Dystonia Associated with Pontomesencephalic Lesions

Secondary dystonia is well known Subsequent to lesions of the basal ganglia or the thalamus. There is evidence that brainstem lesions may also be associated with dystonia, but little is known about pathoanatomical correlations. Here, we report oil it series of four patients with acquired dystonia following brainstem lesions. There were no basal ganglia or thalamic lesions. Three patients suffered tegmental pontomesencephalic hemorrhage and one patient diffuse axonal injury secondary to severe craniocerebral trauma. Dystonia developed with it delay of I to 14 months, at it mean delay of 6 months. The patients' mean age tit onset was 33 years (range 4-56 years). All patients presented with hemidystonia combined with cervical dystonia, and two patients had craniofacial dystonia in addition. Three patients had postural or kinetic tremors. Dystonia was persistent in three patients, and improved gradually it, one. There was little response to medical treatment. One patient with hemidystonia combined with cervical dystonia improved after thalamotomy. Overall. the phenomenology of secondary dystonia due to pontomesencephalic lesions is similar to that caused by basal ganglia or thalamic lesions, Structures involved include the pontomesencephalic tegmentum and the superior cerebellar peduncles. Such lesions are often associated with fatal Outcome. While delayed Occurrence of severe brainstem dystonia appears to be rare, it is possible that mild manifestations of dystonia might he ignored or not be emphasized in the presence of other disabling deficits. (C) 2008 Movement Disorder Society