Sleep and Epilepsy: Demystifying the thousand-year-long conundrum

According to WHO, epilepsy is the fourth most common neurological disease globally. CDC statistics show that 1 in 26 individuals in the U.S. will be diagnosed with epilepsy over a lifetime. While there are 36 epilepsy drugs available on the market, 1 in 3 adult patients and 20 to 25% of child patients have drug-resistant epilepsy. When having a seizure, patients with epilepsy (PWE) may suffer from temporary loss of consciousness, sensation, and motor control. The notorious nature of generalized tonic-clonic seizure (GTCS) has been known for a long time, especially the correlation between high-frequency GTCS and sudden unexpected death in epilepsy (SUDEP)

Based on patient surveys, the seemingly random timing of seizures is one of the worst aspects of epilepsy. Unexpected episodes are disruptive, significantly hindering their daily routines. Sometimes, there may be severe secondary damage, such as having an attack while driving or sporting. Over hundreds of years, patients have subjectively reported bad sleep as a trigger for seizures. However, these claims lacked substantiated and objective evidence. 

We discovered (i) the patient-specific effect of sleep on seizure risk and (ii) how sleep, including sleep deficiency, regularity, efficiency, and fragmentation, can forecast next-day seizure risk with Bayesian hierarchical models from FDA-cleared wearable data of more than 2,000 patients. Also, we investigated circadian and multi-day rhythms in ambulatory wrist electrodermal activity (EDA) with wavelet methods and how these rhythms can serve as prognostic biomarkers for seizures. These findings can pave the way for better patient guidance and possible preventive and GTCS forecasting measures.