Tongue Laceration during Neurophysiologic Monitoring with Motor Evoked Potentials

Although considered a safe modality for monitoring spinal cord function, motor evoked potentials (MEP) may cause tongue laceration in rare cases. Bite blocks are essential in order to prevent tongue and mucosal injury during monitoring with MEP, but there is no consensus on the ideal bite block to use for this purpose. Potential concerns include tongue necrosis from prolonged use of an oral airway as a hard bite block, and TMJ dysfunction caused by occlusal interference when blocks interrupt the normal occlusal surface. We had a case of tongue laceration during MEPs. Bite blocks should be placed prior to the start of monitoring to prevent teeth occlusion. Because rigid bite blocks may cause pressure injury to oropharyngeal structures soft bite blocks are recommended. The bite block needs to be placed in a way to prevent occlusion by both front teeth and molars and to keep the tongue in the middle of the mouth. Ongoing vigilance to bite block placement is strongly recommended.