HAND DYSTONIA SECONDARY TO CERVICAL DEMYELINATING LESION

Dystonia is generally considered a disease of basal ganglia. We report two patients with definite MS who acutely developed hand dystonia and athetoid movements. In both patients: 1) dystonia was electrophysiolo gically demonstrated by tack of reciprocal inhibition between antagoni stic forearm muscles; 2) SEP from median nerve stimulation showed dela yed cervical N 13 and absent frontal and parietal components; 3) the l ong latency response after stimulation of median nerve of the affected hand was absent or delayed; 4) MRI showed lesions in the posterolater al cervical spine but no involvement of basal ganglia and thalami. We think that, in these cases, dystonia and athetoid movements could be a scribed respectively to the involvement of descending pathways regulat ing reciprocal inhibition of motoneurons and to the involvement of lar ge diameter afferents due to the demyelinating lesion at the cervical level.