INTRAOPERATIVE ELECTRONEURODIAGNOSTICS (TRANSCRANIAL ELECTRICAL MOTOREVOKED-POTENTIALS) TO EVALUATE THE FUNCTIONAL STATUS OF ANTERIOR SPINAL ROOTS AND SPINAL NERVES DURING BRACHIAL-PLEXUS SURGERY

Intradural spinal root lesions cannot be recognized by dissecting the brachial plexus and lead to ineffective surgery if they remain undetec ted. Therefore, patients need to undergo a diagnostic procedure to ass ess the intradural status of the spinal roots. Although motor recovery is the main goal of brachial plexus surgery, the techniques currently applied do not permit adequate evaluation of the anterior root. In se arch of an alternative, we performed intraoperative motor evoked poten tials. Ninety spinal nerves in 19 patients suffering from brachial ple xus lesions were dissected. Twenty-seven spinal nerves were avulsed; 8 nerves were disrupted and 17 were completely scarred, resulting in 25 stumps. Thirty-eight nerves appeared to be undamaged. On central stim ulation, nerve compound action potentials were recorded from the expos ed spinal nerves. Nerve compound action potentials could only be recor ded from 21 stumps and from 32 apparently undamaged nerves. No recordi ngs were obtained from 4 stumps and 7 spinal nerves in continuity. Acc ording to these findings, it is highly probable that surgery would hav e been insufficient in 10 spinal nerves if intraoperative motor evoked potentials had not been performed. We conclude that (1) intraoperativ e motor evoked potentials are an effective means for investigating the functional status of anterior motor roots and motor fibers in exposed spinal nerves, and (2) the use of motor evoked potentials should be c onsidered during brachial plexus surgery to improve interventions.