Neuroaxonal dystrophy (Seitelberger's disease) with late onset, protracted course and myoclonic epilepsy.

We present the pathologic findings, including electron microscopy, in one of two affected borthers with severe progressive myoclonus epilepsy, beginning in our patient at the age of 10 and leading to death at age 23. At autopsy there was widespread and marked neuroaxonal dystrophy, severe cerebellar atrophy, and tract degenerations in the gracilis columns and the lateral corticospinal tracts in the spinal cord. There was no increased pigmentation in the globus pallidus or reticular zone of the substantia nigra, on gross or microscopic examination. We regard this case as an example of a juvenile form of neuroaxonal dystrophy (Seitelberger's disease). The absence of pallido-nigral hyperpigmentation distinguishes this disease from Hallervorden-Spatz disease, which we regard as a separate disease entity.