NOT A HEADACHE

New research improves migraine knowledge

Migraine sufferers experience increased or extreme sensitivity to light and sound, and a new study from the University of Birmingham and the University of Lancaster could finally explain why.

Migraines are a neurological condition characterised by intense, debilitating headaches. An estimated six million people suffer from migraines in the UK – approximately 11 per cent of the population.

The study found that people who suffer from migraine headaches appear to have a hyper-excitable visual cortex, which is the part of the brain that receives, integrates and processes visual information from the retinas.

“Most migraineurs also report experiencing abnormal visual sensations in their everyday life, for example, elementary hallucinations, visual discomforts and extra light sensitivity,” said lead author Dr Terence Chun Yuen Fong.

In the research, 60 volunteers – half of whom regularly suffered from migraines – had to rate a striped pattern according to whether it was uncomfortable to look at, and had to record any associated visual phenomena they experienced. A further EEG test was carried out, allowing researchers to track and record specific brain response patterns. Results from both tests agreed. A larger response to the striped pattern was found in the visual cortex among the group of migraine sufferers when compared to the non-migraine sufferers. However, the study also found hyper-excitability in the visual cortex in a subgroup of nonmigraineurs; those who had reported additional visual disturbances but did not experience migraines.

“Our study provides evidence there are likely specific anomalies present in the way the visual cortex of migraine sufferers processes information from the outside world,” said senior author Dr Ali Mazaheri. “However, we suspect it’s only part of the picture since the same patterns of activity can also be seen in non-migraineurs who are sensitive to certain visual stimuli.”