New approaches in the management of hyperkinetic movement disorders

This review covers recent advances in a variety of dyskinesias. Introduction of new drugs for the treatment of myoclonus and sensory biofeedback therapy for focal dystonia are expanding our concepts of these types of movement disorders. Progress in the treatment of action myoclonus is especially noteworthy and has led to the implication of serotonin deficit in the pathophysiology of this syndrome. Knowledge of the biochemical pathology of Huntington's chorea has outpaced therapy for this disorder, but new forms of therapy have been proposed based on the chemical findings. Basic pharmacologic studies suggest pathophysiologic mechanisms for the syndrome known as tardive dyskinesia, but treatment is still far from ideal for this disorder. Other movement disorders with recent therapeutic advances include essential tremor and hemiballism. This review will cover only those dyskinesias in which new therapies have been advanced in the last few years. Aside from parkinsonism, which will not be discussed here, progress in the treatment of movement disorders has been slow, but steady. New drugs are being tested constantly, and the purpose of this review is to call attention to the ongoing evaluation in this field. Descriptions and etiologies for these dyskinesias are covered elsewhere (Fahn, 1976a) and therefore are not repeated here.