The Efficacy of Sphenopalatine Ganglion Block and Radiofrequency Denervation in the Treatment of Cluster Headache: A Case Series

Cellular and molecular mechanisms involved in the analgesic effects of botulinum neurotoxin: A literature review

Botulinum neurotoxins (BoNTs), derived from Clostridium botulinum, have been employed to treat a range of central and peripheral neurological disease. Some studies indicate that BoNT may be beneficial for pain conditions as well. It has been hypothesized that BoNTs may exert their analgesic effects by preventing the release of pain-related neurotransmitters and neuroinflammatory agents from sensory nerve endings, suppressing glial activation, and inhibiting the transmission of pain-related receptors to the neuronal cell membrane. In addition, there is evidence to suggest that the central analgesic effects of BoNTs are mediated through their retrograde axonal transport. The purpose of this review is to summarize the experimental evidence of the analgesic functions of BoNTs and discuss the cellular and molecular mechanisms by which they can act on pain conditions. Most of the studies reviewed in this article were conducted using BoNT/A. The PubMed database was searched from 1995 to December 2022 to identify relevant literature.

Cluster headache: an update on clinical features, epidemiology, pathophysiology, diagnosis, and treatment

Cluster headache (CH) is one of the worst primary headaches that remain underdiagnosed and inappropriately treated. There are recent advances in the understanding of this disease and available treatments. This paper aims to review CH's recent clinical and pathophysiological findings, diagnosis, and treatment. We performed a narrative literature review on the socio-demographics, clinical presentations, pathophysiological findings, and diagnosis and treatment of CH. CH affects 0.1% of the population with an incidence of 2.07-9.8/100,00 person-years-habitants, a mean prevalence of 53/100,000 inhabitants (3-150/100,000 inhabitants). The male-to-female ratio remains inconclusive, as the ratio of 4.3:1 has recently been modified to 1.3-2.6, possibly due to previous misdiagnosis in women. Episodic presentation is the most frequent (80%). It is a polygenetic and multifactorial entity that involves dysfunction of the trigeminovascular system, the trigeminal autonomic reflex, and the hypothalamic networks. An MRI of the brain is mandatory to exclude secondary etiologies. There are effective and safe pharmacological treatments oxygen, sphenopalatine, and great occipital nerve block, with the heterogeneity of clinical trial designs for patients with CH divided into acute, transitional, or bridge treatment (prednisone) and preventive interventions. In conclusion, CH remains underdiagnosed, mainly due to a lack of awareness within the medical community, frequently causing a long delay in reaching a final diagnosis. Recent advances in understanding the principal risk factors and underlying pathophysiology exist. There are new therapeutic possibilities that are effective for CH. Indeed, a better understanding of this challenging pathology will continue to be a subject of research, study, and discoveries in its diagnostic and therapeutic approach.

The analgesic effects of botulinum neurotoxin by modulating pain-related receptors; A literature review

Botulinum neurotoxins (BoNTs), produced by Clostridium botulinum, have been used for the treatment of various central and peripheral neurological conditions. Recent studies have suggested that BoNTs may also have a beneficial effect on pain conditions. It has been hypothesized that one of the mechanisms underlying BoNTs' analgesic effects is the inhibition of pain-related receptors' transmission to the neuronal cell membrane. BoNT application disrupts the integration of synaptic vesicles with the cellular membrane, which is responsible for transporting various receptors, including pain receptors such as TRP channels, calcium channels, sodium channels, purinergic receptors, neurokinin-1 receptors, and glutamate receptors. BoNT also modulates the opioidergic system and the GABAergic system, both of which are involved in the pain process. Understanding the cellular and molecular mechanisms underlying these effects can provide valuable insights for the development of novel therapeutic approaches for pain management. This review aims to summarize the experimental evidence of the analgesic functions of BoNTs and discuss the cellular and molecular mechanisms by which they can act on pain conditions by inhibiting the transmission of pain-related receptors.

Cluster headache: state of the art in treatment

Cluster headache (CH) is the most common and devastating autonomic headache with multiple and recent advances in treatment. However, it usually goes unrecognized and is found to have a delayed and inappropriate treatment. This paper aims to review the current therapeutic options for patients with CH. We conducted a narrative literature review on the treatments available for this condition using the American Academy of Neurology (AAN) classification of therapeutic evidence. We found effective and safe pharmacological and non-pharmacological therapies with heterogeneity of clinical trial designs for patients with CH, and they are divided into three phases, namely, transitional, acute, and preventive interventions. Prednisone (A) is the most studied treatment in the transitional phase; acute attacks are treated using triptans (A), oxygen (A), and non-invasive transcutaneous vagal nerve stimulation (A). Verapamil (A) and monoclonal antibodies (possible A) are considered the first options in preventive treatments, followed by multiple pharmacological and non-pharmacological options in prophylactic treatments. In conclusion, numerous effective and safe treatments are available in treating patients with episodic, chronic, and pharmacoresistant CH according to the clinical profile of each patient.

Evaluation of the Effects of Oral Magnesium Sachet on the Prevention of Spinal Anesthesia-Induced Headache After Cesarean Section: A Randomized Clinical Trial

Background: Post-dural puncture headache (PDPH) is a common complication of spinal anesthesia. It often goes away after a few days but may be more severe in some patients and persists for weeks. Objectives: This study aimed to evaluate the effect of oral magnesium on the prevention of PDPH after cesarean section for the first time. Methods: In this double-blind, randomized clinical trial, 100 candidates for elective cesarean section under spinal anesthesia were randomly divided into 2 groups: (i) the intervention group that received 300 mg of oral magnesium powder and (ii) the control group that received starch powder. The frequency and severity of headache and amount of analgesic consumption in both groups were measured 1, 2, and 3 days after cesarean section. Data were analyzed using SPSS version 22 at 95% CI. Results: The frequency of PDPH 1, 2, and 3 days after surgery was 8% vs 24% (P = 0.029), 10% vs 26% (P = 0.039), and 12% vs 18% (P = 0.401) in the intervention and control groups, respectively. The mean and SD of pain severity was 0.52 ± 1.83 vs 1.5 ± 2.84 (P = 0.03) on the first day, 0.70 ± 2.19 vs 1.58 ± 2.86 (P = 0.05) on the second day, and 0.82 ± 2.32 vs 1.18 ± 2.62 on the third day (P = 0.43) in the intervention and control groups, respectively. Although more patients in the control group received rescue analgesia, no significant difference was seen between the 2 study groups. Conclusions: In women candidates for cesarean section, oral administration of 300 mg magnesium 2 hours before surgery significantly reduces the frequency and severity of PDPH, but its impact on reducing analgesic consumption is not significant.

Aminophylline for Prevention and/or Treatment of Post-Dural Puncture Headache: A Systematic Review and Meta-Analysis Study Protocol

Objectives

Post-dural Puncture Headache (PDPH) is prevalent among individuals undergoing lumbar punctures. The non-invasive effect of some drugs, such as aminophylline on PDPH has been investigated in several clinical studies. As there is no comprehensive systematic review and meta-analysis about the preventive and therapeutic effects of aminophylline on PDPH in the literature, the clinical effectiveness of this drug on the prevention and/or treatment of PDPH will be assessed in this study.

Methods

PubMed/MEDLINE, Embase, WoS (Clarivate Analytics), the Cochrane Central Register of Controlled Trials (CENTRAL), CINAHL Complete, Scopus, and Google Scholar as electronic databases will be precisely searched for clinical studies that assessed the effect of aminophylline on PDPH. Studies between 01-01-1980 and 30-06-2020 will be evaluated in this study, and there will not be any language restrictions. Contradictions between the reviewers within any phase of the study (screening, selecting, quality assessment, and data extraction) will be resolved by consensus; in case of unsolved disagreements, a third reviewer will eventually decide. The combination method will be applied according to the methodological resemblance in the selected articles using the Random Effect Model or the Fixed Effect Model. Also, for the included articles, forest plots will be drawn. For assessing statistical heterogeneity, the I² statistic and the Q-statistic test will be applied. In addition, funnel plots will be used for assessing non-significant study effects and potential reporting bias. Furthermore, Egger’s and Begg’s tests will be done, and publication bias will be indicated by significant findings (P < 0.05).

Conclusions

It is expected that the results of this study will be of benefit to researchers and clinicians for managing PDPH, and will be reported in conferences and publications.

Clinical Applications of Aspirin as a Multi-potent Drug Beyond Cardiovascular Implications: A Proof of Concept for Anesthesiologists- A Narrative Review

To the best of our knowledge, aspirin (ASA) is known as a commonly used medication worldwide. Although the cardiovascular aspects of ASA are well-established, recently, it has been identified that ASA can yield multiple extra-cardiovascular therapeutic potencies in facing neurodegenerative disorders, various cancers, inflammatory responses, and the COVID-19 pandemic. In this review, we aimed to highlight the proven role of ASA administration in the variety of non-cardiovascular diseases, particularly in the field of anesthesiology.

Pulsed Radiofrequency of the Occipital Nerves: Results of a Standardized Protocol on Chronic Headache Management

BACKGROUND

Pulsed radiofrequency (PRF) of the occipital nerves has neuromodulative properties and is used for chronic pain management. However, its role in various types of chronic headaches has not been adequately investigated so far.

OBJECTIVES

Τhis was an observational, open-label, prospective study aiming to assess the efficacy of PRF of occipital nerves on various types of chronic headache management.

METHODS

Patients with chronic headaches followed up at the pain management unit were scheduled for PRF of both occipital nerves after a positive diagnostic nerve block. PRF was applied following a standardized protocol at 42°C, and the number of headaches per month was assessed as a primary outcome at baseline (before treatment), as well as after 1, 3, and 6 months. Pain intensity during headache crises was recorded using the Numeric Rating Scale (NRS, 0 - 10).

RESULTS

Fifty-seven patients suffering from chronic migraines, cluster headaches, tension-type headaches, and occipital neuralgia were studied. PRF significantly improved the number of headache episodes per month, as well as the pain intensity of the crises. The median number of headache episodes per month was significantly reduced in patients with migraine, from 14.5 to 4 after 1 month, and to 6.5 after 6 months. The same was seen for patients with clusters, who were also improved. A statistically significant reduction in NRS values over time was seen for all types of headaches.

CONCLUSIONS

PRF of the occipital nerves can lead to a reduction of the number of headache episodes per month, improving the intensity of pain during each episode.

Safety of Radiofrequency Ablation of Thoracic T2 and T3 Sympathectomy in Palmar Hyperhidrosis: A Case Report

Introduction

Hyperhidrosis is the maladjustment of excess sweating in specific parts of the body. Radiofrequency (RF) therapy has been successfully used to treat hyperhidrosis with a success rate of 85% - 95% in patients refractory to sympathectomy. The main hypothesis was the association between reduced palmar hyperhidrosis and radiofrequency RF therapy. The RF therapy is a less invasive technique, including the utilization of electromagnetic energy that is deposited near the nerve tissue. The mechanism of action of continuous RF could be explained by the destruction of afferent nerve fibers on their way from a nociceptive focus to the central nervous system. Pulsed RF was invented to explore this possibility, with the sole purpose of finding a less destructive and equally effective technique for the application of RF to afferent pathways. Herein, we further evaluated whether the procedure was safe without any complications in routine follow-up in palmar hyperhidrosis.

Case Presentation

Herein, we report the case of a male patient with an age of 22 years undergoing thermal RF sympathectomy therapy of thoracic T2 and T3 sympathetic ganglia for the palmar hyperhidrosis of his right hand observed for 3 months. The patient developed a contraction of the flexor involving the small muscles of the right hand with severe pain and congestion 17 days after the procedure without any other complications. The contraction was relieved by a sonar-guided median nerve block at the wrist with two injections of 2 mL lidocaine 2% and 2 mL dexamethasone.

Conclusions

This study has been the first clinical case report complicated by the development of a contraction of the flexor muscles of the right hand with severe pain and congestion. The spasm was gradually relieved by sonar-guided median nerve injection at the level of the wrist and intended to assess the role of RF ablation with a success rate of 85% - 95% in palmar hyperhidrosis.

The Effect of Pulsed Radiofrequency on Radicular Pain in Lumbal Herniated Nucleus Pulposus: A Systematic Review and Meta-analysis

Context

Radiofrequency therapy is a medical procedure mainly used to reduce pain with a low complication rate (less than 1%), ease of application, and low cost. This review's objective was to (1) evaluate the pulsed radiofrequency (PRF) effectiveness in treating radicular pain and (2) assess the PRF procedure's safety in managing radicular pain in lumbar herniated nucleus pulposus (HNP).

Methods

A systematic review and meta-analysis. A tertiary care center and an academic medical center. Six full articles with the following features were selected for this review: (1) Articles published in English; (2) studies on the PRF effect on radicular pain in lumbar HNP; and (3) randomized control trials.

Results

The studies showed that the PRF group had a reduction in pain scores at each evaluation. In four of the studies, the PRF group showed a more significant reduction in pain scores than the control, and in two of the studies, the reduction in pain scores was not significant in the PRF group compared to the control. An adverse effect was reported in one patient experiencing increased radicular pain after PRF. Lack of data required for statistical analysis, and lack use of a uniform duration for the PRF procedure by all the studies.

Conclusions

PRF can be used as a promising clinical recommendation for pain management with minimally invasive radicular pain techniques due to lumbar HNP.