INTRAOPERATIVE SPINAL ROOT STIMULATION TO DETECT MOST PROXIMAL SITE OF LEPROUS ULNAR NEURITIS

In 10 patients with leprous ulnar neuritis, we investigated the most p roximal site of lesion in the affected nerves. Spinal roots C8 and T1 were stimulated intraoperatively to evoke efferent mixed compound nerv e action potentials which were recorded from the exposed ulnar nerves. The site at which amplitudes reached a maximum was considered the mos t proximal site of lesion. Nerve damage was found far proximally from the thickened segments in otherwise inconspicuous sections. Epineuriot omy within these apparently unaffected segments revealed fibrosis of t he interfascicular epineurium in 9 patients, which is an indication fo r microsurgical interfascicular neurolysis.