MOTOR EVOKED-POTENTIALS FOLLOWING CERVICAL ELECTRICAL-STIMULATION IN BRACHIAL-PLEXUS LESIONS

The diagnostic relevance of recording motor evoked potentials (MEPs) a fter electrical stimulation of the cervical region, as compared with c onventional needle electromyography (EMG), was evaluated in 26 patient s with brachial plexus (BP) damage of different aetiology, severity an d topography. MEP abnormalities (absence or latency increase) were obs erved in at least one muscle of all the patients, with a global incide nce of 61.5% of the muscles examined. Neurogenic EMG signs were presen t in all but one patient with an incidence of 62.2% of the muscles exa mined. Combining the two methods, the global incidence of abnormalitie s rose to 69.9%. MEP abnormalities were consistent with the clinical t opography and severity of BP lesions and were fairly parallel with EMG findings. Recording MEPs after percutaneous electrical stimulation of the cervical region may be regarded as a rapid, non-invasive method f or quantitative electrophysiological assessment of BP damage.