Saccadometry in Primary Headache Syndromes

Migraine is one of the commonest neurological disorders, affecting up to 12% of the general population, but remains relatively under-diagnosed and under-treated. Migraine has a wide socioeconomic impact and brings a large economic burden; estimates suggest that disability due to migraine costs > €27 billion per annum across Europe. Despite its prevalence and impact, migraine pathophysiology is poorly understood. A wider understanding of the functional changes in this disorder would be beneficial to both diagnosis and treatment.

Saccades are the rapid eye movements we make when moving the eyes to a new object in our visual field. Reaction time studies have been used to investigate Huntington's disease and Parkinson's disease with great success. These use saccadic tasks (monitoring eye movements). Even at rest we make approximately three saccades per second, so a lot of data can quickly be gathered with non-invasive testing. We hope to understand more of the underlying mechanisms of migraine by studying reaction time in migraine patients.

Our previous pilot study, with less stringent inclusion and exclusion criteria, looked at fewer patients (32 migraineurs and 32 controls), and found that migraineurs showed significantly different saccadic patterns to non-migraineurs.

This study firstly seeks to corroborate the saccadometric findings of our earlier pilot study in a group of migraineurs, and secondly to explore the specificity of these findings in migraine by also studying patients with another primary headache syndrome, namely cluster headache.

Migraine is known to be a dynamic disorder, with previous studies showing longitudinal changes in the migraine brain. To explore this further we hope to record longitudinally (Every day for 21 days) in a small subset of migraineurs to identify potential longitudinal changes in saccadic reaction time. Because of the portability of the equipment this could be done in the subjects own home if they preferred.