Evolving compartment syndrome detected by loss of somatosensory- and motor-evoked potential signals during cervical spine surgery.

Neurologic injury is a rare but devastating complication of spinal surgery that can result in mild sensory to severe motor deficits. Surgeons increasingly use electrophysiological spinal cord function monitoring, including somatosensory- and motor-evoked potentials, intraoperatively to provide information about spinal cord function, aid in surgical decision making, improve outcomes, and reduce complication rates. By providing real-time information about the dorsal and anterior motor column function, somatosensory- and motor-evoked potentials signals allow surgeons to reverse noticeable changes and avoid devastating neurologic injuries. Recognizing changes in baseline signals in the setting of known risk factors enables surgeons to correct these risks. This article describes a case in which somatosensory- and motor-evoked potentials monitoring were lost in the setting of an impending right forearm compartment syndrome during 2-level anterior cervical diskectomy and fusion. To the authors' knowledge, this is the first reported case of spinal cord monitoring detecting an evolving compartment syndrome during cervical spine surgery. The early changes in signal intensity enabled the surgeon to search for a cause and remedy the situation by removing the infiltrated intravenous line. Without the observed changes in somatosensory- and motor-evoked potentials, it is likely that the compartment syndrome may have progressed to the point of requiring fasciotomy to prevent lasting neuromuscular injury. This article describes a new cause of changes in electrophysiological monitoring and further displays the usefulness of somatosensory- and motor-evoked potentials monitoring during even routine spinal surgery.