Dominant spinopontine atrophy. Report of two additional members of family W.

In five generations of Anglo-Saxon family W, 28 members were affected with dominant hereditary ataxia. In 1969, two members of this family were reported as prototypes of dominant spinopontine atrophy. We discuss two additional members of the original family, with one postmortem examination, including ultrastructual study. In contrast to previously accepted clinical generalizations, we found abolished tendon reflexes and flexion contractures of the lower extremities in patient 1 and onset of illness at the age of 18 years, palatal myoclonus, and optic atrophy in patient 2. Dementia was observed in both patients. Unlike in previous pathological reports, our patient 1 showed definite involvement of the cerebellum and mild degeneration of the inferior olivary nuclei. We conclude, therefore, that clinical and pathological distinction between dominant spinopontine atrophy and olivopontocerebellar atrophy is not clear and raises the question of the justification for regarding dominant spinopontine atrophy as a nosological entity.