Intraoperative monitoring of a patient with craniovertebral junction meningioma

Intraoperative monitoring is considered as a useful tool to prevent neurological damage during different neurosurgical procedures. Somatosensory evoked potentials (SEP) allow simultaneous assessment of several cortical and sub cortical centers. In this case presentation, we report intraoperative monitoring of an elderly patient with craniovertebral junction meningioma. Tibial SEP responses were elicited by stimulation of the tibial nerve; the recordings were visually analyzed for the presence of the main peaks P40-N50, peak to peak amplitudes, peak latencies and compared to baseline recordings throughout the procedure. During decompression from the medial aspect of the medulla SEP responses were lost for a brief period of time. Surgeons achieved total tumor removal and the patient left the operating room without any neurological deficit.