Periodic ataxia: an unusual non-familial variation with paroxysmal EEG features.

A 19-year-old youth suffered from periodic attacks of ataxia and dysarthria. Abnormally high IgG and IgA levels were found in the CSF. The length of the episodes of ataxia, absence of family history and the presence of generalised paroxysmal features in the EEG constitute a combination which is not believed to have been recorded previously. Carbamazepine was ineffective but temporary clinical and electroencephalographic improvement followed the administration of ACTH. Acetazolamide therapy has resulted in prolonged remissions from attacks.