Subdural Direct Wave Intraoperative Neurophysiological Monitoring in Intramedullary Spinal Cord Tumor Resection: Case Report. (3rd April 2022)

• Record Type: Journal Article
• Authors: Green, Ross; Mishra, Akash; Schneider, Daniel; Najjar, Salem; D'Amico, Randy S.; Sciubba, Daniel M.; Lo, Sheng-Fu; Silverstein, Justin W.
• Is Part Of: Neurodiagnostic journal. Volume 62:Number 2(2022)
• Page Start: 87
• Page End: 98
• Publication Date: 2022-04-03
• Subjects: Direct wave monitoring -- D-wave monitoring -- intramedullary spinal cord tumor -- spinal subependymoma -- spine surgery; Neurologic examination -- Periodicals; Nervous system -- Diseases -- Diagnosis -- Periodicals; Diagnostic Techniques, Neurological -- Periodicals; Nervous system -- Diseases -- Diagnosis; Neurologic examination; Periodicals; 616.7407547
• DOI: 10.1080/21646821.2022.2060011
• Languages: English
• ISSNs: 2164-6821

Abstract

ABSTRACT: Direct wave (D-wave) intraoperative neurophysiological monitoring (IONM) is used during intramedullary spinal cord tumor (IMSCT) resection to assess corticospinal tract (CST) integrity. There are several obstacles to obtaining consistent and reliable D-wave monitoring and modifications to standard IONM procedures may improve surgical resection. We present the case of a subependymoma IMSCT resection at the T2–T6 spinal levels where subdural D-wave monitoring was implemented. A 47-year-old male was presented with a five-year history of numbness in his right foot eventually worsening to sharp upper back pain with increased lower extremity spasticity. MRI revealed an expansile non-contrast enhancing multi-loculated cystic lesion spanning T2–T6 as well as a separate T1–T2 lesion. A T2–T6 laminoplasty was performed for intramedullary resection of the lesion. A spinal electrode was placed in the epidural space caudal to the surgical site to monitor CST function; however, action potentials could not be obtained. Post durotomy, the electrode was placed in the subdural space under direct visualization. This resulted in a reliable D-wave recording, which assisted surgical decision-making during the procedure upon D-wave and limb motor evoked potential attenuation. Surgical intervention led to the recovery of the D-wave recording. Subdural D-wave monitoring serves as an alternative in patients where reliable D-waves from the epidural space are unable to be obtained. Further investigation is required to improve the recording technique, including exploring various types of contacts and lead placement locations.