Abstract

Episodic ataxia (EA) is a hereditary disorder characterized by recurrent episodes of ataxia that are triggered by stress and exercise. Most patients recover fully between attacks, but some may develop progressive ataxia with cerebellar atrophy. EA type 1 (EA1) is caused by missense mutations in the potassium channel gene KCNA1, while EA type 2 (EA2) is owing to mutations in the calcium channel gene CACNA1A. Spinocerebellar ataxia type 6 (SCA6) and familial hemiplegic migraine are allelic disorders of EA2 and may show episodic ataxia. Treatment with acetazolamide can be effective in decreasing the frequency of attacks in these diseases.