VANTAGGI DELLA STIMOLAZIONE MAGNETICA TRANSCRANICA IN CORSO DI PARALISI ISOLATE DEL N. ACCESSORIO SPINALE

The isolated spinal accessory nerve palsy is a rare focal neuropathy with typical clinical picture and electromyographic findings. The characteristic clinical features of the palsy are weakness with successively amyotrophy of the sternocleidomastoid (SCM) muscle and of the trapezius muscle. Very few cases of different etiologies have been yet described, but, at our knowledge, only one case of stretch-induced spinal accessory nerve palsy have been reported with complete electrodiagnostic nerve and muscle evaluation. The use of conventional electrophysiological methods applied to lesions of the proximal brachial plexus and of the exit segment of the nerves leaving the skull base is limited by the difficulty to obtain a adequate electrical peripheral surface stimulation. Moreover, the conventional electrical stimulation, using a needle electrode inserted below the lower border of the mastoid process, often causes significant discomfort to the patient. The magnetic coil stimulation at the base of the skull is a valid alternative painless technique able to activate deep structure as the accessory nerve. We report the clinical and electrophysiological findings of stretch-induced accessory nerve palsy using conventional technique compared to magnetic stimulation at the base of the skull.