Headache is clearly key, but non-pain symptoms including cognitive dysfunction are a major contributor to the burden and disability of migraine. Functional brain imaging extends our understanding of the neural substrates and prolonged time-course of this complex condition.1,2 But the complexity and burden also have non-neurological aspects since stigma and self-blame are socially conditioned.
Cognitive dysfunction associated with the prodromal and postdromal phases of migraine was emphasized by Nazia Karsan (Clinical Fellow, King’s College Hospital, London, UK) in her Migraine World Summit 2023 interview focused on non-pain aspects of the condition.3
Global cognitive dysfunction can be present before, during and after an attack
For many patients, inability to concentrate and even difficulties in reading, writing and speaking – along with somnolence – add greatly to the migraine burden, especially when they interfere with study or work, Dr Karsan said. Such non-pain symptoms are present in both prodromal and recovery phases4 which, taken together, mean a migraine episode may last for up to four days.
Disability outside the headache phase contributes greatly to morbidity. And these important elements of what is a heterogeneous disease can be difficult to communicate to friends, family and work colleagues, Dr Karsan commented.
“Triggers” may reflect already evolving functional abnormalities
Migraine is a brain disorder, and the brain controls so much of the body that we should not be surprised that the range of associated symptoms reflects widespread dysfunction.
Other notable non-pain symptoms include irritability, mood swings, neck stiffness, sensory hypersensitivities such as photophobia, and abnormal eating behaviours like skipping meals and cravings for cheese or chocolate.
Phenomena like these have traditionally been considered as possible migraine triggers, but they may in fact be symptoms of a brain dysfunction that is already evolving,5 Dr Karsan suggested. If this is true, and such experiences actually reflect premonitory brain changes, avoidance of bright lights or certain foods, for example, may not help in preventing a full-blown migraine episode.
In the pre-headache phase, the brain is already functioning abnormally
Brain scans validate patient experience
Imaging studies in people with spontaneous migraine attacks and in those triggered by nitroglycerin infusion show good correlations between areas of abnormal brain function and patients’ experiences during the premonitory phase.
The cingulate cortex, involved in mood and cognition, shows up on MRI imaging during the prodrome as well as the acute phase, with regions of the pons and medulla implicated in the pain.
Acute headache is the major symptom of migraine, but we also need research into non-pain aspects if we are more effectively to treat and abort an episode, Dr Karsan said. Clinical trials relating to CGRP inhibition have looked at effects on a range of disabling symptomatology and on return to functional ability, and have shown promising results.
We need to think about intervening before the process escalates to pain, and to recognize that patients are not necessarily “back to normal” once their headache has gone. This fact is massively under-recognized, Dr Karsan argued.
Stigma also contributes to burden
It is not just symptoms of migraine that impose burden. It is also stigma. The causes of migraine morbidity extend from the neurological to the sociological.
Partly because the symptoms of migraine cannot be seen, and there are no lab tests to define it, migraine is considered by some to be a condition that sufferers may exaggerate, possibly to obtain advantage, said Dr Robert Shapiro, of the University of Vermont College of Medicine, Burlington, USA.
Employers in particular may not regard migraine as a serious condition
The stigma associated with the disease may come from family and friends, work colleagues and employers, health professionals, and even patients themselves, Dr Shapiro commented during his Migraine World Summit interview. This unsupportive social environment can limit the ability of people with migraine to live full and productive lives.
Importantly, it may lead those with the condition to conceal symptoms and avoid seeking effective treatment. Hence stigma has a direct effect on the physical morbidity associated with migraine as well as imposing an unnecessary psychological burden.
More positively, Dr Shapiro is hopeful that in the next decade or so we will have biomarkers – perhaps including imaging of the kind described above – which can provide a definitive objective diagnosis of migraine. Meanwhile it is important to continue efforts to educate the health community and the wider public about the realities faced by those with the condition.