Do chronic pain and headache induce cognitive decline in older adults?

A recent systematic review has found studies that report cognitive decline among older patients with chronic pain and headache, but some papers have not seen such association.

“Other studies analysed chronic pain and migraine together, although these conditions are different in presentation and pathophysiology,” the researchers said.

This review, which was presented at the 2022 Annual Meeting of the American Academy of Neurology (AAN 2022), sought to examine the risk of cognitive decline among patients with chronic pain and headache over time.

The researchers accessed the databases of Medline, PubMed, and Embase. Cohort studies assessing the risk of cognitive decline in patients with chronic pain and headache, published until September 2021, were eligible for inclusion.

A total of 1,301 records were identified, of which 20 cohort studies were included in the review. Four out of seven studies (57.1 percent; n=17,368 participants) on chronic pain reported an association between chronic pain and an increased risk of cognitive decline, with risk ratio (RR) ranging from 1.20 to 1.80. [Ferreira K & Velly A, AAN 2022]

Likewise, eight out of 13 studies on headache (61.5 percent; n=315,820 participants) demonstrated the association of headache with greater cognitive decline risk, with RR ranging from 1.15 to 2.97.

Eligible studies included participants with similar range of mean age (for chronic pain: 40‒76.1 years; for headache: 42.2‒70 years) and follow-up (for chronic pain: 4‒27 years; for headache: 5‒19 years).

Notably, the lifelong frequency, intensity, and interference of pain were not consistently evaluated. In addition, cognitive assessment was heterogeneous.

“Future publications can clarify some important points related to the fluctuating trajectory of pain and cognitive decline, since it is not clear whether this association is causal or correlational,” the researchers said.

Migraine

A 2020 study of community dwelling adults (aged >50 years) with migraine and nonmigraine headaches found no increased risk of dementia or cognitive decline at an older age. However, individuals with migraine had more cognitive complaints. [J Headache Pain 2020;21:31]

Notably, while those with migraine had more subjective cognitive complaints (p=0.030), both migraine and nonmigraine headache participants exhibited an age-associated decline identical to that in controls. Migraine features, such as disease and attack duration, were also not associated with cognitive performance. [J Headache Pain 2020;21:31]

On the other hand, an earlier systematic review of all articles containing the key words ‘migraine,’ ‘cognition,’ and ‘cognitive impairment’ found an increased risk of mild changes in several cognitive domains among patients with migraine. [Dement Neuropsychol 2012;6:74-79]

Of the 23 eligible studies, 15 (65.3 percent) reported abnormalities on neuropsychological tests in those with migraine, specifically in tests of memory, attention, and information processing speed. Most of the studies showing cognitive changes in migraine were done in neurological care facilities. In contrast, migraine patients were less likely to exhibit cognitive changes among community-based studies. [Dement Neuropsychol 2012;6:74-79]