THE JERKY DYSTONIC UNSTEADY HAND - A DELAYED MOTOR SYNDROME IN POSTERIOR THALAMIC INFARCTIONS

We report the cases of three patients with a thalamic infarct in the territory of the posterior choroidal artery involving the posterior thalamic nuclei. These patients developed delayed complex hyperkinetic motor syndromes, associating ataxia, tremor, dystonia, myoclonus and chorea, which we call ''the jerky dystonic unsteady hand''. One patient had a severe myoclonic and ataxic-dystonic choreoathetosis; another showed a so-called rubral tremor (myoclonic ataxia with resting, action, and wing-beating tremor) with dystonia; and the third one had a dystonic and ataxic hand with intermittent mild action myoclonus. All of them had sensory dysfunction; two had also presented with a painful Dejerine-Roussy syndrome. All had CT or MRI-proven infarcts in the territory of the posterior cerebral artery involving the posterior choroidal territory with an abnormal signal in the posterior area of the thalamus (pulvinar nucleus) but sparing the other thalamic, subthalamic and midbrain structures. These delayed myoclonic complex hyperkinetic syndromes have not been reported before, and we did not observe them in other topographic forms of thalamic infarcts. They may thus represent a new entity of movement disorders due to lesions in the posterior thalamic nuclei, with specificity for posterior choroidal artery infarcts.