Systematic re-evaluation of intraoperative motor-evoked potential suppression in scoliosis surgery

Abstract

BackgroundMotor- (MEP) and somatosensory-evoked potentials (SSEP) are susceptible to the effects of intraoperative environmental factors.MethodsOver a 5-year period, 250 patients with adolescent idiopathic scoliosis (AIS) who underwent corrective surgery with IOM were retrospectively analyzed for MEP suppression (MEPS).ResultsOur results show that four distinct groups of MEPS were encountered over the study period. All 12 patients did not sustain any neurological deficits postoperatively. However, comparison of groups 1 and 2 suggests that neither the duration of anesthesia nor speed of surgical or anesthetic intervention were associated with recovery to a level beyond the criteria for MEPS. For group 3, spontaneous MEPS recovery despite the lack of surgical intervention suggests that anesthetic intervention may play a role in this process. However, spontaneous MEPS recovery was also seen in group 4, suggesting that in certain circumstances, both surgical and anesthetic intervention was not required. In addition, neither the duration of time to the first surgical manoeuver nor the duration of surgical manoeuver to MEPS were related to recovery of MEPS. None of the patients had suppression of SSEPs intraoperatively.ConclusionThis study suggests that in susceptible individuals, MEPS may rarely occur unpredictably, independent of surgical or anesthetic intervention. However, our findings favor anesthetic before surgical intervention as a proposed protocol. Early recognition of MEPS is important to prevent false positives in the course of IOM for spinal surgery.

Comparison of Motor Evoked Potentials Neuromonitoring Following Pre- and Postoperative Transcranial Magnetic Stimulation and Intraoperative Electrical Stimulation in Patients Undergoing Surgical Correction of Idiopathic Scoliosis

“…Our results confirm Lo et al's observation [35] that MEP abnormalities may rarely occur unpredictably, independent of surgical or anaesthetic intervention. Moreover, they also support the necessity of the preoperative MEP recordings presented in this study, because the early recognition of their parameters is essential to prevent false positives during IS spinal surgery.…”

“…This study also attempts to determine whether the constant level of optimal anaesthesia during surgical scoliosis treatment affects the parameters of MEPs recorded during neuromonitoring procedures. The results of a study by Lo et al [35] confirm that MEPs may, rarely, occur unpredictably in susceptible individuals, independent of surgical or anaesthetic intervention. However, they did not provide specific results for the recorded parameters of MEPs.…”

Spinal arteriovenous malformation in a pediatric patient with a history of congenital syphilis: a case report

“…Total intravenous anesthesia (TIVA) remains the standard of care as intraoperative monitoring (IOM) of SSEPs and MEPs are susceptible to amplitude changes with use of inhalational anesthetic agents and neuromuscular blockade. Hemodynamic stability and use of TIVA remains the mainstay of IOM to preserve SSEPs and MEPs [ 12 ]. For our case, SSEPs and MEPs were obtainable for upper extremities only prior to and during the surgical resection of the spinal AVM.…”

Postoperative Tetraplegia to a Child after Cerebellar Pilocytic Astrocytoma Excision at Prone Position: Case Report and Literature Review

“…In general, there is a discrepancy regarding the exact effect of anesthesia parameters. Hence co-evaluation is needed for action potentials of synaptic transmission, increased refractory period of axons, dampening of motor neuron excitability, and lowering the threshold of GABA-ergic inhibitory neurons [18]. Thus, clinicians need to recognize the shortcomings of intraoperative monitoring, especially in children.…”