Nutritional cerebellar degeneration, with comments on its relationship to Wernicke disease and alcoholism.

Nutritional cerebellar degeneration occurs in alcoholism and other states that predispose to malnutrition, such as gastric bypass surgery. Gait ataxia is the principal clinical manifestation. Ataxia of the lower limbs is not uncommon, but upper extremity ataxia and nystagmus are rare. Atrophy of the anterior superior vermis is the primary pathological manifestation in established disease. Typically, the onset is subacute. This cerebellar disease is part of the spectrum of the Wernicke-Korsakoff syndrome, i.e. the cerebellar manifestation of Wernicke disease. It may occur with other lesions of Wernicke disease or in isolation. Rarely, with florid disease, lesions may be hemorrhagic. Active disease should be treated with thiamine in the same way that one treats Wernicke disease. Clinicopathologic correlation in this disease has provided the best evidence that the anterior superior vermis is important in coordinating bipedal locomotion.