Familial spasmodic torticollis.

Presented are four cases of familial spasmodic torticollis, comprising members of three families. The age of onset tended to be family-specific, and no afflicted family member had evidence of more widespread disease (dystonia musculorum deformans). Familial incidence supports the conclusion that spasmodic torticollis is organic in origin. Familial spasmodic torticollis occurs more often than has been generally recognized.