Treatment of acute migraine by a partial rebreathing device: A randomized controlled pilot study

The Relationship Between Nitrate-Induced Headache and -Blood Viscosity: An Observational Prospective Study

ABSTRACT

Nitrates are one of the most prescribed medications in the treatment of angina pectoris today. Headache is the most common side effect of nitrates, and there is limited prospective data on the determinants of this effect. Our aim in this study is to open a foresight window for clinicians in clinical practice by explaining the possible relationship between nitrate-induced headache and whole-blood viscosity (WBV). After coronary revascularization treatment, 869 patients with angina who were prescribed nitrate preparations were divided into groups according to the development of headache or not and categorized according to the 4-grade scale level. Those who had no headache during nitrate use were graded as grade 0, those who felt mild headache were grade 1, those who felt moderate headache were grade 2, and those who described severe headache were graded as grade 3. The groups were compared according to WBV values. A total of 869 participants were included in the study. Most patients (82.1%) experienced some level of headache. Headache severity correlated with both WBV at high shear rate (r = 0.657; P < 0.001) and WBV at low shear rate (r = 0.687; P < 0.001). In multivariate analysis, WBV was determined as an independent predictor of headache experience. WBV predicted nitrate-induced headache with 75% sensitivity and 75% specificity at high shear rate and 77% sensitivity and 77% specificity at low shear rate. WBV seems to be one of the major determinants for nitrate-induced headache. WBV may be a guide for initiating alternative antianginal drugs without prescribing nitrates to the patient to increase patient compliance.

Acute Treatments for Episodic Migraine in Adults: A Systematic Review and Meta-analysis

IMPORTANCE

Migraine is common and can be associated with significant morbidity, and several treatment options exist for acute therapy.

OBJECTIVE

To evaluate the benefits and harms associated with acute treatments for episodic migraine in adults.

DATA SOURCES

Multiple databases from database inception to February 24, 2021.

STUDY SELECTION

Randomized clinical trials and systematic reviews that assessed effectiveness or harms of acute therapy for migraine attacks.

DATA EXTRACTION AND SYNTHESIS

Independent reviewers selected studies and extracted data. Meta-analysis was performed with the DerSimonian-Laird random-effects model with Hartung-Knapp-Sidik-Jonkman variance correction or by using a fixed-effect model based on the Mantel-Haenszel method if the number of studies was small.

MAIN OUTCOMES AND MEASURES

The main outcomes included pain freedom, pain relief, sustained pain freedom, sustained pain relief, and adverse events. The strength of evidence (SOE) was graded with the Agency for Healthcare Research and Quality Methods Guide for Effectiveness and Comparative Effectiveness Reviews.

FINDINGS

Evidence on triptans and nonsteroidal anti-inflammatory drugs was summarized from 15 systematic reviews. For other interventions, 115 randomized clinical trials with 28 803 patients were included. Compared with placebo, triptans and nonsteroidal anti-inflammatory drugs used individually were significantly associated with reduced pain at 2 hours and 1 day (moderate to high SOE) and increased risk of mild and transient adverse events. Compared with placebo, calcitonin gene-related peptide receptor antagonists (low to high SOE), lasmiditan (5-HT1F receptor agonist; high SOE), dihydroergotamine (moderate to high SOE), ergotamine plus caffeine (moderate SOE), acetaminophen (moderate SOE), antiemetics (low SOE), butorphanol (low SOE), and tramadol in combination with acetaminophen (low SOE) were significantly associated with pain reduction and increase in mild adverse events. The findings for opioids were based on low or insufficient SOE. Several nonpharmacologic treatments were significantly associated with improved pain, including remote electrical neuromodulation (moderate SOE), transcranial magnetic stimulation (low SOE), external trigeminal nerve stimulation (low SOE), and noninvasive vagus nerve stimulation (moderate SOE). No significant difference in adverse events was found between nonpharmacologic treatments and sham.

CONCLUSIONS AND RELEVANCE

There are several acute treatments for migraine, with varying strength of supporting evidence. Use of triptans, nonsteroidal anti-inflammatory drugs, acetaminophen, dihydroergotamine, calcitonin gene-related peptide antagonists, lasmiditan, and some nonpharmacologic treatments was associated with improved pain and function. The evidence for many other interventions, including opioids, was limited.

A Paradoxical Vasodilatory Nutraceutical Intervention for Prevention and Attenuation of Migraine-A Hypothetical Review

Studies suggest that migraine pain has a vascular component. The prevailing dogma is that peripheral vasoconstriction activates baroreceptors in central, large arteries. Dilatation of central vessels stimulates nociceptors and induces cortical spreading depression. Studies investigating nitric oxide (NO) donors support the indicated hypothesis that pain is amplified when acutely administered. In this review, we provide an alternate hypothesis which, if substantiated, may provide therapeutic opportunities for attenuating migraine frequency and severity. We suggest that in migraines, heightened sympathetic tone results in progressive central microvascular constriction. Suboptimal parenchymal blood flow, we suggest, activates nociceptors and triggers headache pain onset. Administration of NO donors could paradoxically promote constriction of the microvasculature as a consequence of larger upstream central artery vasodilatation. Inhibitors of NO production are reported to alleviate migraine pain. We describe how constriction of larger upstream arteries, induced by NO synthesis inhibitors, may result in a compensatory dilatory response of the microvasculature. The restoration of central capillary blood flow may be the primary mechanism for pain relief. Attenuating the propensity for central capillary constriction and promoting a more dilatory phenotype may reduce frequency and severity of migraines. Here, we propose consideration of two dietary nutraceuticals for reducing migraine risk: L-arginine and aged garlic extracts.