Ultrastructural observations on spinal ganglion biopsy in Friedreich's ataxia: a preliminary report.

We report the preliminary study of a dorsal root ganglion obtained at biopsy during a surgical intervention in a patient with Friedreich's ataxia. There was an apparent decrease in the number of large myelinated fibers without necrosis, but with numerous axonal swellings consisting mainly of dense accumulated neurofilaments. Large amounts of lipofuscin were also found as well as some onion bulb formations suggesting a process of axonal atrophy.