A team of University of Iowa neurology researchers found that electrical stimulation of the amygdala of an epilepsy patient can stop the patient from breathing without the patient even realizing breathing had stopped.
The study, which marked the first time researchers have stimulated the amygdala in humans and reported loss of breathing, was published in the Journal of Neuroscience.
Monitoring a research participant with medically intractable epilepsy, researchers found that when seizures spread to the amygdala, the patient stopped breathing. The effect could be reproduced by electrically stimulating the amygdala. The finding was reproduced in two other human subjects.
“Amazingly, the patient was completely unaware that he had stopped breathing,” says lead author Brian Dlouhy, MD, assistant professor of neurosurgery in the University of Iowa Roy J. and Lucille A. Carver College of Medicine. “It was remarkable to all of us that one of the essentials of life—breathing—could be inhibited and the patients themselves were completely unaware of this.”
John Wemmie, MD, PhD, University of Iowa professor of psychiatry, molecular physiology and biophysics, and neurosurgery, says that patient’s breathing stopped for even longer than if he had been asked to hold his breath.
“The patient just sat there, unconcerned that he was not breathing,” Wemmie says. “If we asked him to hold his breath for the same duration of time, it was difficult for him, and he could barely do it. But when the amygdala was stimulated, he didn’t even notice that his breathing had stopped.”
The team’s findings can be used to help to decrease instances of SUDEP, Dlouhy says.
“Identifying brain areas where seizure spread interferes with breathing may help identify patients at risk for SUDEP and lead to preventive strategies,” Dlouhy says.