Link between confusional migraine, hemiplegic migraine and episodic ataxia type 2: hypothesis, family genealogy, gene typing and classification.

An association between hemiplegic migraine (HM) and episodic ataxia type 2 (EA2) has been described; both disorders are linked to mutations in the CACNA1A gene. Although confusion occurs in 21% of patients with HM, we found only one case in the literature of confusional episodes associated with ataxia without hemiplegia. These findings raise the possibility of confusional episodes being part of both the HM and EA2 phenotype. However, a patient with episodic ataxia, confusional spells and CACNA1A gene mutations has not been identified. We describe four individuals, spanning three generations of a family, with episodic ataxia without hemiplegia and confusion, in association with a CACNA1A mutation. We follow with a description of the relationship between the CACNA1A mutations and the three syndromes, suggesting a potential need for a new classification in which the conditions can be subsumed.