Monitoring spinal surgery for extramedullary tumors and fractures

Area of Science:

• Neurosurgery
• Spinal Surgery
• Neurology

Background:

• Meningiomas and nerve sheath tumors are common spinal tumors, while metastases are frequent extradural tumors, often affecting thoracic vertebrae.
• Spinal fractures with instability necessitate surgical fixation, typically involving decompression and stabilization.
• Spine surgery for tumors or fractures carries risks of spinal cord and nerve root injury, especially during nerve sheath tumor resection.

Purpose of the Study:

• To highlight the risks associated with spinal surgeries for extramedullary tumors and fractures.
• To introduce intraoperative neurophysiologic monitoring (IONM) techniques for preventing iatrogenic neurologic deficits.
• To discuss the application of various IONM techniques based on surgical context.

Main Methods:

• Review of common spinal tumor types (meningiomas, nerve sheath tumors, metastases) and fracture management.
• Description of surgical procedures including decompression and instrumentation.
• Overview of IONM techniques: motor evoked potentials (MEPs), sensory evoked potentials (SEPs), electromyography (EMG), compound muscle action potentials (CMAPs), and bulbocavernosus reflex (BCR).

Main Results:

• Nerve root deficits are a significant risk, particularly after nerve sheath tumor resection due to their origin.
• IONM techniques have been developed to mitigate the risk of iatrogenic neurologic injury during spinal procedures.
• The selection of specific IONM techniques is tailored to the surgical level and lesion characteristics.

Conclusions:

• Intraoperative neurophysiologic monitoring is crucial for preventing neurologic deficits in complex spinal surgeries.
• A combination of monitoring techniques provides comprehensive protection against iatrogenic nerve injury.
• Tailoring IONM strategies to individual surgical cases improves patient safety and outcomes.