Lack of oxygen, not excessive stimulation, cause for half of seizure-related brain damage in epilepsy
A new study to be published in the journal Scientific Reports, describes researchers’ investigation into the true culprit for seizure-related neuronal degeneration in epilepsy. Professors Stephen Macknik, PhD, and Susana Martinez-Conde, PhD of SUNY Downstate Medical Center were co-authors in the study.
Advanced imaging enabled researchers to detect a cascade of abnormal capillary vasodynamics which indicate that even though blood can be observed flowing into the hippocampus — a part of the brain that suffers damage from seizures — an unusually high number of microscopic vascular spasms block flow to some of the delicate brain tissue. This cumulative damage over a lifetime of seizures could contribute to severe cognitive decline or even death in patients with epilepsy. The study also discovered that microscopic spasms in capillaries occur, albeit with lower frequency, during normal brain function, too, suggesting that one problem caused by epilepsy is that seizures drive these vasospasms to abnormal levels.
The study delved further into the mechanism of the vasospasms and found that tiny cells on capillaries, called mural cells, are precisely associated with the points of the vasospasms in the vessels. This contributes to the growing literature that suggests that capillaries are not simply passive tubes through which blood cells flow to irrigate tissue, but rather they may actively contribute to the control of local blood flow directly.