Neuropsychological functioning in migraine: clinical and research implications.

AIM: We review the research literature examining neuropsychological performance in migraine. Findings were organized by neuropsychological construct assessed and results were reported using effect size conventions. Factors considered in explaining results included sample characteristics, migraine factors, and control for non-migraine variables.
FINDINGS: There is weak evidence for deficits in processing speed, attention, verbal memory, verbal skills, working memory, sustained attention, and inhibition in migraine relative to healthy controls. There are mixed results regarding deficits in visual memory, motor dexterity, visuospatial/constructional skills, visual reasoning, and mental flexibility in migraine relative to healthy controls. Mixed findings do not seem to be consistently related to study characteristics or presence of aura; other important migraine factors (such as migraine severity or presence of neuroradiological findings) remain understudied. Relative to non-healthy control groups, however, there is weak evidence for an effect of migraine in any cognitive domain. Longitudinal studies provide little evidence that neuropsychological functioning worsens over time in migraine or that migraine is a risk factor for Alzheimer's disease. RESEARCH IMPLICATIONS: It remains possible that cognitive dysfunction is seen in only a subset of migraine sufferers, perhaps those with more severe illness or neurological involvement; however, more research is needed to examine this issue. Non-migraine differences among migraine sufferers, including medical and psychiatric comorbidities and variables associated with treatment seeking, may partially account for inconsistent findings and should be evaluated for in future research. CLINICAL IMPLICATIONS: Clinicians should refer migraine patients for comprehensive neuropsychological evaluation only when there is sufficient evidence for concern. Such evaluations should include consideration of other psychological, neurological, and medical contributors to both migraine and cognitive status.