CLEVELAND, March 9 (UPI) -- Researchers found they can detect epilepsy based on changes to heart activity, even in the absence of seizures, according to a new study.
Case Western University researchers said variations in the autonomic nervous system indicate the condition, and suggest treatment to normalize it could help control epilepsy.
The parasympathetic nervous system controls breathing and slows the heart rates of children with epilepsy when they sleep more than healthy children, and the same was found to be true in children with no neurological issues but the same changes to heart activity.
"All the findings of our study on heart rate variability in epilepsy point to increased activity in the parasympathetic nervous system during sleep," Roberto Fernández Galán, an assistant professor of electrical engineering and computer science at Case Western University, in a press release. "But we don't know if this abnormality compensates for epilepsy, coincides with the disease or is part of the etiology."
For the study, published in the Journal of Neurophysiology, the researchers analyzed electrocardiogram and other data for 91 children and adolescents with epilepsy and 25 neurologically normal children collected during 30 minutes of light sleep.
None of the children had seizures during the study. Researchers found increases in heart rate during inhalation and decreases during exhalation, as well as slower heart rates, were more detectable in children with epilepsy.
They report the changes are consistent with effects of the accelerated activity of the vagus nerve in children with epilepsy -- the more the vagus fires, the more the heart rate slows.
The researchers said the study suggests drugs could be used to help get the autonomous nervous system back in line to help control epilepsy, but that more research is needed.