Seizures Detected at Low Levels of Central Thalamus Stimulation in Mice Study
August 21, 2024
Article Published by News Medical
Researchers at Massachusetts Institute of Technology and Massachusetts General Hospital are testing a method to electrically stimulate the central thalamus (CT), which is located deep in the brain. This method of stimulation, called CT-deep brain stimulation (DBS), can help arouse subjects from unconscious states induced by traumatic brain injury or anesthesia and can boost cognition and performance in awake animals. However, it can also result in seizures. The seizures associated with CT-DBS manifest as absence seizures, in which the subject appears to take on a blank stare and freezes for about 10-20 seconds. Researchers searched for an ideal stimulation current below which seizures could be reliably avoided by developing a protocol of starting brief bouts of CT-DBS and then incrementally ramping up the current until they found a threshold where a seizure occurred. Once they found that threshold, they then tested a longer bout of stimulation at the next lowest current level in hopes that a seizure wouldn’t occur. To their surprise, seizures still occurred during those longer stimulation trials.
The researchers also found that when a seizure occurred, it did so more quickly at higher currents than at lower levels. Finally, they saw that seizures occurred more quickly if they stimulated the thalamus on both sides of the brain versus just one side. “Understanding production and prevalence of this type of seizure activity is important because brain stimulation-based therapies are becoming more widely used,” said co-senior author Emery N. Brown. These findings could also have implications for broader understanding of the basic mechanisms of epilepsy.