Somatosensory evoked potentials: a simple neurophysiological monitoring technique in supra-aortal balloon test occlusions.

The aim of this study was to evaluate somatosensory evoked potentials (SEP) as a simple neurophysiological monitoring method in supra-aortal balloon test occlusions (BTO). The 13 patients examined had carcinoma of the larynx (n = 6), nasopharyngeal malignancy (n = 3), sphenoid meningioma (n = 2), mycotic aneurysm (n = 1), and a tumor of the carotid body (n = 1). Transfemoral balloon occlusion of the internal carotid artery was maintained for 30 min and monitored both clinically and by SEP. None of the 13 patients showed neurological deficits or pathological changes in the SEP. No thromboembolic complications occurred during BTO. In 11 cases the cervical vessels could be spared or reconstructed during surgery. No neurological symptoms occurred during the clinical follow-up. One patient died the day after BTO due to cardiac arrest. Neurophysiological monitoring of preoperative BTO using SEP is a technically simple method. A similar method has been shown to have a high sensitivity and reliability in carotid surgery.