Opsoclonus myoclonus syndrome: response to plasmapheresis.

An 18-month-old with idiopathic opsomyoclonus, refractory to therapy with ACTH, corticosteroids, and clonazepam received plasmapheresis along with oral corticosteroids and azathioprine. The subject improved dramatically following this treatment. Anticerebellar antibodies were detected from the plasma in this patient and in a two and a half year-old girl with cerebellar ataxia secondary to an adrenal ganglioneuroma.