Seizures can occur when brain heals from injuries

Chronic seizures may be triggered by chemicals released by the brain's immune system trying to repair critically injured brain sites, according to a new study.

These findings could help prevent one of the most common forms of adult epilepsy or acquired epilepsy, often found in people who have suffered a brain injury or infection, said Colorado University-Boulder (CU-B) neuroscientist Daniel Barth, chief study co-author.

For decades researchers have focused on neurons as the culprits in seizures, which can be characterised as debilitating "electrical storms" in the brain. However, recent research has shown that micro-glial cells may play a major role in seizures.

Researchers have found that glial cells, which are supportive cells that also constitute a major part of the brain's immune system, cluster within areas in the brain when a severe brain injury has occurred.

"When there has been serious damage to the brain, such as a head injury or infection, the immune system is activated and tries to counteract the damage and repair it," Barth said.

"These glial cells migrate to the damaged area and release chemicals called cytokines that, unfortunately, also profoundly increase the excitability of the neurons that they are near."

"In our new study, we showed for the first time that glial cells moving in and secreting these cytokines cause the neurons in the area to become excitable enough to cause seizures," he added.

The findings are extremely promising, according to Barth, because if the brain's initial immunity reaction could be temporarily shut down, this could prevent the development of acquired epilepsy.

The results appeared in the July issue of the journal Brain.

Last updated on Jul 14^th, 2009 at 15:50 pm IST--IANS