Annals of neurology
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Dystonia is a neurological syndrome involving sustained contractions of opposing muscles leading to abnormal movements and postures. Recent studies report abnormally low pallidal neuronal activity in patients with generalized dystonia, suggesting hyperkinetic disorders result from underactive basal ganglia output. We examined this hypothesis in 11 patients with segmental and generalized dystonia undergoing microelectrode exploration of the internal globus pallidus (GPi) before pallidotomy or deep brain stimulation (DBS) implantation. ⋯ Low-dose propofol in one other dystonia patient also seemed to suppress GPi firing. These results indicate that an abnormally low basal ganglia output is not the sine qua non of dystonia. The widely accepted pathophysiological models of dystonia that propose global decreases in basal ganglia output need to be viewed with caution in light of these findings.