Migraines and Auras
If you are among the one-third of migraine sufferers who experience aura before a
migraine, you know how unsettling this can be. Auras may include: visual disturbances
(jagged lines, called fortification spectra, with bright spots or flashes); temporary,
partial vision loss; numbness; and tingling sensations.
Scientists have tried to understand the migraine aura for years. But, until recently,
they didn't have the tools to study brain activity during a migraine attack. Technology,
such as functional magnetic resonance imaging (MRI) is performed on migraine patients
while they are having a migraine. This has allowed researchers to see waves of altered
electrical activity, (also called spreading depression), spreading across the brain
during an aura. Experts believe that different areas of the brain are stimulated as
these waves cross the brain, causing the symptoms of aura. Researchers have suggested
that the reason why only some people with migraine have auras is that their brain
is overly sensitive to certain triggers.