Insular Tumours Surgery with Intraoperative Continuous Motor and Somatosensory Monitoring

Abstract

Background: Epilepsy surgery for lesions within or adjacent to the motor pathways (like insular tumors) could result to significant risk of a new motor deficit which presents one of the most disabling complications of such surgeries. So it is a major concern to neurosurgeons to delineate and monitor motor regions in order to preserve their structural and functional integrity, while still achieving maximal resection of tumor and epilepsy control.

Materials and Methods: The technique of motor evoked potential recording has been available for clinical use now for almost ten years. In this article we report our clinical experience in 3 cases of intraoperative MEP and SEP monitoring in supratentorial tumors surgeries in and around the motor areas.

Results: In 2 of 3 cases MEP deterioration got reversed and in the third one no changes were found during monitoring. Our results show success of the MEP monitoring method in the prevention of a significant motor impairment. In one case we could resects the lesion totally and in two other cases the lesions resected near totally. Arm paresis (3/5) occurred immediately after surgery in one case.

Conclusion: Intraoperative MEP recordings have been shown to reliably reflect an impending new motor deficit. Irreversible MEP deterioration heralds new paresis, and unaltered recordings predict preserved motor function. In conclusion, intraoperative MEP monitoring is a useful aid in brain surgery to avoid a new motor deficit without compromise to the surgical result. More controlled prospective studies will be required to verify the clinical value of this method.