S44. Peripheral nerve injury repair: When and how by neurophysiology guidance

Abstract

Introduction Peripheral nerve injuries are one of the most causes of dysfunction after trauma in our service, but still current management has remained suboptimal. This review aims to explain our methods to improve functional recovery after peripheral nerve lesions in closed traumas in the last five years. Methods First we classify lesion type (axonal or demyelination), and the time for evolution, acute or chronic. For pathophysiology classification we use for first instance an EMG study, searching for any voluntary activity, and direct nerve stimulation if possible after and above level of lesion, and contralateral evaluation and comparison; and also MRI studies to very proximal nerve lesions (in test); and echography to study nerve continuity in axonal lesions. Results Demyelination acute nerve lesions were treated with rehabilitation and an EMG study every four weeks in the first three months, if no changes or reinnervation was seen at the three month period, surgical exploration was done. Demyelination chronic nerve lesions were treated medical and with rehabilitation, and evaluated in four to six weeks by neurophysiology studies, if no changes were seen surgical exploration was done, if improvement was seen another EMG study was done in four weeks to confirm good clinical evolution, if not surgical exploration was done. Axonal nerve lesions acute or chronic were treated similar, it depended on the severity of the lesion: 1 EMG study is without any voluntary activity, no MEP is obtained below lesion and axonal lesion is high suspected, surgical exploration was done. 2. EMG study showed severe lost of motor units, MEP amplitude very low below lesion, medical treatment was first option, in four to six weeks new EMG study was done, if improvement we continue medical treatment, if not no surgical exploration was done. 3. EMG study shows moderate (50% or less) lost of motor units, medical treatment was the first choice, again control EMG every four weeks for the first three months to evaluate treatment. No differences were seen in terms of nerve (ulnar, radial, median, tibial or peroneal). Conclusion With this simple nerve lesion classification and neurophysiological guidance first and repeated every four to six weeks in the first three to six months, we have had a very high rate of resolution, approaching forces 4/5 and 3/5; excellent surgeon guidance and treatment choices, with not very unpleasant exploration for the patient, so we encourage of the need of an EMG exploration in every nerve lesion timing the evolution (four to six weeks is the best interval, three months limit) and the best method for guiding and evaluating the treatment.