Effect of the Visual Information Change in Functional Dystonia

Study Overview
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Brief Summary
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Cervical dystonia occurring only during the writing task is a rare form for which there is no established treatment. Many authors agree that alteration of sensory integration is associated with dystonia. Similar disturbances in the integration of oculomotor information could have a role in cervical dystonia forms involving visuo-cervico-manual coordination such as handwriting. We hypothesize that orthoptic treatment by wearing prisms when writing (i) will reduce the abnormal posture of the head occurring whilst writing and remove the associated nuchal pain; (ii) the correction after a period of systematic wearing of the prisms during handwriting tasks will have a sustainable effect allowing to keep a normal head position after the suppression of the prisms.

Official Title
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Effect of the Visual Information Change in Functional Dystonia

Conditions
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Dystonia, Dystonic Disorders, Torticollis, Movement Disorders, Central Nervous System Diseases, Nervous System Diseases, Dyskinesias, Neurologic Manifestations

Intervention / Treatment
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* Device: prism glasses


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Case Presenting a cervical dystonia that occurs only during handwriting tasks, diagnosed by a neurologist specialised in movement disorders Being treated or not by injection of Botulinum Neurotoxin (but last injection > 3 months before the initial assessment) Control No cervical dystonia Same sex, age (± 5 years), socio-professional level and hand laterality as the cases Exclusion Criteria: Case Cervical dystonia occuring in other circumstances than handwriting Neurological disease other than cervical dystonia (e.g. Parkinson's syndrome) Pain, trauma or pathology of the cervical spine of another cause than cervical dystonia and which have required medical or surgical treatment in the last 6 months preceding the initial assessment Control Cervical disorders requiring medical or surgical treatment in the last 6 months prior to the tests Neurological disease affecting the cervical region or the writing hand Uncorrected visual disorders

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 71 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: orthoptic treatment<br>Patients with cervical dystonia occuring only during handwriting. | Device: prism glasses<br>* orthoptic treatment by wearing prisms when writing<br>|
| No Intervention: Controls<br>Patients without cervical dystonia. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| measure of head movement occurring when writing | Difference of the angle measured with and without corrective prisms during the handwriting tasks | 3 months |