Heart rate variability analysis in patients with pharmacoresistant focal temporal lobe epilepsy

Abstract

Purpose: Temporal Lobe Epilepsy (TLE) can affect the regulation of autonomic activity. In this study, we propose to validate a methodology to analyse Heart Rate Variability (HRV) in patients with pharmacoresistant TLE within 24 hours of the occurrence of the seizure. Method: Retrospective observational study: case-control conducted in the EEG Unit of the Hospital el Cruce and Cardiology Department of Hospital Regional Rossi (JulyDecember 2023). Holter records acquired over 72 hours with three-channel digital recorders DMS300 7 and DMS300 3A were analysed. The signals were processed using CardioScan 10.0, 11.0 software. Inclusion criteria: Over 18 years old, without cardiovascular comorbidity, and without treatment affecting HRV. The temporal evolution of the following was calculated: mean value of RR intervals (), standard deviation of RR intervals (SDRR), square root of the mean square differences of successive RR intervals (rMSSDRR), and the percentage of intervals varying by more than 50 ms from the previous interval (pNN50). Results: Eight patients (p) with TLE were analysed, aged between 18-47 years, with an average epilepsy duration of 15 years. Five patients presented focal seizures without impairment of consciousness with autonomic onset (cutaneous 3p, cardiovascular 2p). Six patients had a right temporal epileptogenic zone (EZ). Forty-one healthy controls population based were analysed, with Holter records within normal parameters (for 18 years: pNN50 0.04-0.4 rMSSDRR 20-70; for 50 years: pNN50 0.01-0.2 rMSSDRR 10-60). Comparing both populations, differences in pNN50 and rMSSDRR were observed up to 3 hours before the onset of seizures in TLE cases. Conclusion: These preliminary findings could contribute to the development of a methodology for detecting cardiovascular autonomic disorders, such as alterations in HRV, and their use for early detection of seizures or SUDEP (Sudden Unexpected Death in Epilepsy).