[Demyelinating involvement in Borrelian neuropathies]. / Les atteintes démyélinisantes au cours des neuropathies borréliennes.

Five patients (4 men, 1 woman, aged 51-67), were hospitalized for peripheral painful neuropathies. The serological survey and the dramatic responses to penicillin confirmed the responsibility of Borrelia burgdorferi in all 5 cases. Electromyographical studies showed evidence of demyelination: prolonged distal latency, slowing down of nerve conduction velocity. In 3 patients this pattern was related to axonal degeneration as shown by fibrillation potentials and reduced voluntary motor unit potentials recorded on needle examination. The other two showed no axonal degeneration. One also had motor conduction blocks. Such a demyelination could be due to vasculitis of the vasa nervorum described in tick-bone meningoradiculitis.