Heart Rate, Movement Detect Nocturnal Seizures in Epilepsy

heart beat
heart beat
Investigators examined whether a bracelet capable of measuring heart rate and movement would be beneficial for detecting nocturnal seizures in patients with epilepsy.

Measurement of heart rate and movement using a multimodal bracelet sensor may be effective for detecting nocturnal seizures of varying types in patients with epilepsy, according to results of a multicenter, prospective study published in Neurology.

Patients with an intellectual disability and a history of more than 1 major nocturnal seizure per month who resided in a long-term care facility at an epilepsy center in the Netherlands were enrolled (n=28). A bracelet was worn by all participants on the upper arm during sleep for up to 2 to 3 months. Heart rate or movement detected nocturnal seizures via photoplethysmography or 3-dimensional accelerometry, respectively.  Investigators identified seizures as being tonic-clonic, generalized tonic >30 seconds, hyperkinetic, or others (eg, clusters [>30 minutes] of short myoclonic/tonic seizures).

Video recordings were made of all events, and 10% of all screened nights were reviewed to define major seizures (ie, needing an alarm), minor seizures (needing no alarm), or no seizure. Performance in regard to positive predictive value, sensitivity, false-negative alarm rate, and false-positive alarm rate of the multimodal bracelet sensor to detect major seizures was the primary outcome. The quality of signal data, user experience of caregivers, components affecting the sensor’s algorithm performance, and the performance of the bracelet sensor vs a bed sensor were secondary outcomes.

A total of 809 major seizures were recorded in 28 of the 34 admitted participants who completed the study. The interobserver agreement between major seizures and no major seizures was 0.77 (95% CI, 0.65-0.89). The bracelet sensor was associated with better sensitivity than the bed sensor (median difference, 58%; 95% CI, 39%-80%; P <.001). Findings from a questionnaire administered to 33 caregivers found that the multimodal sensor was associated with good acceptance and usability.

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Limitations of this study include its small cohort size and the inclusion of only patients residing in long-term care facilities in the Netherlands, which may likely limit the ability to extrapolate the findings across the broader epilepsy population.

“The multimodal sensor might be of help in preventing [sudden unexpected death in epilepsy],” the researchers added. “Although comparative studies are lacking, combining [heart rate and accelerometry] seems more effective for detecting major seizures because of the shortcomings of current audio detection.”


Arends J, Thijs RD, Gutter T, et al; for the Dutch Tele-Epilepsy Consortium. Multimodal nocturnal seizure detection in a residential care setting: a long-term prospective trial. Neurology. 2018;91(21):e2010-e2019.