Ketamine Infusion Combined With Magnesium as a Therapy for Intractable Chronic Cluster Headache: Report of Two Cases

Ketamine as Treatment for Cluster Headache: A Systematic Review of Literature and a Case Series

INTRODUCTION

Cluster headache is a severe and debilitating neurological condition characterized by intense, excruciating pain with a significant impact on patients' wellbeing. Although different treatment options are available, many patients continue to experience inadequate relief. Therefore, experimental strategies are increasingly studied. One of the more promising approaches is the use of ketamine. We present the currently available evidence and our own data.

METHODS

In this mixed-methods paper, we first summarize the available evidence of ketamine for treatment of cluster headache based on a systematic review of literature in MEDLINE, EMBASE and the Cochrane library of systematic reviews. As the level of evidence is quite limited, we report our own cohort study with ten patients treated with ketamine infusions for cluster headache. They were followed up to investigate the patients' experience of treatment success and quality of life.

RESULTS

The search and review of literature identified four reports with a total of 68 patients. All were uncontrolled case series. The current literature suggests that ketamine might decrease cluster headache. However, as the applied regimes and reported outcomes are highly heterogeneous, further analysis was futile. Our own data show high patient satisfaction with ketamine treatment.

CONCLUSION

Despite the limited evidence, ketamine might be considered a potential therapeutic approach for cluster headache. Therefore, further research including randomized controlled trials should be encouraged.

European Academy of Neurology guidelines on the treatment of cluster headache

BACKGROUND AND PURPOSE

Cluster headache is a relatively rare, disabling primary headache disorder with a major impact on patients' quality of life. This work presents evidence-based recommendations for the treatment of cluster headache derived from a systematic review of the literature and consensus among a panel of experts.

METHODS

The databases PubMed (Medline), Science Citation Index, and Cochrane Library were screened for studies on the efficacy of interventions (last access July 2022). The findings in these studies were evaluated according to the recommendations of the European Academy of Neurology, and the level of evidence was established using GRADE (Grading of Recommendations Assessment, Development, and Evaluation).

RECOMMENDATIONS

For the acute treatment of cluster headache attacks, there is a strong recommendation for oxygen (100%) with a flow of at least 12 L/min over 15 min and 6 mg subcutaneous sumatriptan. Prophylaxis of cluster headache attacks with verapamil at a daily dose of at least 240 mg (maximum dose depends on efficacy and tolerability) is recommended. Corticosteroids are efficacious in cluster headache. To reach an effect, the use of at least 100 mg prednisone (or equivalent corticosteroid) given orally or at up to 500 mg iv per day over 5 days is recommended. Lithium, topiramate, and galcanezumab (only for episodic cluster headache) are recommended as alternative treatments. Noninvasive vagus nerve stimulation is efficacious in episodic but not chronic cluster headache. Greater occipital nerve block is recommended, but electrical stimulation of the greater occipital nerve is not recommended due to the side effect profile.

A systematic review of the efficacy of ketamine for craniofacial pain

Background

Craniofacial pain (CFP) poses a burden on patients and health care systems. It is hypothesized that ketamine, an N-methyl-d-aspartate (NMDA) receptor antagonist, can reverse central sensitization associated with causation and propagation of CFP. This systematic review aims to assess the role of ketamine for CFP.

Methods

Databases were searched for studies published up to September 26, 2022, investigating the efficacy of ketamine for adults with CFP. Primary outcome was the change in pain intensity at 60 min postintervention. Two reviewers screened and extracted data. Registration with PROSPERO was performed (CRD42020178649).

Results

Twenty papers (six randomized controlled trials [RCTs], 14 observational studies) including 670 patients were identified. Substantial heterogeneity in terms of study design, population, dose, route of administration, treatment duration, and follow-up was noted. Bolus dose ranged from 0.2-0.3 mg/kg (intravenous) to 0.4 mg/kg (intramuscular) to 0.25-0.75 mg/kg (intranasal). Ketamine infusions (0.1-1 mg/kg/h) were given over various durations. Follow-up was short in RCTs (from 60 min to 72 h) but longer in observational studies (up to 18 months). Ketamine by bolus treatment failed to reduce migraine intensity but had an effect by reducing intensity of aura, cluster headache (CH), and trigeminal neuralgia. Prolonged ketamine infusions showed sustainable reduction of migraine intensity and frequency of CH attacks, but the quality of the evidence is low.

Conclusion

Current evidence remains conflicting on the efficacy of ketamine for CFP owing to low quality and heterogeneity across studies. Ketamine infusions are suggested to provide sustained improvement, possibly because of prolonged duration and higher dosage of administration. RCTs should focus on the dose-response relationship of prolonged ketamine infusions on CFP.

Preventive treatment of refractory chronic cluster headache: systematic review and meta-analysis

BACKGROUND

Preventive treatment for refractory chronic cluster headache (rCCH) is challenging and many therapies have been tried.

OBJECTIVE

To study what could be considered the therapy of choice in rCCH through a systematic review and meta-analysis.

METHODS

This review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The protocol was registered in PROSPERO (ID CRD42021290983). A systematic search was performed in MEDLINE, Embase, Cochrane, clinicaltrials.gov, and the WHO's-International-Clinical-Trials-Registry-Platform. Studies on the preventive treatment for rCCH as defined by the European Headache Federation consensus statement were included. A meta-analysis of the pooled response rate was conducted for the different therapies.

RESULTS

Of 336 results, 45 were eligible for inclusion. Most articles studied the effect of neuromodulation as a preventive treatment for rCCH. The most studied neuromodulation technique was occipital nerve stimulation (ONS), with a pooled response rate in the meta-analysis of 57.3% (95% CI 0.481-0.665). Deep brain stimulation (DBS) was the second most studied treatment with a pooled response rate of 77.0% (95% CI 0.594-0.957). DBS results were more heterogeneous than ONS, which could be related to the different stimulation targets in DBS studies, and reported more serious adverse events than in ONS studies. The remaining therapies (anti-CGRP pathway drugs, warfarin, ketamine-magnesium infusions, serial occipital nerve blocks, clomiphene, onabotulinum toxin A, ketogenic diet, sphenopalatine ganglion radiofrequency or stimulation, vagus nerve stimulation, percutaneous bioelectric current stimulation, upper cervical cord stimulation, and vidian neurectomy) present weaker results or have less quality of evidence.

CONCLUSIONS

The results of this systematic review and meta-analysis suggest that ONS could be the first therapeutic strategy for patients with rCCH based on the current evidence.

Interactions between Ketamine and Magnesium for the Treatment of Pain: Current State of the Art

BACKGROUND

Over the past three decades, NMDA-receptor antagonists have been shown to be efficient drugs for treating pain, particularly pain resistant to conventional analgesics. Emphasis will be on the old-new drugs, ketamine and magnesium, and their combination as a novel approach for treating chronic pain.

METHODS

The MEDLINE database was searched via PubMed for articles that were published up to March 1, 2020, with the keywords 'ketamine', 'magnesium', and 'pain' (in the title/abstract).

RESULTS

Studies in animals, as well as humans, have shown that interactions of ketamine and magnesium can be additive, antagonistic, and synergistic. These discrepancies might be due to differences in magnesium and ketamine dosage, administration times, and the chronological order of drug administration. Different kinds of pain can also be the source of divergent results.

CONCLUSION

This review explains why studies performed with a combination of ketamine and magnesium have given inconsistent results. Because of the lack of efficacy of drugs available for pain, ketamine and magnesium in combination provide a novel therapeutic approach that needs to be standardized with a suitable dosing regimen, including the chronological order of drug administration.

Current advances in the management of cluster headaches

Introduction: Cluster headache (CH) is probably the most severe idiopathic pain condition, yet its current medical management remains poor.Areas covered: Only repurpose medicines are currently in use for the prevention of CH, partially because the pathophysiology of the condition is still elusive. In this article we performed a systematic review to evaluate the evidence for efficacy of the currently available or emerging treatments for CH.Expert opinion: We found several ongoing randomized clinical trials testing prophylactic treatments for CH and only few for the standard ones. Recent data from randomized trials with monoclonal antibodies targeting the calcitonin gene related peptide pathway (anti-CGRP mAbs) are controversial, although its role in the pathogenesis of the condition is well documented. This inconsistency may depict inadequacies in clinical trial designing. Anti-CGRP mAbs and antagonists of pituitary adenylate cyclase-activating polypeptide (PACAP) along with neuromodulation techniques, are curing the necessary valuable evidence that could illuminate the therapeutical future for cluster headache. Orexin pathway is another attractive target for CH treatment. To improve the evidence for efficacy, we further propose that the design of the clinical trials for CH needs to be radically reviewed to allow more patients to participate.

Ketamine-Magnesium for Refractory Chronic Cluster Headache: A Case Series

OBJECTIVES

To evaluate the safety and efficacy of ketamine-magnesium combination to reduce attacks in a series of patients with refractory chronic cluster headache (rCCH).

BACKGROUND

Refractory chronic cluster headache (CCH) is a rare but highly debilitating condition that needs new treatment options. A previous publication reported that a single infusion of ketamine-magnesium combination was effective in 2 patients with rCCH.

METHODS

The treatment was proposed to consecutive patients with rCCH seen in 2 French hospitals between November 2015 and February 2020 and who were resistant to at least 3 preventive treatments. They received a single ketamine infusion (0.5 mg/kg over 2 hours) combined with magnesium sulfate (3000 mg). The main outcome was a comparison of the number of daily attacks 2 weeks prior to the ketamine-magnesium infusion and 1 week after (on days 7 and 8). The second outcome was the percentage of responders (patients with ≥50% reduction in the frequency of daily attacks). Safety was assessed by the recording of adverse events during infusion. Descriptive statistics are presented as mean ± standard deviation.

RESULTS

Seventeen patients (14 men), with an age of 35.2 ± 8.1 years, were included. They presented with CCH for 6.6 ± 4.3 years. The number of daily attacks decreased from 4.3 ± 2.4 before treatment to 1.3 ± 1.0 after treatment (difference: -3.1 (95% CI: -4.5 to -1.6), P < .001). Seventy six percent (13/17) were responders. Transient and mild sedation was reported by 7/17 patients (41.2%).

CONCLUSIONS

The ketamine-magnesium combination seems an effective and well-tolerated therapy for rCCH. Placebo-controlled studies should be conducted to further confirm these findings.

Alleviative effects of Cannabis flower on migraine and headache

OBJECTIVE

Few studies to date have measured the real-time effects of consumption of common and commercially available Cannabis products for the treatment of headache and migraine under naturalistic conditions. This study examines, for the first time, the effectiveness of using dried Cannabis flower, the most widely used type of Cannabis product in the United States, in actual time for treatment of headache- and migraine-related pain and the associations between different product characteristics and changes in symptom intensity following Cannabis use.

METHODS

Between 06/10/2016 and 02/12/2019, 699 people used the Releaf Application to record real-time details of their Cannabis use, including product characteristics and symptom intensity levels prior to and following self-administration; data included 1910 session-level attempts to treat headache- (1328 sessions) or migraine-related pain (582 sessions). Changes in headache- or migraine-related pain intensity were measured on a 0-10 scale prior to, and immediately, following Cannabis consumption.

RESULTS

Ninety-four percent of users experienced symptom relief within a two-hour observation window. The average symptom intensity reduction was 3.3 points on a 0-10 scale (standard deviation = 2.28, Cohen's d = 1.58), with males experiencing greater relief than females (P < 0.001) and a trend that younger users (< 35 years) experience greater relief than older users (P = 0.08). Mixed effects regression models showed that, among the known (i.e., labeled) product characteristics, tetrahydrocannabinol levels 10% and higher are the strongest independent predictors of symptom relief, and this effect is particularly prominent in headache rather than migraine sufferers (P < 0.05), females (P < 0.05) and younger users (P < 0.001). Females and younger users also appear to gain greater symptom relief from flower labeled as "C. indica" rather than "C. sativa" or other hybrid strains.

CONCLUSION

These results suggest that whole dried Cannabis flower may be an effective medication for treatment of migraine- and headache-related pain, but the effectiveness differs according to characteristics of the Cannabis plant, the combustion methods, and the age and gender of the patient.

A Review of Nonanesthetic Uses of Ketamine

Ketamine, a nonselective NMDA receptor antagonist, is used widely in medicine as an anesthetic agent. However, ketamine's mechanisms of action lead to widespread physiological effects, some of which are now coming to the forefront of research for the treatment of diverse medical disorders. This paper aims at reviewing recent data on key nonanesthetic uses of ketamine in the current literature. MEDLINE, CINAHL, and Google Scholar databases were queried to find articles related to ketamine in the treatment of depression, pain syndromes including acute pain, chronic pain, and headache, neurologic applications including neuroprotection and seizures, and alcohol and substance use disorders. It can be concluded that ketamine has a potential role in the treatment of all of these conditions. However, research in this area is still in its early stages, and larger studies are required to evaluate ketamine's efficacy for nonanesthetic purposes in the general population.

Intravenous Magnesium Sulfate to Treat Acute Headaches in the Emergency Department: A Systematic Review

INTRODUCTION

Non-traumatic headaches comprise up to 4% of all emergency department (ED) visits. Current practice is moving toward multimodal analgesia regimens that limit narcotic use.

OBJECTIVE

The objective of this systematic review is to address the following research question: In patients with non-traumatic headaches (Population), does administration of intravenous magnesium sulfate (Intervention) compared to placebo, corticosteroids, dopamine antagonists, ergot alkaloids, non-steroidal anti-inflammatory drugs (NSAIDs), triptans, or usual care result in better pain control, lower rate of recurrence at 24 hours, lower requirements for rescue analgesia, and less adverse medication effects (Outcomes)?

METHODS

Scholarly databases and relevant bibliographies were searched, as were clinical trial registries and relevant conference proceedings to limit publication bias. Studies were not limited by date, language, or publication status. Inclusion criteria were: (1) randomized clinical trial (RCT), (2) patients age ≥18 years, (3) non-traumatic headache, (4) patients treated in ED or an outpatient acute care treatment center, and (5) magnesium sulfate administered intravenously (IV). Eligible comparison groups included: placebo, conventional therapy, dopamine antagonist, NSAID, corticosteroid, ergot alkaloid, or triptans.

RESULTS

Out of 4018 identified references, 7 RCTs (545 participants) that treated migraine headaches (n = 6) and benign non-traumatic headaches (n = 1) met inclusion criteria. Pain intensity was improved with magnesium sulfate vs comparators at 60-120 minutes, but not at earlier time points. Result for the endpoint of pain reduction by 50% were conflicting as 3 studies reported that headache was improved, unchanged, and less with magnesium sulfate. Complete pain relief was improved with magnesium sulfate in 1 study, and in the migraine with aura (MA) subgroup in another. The need for rescue analgesia at any point was improved with magnesium sulfate in 1 study, and in the MA subgroup in another. Twenty-four-hour headache recurrence was improved with magnesium sulfate in 1 study, but unchanged in a second. The intended meta-analysis was not performed due to the clinical heterogeneity among studies.

CONCLUSION

While we cannot draw a firm conclusion on the efficacy or benefit of intravenous magnesium sulfate in the treatment of acute non-traumatic headaches, the existing evidence indicates potential benefits in pain control beyond 1 hour, aura duration, and need for rescue analgesia.

Cluster Headache in Subjects With Substance Use Disorder: A Case Series and a Review of the Literature

OBJECTIVE

To describe a case series of 7 patients presenting cluster headache (CH) criteria and a substance use disorder, reported to a French Addictovigilance center. Then, to assess clinical, pharmacological, and neurobiological linkages between substance use and CH onset.

BACKGROUND

CH patients are presenting a higher prevalence of comorbidities, among which the use of psychoactive substances, licit or illicit, have been explored by a few authors. Recently, 3 cases of CH in patients seen in the hospital-based addiction care center have been reported to the Toulouse addictovigilance center.

METHODS

Other cases have been identified in the same tertiary hospital after a collaborative investigation done with the departments of neurology and psychiatry and included in the case series. A narrative review was performed to assess the potential of psychoactive substance consumption to induce or facilitate CH.

RESULTS

From 2016 to 2018, 6 males and 1 female aged between 26 and 54 years old, presenting CH criteria and a substance use disorder, were included in our case series. Among substances used, there are: (1) daily use of tobacco and alcohol in 5/7 subjects; (2) daily or almost daily use of cocaine in 5/7 subjects; (3) regular use of cannabis before attacks beginning in 4/7 subjects; and (4) opioids, as a substitutive medication or abused, in 5/7 subjects. The intranasal route administration is reported by all the subjects and precedes the beginning of attacks for 5/7 subjects.

CONCLUSIONS

We have found a CH prevalence of 0.9% in our studied population, while it is estimated at 0.1% in the general population. The coexistence of cluster headache and addiction behaviors reflects possible common neurobiological pathways, which would include the hypothalamus. Research could be conducted on the potential of hypothalamic therapeutic targets.

Consensus Guidelines on the Use of Intravenous Ketamine Infusions for Chronic Pain From the American Society of Regional Anesthesia and Pain Medicine, the American Academy of Pain Medicine, and the American Society of Anesthesiologists

BACKGROUND

Over the past 2 decades, the use of intravenous ketamine infusions as a treatment for chronic pain has increased dramatically, with wide variation in patient selection, dosing, and monitoring. This has led to a chorus of calls from various sources for the development of consensus guidelines.

METHODS

In November 2016, the charge for developing consensus guidelines was approved by the boards of directors of the American Society of Regional Anesthesia and Pain Medicine and, shortly thereafter, the American Academy of Pain Medicine. In late 2017, the completed document was sent to the American Society of Anesthesiologists' Committees on Pain Medicine and Standards and Practice Parameters, after which additional modifications were made. Panel members were selected by the committee chair and both boards of directors based on their expertise in evaluating clinical trials, past research experience, and clinical experience in developing protocols and treating patients with ketamine. Questions were developed and refined by the committee, and the groups responsible for addressing each question consisted of modules composed of 3 to 5 panel members in addition to the committee chair. Once a preliminary consensus was achieved, sections were sent to the entire panel, and further revisions were made. In addition to consensus guidelines, a comprehensive narrative review was performed, which formed part of the basis for guidelines.

RESULTS

Guidelines were prepared for the following areas: indications; contraindications; whether there was evidence for a dose-response relationship, or a minimum or therapeutic dose range; whether oral ketamine or another N-methyl-D-aspartate receptor antagonist was a reasonable treatment option as a follow-up to infusions; preinfusion testing requirements; settings and personnel necessary to administer and monitor treatment; the use of preemptive and rescue medications to address adverse effects; and what constitutes a positive treatment response. The group was able to reach consensus on all questions.

CONCLUSIONS

Evidence supports the use of ketamine for chronic pain, but the level of evidence varies by condition and dose range. Most studies evaluating the efficacy of ketamine were small and uncontrolled and were either unblinded or ineffectively blinded. Adverse effects were few and the rate of serious adverse effects was similar to placebo in most studies, with higher dosages and more frequent infusions associated with greater risks. Larger studies, evaluating a wider variety of conditions, are needed to better quantify efficacy, improve patient selection, refine the therapeutic dose range, determine the effectiveness of nonintravenous ketamine alternatives, and develop a greater understanding of the long-term risks of repeated treatments.