We describe a polysomnographic observation of the acute phase of the alcohol withdrawal syndrome, characterized by an alteration of the sleep-wake cycle and by the absence of non-rapid eye movement sleep. An atypical transitional state between rapid eye movement sleep and wake with hallucinations and enacting-dream behaviors represented the sole sleep pattern. Analogies of alcohol withdrawal syndrome with fatal familial insomnia and Morvan's fibrillary chorea suggest a common pathophysiological mechanism in these conditions.