| 1. |
- Akram, Harith, et al.
(författare)
-
L-Dopa Responsiveness Is Associated With Distinctive Connectivity Patterns in Advanced Parkinson's Disease
- 2017
-
Ingår i: Movement Disorders. - : Wiley-Blackwell. - 0885-3185 .- 1531-8257. ; 32:6, s. 874-883
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Neuronal loss and dopamine depletion alter motor signal processing between cortical motor areas, basal ganglia, and the thalamus, resulting in the motor manifestations of Parkinson's disease. Dopamine replacement therapy can reverse these manifestations with varying degrees of improvement. Methods: To evaluate functional connectivity in patients with advanced Parkinson's disease and changes in functional connectivity in relation to the degree of response to L-dopa, 19 patients with advanced Parkinson's disease underwent resting-state functional magnetic resonance imaging in the on-medication state. Scans were obtained on a 3-Tesla scanner in 3x3x2.5mm(3) voxels. Seed-based bivariate regression analyses were carried out with atlas-defined basal ganglia regions as seeds, to explore relationships between functional connectivity and improvement in the motor section of the UPDRS-III following an L-dopa challenge. False discovery rate-corrected P was set at < 0.05 for a 2-tailed t test. Results: A greater improvement in UPDRS-III scores following L-dopa administration was characterized by higher resting-state functional connectivity between the prefrontal cortex and the striatum (P=0.001) and lower resting-state functional connectivity between the pallidum (P=0.001), subthalamic nucleus (P=0.003), and the paracentral lobule (supplementary motor area, mesial primary motor, and primary sensory areas). Conclusions: Our findings show characteristic basal ganglia resting-state functional connectivity patterns associated with different degrees of L-dopa responsiveness in patients with advanced Parkinson's disease. L-Dopa exerts a graduated influence on remapping connectivity in distinct motor control networks, potentially explaining some of the variance in treatment response.
|
|
| 2. |
- Dayal, Viswas, et al.
(författare)
-
Short Versus Conventional Pulse-Width Deep Brain Stimulation in Parkinson's Disease : A Randomized Crossover Comparison
- 2020
-
Ingår i: Movement Disorders. - : John Wiley & Sons. - 0885-3185 .- 1531-8257. ; 35:1, s. 101-108
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Subthalamic nucleus deep brain stimulation (STN-DBS) is an effective therapy for selected Parkinson's disease patients with motor fluctuations, but can adversely affect speech and axial symptoms. The use of short pulse width (PW) has been shown to expand the therapeutic window acutely, but its utility in reducing side effects in chronic STN-DBS patients has not been evaluated. Objective To compare the effect of short PW settings using 30-mu s with conventional 60-mu s settings on stimulation-induced dysarthria in Parkinson's disease patients with previously implanted STN-DBS systems.Methods: In this single-center, double-blind, randomized crossover trial, we assigned 16 Parkinson's disease patients who had been on STN-DBS for a mean of 6.5 years and exhibited moderate dysarthria to 30-mu s or 60-mu s settings for 4 weeks followed by the alternative PW setting for a further 4 weeks. The primary outcome was difference in dysarthric speech measured by the Sentence Intelligibility Test between study baseline and the 2 PW conditions. Secondary outcomes included motor, nonmotor, and quality of life measures.Results: There was no difference in the Sentence Intelligibility Test scores between baseline and the 2 treatment conditions (P = 0.25). There were also no differences noted in motor, nonmotor, or quality of life scores. The 30-mu s settings were well tolerated, and adverse event rates were similar to those at conventional PW settings. Post hoc analysis indicated that patients with dysarthria and a shorter duration of DBS may be improved by short PW stimulation.Conclusions: Short PW settings using 30 mu s did not alter dysarthric speech in chronic STN-DBS patients. A future study should evaluate whether patients with shorter duration of DBS may be helped by short PW settings.
|
|
| 3. |
- Hariz, Marwan, et al.
(författare)
-
Future of Brain Stimulation : New Targets, New Indications, New Technology
- 2013
-
Ingår i: Movement Disorders. - : Wiley-Blackwell. - 0885-3185 .- 1531-8257. ; 28:13, s. 1784-1792
-
Forskningsöversikt (refereegranskat)abstract
- In the last quarter of a century, DBS has become an established neurosurgical treatment for Parkinson's disease (PD), dystonia, and tremors. Improved understanding of brain circuitries and their involvement in various neurological and psychiatric illnesses, coupled with the safety of DBS and its exquisite role as a tool for ethical study of the human brain, have unlocked new opportunities for this technology, both for future therapies and in research. Serendipitous discoveries and advances in structural and functional imaging are providing abundant new brain targets for an ever-increasing number of pathologies, leading to investigations of DBS in diverse neurological, psychiatric, behavioral, and cognitive conditions. Trials and proof of concept studies of DBS are underway in pain, epilepsy, tinnitus, OCD, depression, and Gilles de la Tourette syndrome, as well as in eating disorders, addiction, cognitive decline, consciousness, and autonomic states. In parallel, ongoing technological development will provide pulse generators with longer battery longevity, segmental electrode designs allowing a current steering, and the possibility to deliver on-demand stimulation based on closed-loop concepts. The future of brain stimulation is certainly promising, especially for movement disordersthat will remain the main indication for DBS for the foreseeable futureand probably for some psychiatric disorders. However, brain stimulation as a technique may be at risk of gliding down a slippery slope: Some reports indicate a disturbing trend with suggestions that future DBS may be proposed for enhancement of memory in healthy people, or as a tool for treatment of antisocial behavior and for improving morality. (c) 2013 International Parkinson and Movement Disorder Society
|
|
| 4. |
- Martinez-Fernandez, Raul, et al.
(författare)
-
Deep Brain Stimulation for Gilles de la Tourette Syndrome : A Case Series Targeting Subregions of the Globus Pallidus Internus
- 2011
-
Ingår i: Movement Disorders. - New York, N.Y. : Raven Press. - 0885-3185 .- 1531-8257. ; 26:10, s. 1922-1930
-
Tidskriftsartikel (refereegranskat)abstract
- Deep brain stimulation remains an experimental treatment for patients with Gilles de la Tourette syndrome. Currently, a major controversial issue is the choice of brain target that leads to optimal patient outcomes within a presumed network of basal ganglia and cortical pathways involved in tic pathogenesis. This report describes our experience with patients with severe refractory Gilles de la Tourette syndrome treated with globus pallidus internus deep brain stimulation. Five patients were selected for surgery, 2 targeting the posteroventral globus pallidus internus and 2 targeting the anteromedial region. The remaining patient was first targeted on the posterolateral region, but after 18 months the electrodes were relocated in the anteromedial area. Tics were clinically assessed in all patients pre- and postoperatively using the Modified Rush Video protocol and the Yale Global Tic Severity Scale. Obsessive-compulsive behaviors were quantified with the Yale Brown Obsessive Compulsive Scale. The Gilles de la Tourette Syndrome Quality of Life Scale was also completed. All patients experienced improvements in tic severity but to variable extents. More convincing improvements were seen in patients with electrodes sited in the anteromedial region of the globus pallidus internus than in those with posterolateral implants. Mean reduction in the Modified Rush Video Rating scale for each group was 54% and 37%, respectively. Our open-label limited experience supports the use of the anteromedial globus pallidus internus as a promising target for future planned randomized double-blind trials of deep brain stimulation for patients with Gilles de la Tourette syndrome.
|
|
| 5. |
- Tisch, Stephen, et al.
(författare)
-
Cortical evoked potentials from pallidal stimulation in patients with primary generalized dystonia.
- 2008
-
Ingår i: Movement disorders : official journal of the Movement Disorder Society. - : Wiley. - 1531-8257. ; 23:2, s. 265-73
-
Tidskriftsartikel (refereegranskat)abstract
- Deep brain stimulation (DBS) of globus pallidus internus (GPi) has emerged as an effective treatment for primary generalized dystonia. However, the physiological mechanisms of improvement are not fully understood. Cortical activity in response to pallidal stimulation was recorded in 6 patients with primary generalized dystonia >6 months after bilateral GPi DBS. Scalp electroencephalogram was recorded using 60 surface electrodes during 10 Hz bipolar pallidal DBS at each electrode contact pair. Anatomical position of the electrode contacts in relation to the GPi, medial medullary lamina and globus pallidus externus (GPe) was determined from the postoperative stereotactic MRI. In all six patients an evoked potential (EP) was observed with average onset latency of 10.9 ms +/- 0.77, peak latency 26.6 ms +/- 1.6, distributed mainly over the ipsilateral hemisphere, maximal centrally. The mean amplitude of this potential was larger with stimulation in posteroventral GPi than in GPe (3.36 microV vs. 0.50 microV, P < 0.0001). The EP was absent in one patient-side, ipsilateral to a previous thalamotomy. Low frequency GPi stimulation produces an EP distributed centrally over the ipsilateral hemisphere. The latency and distribution of the EP are consistent with stimulation of pallidothalamic neurons projecting to the sensorimotor cortex. Because the EP is larger and more consistently present with stimulation of posteroventral GPi than GPe, it may provide a physiological tool to identify contacts within the optimal surgical target.
|
|
| 6. |
- Tripoliti, Elina, et al.
(författare)
-
Effects of contact location and voltage amplitude on speech and movement in bilateral subthalamic nucleus deep brain stimulation.
- 2008
-
Ingår i: Movement disorders : official journal of the Movement Disorder Society. - : Wiley. - 1531-8257. ; 23:16, s. 2377-83
-
Tidskriftsartikel (refereegranskat)abstract
- Subthalamic nucleus deep brain stimulation (STN-DBS) is particularly effective in improving limb symptoms in Parkinson's disease. However, speech shows a variable response. Contact site and amplitude of stimulation have been suggested as possible factors influencing speech. In this double blind study, we assessed 14 patients post bilateral STN-DBS, without medication. Six conditions were studied in random order as follows: stimulation inside the STN at low voltage (2 V) and at high voltage (4 V); above the STN at 2 V and at 4 V, at usual clinical parameters, and off-stimulation. The site of stimulation was defined on the postoperative stereotactic MRI data. Speech protocol consisted of the assessment of intelligibility of the dysarthric speech, maximum sustained phonation, and a 1-minute monologue. Movement was assessed using the UPDRS-III. Stimulation at 4 V significantly reduced the speech intelligibility (P = 0.004) independently from the site of stimulation. Stimulation at 4 V significantly improved the motor function. Stimulation inside the nucleus was significantly more effective than outside the nucleus (P = 0.0006). The significant improvement in movement coupled with significant deterioration in speech intelligibility when patients are stimulated inside the nucleus at high voltage indicates a critical role for electrical stimulation parameters in speech motor control.
|
|
| 7. |
|
|
| 8. |
|
|
