Progressive myoclonic epilepsy, nerve deafness and spinal muscular atrophy.

A boy of Finnish descent developed nerve deafness at six years of age, action myoclonus two years later, generalized myoclonic seizures when 16 years old and muscular atrophy at the age of 17 years. Bulbar palsy caused his death from inhalational pneumonia when he was 19 years old. Autopsy disclosed no significant changes in the cerebral cortex, thalamus, striatum, Purkinje cells or dentate nucleus. The most striking histological finding was degeneration of motor neurones in cranial nerves and anterior horns of the spinal cord, with neuroaxonal dystrophy of nucleus gracilis and cuneatus. While nerve deafness and spinal muscular atrophy have been recorded (each in different families) in association with progressive myoclonic epilepsy, the combination of these features has not previously been reported. Reasons are put forward for regarding all the system degenerations found in PME, including Unverricht-Lundborg disease (Baltic myoclonus) and the Ramsay Hunt syndrome, as variations of the same disorder.