Smartwatch seizure detection app may help reduce epilepsy-related deaths

In people with epilepsy, a new study has found a smartwatch application accurately detected tonic-clonic seizures, seizures with major convulsions, with a low rate of false alarms. The study was published May 27, 2026, in Neurology^® Open Access, an official journal of the American Academy of Neurology.

For people who have uncontrolled tonic-clonic seizures, which can include a loss of muscle tone and airway obstruction, the risk of sudden unexpected death in epilepsy, called SUDEP, is high, particularly for those who sleep alone. Wearable seizure detection devices can alert caregivers so they can provide first aid, but some devices have high false alarm rates that can discourage use and timely intervention. Our study found the EpiWatch smartwatch app detected nearly all tonic-clonic seizures in participants and had a lower rate of false alarms."

James W. Wheless, MD, study author of Le Bonheur Children's Hospital in Memphis, Tennessee, and a Fellow of the American Academy of Neurology

The study included 242 adults and children with epilepsy, with an average age of 23, who had tonic-clonic seizures or the potential to have such seizures. Participants were each monitored an average of two-and-a-half days in a specialized hospital unit with video-electroencephalograph (EEG) monitoring to track their seizures. Neurologists who specialize in epilepsy classified tonic-clonic and other types of seizures based on the video-EEG monitoring.

A total of 83 people had seizures that involved muscle activity, and 37 experienced at least one tonic-clonic seizure.

Participants also wore smartwatches with the EpiWatch app to track tonic-clonic seizures. Researchers compared video-EEG results with results from the app.

Researchers found the app detected 46 of 47 tonic-clonic seizures, noting that one seizure was missed due to a caregiver restraining a participant's arm.

After over 16,000 hours of study monitoring, there were 56 false alarms, a rate of 0.08 per day, equivalent to one false alarm every 12.4 days. Researchers determined this rate was 90% lower than the rate of other devices which had a range of 0.67 to 2.52 per day.

Of participants, 87% had no false alarms, 9% had one and 4% had two or more. Of the false alarms, 35 were associated with activities such as playing video games or other repetitive movements. There were no adverse effects.

The app had an overall sensitivity of 98%, compared to other devices that had a range of 76% to 94%.

"Wearing some seizure monitoring devices may carry a stigma, but using a common smartwatch with an app does not, which is important for encouraging regular use," said Wheless. "Being prescribed an app with fewer false alarms can encourage long-term use and provide reliable caregiver alerts to help reduce sudden unexpected deaths and other risks associated with tonic-clonic seizures."

A limitation of the study was that all seizures occurred in the controlled environment of an epilepsy monitoring unit and may not represent the variety of conditions in which people experience seizures.

The study was supported by EpiWatch, Inc., the developer of the app.