Migraines linked to decrease in cognitive performance

When people experience migraines, their cognitive performance may decrease, and the duration and frequency of the migraine may be related to the degree of cognitive dysfunction, according to research published in The Journal of Headache and Pain.

“Given the high prevalence of migraine in the general population, it is clear that the relationship between cognitive dysfunction and migraines present a significant public health interest,” wrote lead author Lifang Huang, Department of Neurology, Renmin Hospital of Wuhan University, Wuhan, People’s Republic of China, and colleagues. “Previously, people paid more attention to the pain of migraines and usually ignored the impairments of cognitive function in migraineurs. Although this functional phenomenon is present in the absence of clinically relevant deficits, it may reflect a vulnerability to executive high-demanding conditions of daily living activities in patients with migraine,” they added.

In this randomized, cross-sectional study, Huang et al sought to assess changes in cognitive performance in patients with migraine with a comprehensive series of cognitive/behavioral and electrophysiologic tests.

“This study aimed to characterize cognitive testing and P3 [the most studied cerebral wave in the evaluation of cerebral information processing] in migraineurs. We hypothesized that migraine patients have cognitive dysfunction and P3 abnormalities, such as reduced P3 amplitude and/or a prolonged latency, suggesting alterations in the cognitive-evaluative component.”

The study included 34 migraine patients (average age: 36 years; 6 males; 10 with aura) from the Renmin Hospital of Wuhan University. The patients had experienced an average of 3.532 headaches per month, with an average duration of 23.4 hours, and had migraines for an average of 11 years. Patients were not being treated with prophylactic medications, were medicine-free for at least 24 hours, and in the interictal period when recruited. The control group was comprised of 24 healthy, age-matched subjects (mean age: 36 years; 6 males) who had no history of headache or drug or alcohol abuse.

Compared with healthy subjects, patients with migraine performed worse on most of the Montreal Cognitive Assessments (MoCA) (P=0.007), which screened for general cognitive ability. Significant differences were seen in language (P=0.005), memory (P=0.006), executive functions (P=0.042), calculation (P=0.018), and orientation (P=0.012).

Results from the Rey-Osterrieth complex figure test (ROCF), used to assess visual perception, constructional praxis, and visuo-spatial memory, also showed that patients with migraines had lower memory scores (P=0.012).

In electrophysiologic assessments designed to assess event-related potential (ERPs), Huang and colleagues focused on measuring P3, because it is the most studied cerebral wave in the evaluation of cerebral information processing. They found no significant differences in accuracy between migraineurs and controls (97.4% vs 98.38%, respectively; P=0.187) or in appropriate reaction time (449.1 vs 445.1 ms; P=0.272).

They did find, however, prolonged P3 latency in the Fz, Cz, and Pz electrode sites in patients with migraines compared with normal controls (P < 0.001). In the migraine group, the P3 amplitude was variable between sites, maximal in the parietal lobe (Pz: 9.906 µV), and minimal in the frontal lobe (Fz: 8.243 µV).

In addition, researchers observed significant, negative correlations between the MoCA score and duration of migraine, particularly in language, executive function, calculation, and memory. Also correlated to the frequency of migraine were decreases in MoCA-executive function and calculation score and decreases in the ROCF-recall scores.

Finally, patients with migraines were more anxious than healthy controls (P=0.001). The differences were not related to age, gender, or literacy.

“Cognitive performance decreases during migraine, especially in language, memory, executive functions, calculation, and orientation, and cognitive dysfunctions can be related to the duration and the frequency of headache. These findings suggest the existence of brain dysfunction during attacks of migraine, which can relate specifically to migraine. We believe that it is necessary to shorten the duration and reduce the frequency of migraine attack. Careful clinical evaluation should be performed in migraine patients to diagnose early cognitive dysfunction and, if available, have them treated properly,” concluded Huang and fellow authors.