Mobile Devices May Provide Accurate Seizure Detection and Help Prevent SUDEP

Devices in development could alert caregivers and enable interventions to prevent SUDEP.

Neurology Reviews. 2017 February;25(2):28-29

January 27, 2017|Neurology Reviews

Brain Sentinel

The FDA is reviewing the Brain Sentinel seizure-monitoring system, which uses EMG recordings to detect convulsive seizures. The device takes advantage of a characteristic firing pattern on EMG that is associated with convulsive seizures. Research has indicated that, when used properly, the system detects seizures with near-perfect accuracy. The system’s accuracy was slightly higher in adults than in a group of adults and children. The average time between seizure onset and alarm was 5.34 seconds in adults and 7.70 seconds in adults and children. The rate of false positives per eight-hour period was 0.51 in adults and 0.48 in adults and children. Most false alarms occurred in a minority of participants. “This device is probably going to be effective for detecting convulsive seizures in patients with uncontrolled epilepsy,” said Dr. Krauss.

EpiWatch App

Dr. Krauss and Nathan Crone, MD, Professor of Neurology at Johns Hopkins University School of Medicine, are developing a seizure-detection app called EpiWatch for use on the Apple Watch. Their objective is to use the Apple Watch’s ability to monitor heart rate, movement, and position to detect seizures. Through the Apple Watch’s user interface, the app asks patients to label seizures and attempts to reduce the number of false detections. During a seizure, the app tests the user’s responsiveness by asking him or her to tap the watch. The test occurs at 20 seconds after seizure onset and at one-minute intervals thereafter. If the user is responsive, the app administers a test of working memory that involves repeating a series of random numbers. At 10 minutes after the seizure ends, the app asks the user whether he or she had had a seizure, whether he or she had had an aura, and whether he or she had lost awareness. These data are logged into a journal that can be transmitted.

Drs. Krauss and Crone are using Apple ResearchKit to study the app’s efficacy. They have enrolled approximately 700 participants in the study, and about 40% of them were able to activate the app during a seizure. The seizure types recorded so far are representative of those of the general US population of patients with epilepsy. Approximately 30% of participants had a 50% increase in heart rate during their seizure. About two-thirds of patients had a 30% increase in heart rate. A significant number of patients with complex partial seizures had decreases in heart rate during their seizure. “Heart rate alone would probably not be a sensitive screening technique for seizures, but it could be one component of an algorithm,” said Dr. Krauss.

Can These Devices Prevent SUDEP?

Many of these devices were designed with the goal of enabling interventions, particularly during severe nocturnal convulsive seizures, to prevent SUDEP. The current understanding of SUDEP provides grounds for optimism that such interventions could be achieved, said Dr. Krauss. Many patients with tonic–clonic seizures have oxygen saturation, postictal generalized EEG suppression, and autonomic alterations. If patients become immobile during a seizure and are lying face down, they may become asphyxiated. “The question is whether we can intervene at that point to prevent the subsequent cardiac arrhythmias which lead to their death,” said Dr. Krauss. A caregiver, for example, could turn a patient on his or her side and stimulate him or her to promote breathing. If the caregiver finds the patient at a later time after seizure onset, he or she could attempt resuscitation. “This is our general concept of perhaps how SUDEP intervention could be performed using mobile device detectors,” Dr. Krauss concluded.

—Erik Greb

Mobile Devices May Provide Accurate Seizure Detection and Help Prevent SUDEP

Brain Sentinel

EpiWatch App

Can These Devices Prevent SUDEP?

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