Light and Ultrastructural Studies in Sural Biopsies of the Pseudopolyneuropathic form of ALS

Amyotrophic lateral sclerosis (ALS) is usually accepted as a disease in which degeneration of the first and second motor neuron is not accompanied by a sensory abnormality. Neuropathological studies on the sural nerve[l-4], and on deep and superficial peroneal nerves[5] of ALS patients have suggested that the primary sensory neuron may also be involved in this disease. We have studied the biopsy of the sural nerve using light and ultrastructural investigation in patients with the pseudopolyneuritic form of ALS. The aim of our work was to verify primary sensory neuron involvement in this particular form of ALS in order to single out an eventual pathogenetic mechanism.