RecruitingPhase 4Drug trialEffect of Magnesium Sulfate Bolus on Intraoperative NeuromonitoringMagnesium Sulfate(MgSo4) is increasingly being used as part of the multimodal pain regimen in the perioperative period. The intraoperative neurophysiological monitoring (IONM) is utilized in complex spine and cranial surgeries to assess the functional integrity of the neural pathways. The effect of Magnesium sulfate on IONM has not been studied. This is a prospective, double blind, randomized placebo controlled trial to study the effect of Magnesium sulfate bolus on the amplitude and latency of somatosensory(SSEPs) and motor evoked potentials(MEPs) in patients undergoing surgery requiring IONM.