Decreased electrodermal activity in patients with epilepsy

Biofeedback therapy using electrodermal activity (EDA) is a new noninvasive therapy for intractable epilepsy. However, the characteristics of EDA in patients with epilepsy are little known; therefore, we assessed the EDA characteristics in patients with epilepsy.

A cross-sectional observational study was conducted in 22 patients with epilepsy and 24 healthy individuals. We collected information on demographic characteristics, EDA, and state anxiety from both groups, and epilepsy diagnosis, seizure number per month, disease duration, and number of antiepileptic drugs (AED) from the epilepsy group. A wristband device was used to measure resting EDA from both wrists for 10 min under controlled temperature and humidity. We compared the EDA levels between the epilepsy group and the control group and examined correlations between EDA and epilepsy-associated factors in the epilepsy group.

A decreasing trend in EDA was observed during the first 1 min from the start of the measurement in 22 patients with epilepsy (with or without seizures) compared with healthy controls (P = 0.12). However, a significant decrease in EDA was found in 18 patients with epilepsy with seizures compared with healthy controls (-0.48 versus -0.26; P = 0.036). Furthermore, seizure frequency showed a significant inverse correlation with EDA in the epilepsy group (ρ = -0.50, P = 0.016). However, neither disease duration nor the number of drugs prescribed correlated with EDA in the epilepsy group .

Marginally decreased EDA was observed in patients with epilepsy, and significantly decreased EDA was found in patients with a higher seizure frequency. The present findings shed light on the appropriateness of EDA-biofeedback therapy in epilepsy.