Neuroablative Procedures Research Articles

Surgical Options for Treatment of Medically Intractable Neuropathic Facial Pain: An Outcome Assessment Study

Abstract Background Facial pain is a common condition with a worldwide prevalence of 10-25% in adults. It often us a serious condition that can have a significant impact on patients’ daily life activities. The three main categories of facial pain are trigeminal neuralgia, trigeminal neuropathic pain and persistent idiopathic facial pain. To date, trigeminal neuropathy remains a potentially surgical pathology for the purpose of pain control with poor response to medical treatment. Aim and Objectives The aim of this study is to present our experience in the management of different pathologies of trigeminal neuropathy and to review the effectiveness and long-term efficacy of the different surgical procedures. Subjects and Methods This is a mixed prospective-retrospective study conducted at Ain Shams University (ASU) hospital and Oregon Health and Science University (OHSU) during the period from December 2012 till July 2020 for the retrospective part and from January 2019 till September 2021 for the prospective part. Patients with neuropathic facial pain treated during this time frame were included in the study. Result 28 patients were included in this study. They underwent 40 surgical interventions for the management of different categories of trigeminal neuropathy. Neuro-modulatory procedures were performed in 9 patients (3 ucSCS and 6 PNS) while neuro-ablative procedures were performed in 19 patients. Median time to pain recurrence after SCS device implantation for the neuropathic trigeminal neuralgia was 19.5 months. For the patients treated with PNS, 2 out of 6 of patients had satisfactory pain relief, whereas half of the patients had no improvement. Overall median time to pain recurrence after CT guided T/N was 5.6 months. In the cohort of patients treated with caudalis DREZ, 4 patients out of 6 had grade I pain relief at last follow up and the overall median time to pain recurrence was 3.9 months. Conclusion Trigeminal neuropathy is a difficult to treat entity of facial pain syndromes. Although many neuro- modulatory and neuro-ablative interventions are available in the armamentarium for the treatment of such pathology, outcomes remain suboptimal. Pain relief in the immediate postoperative period is usually higher than at last follow up which is a common finding in after these interventions. The long-term efficacy of most available interventions does not meet patients’ satisfaction.

Trigeminal neuralgia.

Trigeminal neuralgia (TN) is a facial pain disorder characterized by intense and paroxysmal pain that profoundly affects quality of life and presents complex challenges in diagnosis and treatment. TN can be categorized as classical, secondary and idiopathic. Epidemiological studies show variable incidence rates and an increased prevalence in women and in the elderly, with familial cases suggesting genetic factors. The pathophysiology of TN is multifactorial and involves genetic predisposition, anatomical changes, and neurophysiological factors, leading to hyperexcitable neuronal states, central sensitization and widespread neural plasticity changes. Neurovascular compression of the trigeminal root, which undergoes major morphological changes, and focal demyelination of primary trigeminal afferents are key aetiological factors in TN. Structural and functional brain imaging studies in patients with TN demonstrated abnormalities in brain regions responsible for pain modulation and emotional processing of pain. Treatment of TN involves a multifaceted approach that considers patient-specific factors, including the type of TN, with initial pharmacotherapy followed by surgical options if necessary. First-line pharmacological treatments include carbamazepine and oxcarbazepine. Surgical interventions, including microvascular decompression and percutaneous neuroablative procedures, can be considered at an early stage if pharmacotherapy is not sufficient for pain control or has intolerable adverse effects or contraindications.

Outcomes and Predictors of Response to Pregabalin for the Treatment of Post-Traumatic Trigeminal Neuropathic Pain Following Neuroablative Procedures: A Retrospective Observational Study

BACKGROUND: Post-traumatic trigeminal neuropathic pain (PTNP) following trigeminal neuralgia (TN)-related neuroablative procedures is relatively rare. Due to the fear of debilitating complications, its treatment has been generally suboptimal. Pregabalin (PGB) has been reported to relieve neuropathic pain. However, the potential role of PGB and the predictors of response of PGB use as a strategy in the treatment of PTNP following TN-related neuroablative procedures have not been identified yet. OBJECTIVES: To report the efficacy and safety of PGB and the identification of predictors of PGB for PTNP following TN-related neuroablative procedures. STUDY DESIGN: Monocentric, retrospective, observational study. SETTING: This study consecutively enrolled patients with PTNP following TN-related neuroablative procedures who were prescribed PGB at Beijing Tiantan Hospital. METHODS: From January 2018 to June 2022, a total of 112 patients were included in this study, of whom 10 were excluded because of incomplete follow-up data and side effects immediately after taking PGB. Final analysis included 102 patients. Demographic data, pain-related baseline data, efficacy of patients with PTNP after one month of PGB evaluated by the Barrow Neurological Institute (BNI) scores for pain, and side effects of PGB were extracted and analyzed. The predictors of pain-relieving effects of PGB were identified by logistic regression analysis. RESULTS: Within one month after the use of PGB alone, 29 out of the 102 (28.4%) patients achieved pain relief with a significant reduction in the BNI scores (P < 0.01). All of the 73 patients who did not respond to PGB monotherapy either switched to other medications (n = 8) or combined additional oral medications to the existing PGB therapy (n = 65). The main side effect of PGB in our study was dizziness. Binary logistic regression analysis showed that longer disease durations (Adjusted odds ratio [OR] = 0.55, 95% confidence interval [CI] 0.43 to 0.72, P = 0.000) and higher Hospital Anxiety and Depression Scale (HADS) scores (Adjusted OR = 0.29, 95% CI 0.10 to 0.87, P = 0.022) were poor predictors of response to PGB. LIMITATIONS: This was a retrospective observational study. Long-term efficacy and safety of PGB in the treatment of PTNP patients were not evaluated. CONCLUSIONS: This study confirms that PGB monotherapy is not a very effective treatment for PTNP following TN-related neuroablative procedures. PGB was more beneficial in patients with shorter disease durations and lower HADS scores. KEY WORDS: Post-traumatic trigeminal neuropathic pain, efficacy, safety, predictor of response, pregabalin

Neurosurgical interventions for cancer pain.

Half of all cancer patients will develop cancer-related pain, and a fifth of these patients will continue to experience pain refractory to maximal pharmacological therapy. This, together with the opioid crisis, has prompted a resurgence in neurosurgical treatments. Neuromodulatory or neuroablative procedures are largely used for various nonmalignant, chronic pain conditions, but there is growing evidence to support their use in cancer pain. This review aims to cover the main neurosurgical treatments that may prove useful in the changing sphere of cancer pain treatment. Neuromodulation techniques for pain have largely replaced neuroablation in neurosurgical practice due to the higher risk of inadvertent permanent neurological deficits from the latter. When compared to neuroablative approaches for severe treatment-refractory cancer pain, neuromodulation is more expensive (largely due to implant cost) and requires more follow-up, with greater engagement needed from the health service, the patient and their carers. Furthermore, neuroablation has a more rapid onset of effect. Neuromodulation techniques for pain have largely replaced neuroablation in neurosurgical practice due to the higher risk of inadvertent permanent neurological deficits from the latter. Whilst this approach is beneficial when treating nonmalignant pain, neuromodulation in patients with pain related to advanced cancer still has a limited role. Neuroablative procedures are less expensive, require less follow-up, and can have a lower burden on health services, patients and their carers.

155 Cost-Effectiveness Analysis of Deep Brain Stimulation Versus Treatment as Usual for Treatment-Resistant Obsessive-Compulsive Disorder

INTRODUCTION: Deep brain stimulation (DBS) is an effective neurosurgical option for patients with treatment-resistant obsessive-compulsive disorder (TROCD). Despite being more costly than neuroablative procedures of comparable efficacy, DBS has gained popularity for its reversibility. Though its cost-effectiveness has been investigated in movement disorders, few economic analyses of DBS for psychiatric disorders exist. METHODS: We developed decision analytic models to compare the cost-effectiveness of DBS to treatment as usual (TAU) for TROCD, varying device type (non-rechargeable or rechargeable) or time-horizon (three or five years). Effectiveness data were based on literature review. Published algorithms were used to convert Y-BOCS scores into utilities. Costs were approached from the healthcare sector perspective and drawn from Medicare reimbursement rates. Monte Carlo (MC) simulations and probabilistic sensitivity analyses were performed to estimate the incremental cost-effectiveness ratio (ICER) in USD ($) per quality-adjusted life-year (QALY). RESULTS: We included 238 and 265 TROCD patients across 28 studies who underwent DBS and had sufficient follow-up in our 3- and 5-year models, respectively. Non-rechargeable DBS was less cost-effective than TAU (3-year ICER = $153,221/QALY; 5-year ICER = $194,043/QALY). Rechargeable DBS was moderately more cost-effective at three years (ICER = $70,646/QALY) and definitively more cost-effective at five years (ICER = $37,652/QALY) compared to TAU. At three and five years, net QALYs gained were greater in DBS than TAU by 0.36 and 0.59, respectively. At willingness-to-pay thresholds of $50,000/QALY for definitive cost-effectiveness and $100,000/QALY for moderate cost-effectiveness, rechargeable DBS was moderately more cost-effective than TAU at 3 years in 100% and more cost-effective at 5 years in 96% of iterations. CONCLUSIONS: Compared to TAU, in the U.S., rechargeable DBS for TROCD is more cost-effective under a range of possible cost and effectiveness values. However, non-rechargeable DBS is not more cost-effective than TAU for TROCD due to high costs of battery replacement.

Durable patient-reported outcomes following 60-day percutaneous peripheral nerve stimulation (PNS) of the medial branch nerves

BackgroundChronic low back pain (CLBP) is often associated with clinical evidence of central nervous system sensitization and finding a clear source of nociceptive input can be challenging. Conventional therapies targeting peripheral spinal pain structures can fail to address centrally-mediated, underlying causes of pain. Sixty-day percutaneous peripheral nerve stimulation (PNS) applied to the lumbar medial branch nerves is a non-surgical, non-opioid treatment that may restore the balance of peripheral inputs to the central nervous system and reverse maladaptive changes in central pain processing. As a minimally invasive, non-destructive treatment, percutaneous PNS was designed to be used earlier in the treatment continuum than radiofrequency ablation or permanently-implanted neurostimulation systems. ObjectiveThe objective of this clinical trial was to characterize the durability of responses to medial branch PNS in a prospective multicenter case series study of CLBP patients recalcitrant to multiple non-surgical treatments. DesignProspective, multicenter clinical trial. PopulationAdults with CLBP without radicular leg pain who had previously failed multiple types of conventional treatments. InterventionSixty-day percutaneous PNS applied to the lumbar medial branch nerves. MethodsPercutaneous PNS leads were implanted under image guidance (ultrasound and/or fluoroscopy) and treatment was applied for up to 60 days, after which the leads were removed. Participants were followed through 14 months (12 months after the 2-month PNS treatment). Prospectively-defined endpoints included assessments of pain intensity, disability, pain interference, health-related quality of life, depression, and patient global impression of change. ResultsTreatment of CLBP with 60-day percutaneous PNS treatment produced clinically meaningful improvements in average pain intensity, disability, and/or pain interference for a majority of participants through the entire 14 month follow up period without requiring permanent system implantation. The proportion of participants experiencing clinically meaningful improvement in at least one outcome (pain intensiy, disability, pain interference) with PNS was 91% after 2 months, 79% at 5 months, 73% at 8 months, 75% at 11 months, and 77% at 14 months. There were no serious or unanticipated study-related adverse events. ConclusionThis prospective multicenter clinical trial demonstrates the clinical utility of percutaneous PNS when applied to the medial branch nerves for the treatment of chronic low back pain recalcitrant to non-surgical treatments. Given the minimally invasive nature of percutaneous PNS and the significant benefits experienced by participants, percutaneous PNS provides a safe and effective first-line neuromodulation treatment for patients with CLBP that may obviate the need for neuroablative procedures or permanent neurostimulation system implantation.

Cervical Spinal Cord Stimulation for Trigeminal Neuralgia: a Narrative Review.

Trigeminal neuralgia (TN) is a chronic neuropathic pain condition affecting one or more divisions of the fifth cranial (trigeminal) nerve. TN is defined by recurrent unilateral electric shock-like pain that is abrupt in both onset and termination. The pain is triggered by innocuous sensory stimuli and is classified as either classic TN, related to vascular compression; secondary TN, due to a tumor along the trigeminal nerve or an underlying disease like multiple sclerosis; or idiopathic TN. Among the various therapies available for TN, carbamazepine remains the first-line treatment. Newer medications have demonstrated efficacy in patients who do not respond to or cannot tolerate carbamazepine. When medical management and neuroablative procedures fail, spinal cord stimulation (SCS) serves as a promising and popular option, with an estimated 34,000 SCS procedures performed annually worldwide. SCS employs the implantation of electrical leads in the epidural space to manage pain. A review of literature was conducted to explore the use of cervical spinal cord stimulation (SCS) for the treatment of trigeminal neuralgia. A MEDLINE/PubMed search using the search terms "spinal cord stimulation" and "trigeminal neuralgia" was employed to find any case reports and research studies (retrospective studies, double-blinded studies, observational studies) on the topic. No date limiters were used for the search. The initial search resulted in 76 non-duplicate entries from the database. After application of the search criteria, 58 studies were excluded because they were not relevant to the study. A further detailed review of the included articles was conducted by all the reviewers. During this phase of the review, additional 6 studies were excluded. A total of 11 studies were included: 7 case reports and 4 retrospective review studies. In the review, we discuss 7 different case reports on the use of cervical SCS for trigeminal neuralgia and an additional 4 retrospective studies reviewing outcomes and pain relief in patients who underwent treatment. The case reports and retrospective studies reviewed demonstrated that TN patients realized > 50% pain relief following permanent electrode implantation. In all the cases discussed, complications from SCS were rare and/or not reported. Additionally, most of the cases report that patients who had adequate pain relief from SCS were able to wean off, or significantly reduce, oral medications given the vast improvement in pain reduction. Cervical spinal cord stimulation (SCS) is a safe and effective procedure for patients with trigeminal neuralgia (TN) who have refractory pain despite the use of medications. In many cases, the procedure provides an adequate level of pain relief with very few complications or side effects. The vast majority of current research on the use of cervical SCS for TN currently consists of case reports and retrospective analysis. In order to further evaluate the efficacy of SCS for treatment, large-scale randomized controlled studies or observational studies need to be conducted to properly evaluate SCS as a treatment modality for trigeminal neuralgia.

Novel Therapies for the Treatment of Neuropathic Pain: Potential and Pitfalls.

Neuropathic pain affects more than one million people across the globe. The quality of life of people suffering from neuropathic pain has been considerably declining due to the unavailability of appropriate therapeutics. Currently, available treatment options can only treat patients symptomatically, but they are associated with severe adverse side effects and the development of tolerance over prolonged use. In the past decade, researchers were able to gain a better understanding of the mechanisms involved in neuropathic pain; thus, continuous efforts are evident, aiming to develop novel interventions with better efficacy instead of symptomatic treatment. The current review discusses the latest interventional strategies used in the treatment and management of neuropathic pain. This review also provides insights into the present scenario of pain research, particularly various interventional techniques such as spinal cord stimulation, steroid injection, neural blockade, transcranial/epidural stimulation, deep brain stimulation, percutaneous electrical nerve stimulation, neuroablative procedures, opto/chemogenetics, gene therapy, etc. In a nutshell, most of the above techniques are at preclinical stage and facing difficulty in translation to clinical studies due to the non-availability of appropriate methodologies. Therefore, continuing research on these interventional strategies may help in the development of promising novel therapies that can improve the quality of life of patients suffering from neuropathic pain.

Combined Unilateral Radiofrequency Lesioning of the Motor Thalamus, Field of Forel, and Zona Incerta: A Series of Cases With Dystonia.

Dystonia is a group of disorders characterized by involuntary slow repetitive twisting movements and/or abnormal posture. Surgical options such as neuromodulation through deep brain stimulation and neuroablative procedures are available for patients who do not respond to conservative treatment. To present our series of patients with dystonia who were treated with stereotactic combined unilateral radiofrequency lesioning of the motor thalamus, field of Forel, and zona incerta. Medical records of 50 patients with dystonia who were treated with unilateral combined lesions were reviewed. Outcomes of the surgical procedure were evaluated using the Burke-Fahn-Marsden Dystonia Rating Scale (with movement and disability subscales) and Unified Parkinson's Disease Rating Scale-tremor items. Based on the symptoms, patients were categorized as having generalized dystonia (34%), hemidystonia (30%), and dystonic tremor (DT) (36%). Primary/idiopathic dystonia, primary genetic/hereditary dystonia, and secondary dystonia accounted for 16%, 4%, and 80% of patients, respectively. The mean follow-up duration was 156.2 ± 88.9 mo. The overall improvement in the Burke-Fahn-Marsden Dystonia Rating Scale scores (movement and disability, respectively) was 57.8% and 36.4% in generalized dystonia, 60.0% and 45.8% in hemidystonia, and 65.6% and 56.8% in DT. Patients with DT showed an 83.3% improvement in mean Unified Parkinson's Disease Rating Scale tremor score. Patients with cerebral palsy showed mean improvements of 66.7% in movement scores and 50.8% in disability scores. No mortality or major morbidity was observed postoperatively. Stereotactic radiofrequency unilateral combined thalamotomy, campotomy, and zona incerta lesions may be an effective surgical alternative for patients with dystonia, especially those with secondary dystonia resistant to deep brain stimulation.

Commentary: 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.

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

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

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

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

Advances in the interventional management of neuropathic pain

The management of neuropathic pain, defined as pain as a result of a lesion or disease in the somatosensory nervous system, continues to be researched and explored. As conventional methods demonstrate limited long-term efficacy, there is a significant need to discover therapies that offer both longitudinal and sustained management of this highly prevalent disease, which can be offered through interventional therapies. Tricyclic antidepressants (TCAs), gabapentinoids, lidocaine, serotonin norepinephrine reuptake inhibitors (SNRIs), and capsaicin have been shown to be the most efficacious pharmacologic agents for neuropathic pain relief. With respect to infusion therapies, the use of intravenous (IV) ketamine could be useful for complex regional pain syndrome, fibromyalgia, and traumatic spinal cord injury. Interventional approaches such as lumbar epidurals are a reasonable treatment choice for up to 3 months of pain relief for patients who failed to respond to conservative treatment, with a “B” strength of recommendation and moderate certainty. Neuroablative procedures like pulsed radiofrequency ablation work by delivering electrical field and heat bursts to targeted nerves or tissues without permanently damaging these structures, and have been recently explored for neuropathic pain relief. Alternatively, neuromodulation therapy is now recommended as the fourth line treatment of neuropathic pain after failed pharmacological therapy but prior to low dose opioids. Finally, the intrathecal delivery of various pharmacologic agents, such as quinoxaline-based kappa-opioid receptor agonists, can be utilized for neuropathic pain relief. In this review article, we aim to highlight advances and novel methods of interventional management of neuropathic pain.

Stereotactic radiofrequency ventral posterolateral thalamotomy for cancer pain.

Palliative neuroablative procedures are often performed for medication-refractory cancer pain. A 57-year-old female with lung carcinoma and metastases to the brachial plexus and cervical spine with severe neuropathic pain affecting the right upper limb was referred to the authors’ functional neurosurgery service. This video shows her treatment with an awake stereotactic radiofrequency thalamotomy targeting the left ventral posterolateral nucleus. Postoperatively, she experienced immediate and complete resolution of the pain. Palliative radiofrequency thalamotomy can be a viable and effective procedure for somatotopically distributed regional cancer pain.The video can be found here: https://youtu.be/jykYWXTP3c4

Effectiveness and safety of neuroablation for severe and treatment-resistant obsessive-compulsive disorder: a systematic review and meta-analysis.

Several neuroablative procedures are available for severe and treatment-resistant obsessive-compulsive disorder (OCD), but limited knowledge about their relative clinical advantages and disadvantages poses obstacles for treatment decision-making. We searched PubMed, Embase, Scopus, Web of Knowledge and the Cochrane Library for reports up to February 2019. We reviewed the literature on the effectiveness (assessed using the Yale-Brown Obsessive Compulsive Scale [Y-BOCS]) and safety of various neuroablative interventions for severe and treatment-resistant OCD. We included 23 studies involving 487 patients in the systematic review; 21 studies with 459 patients entered meta-analysis. Overall, neuroablation achieved a response rate (proportion of patients with ≥ 35% reduction in Y-BOCS) of 55%. Most of the adverse events (88.4%) were mild and transient. The top 3 adverse events were headache (14.9%), cognitive deficits (9.1%) and behaviour problems (8.1%). Severe or permanent adverse events included personality changes (2.3%) and brain edema or brain cyst (1.5%). The response rates associated with capsulotomy, limbic leucotomy and cingulotomy were 59% (95% confidence interval [CI] 54-65), 47% (95% CI 23-72) and 36% (95% CI 23-50), respectively. Interventions with different coverages of the dorsal part of the internal capsule were associated with different adverse-event profiles but were unlikely to modify clinical effectiveness. The level of evidence of most included studies was relatively low. Ablative surgeries are safe and effective for a large proportion of patients with severe and treatment-resistant OCD. Among the available procedures, capsulotomy seemed to be the most effective. Further research is needed to improve clinical effectiveness and minimize risks.

Abstract P-395: A STRUCTURED APPROACH TO REFRACTORY PAIN AND OTHER DISTRESSING SYMPTOMS IN CRITICALLY-ILL CHILDREN

Aims & Objectives: Pain refractory to properly titrated multimodal analgesics, and other difficult-to-control distressing symptoms may occur in the PICU, usually in children with advanced cancer causing malignant effusions, obstruction or osseous metastases, and in children with sequelae of neurologic disorders. This may constitute a barrier to transfer to other healthcare settings. Methods Methods: A literature search was performed utilizing the PubMed engine through January of 2018, querying terms relevant to refractory symptoms in critically-ill patients. Results There is an emerging body of experience in critical care. Impeccable assessment, appropriate integration of pharmacologic (non-opioid, opioid and adjuvant medications) and non-pharmacologic (integrative) measures consistent with WHO guidelines are key. Inadequate perioperative analgesia may precipitate refractory pain and dystonia. Delirium, opioid-associated neurotoxicity and hyperalgesia should be considered when escalating pain is encountered. Titratable intravenous agents may be effective. Dexmedetomidine, along with environmental measures, may mitigate delirium. This agent, Ketamine and lidocaine can be transitioned to enteral formulations or analogs, facilitating transfer. Medications (dexamethasone, octreotide) and Interventions to vent, stent and decompress may palliate malignant effusions or obstruction. Neuroaxial (epidural, intrathecal) techniques using opioids, adjuvants or ziconotide may be appropriate. Recently described image-guided percutaneous neuroablative procedures (myelotomy, cordotomy) appear to be safe and effective. Respite (overnight) or intermittent (hours / days) sedation can be attempted in selected patients prior to institution of traditional unidirectional, continuous palliative sedation. Conclusions A structured, multidisciplinary, individualized approach to care may achieve rapid control of complex symptoms, facilitating transfer from PICU to other inpatient or hospice settings.

Recent data from radiofrequency denervation trials further emphasise that treating nociception is not the same as treating pain

Persistent low back pain (LBP) is the leading cause of disability globally, for which ever-larger increases in healthcare expenditure have not made a difference in terms of prevalence or burden.1...

Minimally invasive procedures for neuropathic pain.

Neuropathic pain is "pain arising as a direct consequence of a lesion or disease affecting the somatosensory system". The prevalence of neuropathic pain ranges from 7 to 11% of the population and minimally invasive procedures have been used to both diagnose and treat neuropathic pain. Diagnostic procedures consist of nerve blocks aimed to isolate the peripheral nerve implicated, whereas therapeutic interventions either modify or destroy nerve function. Procedures that modify how nerves function include epidural steroid injections, peripheral nerve blocks and sympathetic nerve blocks. Neuroablative procedures include radiofrequency ablation, cryoanalgesia and neurectomies. Currently, neuromodulation with peripheral nerve stimulators and spinal cord stimulators are the most evidence-based treatments of neuropathic pain.

Novel therapies in the treatment of Parkinsons disease

Although various effective treatments for Parkinsons disease are available, novel therapies targeting the different pathways that lead to cell dysfunction and death are still required. Some of these pathways that have been implicated so far include mitochondrial dysfunction, oxidative stress, kinase pathways, calcium dysregulation, inflammation, protein handling and prion-like processes. Safinamide, currently in phase III clinical trials for the treatment of PD, is a unique molecule with multiple mechanisms of action and a very high therapeutic index. It combines potent, selective, and reversible inhibition of MAO-B with blockade of voltage-dependent Na+ and Ca2+ channels and inhibition of glutamate release. Several of these proposed newer agents have innovative mechanisms of action (increase mitochondrial biogenesis, reduce apoptosis, upregulation of heat shock proteins, increase endosomal release and uptake of ? synuclein by recipient cells.) Finally, surgical-based approaches such as deep brain stimulation , neuroablative procedures such as thalamotomy and pallidotomy and neural transplantation are other potential treatments. However, technical improvements in these procedure are required to address procedural safety concerns.

The Surgical Treatment of Trigeminal Neuralgia

Trigeminal Neuralgia is a clinical presentation of different diseases, defined in the last edition of the International Classification of Headache Disorders (ICHD-3) as “Classical Trigeminal Neuralgia” and “Painful Trigeminal Neuropathy”. In both groups typical and atypical clinical findings are present. They must be taking into consideration for defining a correct clinical diagnosis. In addition MRI findings and other objective signs allow to disclose the Etiology of the Trigeminal Neuralgia. The surgical treatment offers many options: open surgery in posterior fossa, neuroablative procedures on the trigeminal nerve, neuromodulation techniques on the trigeminal pathways. Open surgery and neuroablative procedures are the treatments chosen in Classical Trigeminal Neuralgia and in Painful Trigeminal Neuropathy showing pure or prevalent typical clinical findings. Instead in Painful Trigeminal Neuropathy with pure or prevalent atypical clinical findings the neuromodulation techniques are the treatments to be chosen. Looking at the Literature reports and at our own experience, techniques, results, and indications of microvascular decompression, radiofrequency thermocoagulation, glycerol rhizolysis, balloon microcompression, and sterotactic radiosurgery of the trigeminal root are reported and discussed