[Hereditary fragility of the peripheral nerves. Clinical and neurophysiologic study of 23 cases. Review of the literature].

The literature concerning hereditary neuropathy with liability to pressure palsies is reviewed. We describe 23 affected members of 7 families; one of them studied since 1966. The differential diagnosis with heredofamilial plexus brachialis neuropathy and Charcot-Marie-Tooth syndrome is discussed. Our subjects are similar to those described in the literature; they have presented episodes of recurring painless palsies, most often related to minimal neural trauma. Neuromyographic examinations revealed chronic denervation, slowed conduction velocities particularly at entrapment sites and sometimes neurapraxia. We emphasise the conduction blocks for we believe their tendency to long duration (up to 8 years) and presence at several sites in a same patient are characteristic of this affection. Moreover we suggest that this neurapraxia is related to the existence of the tomacula. The possibilities of prevention and treatment are reviewed (two neurolyses performed in one patient presenting with long lasting conduction blocks at 2 entrapment sites have proved to be a successful treatment.