Migraine refers to recurrent, unilateral headache attacks, lasting 4-72 hours, that have a pulsating quality and can occur with or without aura. Aura is a symptom, usually preceding the onset of a migraine, where there is an experience of gradually spreading focal neurological symptoms which typically last less than one hour. A meta-analysis was conducted which quantitatively synthesized literature documenting performance on clinical measures of processing speed (PS) in individuals with migraine with (MwA) and without aura (MwoA).

Data for this study came from a larger study that compared overall neuropsychological functioning in primary headache disorders (PHD) and healthy controls (HC). We searched OneSearch and PubMed using a uniform search-strategy to locate original research comparing cognition between PHD and HC. Analyses were modeled under random effects. Hedge’s g was used as a bias-corrected estimate of effect size. We assessed between-study heterogeneity using Cochran’s Q and I2. Egger’s regression test was used to assess publication bias (i.e., the association between standard error and effect size). High heterogeneity in effects was analyzed for possible moderating variables using metaregression and sub-group analyses.

The initial search interval spanned inception-May 2021 and yielded 6692 results. Twelve studies met inclusion criteria, included clinical measures of PS, and included PHD subgroups with MwA and/or MwoA (MwA n = 279, MwoA n = 655, HC n = 2159). MwA demonstrated moderately worse performance in PS overall when compared to HC (k = 7, g = -0.41, p = 0.028). MwoA also demonstrated worse performance in PS overall when compared to HC but the effect size was small (k = 12, g = -0.21, p = 0.006). Heterogeneity of MwoA studies was low (Q = 15.12, I2 = 21.19) while heterogeneity of MwA studies was high (Q = 21.91, I2 = 72.61). Meta-regressions of MwA studies indicated clinical age and disease duration to be related to effect sizes such that studies with older clinical participants and longer disease durations yielded greater (negative) differences. Egger’s regression intercept noted a possible association effect size and standard error for MwA articles (t = 3.60, p = 0.02) and MwoA articles (t = 5.21, p < 0.005). Trim-and-fill procedure estimated 0 MwA studies to be missing due to publication bias (adjusted g = -0.41, p = 0.028) while 7 MwoA studies were estimated to be missing due to publication bias (adjusted g = -0.03, Q = 34.79).

Individuals with migraine demonstrated worse performances on tests of PS compared to controls. Effect sizes were generally moderate in strength for MwA while effect sizes were generally small in strength for MwoA. This quantitative summary confirmed that individuals with migraine experience slowed processing speed in general and this effect is magnified when aura is a presenting symptom.

Primary headache disorder is characterized by recurrent headaches which lack underlying causative pathology or trauma. Primary headache disorder is common and encompasses several subtypes including migraine. Vestibular migraine (VM) is a subtype of migraine that causes vestibular symptoms such as vertigo, difficulties with balance, nausea, and vomiting. Literature indicates subjective and performance-based cognitive problems (executive dysfunction) among migraineurs. This study compared the magnitude of the total effect size across neuropsychological domains to determine if there is a reliable difference in effect sizes between individuals with VM and healthy controls (HC). An additional aim was to meta-analyze neuropsychological outcomes in migraine subtypes (other than VM) in reference to healthy controls.

This study was a part of a larger study examining neuropsychological functioning and impairment in individuals with primary headache disorder and HCs. Standardized search terms were applied in OneSearch and PubMed. The search interval covered articles published from 1986 to May 2021. Analyses were random-effects models. Hedge’s g was used as a bias-corrected estimate of effect size. Between-study heterogeneity was assessed using Cochran’s Q and I2. Publication bias was assessed with Duval and Tweedie’s Trim-and-Fill method to identify evidence of missing studies.

The initial omnibus literature search yielded 6692 studies. Three studies (n=151 VM and 150 HC) met our inclusion criteria of having a VM group and reported neuropsychological performance. VM demonstrated significantly worse performance overall when compared to HCs (k=3, g=-0.99, p<0.001; Q=4.41, I2=54.66) with a large effect size. Within-domain effects of VM were: Executive Functioning=-0.99 (Q=0.62, I2=0), Screener=-1.15 (Q=3.29, I2=69.59), and Visuospatial/Construction=-1.47 (Q=0.001, I2=0.00). Compared to chronic migraine (k=3, g=-0.59, p<0.001; Q=0.68, I2=0.00) and migraine without aura (k=23, g=-0.39, p<0.001; Q=109.70, I2=79.95), VM was the only migraine subgroup to display a large effect size. Trim-and-fill procedure estimated zero VM studies to be missing due to publication bias (adjusted g=-0.99, Q=4.41).

This initial attempt at a meta-analysis of cognitive deficits in VM was hampered by a lack of studies in this area. Based on our initial findings, individuals with VM demonstrated overall worse performances on neuropsychological tests compared to HCs with the greatest level of impairment seen in visuospatial/construction. Additionally, VM resulted in a large effect size while other migraine subtypes yielded small to moderate effect sizes. Despite the small sample of studies, the overall effect across neuropsychological performance was generally stable (i.e., low between-study heterogeneity). Given than VM accounts for 7% of patients seen in vertigo clinics and 9% of all migraine patients, our results suggest that neuropsychological impairment in VM deserves significantly more study.