[Complex electrophysiologic diagnosis of traumatic lesions of the brachial plexus at the preganglionic level].

In 20 patients with preganglionic injuries to the brachial plexus the authors recorded short-latent somatosensory evoked potentials (EP) and sensory EP in response to stimulation of the musculocutaneous, radial, median, and ulnar nerves on both sides. The preganglionic level of brachial plexus injury was characterized by the absence of short-latent somatosensory EP, which reflected disturbance of the connection of the neuromuscular apparatus with the spinal cord, and the presence of sensory EP which bore evidence of maintained connection of the sensory fibers with the spinal ganglia. The electrophysiological data corresponded completely to the operative findings in 11 and partly in 7 cases.