Migraine and its cognitive differences: a blessing or a curse?

Migraine and its special set of cognitive differences: a blessing or a curse?

The brains of people with migraine have a special way of processing sensory input. Headache research suggests that a migraine brain responds to incoming stimuli sooner and faster than a non-migraine brain. Recent evidence based on extensive research demonstrates that specific changes in the human genome are responsible for this particular cognitive predisposition. Researchers combed through the genome in search of minuscule mutations that might link to a predisposition for migraine. Reliable studies in this area are challenging because of the very large sample sizes required. A paper published in 2016 presented the results of research in over 375,000 participants. Analysis of the data identified 44 positions in the human genome where tiny variations are associated with an increased risk of migraine disorder.

The big difference in people with migraine: how they process sensory input

With sensory response on permanent overdrive, the nervous system of people with migraine is constantly on alert. Processing stimuli too quickly or for too long can cause a breakdown in energy supply to the nerves. The mechanisms controlling nerve activity go haywire; pain-triggering chemicals are released non-stop, and the pounding pain of a migraine headache sets in. Heightened stimulus processing is a cognitive trait shared by brilliant achievers like Pablo Picasso, Richard Wagner, and Marie Curie, all of whom had migraine.

Does migraine cause cognitive impairment?

Recent studies have focused on whether migraineurs with their highly active brains experience cognitive impairment during migraine attacks. Scientists are also investigating whether impairment can also occur between attacks, and whether a lifetime of migraine can hasten cognitive decline as you age.

Research pitfalls

Clearly, these questions are at least as relevant to migraineurs as to scientists. But the evidence is not quite as clear (yet), as a look at the latest research literature shows. One reason is because the research involved is heavily based on subjective perception and the personal judgment and experience of those affected. Research into cognitive impairment due to migraine attacks relies on what subjects tell the researchers. For instance, some questionnaires ask whether migraineurs notice any bad effects on their mental performance during or between attacks. Assessments like these are not based on objective test systems but information provided by patients based on their own personal judgment. The impairments are no less relevant for the patients involved. Subjective perception of cognitive impairment can add significantly to the disease burden. Nevertheless, research in these areas walks a tightrope between scientific accuracy and reproducibility on the one hand, and subjective patient perception on the other hand.

Cognitive symptoms during a migraine attack

A comprehensive 2019 review evaluates a number of papers investigating potential cognitive impairment during the various phases of a migraine attack. The authors conclude that cognitive symptoms seem to herald an approaching attack. Speech and reading disorders and poor concentration are common. Low mood and anxiety are also reported. Speech disorders and poor concentration are manifest in the acute phase of an attack, with patients reporting slowed thinking, confused thinking or retardation of thought processes. They also report feeling tired, lethargic, having no energy, or feeling depressed. According to the study, symptoms usually subside when the attack ends. Imaging scans support this observation.

What about between attacks?

In episodic migraine (≤14 migraine days per month), cognition returns to normal between attacks in most people living with migraine. Some people nonetheless experience increased sensitivity to light and some report abnormal pain processing. In chronic migraine (≥15 migraine days per month), recovery periods between attacks are typically shorter. Scans show that the hyperexcitability of certain nerve areas does not completely go away between attacks. In very severe cases, it may become permanent. Another possible consequence is chronic activation of the trigeminal nerve resulting in permanently altered pain processing. This can go on to affect neural processing of emotions and interfere with cognition.

Cognitive dysfunction likely related to attack frequency and duration

A 2017 study investigating the connection between cognitive impairment and the duration and frequency of migraine attacks found that the higher attack frequency associated with chronic migraine has negative impacts on cognition in migraineurs. The authors identified significant deficits in language, memory, executive function (your cognitive control system that helps you stay organized and pay attention), numeracy and orientation. Concomitant electrophysiology studies (EEG: electroencephalogram) suggest that these deficits may correlate with longer neural processing latency, consistent with slowing of impulse conduction and processing. The authors conclude that the effects correlate significantly with attack duration. Some components (executive function and numeracy) also correlate with attack frequency.

Lasting harm is unlikely

Most studies over the past ten years see no evidence of a correlation between lifelong migraine and cognitive deficits; migraine status is not associated with faster rates of cognitive decline late in life (eligible subjects were over 65 or over 50, depending on the study design). So with all the serious limitations migraine brings, there is one consolation: despite the undoubtedly significant (including cognitive) ill-effects of migraine in the course of a lifetime, these events do not seem to leave a lasting mark on later-life cognitive health.