Abstract
A case of nystagmus alternans is reported. The patient is a 14 year-old girl who has been complaining of unsteady gait for the past 10 years. Neurotological examination revealed active spontaneous nystagmus of which direction alternated every 70 to 100 seconds. Optokinetic nystagmus was markedly inhibited, but caloric response was present bilaterally. Neurological examination showed unsteadiness of the body, adiadochokinesis and hypermetria of the upper extremities, all of which indicate cerebellar ataxia. A lesion in the cerebellum or its neighboring structures was presumably responsible for the nystagmus alternans in this case.
