[Familial paroxysmal ataxia: a new case].

Over the last years several families affected of a clinical syndrome characterized by sudden ataxia, related to physical or mental stress, and lasting a few days have been described. Intercritical exploration is otherwise normal. We describe a new case which presents the clinical, laboratory and neuroradiological data characteristic of periodic familial ataxia. The patient is a 34 year old male who from his 23 has suffered three crisis of gait inestability, ataxia of trunk and limbs and spontaneous nystagmus in every direction, which increased in association with head movement. These episodes were always in relation with fatigue and stress and have decreased in severity. Mean duration of crisis has been 4 to 6 days. After starting treatment with acetazolamide there have no new crisis. In this case we have found no family history of the disease as it was the rule in previous description.