BACKGROUND AND OBJECTIVES Cordotomy, the selective disconnection of the nociceptive fibers in the spinothalamic tract, is used to provide pain palliation to oncological patients suffering from intractable cancer-related pain. Cordotomies are commonly performed using a cervical (C1-2) percutaneous approach under imaging guidance and require patients' cooperation to functionally localize the spinothalamic tract. This can be challenging in patients suffering from extreme pain. It has recently been demonstrated that intraoperative neurophysiology monitoring by electromyography may aid in safe lesion positioning. The aim of this study was to evaluate the role of compound muscle action potential (CMAP) in deeply sedated patients undergoing percutaneous cervical cordotomy (PCC). METHODS A retrospective analysis was conducted of all patients who underwent percutaneous cordotomy while deeply sedated between January 2019 and November 2022 in 2 academic centers. The operative report, neuromonitoring logs, and clinical medical records were evaluated. RESULTS Eleven patients underwent PCC under deep sedation. In all patients, the final motor assessment prior to ablation was done using the electrophysiological criterion alone. The median threshold for evoking CMAP activity at the lesion site was 0.9 V ranging between 0.5 and 1.5 V (average 1 V ± 0.34 V SD). An immediate, substantial decrease in pain was observed in 9 patients. The median pain scores (Numeric Rating Scale) decreased from 10 preoperatively (range 8-10) to a median 0 (range 0-10) immediately after surgery. None of our patients developed motor deficits. CONCLUSION CMAP-guided PCC may be feasible in deeply sedated patients without added risk to postoperative motor function. This technique should be considered in a group of patients who are not able to undergo awake PCC.

Introduction: Pain is one of the most common symptoms among cancer patients, and particularly in those who suffer from metastatic or terminal disease. There is great importance in delivering good pain management to these patients in order to alleviate their suffering, improve their functional status and their overall quality of life. In most cases, pain management is based on pharmacotherapy with opioids and other medications. However, there are selected patients for whom pharmacotherapy does not achieve acceptable pain relief or is associated with marked side effects. These patients, who suffer from refractory cancer pain, may benefit from neurosurgical procedures selectively intervening in different locations along the pain signaling pathways. This article summarizes several of these neurosurgical procedures: percutaneous cordotomy for unilateral pain, punctuate midline myelotomy for visceral pain and stereotactic cingulotomy for diffuse pain syndromes. This article demonstrates the use of careful patient selection by an interdisciplinary team which is critical for the success of these procedures. The team consists of palliative care specialists, pain specialists and a neurosurgeon. These neurosurgical interventions are presented through representative clinical cases, followed by a discussion of the clinical considerations that guided the choice of the therapeutic approach for each case.