Inhibition of the dorsal premotor cortex does not repair surround inhibition in writer's cramp patients
Publication year
2013Number of pages
8 p.
Source
Experimental Brain Research, 225, 1, (2013), pp. 85-92ISSN
Publication type
Article / Letter to editor
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Organization
Biophysics
Neurology
Donders Centre for Cognitive Neuroimaging
Former Organization
F.C. Donders Centre for Cognitive Neuroimaging
Journal title
Experimental Brain Research
Volume
vol. 225
Issue
iss. 1
Languages used
English (eng)
Page start
p. 85
Page end
p. 92
Subject
Biophysics; DCN MP - Plasticity and memoryAbstract
Writer's cramp is a task-specific form of focal dystonia, characterized by abnormal movements and postures of the hand and arm during writing. Two consistent abnormalities in its pathophysiology are a loss of surround inhibition and overactivity of the dorsal premotor cortex (PMd). This study aimed to assess a possible link between these two phenomena by investigating whether PMd inhibition leads to an improvement of surround inhibition, in parallel with previously demonstrated writing improvement. Fifteen writer's cramp patients and ten controls performed a simple motor hand task during which surround inhibition was measured using transcranial magnetic stimulation. Motor cortical excitability was measured of the active and surround muscles at three phases of the task. Surround inhibition and writing performance were assessed before and after PMd inhibitory continuous theta burst stimulation. In contrast to healthy controls, patients did not show inhibition of the abductor digiti minimi muscle during movement initiation of the first dorsal interosseus muscle, confirming the loss of surround inhibition. PMd inhibition led to an improvement of writing speed in writer's cramp patients. However, in both groups, no changes in surround inhibition were observed. The results confirm a role for the PMd in the pathophysiology of writer's cramp. We show that PMd inhibition does not lead to restoration of the surround inhibition defect in writer's cramp, despite the improvement in writing. This questions the involvement of the PMd in the loss of surround inhibition, and perhaps also the direct link between surround inhibition and dystonia.
This item appears in the following Collection(s)
- Academic publications [238441]
- Donders Centre for Cognitive Neuroimaging [3824]
- Faculty of Medical Sciences [90373]
- Faculty of Science [34986]
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