Somatotopic organization of the human spinothalamic tract: in vivo computed tomography-guided mapping in awake patients undergoing cordotomy

Optimization of Radiofrequency Needle Placement in Percutaneous Cordotomy Using Electromyography in the Deeply Sedated Patient

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.

Pathophysiology, Classification and Comorbidities after Traumatic Spinal Cord Injury

The spinal cord is a conduit within the central nervous system (CNS) that provides ongoing communication between the brain and the rest of the body, conveying complex sensory and motor information necessary for safety, movement, reflexes, and optimization of autonomic function. After a spinal cord injury (SCI), supraspinal influences on the spinal segmental control system and autonomic nervous system (ANS) are disrupted, leading to spastic paralysis, pain and dysesthesia, sympathetic blunting and parasympathetic dominance resulting in cardiac dysrhythmias, systemic hypotension, bronchoconstriction, copious respiratory secretions and uncontrolled bowel, bladder, and sexual dysfunction. This article outlines the pathophysiology of traumatic SCI, current and emerging methods of classification, and its influence on sensory/motor function, and introduces the probable comorbidities associated with SCI that will be discussed in more detail in the accompanying manuscripts of this special issue.

Congress of Neurological Surgeons Systematic Review and Evidence-Based Guideline on Neuroablative Procedures for Patients With Cancer Pain

BACKGROUND

Managing cancer pain once it is refractory to conventional treatment continues to challenge caregivers committed to serving those who are suffering from a malignancy. Although neuromodulation has a role in the treatment of cancer pain for some patients, these therapies may not be suitable for all patients. Therefore, neuroablative procedures, which were once a mainstay in treating intractable cancer pain, are again on the rise. This guideline serves as a systematic review of the literature of the outcomes following neuroablative procedures.

OBJECTIVE

To establish clinical practice guidelines for the use of neuroablative procedures to treat patients with cancer pain.

METHODS

A systematic review of neuroablative procedures used to treat patients with cancer pain from 1980 to April 2019 was performed using the United States National Library of Medicine PubMed database, EMBASE, and Cochrane CENTRAL. After inclusion criteria were established, full text articles that met the inclusion criteria were reviewed by 2 members of the task force and the quality of the evidence was graded.

RESULTS

In total, 14 646 relevant abstracts were identified by the literature search, from which 189 met initial screening criteria. After full text review, 58 of the 189 articles were included and subdivided into 4 different clinical scenarios. These include unilateral somatic nociceptive/neuropathic body cancer pain, craniofacial cancer pain, midline subdiaphragmatic visceral cancer pain, and disseminated cancer pain. Class II and III evidence was available for these 4 clinical scenarios. Level III recommendations were developed for the use of neuroablative procedures to treat patients with cancer pain.

CONCLUSION

Neuroablative procedures may be an option for treating patients with refractory cancer pain. Serious adverse events were reported in some studies, but were relatively uncommon. Improved imaging, refinements in technique and the availability of new lesioning modalities may minimize the risks of neuroablation even further.The full guidelines can be accessed at https://www.cns.org/guidelines/browse-guidelines-detail/guidelines-on-neuroablative-procedures-patients-wi.

Percutaneous Cervical Cordotomy for the Treatment of Cancer Pain: A Prospective Case Series of 52 Patients with a Long-Term Follow-Up

AIM

The aim of this study is to describe the effects of percutaneous cervical cordotomy (PCC) on pain, opioid consumption, adverse events, and satisfaction in palliative care patients with cancer pain after PCC until end of life.

METHODS

This is a prospective observational case series of 58 PCCs in 52 consecutive patients. Indication for PCC was unilateral cancer pain with a maximum numeric rating scale (NRS) of pain above 5 despite maximal conservative treatment. The PCC was fluoroscopy guided. A radiofrequency lesion was made at 95°C for 20 seconds. The pain location and pain scores, analgesic medication, the cranial and caudal borders of dermatomes hypoesthetic for pin pricks, dysesthesia, urinary retention, Horner's syndrome, muscle strength, Karnofsky performance scale (KPS) score, patient satisfaction, hospital anxiety and distress score (HADS), and RAND 36 score were evaluated at 1 day; 1 and 6 weeks; and 3, 6, 9, 12 18, and 24 months after PCC, or until death if death occurred during the follow-up period.

RESULTS

Pain relief after PCC was intense (change in median maximum NRS from 9 to 0) and persistent. Median opioid use per day was 240 mg (145 to 565 mg) before PCC and 55 mg (0 to 120 mg) after PCC. The upper and lower borders of dermatomes hypoesthetic for pin pricks were stable over time. The most common side effects were short-term (< 1 week) neck pain (28%), dysesthesia (40%), and mild loss of muscle strength (11%). Approximately 83% of the patients were satisfied or very satisfied with the results of PCC 1 week after the procedure, and this percentage remained high in the long term. There was no significant change in the KPS score, HADS, and RAND 36 score.

CONCLUSION

Percutaneous cervical cordotomy is an effective treatment for unilateral cancer pain. The reduction in pain, reduction in opioid consumption, and hypoesthetic area remain stable until death.