ELECTROPHYSIOLOGICAL FINDINGS IN PATIENTS WHO RECEIVED RADIATION-THERAPY OVER THE BRACHIAL-PLEXUS - A MAGNETIC STIMULATION STUDY

Clinical and electrophysiological findings of 47 asymptomatic females who received radiation therapy (RT) over their brachial plexus region are presented and compared with 8 radiation-induced brachial plexopath y (REP) and 4 neoplastic brachial plexopathy (NBP) patients. In the as ymptomatic group, abnormal findings were more frequent in patients who se post-RT period was longer than 1 year. Flexor carpi radialis H refl ex was delayed or absent in 19 patients (52%) in this subgroup of asym ptomatic cases, as compared to only 2 (18%) of the patients with post- RT periods of less than 1 year. Magnetic cervical nerve root stimulati on was performed in 16 asymptomatic cases, with the conclusion that th ere was no significant difference between the irradiated and non-irrad iated sides with regard to latencies, amplitudes and areas of the musc le responses. In spite of this, muscle response amplitudes and areas o n both sides were significantly lower than those obtained from healthy controls. It was postulated that this finding resulted from hypoexcit ability to magnetic stimulation produced by slight nerve root damage. Any part of the brachial plexus could be affected in REP and NBP patie nts. Myokymic discharges were found at a high rate (87.5%) in REP grou p. Cervical magnetic nerve root stimulation may have a diagnostic valu e in these patients in localizing the nerve lesion over the brachial p lexus. Copyright (C) 1996 Elsevier Science Ireland Ltd.