Almitrine neuropathy. A nerve biopsy study of 8 cases.

We report the quantitative and qualitative, light and electron microscopic studies, including teased fiber preparations of nerve biopsies obtained from eight patients, treated with almitrine, presenting with the characteristic association of a sensory peripheral neuropathy with a recent body weight loss. The data were consistent with an axonal damage affecting myelinated fibers, predominantly large ones and to a lesser degree unmyelinated fibers, some degree of segmental demyelination. Marked axonal regeneration was observed when the nerve biopsy was delayed after withdrawal of the drug, Micro-angiopathy secondary to the formation of concentric lamellae from the basement membrane was observed in five patients suffering from chronic hypoxemia. Almitrine is an agonist of the chemoreceptors. The pathogenesis of the toxic neuropathy induced by this compound remains obscure. Clinical features do not fit with a purely hypoxic mechanism at the origin of the neuropathy.