A CASE OF SYMPTOMATIC HEMIDYSTONIA IMPROVED BY VENTROPOSTEROLATERAL THALAMIC ELECTROSTIMULATION

A 16-year-old boy presented with a left anterothalamic lesion secondary to an extradural hematoma. A few months later, a right hemidystonia developed. The dystonic posture, which predominated in the right hand, was not associated with any motor deficit or sensory loss. Superficial sensory stimulation of the right palm and forearm and proprioceptive stimuli induced by passive movements of the right thumb decreased the dystonic posture. Electrical stimulation of the left ventroposterolateral nucleus of the thalamus induced a dramatic improvement in the dystonic postures and movement of the upper right limb. This finding suggests that the role of tactile and proprioceptive stimulation should be analyzed in patients presenting with a symptomatic hemidystonia. When such sensory stimulation is effective, thalamic stimulation may be tried in patients whose condition is incapacitating.