Detecting nocturnal convulsions: Efficacy of the MP5 monitor

Abstract

Although the cause of sudden unexplained death in epilepsy patients (SUDEP) is unknown, evidence implicates respiratory compromise. Most cases occur while the patient is in bed and unsupervised. We investigated the efficacy of the Medpage bed seizure monitor to detect generalized tonic-clonic seizures. Patients with a history of tonic-clonic seizures were enrolled on a video-EEG unit. The MP5 device was placed between the mattress and bed base between midnight and 8:00 a.m. 64 subjects were enrolled (1528 h). Five of eight tonic-clonic seizures were detected. There were 269 false positive alarms (146 h with false positive alarms). The sensitivity and specificity of the alarm were 62.5% and 90.4%, respectively. The negative predictive value of 99.8% illustrates the potential for this device to provide additional security for patients with tonic-clonic seizures, however individual calibration would likely be necessary to improve the positive predictive value of 3.3%, which requires further validation.

Automated seizure detection systems and their effectiveness for each type of seizure

“…A c c e p t e d M a n u s c r i p t evidence confirms that patient specific algorithms are crucial for achieving accurate detection devices [54,64,69,71,74,94,95,102,119]. Different sensors have been used for detecting GTCS, including mattress sensors, EDA, sEMG, ACM, cerebral oxygen saturation sensors and seizure-alert dogs with promising results [55,57,58,60,61,65,83,84,90,102,103,105,132].…”

“…For GTCS during sleep the MP5 sensitivity was 62.5% and specificity 90% [102]. In another study including multiple seizure types, the device only detected one GTCS during sleep (16.7%) [103].…”

“…Mattress sensors were developed because most cases of SUDEP occur in patients with GTCS while unsupervised in bed at night [101][102][103][104][105]. These devices consist of a sensor placed under the patient's mattress and connected to a monitor.…”

“…These devices consist of a sensor placed under the patient's mattress and connected to a monitor. The sensor alerts the family when it detects a stimulus above the set threshold [102,103,105]. The MP5 bed seizure monitor detects movement and noise frequency and intensity, with a minimum patient weight of 25 kg [102].…”

“…Mattress devices allow for adjustment of the parameters to compensate for individual differences in movement during sleep [103]. Individual calibration and testing over a couple of nights in a home setting are recommended [102]. None of these systems perform as well as video EEG in detecting nocturnal seizures but this is a step in the right direction for a much needed device.…”