THE ELECTROPHYSIOLOGIC FEATURES OF SCIATIC NEUROPATHY IN 100 PATIENTS

We reviewed the electrophysiologic data of 100 consecutive patients wi th sciatic neuropathy in order to better understand this disorder. Mos t patients (93%) had electrodiagnostic signs of significant axonal los s. Seven patients had predominantly signs of demyelination; 6 were due to compression and 1 was idiopathic. The peroneal division was more s everely affected than the tibial division in 64% of patients. Tibialis anterior EMGs were abnormal in 92%, and the EDB CMAP was low in ampli tude or absent in 80%. CMAP and SNAP amplitudes and EMGs were all norm al in the tibial division in 12%. In contrast, the tibial division was more severely affected in only 8 patients. Of those, 5 were due to th igh trauma (gunshot wounds or femur fracture), 2 from gunshot wounds t o the hip, and the other was chronic and idiopathic. Sciatic neuropath ies are commonly, but not always, axonal loss lesions that affect the peroneal greater than tibial division. (C) 1995 John Wiley and Sons, I nc.