Introduction. We aimed to define the prevalence of objective cognitive impairment in a group of chronic migraineurs, and to define how migraineurs with cognitive impairment differed from those without impairment, and in doing so to compare cognitive impairment in chronic migraine to another chronic headache-related disorder already associated with cognitive impairment (i.e. pseudotumor cerebri syndrome).

Objectives. Cognitive impairment in migraine, especially chronic migraine, has been too little studied. Only a few studies have been done, demonstrating that cognitive impairment exists in chronic migraineurs. It is not known how this compares to other headache-related conditions.

Material and methods. We administered a cognitive battery consisting of the National Adult Reading Test, Mini-Mental Status Examination, Digit Span, Boston Naming Test, Rey Auditory Verbal Learning Test, Trail Making Test, Controlled Oral Word Association, and Category Fluency. Cognitive impairment was defined as mild single-domain with one test score, and mild multi- -domain with two scores more than two standard deviations below the mean for age-, gender-, and education-adjusted norms. The data from this study was compared to our previously published population of patients with pseudotumor cerebri syndrome.

Results. One hundred prospectively recruited patients with chronic migraine were enrolled. Fifty-seven patients had normal cognitive profiles. Forty-three patients demonstrated mild cognitive impairment, and more than half (n = 24) showed impairment in multiple cognitive domains. Migraineurs with multi-domain impairment had higher pain intensity, shorter duration of disease, were taking narcotics, had more impaired vision-related mental health scores, and worse social health scores. We found an association between objective cognitive impairment and subjective perception of impairment only when controlling for pain. We found no associations with depression and topiramate use. The mean composite cognitive Z score was no different in chronic migraineurs and patients with pseudotumor cerebri.

Conclusions and clinical implications. Most chronic migraineurs have normal cognitive profiles, but a large proportion of them do experience mild cognitive impairment, especially in multiple domains. The impairment seen in migraine is similar to that in pseudotumor cerebri syndrome, which has already been associated with mild cognitive impairment. Cognitively impaired migraineurs are different from non-impaired/less impaired migraineurs in several ways, which may be an important factor in influencing their migraine treatment.