Prevalence and burden of migraine in the United States: A systematic review.

BACKGROUND: This study reviewed migraine prevalence and disability gathered through epidemiologic survey studies in the United States conducted over the past three decades. We summarized these studies and evaluated changing patterns of disease prevalence and disability. METHODS: We conducted a systematic review of US studies addressing the prevalence, disability, and/or burden of migraine, including both episodic migraine (EM) and chronic migraine (CM). A Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocol was used in conjunction with the PubMed search engine. Eligible studies were published before February 2022, were conducted in the United States, included representative samples, and used a case definition of migraine based on the International Classification of Headache Disorders (ICHD). The primary measure of disease burden was the Migraine Disability Assessment Scale (MIDAS). The MIDAS measures days lost due to migraine over 3 months in three domains and defines groups with moderate (Grade III) or severe disability (Grade IV) using cut-scores. RESULTS: Of the 1609 identified records, 26 publications from 11 US population-based studies met eligibility criteria. The prevalence of migraine in the population has remained relatively consistent for the past 30 years: ranging from 11.7% to 14.7% overall, 17.1% to 19.2% in women, and 5.6% to 7.2% in men in the studies reviewed. CM prevalence is 0.91% (1.3% among women and 0.5% of men) in adults and 0.8% in adolescents. The proportion of people with migraine and moderate-to-severe MIDAS disability (Grades III-IV), has trended upward across studies from 22.0% in 2005 to 39.0% in 2012, to 43.2% in 2016, and 42.4% in 2018. A consistently higher proportion of women were assigned MIDAS Grades III/IV relative to men. CONCLUSION: The prevalence of migraine in the United States has remained stable over the past three decades while migraine-related disability has increased. The disability trend could reflect changes in reporting, study methodology, social and societal changes, or changes in exacerbating or remediating factors that make migraine more disabling, among other hypotheses. These issues merit further investigation.

Unraveling the MSG-Headache Controversy: an Updated Literature Review.

PURPOSE OF REVIEW: To review the evidence and role of monosodium glutamate (MSG) as a headache and migraine trigger. RECENT FINDINGS: MSG is a common food additive, has widely been linked as a trigger of headache, as well as other symptoms. However, the evidence for MSG as a causative agent for headache is debated. Various clinical trials over the past several decades have reported conflicting results, with studies suggesting that MSG does and does not increase the incidence of headache. However, the dosages of MSG exposure are often inconsistent across studies, with many studies administering a dose significantly higher than the average consumption.. Additionally, there are misconceptions about which foods and cuisines have MSG in them. MSG could be a potential trigger for migraine and headaches. It is unclear exactly how MSG plays into the migraine pathophysiology. It's crucial to accurately determine if MSG is present in one's diet to evaluate its potential impact on headaches.

A randomized study of IV prochlorperazine plus diphenhydramine versus IV hydromorphone for migraine-associated symptoms: A post hoc analysis.

OBJECTIVE: We conducted a randomized trial among emergency department patients with migraine to determine the relative impact on migraine-associated symptoms of hydromorphone, an opioid, versus prochlorperazine, an antidopaminergic antiemetic. METHODS: This was a post hoc analysis of data from a double-blind study registered at http://clinicaltrials.gov (NCT02389829). Patients who met International Classification of Headache Disorders, 3rd edition criteria for migraine without aura or for probable migraine without aura were eligible for participation. Participants received either hydromorphone 1 mg IV or prochlorperazine 10 mg IV plus diphenhydramine 25 mg IV and could receive a second dose of the same medication 1 h later if needed. The outcomes were sustained relief of nausea, photophobia, and phonophobia. RESULTS: A total of 127 patients were enrolled, of whom 63 received prochlorperazine and 64 received hydromorphone. Of 49 patients in the prochlorperazine arm who reported nausea at baseline, 34 (69.4%) reported complete resolution without relapse versus 15/49 (30.6%) in the hydromorphone arm (absolute risk reduction [ARR] = 38.8%, 95% CI: 20.5%-57.0%, p < 0.001). Of 55 patients in the prochlorperazine arm who reported photophobia at baseline, 23 (41.8%) reported complete resolution without relapse versus 13/62 (20.9%) patients treated with hydromorphone (ARR = 20.8%, 95% CI: 4.3%-37.3%, p = 0.014). Of 56 patients in the prochlorperazine arm who reported phonophobia at baseline, 25 (44.6%) reported complete resolution without relapse versus 16/59 (27.1%) in the hydromorphone arm (ARR = 17.5%, 95% CI: 0.3%-34.8%, p = 0.049). For adverse events, three patients in the prochlorperazine arm reported anxiety or restlessness, and nine patients in the hydromorphone arm reported dizziness or weakness. CONCLUSIONS: Prochlorperazine plus diphenhydramine is more efficacious than hydromorphone for the treatment of migraine-associated symptoms.

Efficacy and Tolerability of Calcitonin Gene-Related Peptide-Targeted Monoclonal Antibody Medications as Add-on Therapy to OnabotulinumtoxinA in Patients with Chronic Migraine.

BACKGROUND: We examined the efficacy and tolerability of calcitonin gene-related peptide-targeted monoclonal antibodies (CGRP-targeted mAbs) as add-on therapy for patients with chronic migraine (CM) undergoing treatment with onabotulinumtoxinA (onabot) who require additional preventive therapy. METHODS: We reviewed medical records of patients with CM receiving treatment with onabot who were subsequently prescribed a CGRP-targeted mAb medication. The primary outcome was the change in number of monthly headache days (MHDs) reported. Secondary outcomes were change in headache pain severity, discontinuation due to lack of tolerability, and severe adverse events. RESULTS: Of 153 patients, 111 (72.5%) reported a decrease in either MHDs or headache pain severity, with documentation of MHDs in 66 patients. Among these 66 patients, the average number of MHDs before initiation of onabot treatment was 25.7. After onabot treatment, an average decrease of 10.9 MHDs was reported (P < 0.001). After the addition of a CGRP-targeted mAb medication, patients experienced a further decrease of 5.7 MHDs (P < 0.001). With combined therapy, patients reported a total decrease of 16.6 MHDs (P < 0.001). Adverse effects occurred in 13 patients (8.5%) after addition of the CGRP-targeted mAb and included constipation, injection site reaction, and fatigue. No serious adverse events were reported. CONCLUSION: Adding a CGRP-targeted mAb to onabot in patients with CM was associated with further reductions in MHDs without major tolerability issues across a range of mAbs. This retrospective review supports the conduct of a well-designed double-blind study adding a CGRP-targeted mAb or placebo to onabot.

Protease-sensitive synthetic prions.

Prions arise when the cellular prion protein (PrP(C)) undergoes a self-propagating conformational change; the resulting infectious conformer is designated PrP(Sc). Frequently, PrP(Sc) is protease-resistant but protease-sensitive (s) prions have been isolated in humans and other animals. We report here that protease-sensitive, synthetic prions were generated in vitro during polymerization of recombinant (rec) PrP into amyloid fibers. In 22 independent experiments, recPrP amyloid preparations, but not recPrP monomers or oligomers, transmitted disease to transgenic mice (n = 164), denoted Tg9949 mice, that overexpress N-terminally truncated PrP. Tg9949 control mice (n = 174) did not spontaneously generate prions although they were prone to late-onset spontaneous neurological dysfunction. When synthetic prion isolates from infected Tg9949 mice were serially transmitted in the same line of mice, they exhibited sPrP(Sc) and caused neurodegeneration. Interestingly, these protease-sensitive prions did not shorten the life span of Tg9949 mice despite causing extensive neurodegeneration. We inoculated three synthetic prion isolates into Tg4053 mice that overexpress full-length PrP; Tg4053 mice are not prone to developing spontaneous neurological dysfunction. The synthetic prion isolates caused disease in 600-750 days in Tg4053 mice, which exhibited sPrP(Sc). These novel synthetic prions demonstrate that conformational changes in wild-type PrP can produce mouse prions composed exclusively of sPrP(Sc).

Natural and synthetic prion structure from X-ray fiber diffraction.

A conformational isoform of the mammalian prion protein (PrP(Sc)) is the sole component of the infectious pathogen that causes the prion diseases. We have obtained X-ray fiber diffraction patterns from infectious prions that show cross-beta diffraction: meridional intensity at 4.8 A resolution, indicating the presence of beta strands running approximately at right angles to the filament axis and characteristic of amyloid structure. Some of the patterns also indicated the presence of a repeating unit along the fiber axis, corresponding to four beta-strands. We found that recombinant (rec) PrP amyloid differs substantially from highly infectious brain-derived prions, both in structure as demonstrated by the diffraction data, and in heterogeneity as shown by electron microscopy. In addition to the strong 4.8 A meridional reflection, the recPrP amyloid diffraction is characterized by strong equatorial intensity at approximately 10.5 A, absent from brain-derived prions, and indicating the presence of stacked beta-sheets. Synthetic prions recovered from transgenic mice inoculated with recPrP amyloid displayed structural characteristics and homogeneity similar to those of naturally occurring prions. The relationship between the structural differences and prion infectivity is uncertain, but might be explained by any of several hypotheses: only a minority of recPrP amyloid possesses a replication-competent conformation, the majority of recPrP amyloid has to undergo a conformational maturation to acquire replication competency, or inhibitory forms of recPrP amyloid interfere with replication during the initial transmission.