Double Anterior Stereotactic Cingulotomy for Intractable Oncological Pain

A nationwide neurosurgical inter-disciplinary service for cancer-related refractory pain

PURPOSE

Neurosurgical ablative procedures, such as cordotomy and cingulotomy, are often considered irreversible and destructive but can provide an effective and individualized solution for cancer-related refractory pain, when all other approaches have been unsuccessful. This paper provides an in-depth exploration of a novel approach to managing refractory cancer pain. It involves an interdisciplinary team led by a neurosurgeon at a renowned national referral center.

METHODS

a retrospective analysis of the medical records of all sequential patients who underwent their initial evaluation at our interdisciplinary refractory cancer pain clinic from February 2017 to January 2023.

RESULTS

A total of 207 patients were examined in the clinic for a first visit during the study period. All patients were referred to the clinic due to severe pain that was deemed refractory by the referring physician. The mean age was 61 ± 12.3 years, with no significant sex difference (P = 0.58). The mean ECOG Performance Status score was 2.35. Conservative measures had not yet been exhausted in 28 patients (14%) and 9 patients were well controlled (4%). Neurosurgical ablative procedures were recommended for 151 (73%) of the patients. Sixty-six patients (32%) eventually underwent the procedure. 91 patients (44%) received a negative recommendation for surgery. Thirty-five patients (17%) were referred for further invasive procedures at the pain clinic.

CONCLUSION

An Interdisciplinary cooperation between palliative care specialists, pain specialists, and neurosurgeons ensures optimal patient selection and provides safe and effective neurosurgery for the treatment of refractory cancer-related pain.

Distinctive Neurophysiological Signatures of Analgesia after Inflammatory Pain in the ACC of Freely Moving Mice

Preclinical assessments of pain have often relied upon behavioral measurements and anesthetized neurophysiological recordings. Current technologies enabling large-scale neural recordings, however, have the potential to unveil quantifiable pain signals in conscious animals for preclinical studies. Although pain processing is distributed across many brain regions, the anterior cingulate cortex (ACC) is of particular interest in isolating these signals given its suggested role in the affective ("unpleasant") component of pain. Here, we explored the utility of the ACC toward preclinical pain research using head-mounted miniaturized microscopes to record calcium transients in freely moving male mice expressing genetically encoded calcium indicator 6f (GCaMP6f) under the Thy1 promoter. We verified the expression of GCaMP6f in excitatory neurons and found no intrinsic behavioral differences in this model. Using a multimodal stimulation paradigm across naive, pain, and analgesic conditions, we found that while ACC population activity roughly scaled with stimulus intensity, single-cell representations were highly flexible. We found only low-magnitude increases in population activity after complete Freund's adjuvant (CFA) and insufficient evidence for the existence of a robust nociceptive ensemble in the ACC. However, we found a temporal sharpening of response durations and generalized increases in pairwise neural correlations in the presence of the mechanistically distinct analgesics gabapentin or ibuprofen after (but not before) CFA-induced inflammatory pain. This increase was not explainable by changes in locomotion alone. Taken together, these results highlight challenges in isolating distinct pain signals among flexible representations in the ACC but suggest a neurophysiological hallmark of analgesia after pain that generalizes to at least two analgesics.

Cingulotomy: the last man standing in the battle against medically refractory poststroke pain

Introduction

Central poststroke pain (CPSP) places a huge burden on patient lives because patients are often refractory to conventional strategies and have little chance for spontaneous recovery. A subset of patients is even given approval for euthanasia and is without any perspective. Because the anterior cingulate cortex historically seems to be a promising target for patients with both mental and chronic pain disorders, lesioning of this central "hub" with cingulotomy may be a useful strategy for medically refractory CPSP. However, limited research is available on cingulotomy for central pain. Hence, we represent a rare case in which cingulotomy is performed on a patient with CPSP.

Objectives

To describe the potential of cingulotomy in a case with CPSP.

Methods

The case presented in this study concerns a 60-year-old woman who experienced CPSP, caused by a hemorrhagic stroke in the basal ganglia and thalamus. The patient visited several centers and tried multiple off-label treatments; however, she was told nothing else could be done and was even given approval for euthanasia. Hence, anterior cingulotomy was performed.

Results

After surgery, no transient adverse events occurred, except for vocabulary disturbances post stroke, which disappeared after several weeks. After 14 weeks, changes in pain behavior were observed, followed by a decreased pain intensity. At a later follow-up, the pain had completely disappeared.

Conclusion

Anterior cingulotomy seems to be a suitable "last-resort" option for patients with CPSP. Future research, including homogenous groups, to define the best location for lesioning is required to allow the revival of this "old" technique in the current era.

Cingulotomy for Intractable Pain: A Systematic Review of an Underutilized Procedure

Pain management is a critical aspect of cancer treatment and palliative care, where pain can significantly impact quality of life. Chronic pain, which affects a significant number of people worldwide, remains a prevalent and challenging symptom for patients. While medications and psychosocial support systems play a role in pain management, surgical and radiological interventions, including cingulotomy, may be necessary for refractory cases. Cingulotomy, a neurosurgical procedure targeting the cingulate gyrus, aims to disrupt neural pathways associated with emotional processing and pain sensation, thereby reducing the affective component of pain. Although cingulotomy has shown promise in providing pain relief, particularly in patients refractory to traditional medical treatment, its use has declined in recent years due to advancements in non-destructive therapies and concerns about long-term efficacy and patient suitability. Modern stereotactic methods have enhanced the precision and safety of cingulotomy, reducing associated complications and mortality rates. Despite these advancements, questions remain regarding its long-term efficacy and suitability for patients with limited life expectancy, particularly those with cancer. A comprehensive systematic review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines, aimed at providing insights into the efficacy, potential benefits, and limitations of this neurosurgical procedure in managing intractable pain. An electronic search of PubMed, Embase, Scopus, and Web of Science was conducted with open database coverage dates. The review focused on outcomes such as pain intensity and quality of life. The inclusion criteria encompassed human studies of any age experiencing intractable cancer or non-cancer pain, with cingulotomy as the primary intervention. Various study designs were considered, including observational studies, clinical trials, and reviews focusing on pain and cingulotomy. Exclusion criteria included non-human studies, non-peer-reviewed articles, and studies unrelated to pain or cingulotomy. This review highlights the efficacy of stereotactic anterior cingulotomy in managing intractable pain, particularly when conventional treatments fail. Advanced MRI-guided techniques enhance precision, but challenges like cost and expertise persist. Studies included in this review showed significant pain relief with minimal adverse effects, although the optimal target remains debated. Neurocognitive risks exist, but outcomes are generally favorable. Expected adverse events include transient effects like urinary incontinence and confusion. Reoperation may be necessary for inadequate pain control, with a median pain relief duration of three months to a year. A double stereotactic cingulotomy appears to be safe and effective for refractory pain.

Multidisciplinary Approaches: Cingulotomy in an Adult With Refractory Neuropathic Cancer-Related Pain

Background: Oral medications, intravenous medications, and invasive interventions are effective means of neuropathic pain control. In patients with pain refractory to more conventional approaches, cingulum bundle ablation is an alternative treatment modality not routinely considered by providers. Case Description: A 42-year-old woman with history of cervical cancer in remission presented with intractable left lower extremity pain. Workup revealed radiation-induced left iliopsoas osteosarcoma complicated by deep venous occlusion and thrombosis. Her pain remained intractable to pharmacologic therapies and more invasive pain control interventions. A multidisciplinary decision was made to pursue bilateral subcortical cingulum bundle radiofrequency ablation. After a technically successful surgery, the patient exhibited improved pain control as evidenced by a decline in her numerical rating scale of pain and analgesic medication requirements. Conclusion: Cancer-related neuropathic pain often requires treatment with multiple modalities involving multidisciplinary teams. In select refractory cases, cingulum bundle ablation may be an effective alternative treatment modality.

Paradoxical increases in anterior cingulate cortex activity during nitrous oxide-induced analgesia reveal a signature of pain affect

The general consensus is that increases in neuronal activity in the anterior cingulate cortex (ACC) contribute to pain's negative affect. Here, using in vivo imaging of neuronal calcium dynamics in mice, we report that nitrous oxide, a general anesthetic that reduces pain affect, paradoxically, increases ACC spontaneous activity. As expected, a noxious stimulus also increased ACC activity. However, as nitrous oxide increases baseline activity, the relative change in activity from pre-stimulus baseline was significantly less than the change in the absence of the general anesthetic. We suggest that this relative change in activity represents a neural signature of the affective pain experience. Furthermore, this signature of pain persists under general anesthesia induced by isoflurane, at concentrations in which the mouse is unresponsive. We suggest that this signature underlies the phenomenon of connected consciousness, in which use of the isolated forelimb technique revealed that pain percepts can persist in anesthetized patients.

Case report: MR-guided laser induced thermal therapy for palliative cingulotomy

In end-stage cancer, oncologic pain refractory to medical management significantly reduces patients' quality of life. In recent years, ablative surgery has seen a resurgence in treating diffuse and focal cancer pain in terminal patients. The anterior cingulate gyrus has been a key focus as it plays a role in the cognitive and emotional processing of pain. While radiofrequency ablation of the dorsal anterior cingulate is well described for treating cancer pain, MRI-guided laser-induced thermal therapy (LITT) is novel. Our paper describes a patient treated with an MRI-guided LITT therapy of the anterior cingulate gyrus for intractable debilitating pain secondary to terminal metastatic cancer.

Ablation Procedures

Although ablation has a limited role in the management of chronic noncancer pain, ablation continues to help patients with treatment of refractory cancer-related pain. Interdisciplinary treatment involving supportive care, pain medicine, oncology, and neurosurgery is critical to optimizing the timing and outcome of neurosurgical ablative options for pain management. In this review, 3 targets for ablative surgery-the spinothalamic tract, the dorsal column's visceral pain pathway, and the anterior cingulate cortex-are discussed with a focus on patient selection and key aspects of surgical technique.

Event-based control of autonomic and emotional states by the anterior cingulate cortex

Despite being an intensive area of research, the function of the anterior cingulate cortex (ACC) remains somewhat of a mystery. Human imaging studies implicate the ACC in various cognitive functions, yet surgical ACC lesions used to treat emotional disorders have minimal lasting effects on cognition. An alternative view is that ACC regulates autonomic states, consistent with its interconnectivity with autonomic control regions and that stimulation evokes changes in autonomic/emotional states. At the cellular level, ACC neurons are highly multi-modal and promiscuous, and can represent a staggering array of task events. These neurons nevertheless combine to produce highly event-specific ensemble patterns that likely alter activity in downstream regions controlling emotional and autonomic tone. Since neuromodulators regulate the strength of the ensemble activity patterns, they would regulate the impact these patterns have on downstream targets. Through these mechanisms, the ACC may determine how strongly to react to the very events its ensembles represent. Pathologies arise when specific event-related representations gain excessive control over autonomic/emotional states.

Brain circuits for pain and its treatment

[Figure: see text].

Neurosurgical Treatments for Cancer Pain

Cancer-related pain is a uniquely challenging entity for treating practitioners for a variety of reasons, including its often severe and medically refractory nature, the emotional and social circumstances surrounding the disease process, and the frequently associated limited life expectancy.

Neocortical circuits in pain and pain relief

The sensory, associative and limbic neocortical structures play a critical role in shaping incoming noxious inputs to generate variable pain perceptions. Technological advances in tracing circuitry and interrogation of pathways and complex behaviours are now yielding critical knowledge of neocortical circuits, cellular contributions and causal relationships between pain perception and its abnormalities in chronic pain. Emerging insights into neocortical pain processing suggest the existence of neocortical causality and specificity for pain at the level of subdomains, circuits and cellular entities and the activity patterns they encode. These mechanisms provide opportunities for therapeutic intervention for improved pain management.

The American Society of Pain and Neuroscience (ASPN) Best Practices and Guidelines for the Interventional Management of Cancer-Associated Pain

Moderate to severe pain occurs in many cancer patients during their clinical course and may stem from the primary pathology, metastasis, or as treatment side effects. Uncontrolled pain using conservative medical therapy can often lead to patient distress, loss of productivity, shorter life expectancy, longer hospital stays, and increase in healthcare utilization. Various publications shed light on strategies for conservative medical management for cancer pain and a few international publications have reviewed limited interventional data. Our multi-institutional working group was assembled to review and highlight the body of evidence that exists for opioid utilization for cancer pain, adjunct medication such as ketamine and methadone and interventional therapies. We discuss neurolysis via injections, neuromodulation including targeted drug delivery and spinal cord stimulation, vertebral tumor ablation and augmentation, radiotherapy and surgical techniques. In the United States, there is a significant variance in the interventional treatment of cancer pain based on fellowship training. As a first of its kind, this best practices and interventional guideline will offer evidenced-based recommendations for reducing pain and suffering associated with malignancy.

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.

The anterior cingulate cortex and event-based modulation of autonomic states

In spite of being an intensive area of research focus, the anterior cingulate cortex (ACC) remains somewhat of an enigma. Many theories have focused on its role in various aspects of cognition yet surgically precise lesions of the ACC, used to treat severe emotional disorders in human patients, typically have no lasting effects on cognition. An alternative view is that the ACC has a prominent role in regulating autonomic states. This view is consistent with anatomical data showing that a main target of the ACC are regions involved in autonomic control and with the observation that stimulation of the ACC evokes changes in autonomic states in both animals and humans. From an electrophysiological perspective, ACC neurons appear able to represent virtually any event or internal state, even though there is not always a strong link between these representations and behavior. Ensembles of neurons form robust contextual representations that strongly influence how specific events are encoded. The activity patterns associated with these contextually-based event representations presumably impact activity in downstream regions that control autonomic state. As a result, the ACC may regulate the autonomic and perhaps emotional reactions to events it is representing. This event-based control of autonomic tone by the ACC would likely arise during all types of cognitive and affective processes, without necessarily being critical for any of them.

Neuroablative surgical treatments for pain due to cancer

Cancer pain is common and challenging to manage - it is estimated that approximately 30% of cancer patients have pain that is not adequately controlled by analgesia. This paper discusses safe and effective neuroablative treatment options for refractory cancer pain. Current management of cancer pain predominantly focuses on the use of medications, resulting in a relative loss of knowledge of these surgical techniques and the erosion of the skills required to perform them. Here, we review surgical methods of modulating various points of the neural axis with the aim to expand the knowledge base of those managing cancer pain. Integration of neuroablative approaches may lead to higher rates of pain relief, and the opportunity to dose reduce analgesic agents with potential deleterious side effects. With an ever-increasing population of cancer patients, it is essential that neurosurgeons maintain or train in these techniques in tandem with the oncological multi-disciplinary team.

Tailoring of neurosurgical ablative procedures in the management of refractory cancer pain

INTRODUCTION

Neurosurgical ablative procedures can offer immediate and effective pain relief for patients suffering from refractory cancer pain. However, choosing the appropriate procedure for each patient may not be straightforward and warrants an interdisciplinary approach. The purpose of the current study was to evaluate the outcome of patients with cancer who were carefully selected for neurosurgical intervention by a dedicated interdisciplinary team composed of a palliative physician and nurse practitioner, a pain specialist and a neurosurgeon.

METHODS

A retrospective review was carried out on all patients who underwent neurosurgical ablative procedures in our institute between March 2015 and September 2019. All patients had advanced metastatic cancer with unfavorable prognosis and suffered from intractable oncological pain. Each treatment plan was devised to address the patients' specific pain syndromes.

RESULTS

A total of 204 patients were examined by our service during the study period. Sixty-four patients with localized pain and nineteen patients with diffuse pain syndromes were selected for neurosurgical interventions, either targeted disconnection of the spinothalamic tract or stereotactic cingulotomy. Substantial pain relief was reported by both groups immediately (cordotomy: Numerical Rating Scale (NRS) 9 ≥1, p=0.001, cingulotomy: NRS 9 ≥2, p=0.001) and maintained along the next 3-month follow-up visits.

CONCLUSIONS

An interdisciplinary collaboration designated to provide neurosurgical ablative procedures among carefully selected patients could culminate in substantial relief of intractable cancer pain.

TRIAL REGISTRATION NUMBER

IR0354-17.

Neurosurgical ablative procedures for intractable cancer pain

OBJECTIVE

Cancer patients suffering from severe refractory pain may benefit from targeted ablative neurosurgical procedures aimed to disconnect pain pathways in the spinal cord or the brain. These patients often present with a plethora of medical problems requiring careful consideration before surgical interventions. The authors present their experience at an interdisciplinary clinic aimed to facilitate appropriate patient selection for neurosurgical procedures, and the outcome of these interventions.

METHODS

This study was a retrospective review of all patients who underwent neurosurgical interventions for cancer pain in the authors' hospital between March 2015 and April 2018. All patients had advanced metastatic cancer with limited life expectancy and suffered from intractable oncological pain.

RESULTS

Sixty patients underwent surgery during the study period. Forty-three patients with localized pain underwent disconnection of the spinal pain pathways: 34 percutaneous-cervical and 5 open-thoracic cordotomies, 2 stereotactic mesencephalotomies, and 2 midline myelotomies. Thirty-nine of 42 patients (93%) who completed these procedures had excellent immediate postoperative pain relief. At 1 month the improvement was maintained in 30/36 patients (83%) available for follow-up. There was 1 case of hemiparesis.Twenty patients with diffuse pain underwent stereotactic cingulotomy. Nineteen of these patients reported substantial pain relief immediately after the operation. At 1 month good pain relief was maintained in 13/17 patients (76%) available for follow-up, and good pain relief was also found at 3 months in 7/11 patients (64%). There was no major morbidity or mortality.

CONCLUSIONS

With careful patient selection and tailoring of the appropriate procedure to the patient's pain syndrome, the authors' experience indicates that neurosurgical procedures are safe and effective in alleviating suffering in patients with intractable cancer pain.

Ablative brain surgery: an overview

Background: Ablative therapies have been used for the treatment of neurological disorders for many years. They have been used both for creating therapeutic lesions within dysfunctional brain circuits and to destroy intracranial tumors and space-occupying masses. Despite the introduction of new effective drugs and neuromodulative techniques, which became more popular and subsequently caused brain ablation techniques to fall out favor, recent technological advances have led to the resurgence of lesioning with an improved safety profile. Currently, the four main ablative techniques that are used for ablative brain surgery are radiofrequency thermoablation, stereotactic radiosurgery, laser interstitial thermal therapy and magnetic resonance-guided focused ultrasound thermal ablation. Object: To review the physical principles underlying brain ablative therapies and to describe their use for neurological disorders. Methods: The literature regarding the neurosurgical applications of brain ablative therapies has been reviewed. Results: Ablative treatments have been used for several neurological disorders, including movement disorders, psychiatric disorders, chronic pain, drug-resistant epilepsy and brain tumors. Conclusions: There are several ongoing efforts to use novel ablative therapies directed towards the brain. The recent development of techniques that allow for precise targeting, accurate delivery of thermal doses and real-time visualization of induced tissue damage during the procedure have resulted in novel techniques for cerebral ablation such as magnetic resonance-guided focused ultrasound or laser interstitial thermal therapy. However, older techniques such as radiofrequency thermal ablation or stereotactic radiosurgery still have a pivotal role in the management of a variety of neurological disorders.

Interventional Techniques to Management of Cancer-Related Pain: Clinical and Critical Aspects

Interventional techniques to manage cancer-related pain may be efficient treatment modalities in patients unresponsive or unable to tolerate systemic opioids. However, indication and selection of the right technique demand knowledge, which is still incipient among clinicians. The present article summarizes the current evidence regarding the five most essential groups of interventional techniques to treat cancer-related pain: Neuraxial analgesia, minimally invasive procedures for vertebral pain, sympathetic blocks for abdominal cancer pain, peripheral nerve blocks, and percutaneous cordotomy. Furthermore, indication, mechanism, drug agents, contraindications, and complications of the main techniques of each group are discussed.