RESUMO
Neuropathic pain (NP), resulting from damage to the somatosensory system, is characterized by either spontaneous or evoked pain. In the context of NP, wherein aberrant signaling pathways contribute to the perception of pain, the thalamus emerges as a key player. This structure is integral to the pain network that includes connections to the dorsal horn of the spinal cord, highlighting its role in the affective-motivational aspects of pain perception. Given its significant involvement, the thalamus is targeted in advanced treatments such as thalamotomy and deep brain stimulation (DBS) when traditional therapies fail, emphasizing the need to understand its function in NP to improve management strategies. This review aimed to provide an overview of the role of the thalamus in the transmission of nociceptive information in NP by discussing the existing evidence, including the effectiveness and safety of current techniques in the management and treatment of NP. This is an integrative review involving the qualitative analysis of scientific articles published in PubMed/MEDLINE, Embase, Scopus, and Web of Science. A total of 687 articles were identified, and after selection, 15 articles were included in this study. All studies reviewed demonstrated varying degrees of effectiveness of DBS and thalamotomy in alleviating painful symptoms, although the relief was often temporary. Many studies noted a reduction in pain perception at the conclusion of treatment compared to pre-treatment levels, with this decrease maintained throughout patient follow-ups. However, adverse events associated with these treatments were also reported. In conclusion, there are some benefits, albeit temporary, to using thalamotomy and DBS to alleviate the painful symptoms of NP. Both procedures are considered advanced forms of surgical intervention that aim to modulate pain pathways in the brain, providing significant relief for patients suffering from chronic pain resistant to conventional treatment. Despite limitations, these surgical interventions offer renewed hope for patients facing disabling chronic pain and can provide a significant improvement in quality of life.
RESUMO
Chronic pain affects a substantial portion of the global population, significantly impacting quality of life and well-being. This condition involves complex mechanisms, including dysfunction of the autonomic nervous system, which plays a crucial role in pain perception. The insula, a key brain region involved in pain processing, plays a critical role in pain perception and modulation. Lesions in the insula can result in pain asymbolia, where pain perception remains intact but emotional responses are inappropriate. The insula is anatomically and functionally divided into anterior and posterior regions, with the posterior insula processing nociceptive input based on intensity and location before relaying it to the anterior insula for emotional mediation. Understanding the insula's intricate role in pain processing is crucial, as it is involved in encoding prediction errors and mediating emotional dimensions of pain perception. The focus of this review was on synthesizing existing literature on the role of the insula in chronic pain and associated structural changes. The goal was to integrate findings from various sources to provide a comprehensive overview of the topic. The search strategy included a combination of Medical Subject Headings (MeSH) and relevant keywords related to insula and chronic pain. The following databases were surveyed: PubMed, Embase, Scopus, and Web of Science. We identified a total of 2515 articles, and after following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline based on eligibility criteria, 46 articles were used to synthesize this review. Our study highlights the pivotal role of the insula in chronic pain processing and associated structural changes, integrating findings from diverse studies and neuroimaging investigations. Beyond mere pain sensation, the insula contributes to emotional awareness, attention, and salience detection within the pain network. Various chronic pain conditions reveal alterations in insular activity and connectivity, accompanied by changes in gray matter volume and neurochemical profiles. Interventions targeting the insula show promise in alleviating chronic pain symptoms. However, further research is needed to understand underlying mechanisms, which can aid in developing more effective therapeutic interventions for pain.
RESUMO
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.
