Brain Cooling to Treat Epilepsy Moves Closer to Human Application

Neuroscientists from Japan’s Yamaguchi University today reported during the 66th annual scientific meeting of the American Epilepsy Society (AES) that chronic focal brain cooling suppresses seizures during wakefulness and achieves the effect without significantly affecting brain function. Their research, and that of others in the field, provides critical evidence that this approach to seizure control has reached a stage where testing in humans will soon be possible.

Focal brain cooling is well established as an effective method for suppressing seizures. But the technology for creating a practical device with potential clinical application has only recently become available and tested in rodents. More evidence from large animals and humans is needed prior to testing in clinical trials for drug-resistant epilepsy.

The Yamaguchi researchers implanted two feline and two non-human primates with a titanium cooling plate, or heat exchanger. The brain cooling device was placed in contact with the brain surface over cortex areas responsible for movement and sensation. Seizures were then induced in the motor cortex. Brain wave recordings to assess seizure activity and temperature recordings were performed under wakefulness.

According to Masami Fujii, M.D.,Ph.D., and Takao Inoue, Ph.D., and Michiyasu Suzuki, M.D., Ph.D., who presented the report, seizure discharges were significantly suppressed at 15˚C (59˚F).

“The results of our study suggest that focal brain cooling has a strong effect to suppress the epileptiform seizures under the awake condition,” Dr. Fujii said. “Moreover, implantation of the device for at least five months did not result in detrimental changes in brain tissue subjected to cooling compared to tissue from a similar site in the opposing hemisphere.”

Yawning may cool brain when needed

Yawning isn’t triggered because you’re bored, tired or need oxygen. Rather, yawning helps regulate the brain’s temperature, according to Gary Hack, of the University of Maryland School of Dentistry, and Andrew Gallup, of Princeton University.

"The brain is exquisitely sensitive to temperature changes and therefore must be protected from overheating," they said in a University of Maryland news release. "Brains, like computers, operate best when they are cool."

During yawning, the walls of the maxillary sinuses (located in the cheeks on each side of the nose) flex like bellows and help with brain cooling, according to the researchers.

They noted that the actual function of sinuses is still the subject of debate, and this theory may help clarify their purpose.

"Very little is understood about them, and little is agreed upon even by those who investigate them. Some scientists believe that they have no function at all," Hack said in the news release.

The researchers said their theory that yawning helps cool the brain has medical implications. For example, excessive yawning often precedes seizures in people with epilepsy and pain in people with migraine headaches.

Doctors may be able to use excessive yawning as a way to identify patients with conditions that affect temperature regulation.

"Excessive yawning appears to be symptomatic of conditions that increase brain and/or core temperature, such as central nervous system damage and sleep deprivation," Gallup said in the news release.