Patients with chronic migraine (CM) display cognitive deficits with respect to many tasks, irrespective of comorbidities or medication use, according to a new study published in Arquivos de Neuro-Psiquiatria.
“Several studies have looked at the association between migraine and cognitive function but results from these studies are mixed,” wrote authors, led by Karen S. Ferreira, Centro Universitário Barão de Mauá, Faculdade de Medicina, Neurologia Clínica, Ribeirão Preto, Brazil.
In one multicenter prospective cohort study, for instance, researchers found that migraine without aura was associated with decreased cognitive function, although CM was not specifically studied. Researchers in another study, however, found that there was no association between migraine and faster cognitive decline in elderly patients.
In this study, investigators evaluated the presence of cognitive deficits in patients with CM vs controls. They also analyzed factors that trigger cognitive disorders, including depression, anxiety, nonrestorative sleep, alcohol abuse, head trauma, and use of medications that affect the central nervous system (ie, topiramate). The team hopes that the results of their study will help improve strategies to manage cognitive disorders in patients with CM.
In this descriptive cross-sectional study, the researchers included 60 subjects: 30 with CM and 30 controls. In both the CM group and control group, 29 of 30 patients (96.7%) were women, and the average age was 33.7 years.
The team ascertained the frequency and intensity of headache, medication used, and associated comorbidities in the patients, and these patients were given extended neuropsychological assessment.
Overall, the CM group exhibited a worse performance on the Montreal Cognitive Assessment (P=0.00), Verbal Fluency (P=0.00), Stroop (P=0.00), Clock Drawing (P=0.00), Wechsler Adult Intelligence Scale (WAIS-III) Digit Span (P=0.00), and WAIS-III Matrix Reasoning tests compared with the control group. After controlling for covariates via linear regression, migraine endured as the only relevant factor for diminished performance on the Montreal Cognitive Assessment, Verbal Fluency, Clock Drawing, and Stroop tests.
“These data indicate significant impairment of cognition caused specifically by CM, including language use (Verbal Fluency Test), visuospatial skills (Clock Drawing Test), and attention (Stroop Test),” wrote the authors.
Notably, comorbidities such as nonrestorative sleep and topiramate use yielded the worst results in patients with CM per the WAIS-III Digit Span assessment, which measures short-term memory, attention, and concentration. Topiramate has been previously tied to attention deficit, which may explain these results.
The investigators noted that the relationship between the pain of CM and cognitive deficits is complex and could be explained by overlapping neural rates. Furthermore, pain leads to hypervigilance and focusing attention away from cognitive tasks.
The team suggested that one potential clinical implication of their findings is that patients with CM should be more closely assessed for cognitive deficits, including brief neuropsychological examination. Clinicians can optimize treatments based on the detection of these deficits.
One limitation of this study involved the lack of MRI scans to examine brain lesions, which are linked to cognitive and migraine decline.
“There are strategies for cognitive interventions to improve these deficits that go beyond the treatment of pain itself and of depressive and anxiety disorders,” the authors concluded. “Thus, patients diagnosed with these deficits would benefit from ‘cognitive training,’ improving their quality of life.”