Sudden Loss of Motor Evoked Response Followed by Clinical Recovery After Resection of an Intradural Dorsal Meningioma: A Unique Case of a ClinicalNeurophysiological Dissociation

In the neuromonitoring era, resection surgery of spinal intradural lesions is guided by Intraoperative Neurophysiological Monitoring (IONM) of Motor Evoked Potentials (MEP). We describe a single case of a 70s-year-old patient who underwent surgery as a treatment for a voluminous dorsal intradural juxtamedullary meningioma: during surgery, we observed a sudden loss of bilateral lower limbs muscle MEPs, followed by a rapid recurrence of normal responses exclusively in the right side, but not in the left one. After awakening, the patient presented a transitory complete monoplegia of the left inferior limb for 30 minutes, and then it was resolved with rapid restoration of the neurological status.