Sensory nerve conduction in the spinal muscular atrophies.

Sensory conduction velocities were determined in the sural or median nerve in 16 patients with spinal muscular atrophy of the severe (Werdnig-Hoffmann), intermediate, or mild (Kugelberg-Welander) forms. In all cases there were normal sensory conduction velocities in one of the nerves tested, although sural nerve responses were not obtained in the four youngest patients.