Ocular motor features of alternating hemiplegia of childhood.

A 14-month-old boy with alternating hemiplegia of childhood, an idiopathic disorder of early childhood causing episodic hemibody tonic spasms and hemiplegia, showed repetitive jerks of abduction of the ipsilateral eye during the spells. The mechanism of this ocular motor abnormality is unknown but may be unique to this disorder.