Millions of people who experience an aura before a migraine live with little understanding of the flashing lights, tingling arms, incoherent speech or other symptoms that presage an attack. But a new study led by a University of Utah neurologist shows that these pre-migraine symptoms, caused by a wave of brain activity, may change the way the brain responds. This wave, called a cortical spreading depression (CSD), might also explain how migraines become chronic in millions of people, according to K.C. Brennan, M.D., Assistant Professor of Neurology at the U of U School of Medicine and senior author on the study.“CSD moves across the brain like a ripple in a pond,” Brennan says. It drives nerve cells to fire uncontrollably, and causes large changes in blood flow. For at least an hour afterward, it changes the way the brain reacts to its environment. “It’s like turning up the volume in all of the senses.” ....After the CSD passed, they saw larger and sharper sensory responses, and a decreased ability to adapt to stimuli.“The CSD wave causes the brain to react differently,” says Brennan. “Every sense is heightened, which is remarkably like what patients describe during their migraines.”The changes – or sensory plasticity – identified by Brennan and colleagues can last long after CSD passes. If repeated over time, they might help explain why some migraines become chronic, according to Brennan.Migraine Auras 'Turn Up the Volume'of the Senses
Makes sense. Wonder what it means when you have persistent migraine auras then? My brain is on fire!