to investigate the additional benefits of structured postoperative rehabilitation (SPT), which was performed in all patients, compared with a pragmatic standard postoperative approach (SA), in which rehabilitation was used as needed and patients sought physiotherapy on their own without a referral, in patients with MRI evidence of disc herniation and concomitant clinical signs who underwent surgery for CR. METHODS Patients (n = 202) were randomized to receive SPT or SA. Included key variables in the present study were primary and selected secondary outcomes of a prospective randomized controlled multicenter study. The main outcome was the Neck Disability Index (NDI) score. The NDI score, pain variables, self-efficacy, and health-related quality of life were investigated at baseline and 3, 6, 12, and 24 months postoperatively. RESULTS SPT provided no additional benefits over SA (p = 0.08 to p = 0.99) at the postoperative 2-year follow-up. Both groups improved over time (p amp;lt; 0.0001), with no reported adverse effects. CONCLUSIONS One can conclude that SPT offered no additional benefits over SA; however, patients tolerated postoperative neck exercises without any negative side effects. These findings are important for the development of future active and neck-specific post-operative rehabilitation interventions for patients with CR.
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- Peolsson, Anneli, et al.
(författare)
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Work Ability After Anterior Cervical Decompression and Fusion Followed by a Structured Postoperative Rehabilitation : Secondary Outcomes of a Prospective Randomized Controlled Multi-Centre Trial with a 2-year Follow-up
- 2022
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Ingår i: Journal of occupational rehabilitation. - : Springer / Plenum. - 1053-0487 .- 1573-3688. ; 32:3, s. 473-482
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Tidskriftsartikel (refereegranskat)abstract
- Purpose Information on work ability after ACDF and postoperative rehabilitation is lacking. The aim of the present study is therefore to investigate the work ability benefits of a structured postoperative treatment (SPT) over a standard care approach (SA) in patients who underwent anterior cervical decompression and fusion (ACDF) for cervical radiculopathy and factors important to the 2-year outcome. Methods Secondary outcome and prediction model of a prospective randomized controlled multi-centre study with a 2-year follow-up (clinicaltrials.gov NCT01547611). The Work Ability Index (WAI) and Work Ability Score (WAS) were measured at baseline and up to 2 years after ACDF in 154 patients of working age who underwent SPT or SA after surgery. Predictive factors for the WAI at 2 years were analysed. Results Both WAI and WAS significantly improved with SPT and SA (p < 0.001), without any between-group differences. Thoughts of being able to work within the next 6 months, Neck Disability Index (NDI), and work-related neck load explained 59% of the variance in WAI at the 2-year follow-up after ACDF. Conclusions Patients improved over time without group differences, suggesting the improvement to be surgery related. Expectation to work within the next 6 months, self-reported neck functioning and work-related neck load were important to work ability and are central factors to ask early after ACDF, to identifying further interventions promoting return to work.
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