Infantile neuronal degeneration masquerading as Werdnig-Hoffmann disease.

We investigated two infants whose clinical illness resembled Werdnig-Hoffmann disease (WHD). Motor nerve conduction velocities in one infant were markedly decreased, suggesting a demyelinative neuropathy. Pathological examination of the central nervous system in both patients revealed the expected loss of cell bodies in the anterior horn and motor cranial nerves. In addition, there was widespread neuron loss and gliosis in both gray and white matter of the thalamus, cerebellum, pons, and spinal cord. Motor sensory, and mixed peripheral nerves of one infant showed evidence of segmental demyelination with only mild fiber loss. These and similar patients previously described have a disorder that should be separated from WHD and can be termed infantile neuronal degeneration.