ABSTRACT
BACKGROUND AND OBJECTIVES: A sizable literature has studied neuropsychologic function in persons with migraine (PwM), but despite this, few quantitative syntheses exist. These focused on circumscribed areas of the literature. In this study, we conducted an expanded comprehensive meta-analysis comparing performance on clinical measures of neuropsychological function both within and across domains, between samples of PwM and healthy controls (HCs). METHODS: For this Meta-analyses Of Observational Studies in Epidemiology-compliant meta-analysis, a unified search strategy was applied to OneSearch (a comprehensive collection of electronic databases) to identify peer-reviewed original research published across all years up until August 1, 2023. Using random-effects modeling, we examined aggregated effect sizes (Hedges' g), between-study heterogeneity (Cochran Q and I2), moderating variables (meta-regression and subgroup analyses), and publication bias (Egger regression intercept and Duval and Tweedie Trim-and-Fill procedure). Study bias was also coded using the NIH Study Quality Assessment Tools. RESULTS: Omnibus meta-analysis from the 58 studies included (PwM n = 5,452, HC n = 16,647; 612 effect sizes extracted) indicated lower overall cognitive performance in PwM vs HCs (g = -0.37; 95% CI -0.47 to -0.28; p < 0.001), and high between-study heterogeneity (Q = 311.25, I2 = 81.69). Significant domain-specific negative effects were observed in global cognition (g = -0.46, p < 0.001), executive function (g = -0.45, p < 0.001), processing speed (g = -0.42, p < 0.001), visuospatial/construction (g = -0.39, p = 0.006), simple/complex attention (g = -0.38, p < 0.001), learning/memory (g = -0.25, p < 0.001), and language (g = -0.24, p < 0.001). Orientation (p = 0.146), motor (p = 0.102), and intelligence (p = 0.899) were not significant. Moderator analyses indicated that age (particularly younger HCs), samples drawn from health care facility settings (e.g., tertiary headache centers) vs community-based populations, and higher attack duration were associated with larger (negative) effects and accounted for a significant proportion of between-study heterogeneity in effects. Notably, PwM without aura yielded stronger (negative) effects (omnibus g = -0.37) vs those with aura (omnibus g = -0.10), though aura status did not account for heterogeneity observed between studies. DISCUSSION: Relative to HCs, PwM demonstrate worse neurocognition, as detected by neuropsychological tests, especially on cognitive screeners and tests within executive functioning and processing speed domains. Effects were generally small to moderate in magnitude and evident only in clinic (vs community) samples. Aura was not meaningfully associated with neurocognitive impairment.
Subject(s)
Epilepsy , Migraine Disorders , Humans , Headache , Ambulatory Care Facilities , Cognition , Observational Studies as TopicABSTRACT
BACKGROUND: Primary dystonia is conventionally considered as a motor disorder, though an emerging literature reports associated cognitive dysfunction. OBJECTIVES: Here, we conducted meta-analyses on studies comparing clinical measures of cognition in persons with primary dystonia and healthy controls (HCs). METHODS: We searched PubMed, Embase, Cochrane Library, Scopus, and PsycINFO (January 2000-October 2020). Analyses were modeled under random effects. We used Hedge's g as a bias-corrected estimate of effect size, where negative values indicate lower performance in dystonia versus controls. Between-study heterogeneity and bias were primarily assessed with Cochran's Q, I2 , and Egger's regression. RESULTS: From 866 initial results, 20 studies met criteria for analysis (dystonia n = 739, controls n = 643; 254 effect sizes extracted). Meta-analysis showed a significant combined effect size of primary dystonia across all studies (g = -0.56, P < 0.001), with low heterogeneity (Q = 25.26, P = 0.15, I2 = 24.78). Within-domain effects of primary dystonia were motor speed = -0.84, nonmotor speed = -0.83, global cognition = -0.65, language = -0.54, executive functioning = -0.53, learning/memory = -0.46, visuospatial/construction = -0.44, and simple/complex attention = -0.37 (P-values <0.01). High heterogeneity was observed in the motor/nonmotor speed and learning/memory domains. There was no evidence of publication bias. Moderator analyses were mostly negative but possibly underpowered. Blepharospasm samples showed worse performance than other focal/cervical dystonias. Those with inherited (ie, genetic) disease etiology demonstrated worse performance than acquired. CONCLUSIONS: Dystonia patients consistently demonstrated lower performances on neuropsychological tests versus HCs. Effect sizes were generally moderate in strength, clustering around -0.50 SD units. Within the speed domain, results suggested cognitive slowing beyond effects from motor symptoms. Overall, findings indicate dystonia patients experience multidomain cognitive difficulties, as detected by neuropsychological tests. © 2022 International Parkinson and Movement Disorder Society.
