Distinction between epileptic and non-epileptic arousal by heart rate change.

OBJECTIVE: We investigated the difference in heart rate (HR) change between epileptic and non-epileptic arousals in adult patients with epilepsy (PWE).

METHODS: This is a case-control study conducted at the University Hospitals of Cleveland Medical Center. Inclusion criteria are (1) adult (≥18 years old) PWE who had arousal related to a focal aware or impaired awareness automatism seizure with or without focal to bilateral tonic-clonic seizure during an Epilepsy Monitoring Unit (EMU) admission between January 2009 and January 2021 or (2) adult PWE who had a non-epileptic arousal during an EMU admission between July 2020 and January 2021. Outcomes are (1) a percent change in baseline HR within 60 s after arousal and (2) the highest percent change in baseline HR within a 10-s sliding time window within 60 s after arousal.

RESULTS: We included 20 non-epileptic arousals from 20 adult PWE and 29 epileptic arousals with seizures from 29 adult PWE. Within 60 s after arousal, HR increased by a median of 86.7% (interquartile range (IQR), 52.7%-121.3%) in the epileptic arousal group compared to a median of 26.1% (12.9%-43.3%) in the non-epileptic arousal group (p < 0.001). The cut-off value was 48.7%. The area under the curve (AUC), sensitivity, and specificity were 0.85, 0.79, and 0.80, respectively. More than 70.1% was only in the epileptic arousals, with 100% specificity. Within 10 s of the greatest change, HR increased by 36.5 (18.7%-48.4%) in the epileptic arousal group compared to 17.7 (10.9%-23.7%) in the non-epileptic arousal group (p < 0.001). The cut-off value was 36.5%. The AUC, sensitivity, and specificity were 0.79, 0.52, and 0.95, respectively. More than 48.1% was only in the epileptic arousals, with 100% specificity.

SIGNIFICANCE: Tachycardia during epileptic arousals was significantly higher and more robust compared to tachycardia during non-epileptic arousals.