Chronic migraines increase the risk for decline in cognitive function

Patients with chronic migraine may have a higher risk of cognitive decline, especially in language fluency, and the overuse of nonsteroidal anti-inflammatory drugs (NSAIDs) did not exert any protective effects, according to results from a recent study published in Cephalalgia. In addition, researchers found a higher risk of memory and executive dysfunction in patients with chronic migraine with medication overuse headaches (CM-MOH)—the most common form of chronic migraine.

“Repeated migraine episodes can increase the risk of cerebrovascular diseases, such as stroke and increasing white matter lesion. These pathologies were known to be responsible for cognitive decline in migraineurs,” wrote lead author Xiaoying Cai, Department of Anesthesiology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China, and colleagues.

“So far, it has been demonstrated that these sufferers usually exhibit cognitive decline during acute attacks, including the deficit of executive function, language, visuospatial ability, and complex tasks. These might be attributed to the reduction of intracranial blood perfusion and the related changes during episodes. However, the cognitive performances recovered in the interictal periods, suggesting the reversibility of cognition among them,” they added.

In this cross-sectional study, Cai and fellow researchers divided 116 patients recruited from a neurology outpatient clinic according to type of chronic migraine: CM-MOH (n=21), chronic migraine without medication overuse headache (CMwoMOH; n=20), and migraine without aura (MO; n=35). They assessed interictal cognitive function via Addenbrooke’s Cognitive Examination Test (ACE-R), the Trail Making Test A/B (TMT A/B), and the Digit Symbol Test (DST), and compared results from all migraine patients with those from 40 controls.

For headache relief, all patients took NSAIDs, including aminopyrine, phenacetin, aspirin, ibuprofen, and acetaminophen. Patients with CM-MOH took higher doses with greater frequency compared with the other two headache groups.

The researchers found that the independent risk factors for cognitive decline included age and education (P < 0.05). After adjustment, they also observed a higher risk of cognitive decline in chronic migraineurs compared with controls in both the ACE-R score and language fluency (P < 0.05).

CM-MOH patients had a higher risk of memory and executive dysfunction compared with MO and controls (P < 0.05). But, there were no significant differences in memory and TMT A+B between the groups, with similar findings in attention, language fluency, language, and visuospatial testing.

In patients with cognitive decline, defined as the lowest 20% performance of each cognitive score, CM-MOH and CMwoMOH subjects had a higher morbidity rate compared with controls. This was especially true for ACE-R total scores, language fluency, and executive function scores (P < 0.05).

Cognitive function did not differ between the CM-MOH and CMwoMOH patients (P < 0.05); however, CM-MOH patients scored significantly higher in both anxiety and depression compared with MO, and had poorer sleep and quality of life (P < 0.05). Anxiety and depression scores were not significantly different between the CMwoMOH, CM-MOH, and MO groups.

Finally, in evaluating the association between chronic migraine and cognitive function, researchers found no significant differences between the CMwoMOH and MO groups.

“[O]ur study displayed that the estimation of anxiety and depression was severe in CM-MOH sufferers, as well as worse in life quality and sleep quality, compared with MO. Previous studies had found that constant suffering of anxiety, depression, or lack of sleep could influence cognition. Meanwhile, they could also induce migraine chronification. Although, in our study, they were not the independent risk factors of cognitive decline under univariate regression analysis, we should still pay attention to them in clinical practice,” said Cai et al.

Many studies have documented the detrimental effects of inflammation on cognitive function, and the long-term exposure to inflammation experienced by patients with chronic migraine may play a role in their cognitive decline, noted the authors.

“In the present study, we did not find any differences in cognitive performance between CMMOH and CMwoMOH. This indicated that the brain lesion-related dysfunction of [chronic migraine] patients might be irreversible, and it exceeded the protective effect of NSAIDs,” they concluded.

This study was supported by grants from the National Natural Science Foundation of China and Science and Technology Program of Guangzhou.