REM-SLEEP BEHAVIOR DISORDER DIFFERENTIATES PURE AUTONOMIC FAILURE FROM MULTIPLE SYSTEM ATROPHY WITH AUTONOMIC FAILURE

Ten patients with primary autonomic failure, followed up in a prospect ive clinical and laboratory study, were finally diagnosed as pure auto nomic failure or multiple system atrophy with autonomic failure. Polys omnographic studies were performed in all patients. Whereas all four p atients with multiple system atrophy complained of sleep related episo des suggesting REM sleep behaviour disorder (RBD) confirmed by polysom nography, RBD remained absent in the remaining six patients with pure autonomic failure. The data indicate that RBD is an important clinical feature, often heralding multiple system atrophy, but which is absent throughout the course of pure autonomic failure; its recognition can thus be useful in the prognostic evaluation of early primary autonomic failure syndromes.