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Lesions of the brain microvessels include white-matter hyperintensities and the much less common silent infarcts leading to loss of white-matter tissue. White-matter hyperintensities are common in the elderly, and are generally regarded as ‘normal’ (although a recent study suggested we should be less blasé about them — that ‘normal’ age-related cognitive decline reflects the presence of these small lesions). However, the degree of white-matter lesions is related to the severity of decline (including increasing the risk of Alzheimer’s), and those with hypertension or diabetes are more likely to have a high number of them.

A new study has investigated the theory that migraines might also lead to a higher number of white-matter hyperintensities. The ten-year French population study involved 780 older adults (65+; mean age 69). A fifth of the participants (21%) reported a history of severe headaches, of which 71% had migraines.

Those with severe headaches were twice as likely to have a high quantity of white-matter hyperintensities as those without headaches. However, there was no difference in cognitive performance between the groups. Those who suffered from migraines with aura (2% of the total), also showed an increased number of silent cerebral infarcts — a finding consistent with other research showing that people suffering from migraine with aura have an increased risk of cerebral infarction (or strokes). But again, no cognitive decline was observed.

The researchers make much of their failure to find cognitive impairment, but I would note that, nevertheless, the increased number of brain lesions does suggest that, further down the track, there is likely to be an effect on cognitive performance. Still, headache sufferers can take comfort in the findings, which indicate the effect is not so great that it shows up in this decade-long study.

Older news items (pre-2010) brought over from the old website

Chronic pain can impair working memory

A study of 24 patients with chronic pain has found that 2/3 of them showed cognitive impairment on attentional tasks on days when their pain was high (i.e. without receiving a pain-reducing procedure).

Dick, B.D. & Rashiq, S. 2007. Disruption of Attention and Working Memory Traces in Individuals with Chronic Pain. Anesthesia & Analgesia, 104 (5), 1223-1229.

Does migraine protect your memory?

A long-running study involving 1,448 women, of whom 204 had migraine, has found that, while women with migraine performed worse on cognitive tests at the beginning of the study, their performance declined 17% less over 12 years than women without migraine. The benefit was restricted to women over 50 who experience migraine with aura. It’s possible that some medications for migraine may have a protective effect, but the researchers did account for this possibility and the medications showed no indication of a significant protective effect. It is possible that women with migraine may change their diet or behavior in some way that might improve cognition. It’s also possible that there is some underlying biological mechanism, such as changes in blood vessels or underlying differences in brain activity.

Kalaydjian, A., Zandi, P.P., Swartz, K.L., Eaton, W.W. & Lyketsos, C. 2007. How migraines impact cognitive function: Findings from the Baltimore ECA. Neurology, 68 (17), 1417-1424.

Chronic back pain shrinks 'thinking parts' of the brain

A new study has found chronic back pain shrinks the brain by as much as 11% — equivalent to the amount of gray matter lost in 10 to 20 years of normal aging. Loss in brain density is related to pain duration, indicating that 1.3 cubic centimeters of gray matter are lost for every year of chronic pain. The study compared 26 participants with chronic back pain for more than a year with matched normal subjects.

Apkarian, A.V., Sosa, Y., Sonty, S., Levy, R.M., Harden, R.N., Parrish, T.B. & Gitelman, D.R. 2004. Chronic Back Pain Is Associated with Decreased Prefrontal and Thalamic Gray Matter Density. Journal of Neuroscience, 24, 10410-10415.