Time course of postanoxic akinetic-rigid and dystonic syndromes.

Twelve previously normal patients with anoxic brain damage due to various causes are described. The mean age at anoxia was 27.4 years. Six patients, in their fourth decade or older, developed an early akinetic-rigid syndrome; the mean interval between anoxia and akinetic-rigid syndrome was 3.1 months (range, less than 1 week to 12 months). Four of these six patients also developed dystonia, usually after some months. Six other patients, all children or young adults, developed a pure dystonic syndrome; the mean interval between anoxia and dystonia was 9.7 months (range, 1 week to 36 months). Dystonia was generalized and progressed over a mean period of 21.9 months (range, 3 to 96 months). Severe bulbar involvement was common. Age determined whether an akinetic-rigid or a dystonic syndrome developed in our patients and those reported in the literature. Many, but not all, patients had lesions on brain imaging (or at autopsy). In those with visible lesions in the basal ganglia, those with dystonia tended to have damage in putamen, while those with an akinetic-rigid syndrome tended to have damage in the globus pallidus. There were exceptions.