Infantile neuroaxonal dystrophy and giant axonal neuropathy: are they related?

Light and electron microscopic findings from two sural nerve biopsies obtained at a one-year interval from a patient with the clinical features of Seitelberger's disease are described. Ballooned axons with accumulations of membranous profiles, vesicles, mitochondria, and a homogeneous center were present, and there were masses of 90 A filaments in endothelial, endoneurial, perineurial, and Schwann cells. These pathological alterations were less prominent in the second nerve biopsy, which showed a more pronounced decrease in myelinated fibers. The case shows that a generalized increase of 90 A filaments in structures of the peripheral nervous system is not a phenomenon exclusively occurring in patients with giant axonal neuropathy and, furthermore, that it may be a transitory feature.