Awake far lateral craniotomy for resection of foramen magnum meningioma in a patient with tenuous motor and somatosensory evoked potentials

We report a patient with an infratentorial lesion resected under a far-lateral approach during awake craniotomy to optimize intraoperative monitoring. A 72-year-old man presented with falls, difficulty walking, and lower extremity weakness. MRI revealed a 2.2 by 2.3 by 2.8cm mass at the right cervicomedullary junction, with mass effect on the adjacent spinal cord. During two attempts during surgical positioning under general anesthesia, motor evoked potentials were lost. Each time the operation was aborted. During the third operation, the patient underwent monitored, light anaesthesia and was awakened periodically to confirm conscious motor function. The operation proceeded without complication, and postoperatively there was no further decrease in motor function. This is, to our knowledge, the first use of an awake operation for an infratentorial meningioma via the far-lateral approach, demonstrating the technique may be used safely and can be useful in optimizing motor function monitoring.