Multiday Cycles of Heart Rate Are Comodulated with Rhythms of Epileptic Activity
Abstract number :
3.076
Submission category :
2. Translational Research / 2A. Human Studies
Year :
2021
Submission ID :
1825683
Source :
www.aesnet.org
Presentation date :
12/6/2021 12:00:00 PM
Published date :
Nov 22, 2021, 06:44 AM
Authors :
Philippa Karoly, PhD - The University of Melbourne; Rachel Stirling, ME - The University of Melbourne; Wendyl D'Souza, MBBS, MD, MPH, PhD - St Vincent's Hospital, The University of Melbourne; David grayden, PhD - The University of Melbourne; Matias Maturana, PhD - Seer Medical; Ewan Nurse, PhD - Seer Medical; Amy Halliday, MBBS, MD - St Vincent's Hospital; Andrew Neal, MBBS, BMedSci, FRACP, PhD - Monash University; Benjamin Brinkmann, PhD - Mayo Clinics; Mark Richardson, BMBCh, PhD, FRCP - Kings College London; Dean Freestone, PhD - Seer Medical; Mark Cook, MBBS, MD - St Vincent's Hospital, The University of Melbourne
Rationale: Circadian and multiday rhythms are found across many biological systems, including cardiology, endocrinology, neurology, and immunology. In people with epilepsy, epileptic brain activity and seizure occurrence have been found to follow circadian, weekly, and monthly rhythms. Understanding the relationship between these cycles of brain excitability and other physiological systems can provide new insight into the causes of multiday cycles. The brain-heart link is highly relevant for epilepsy, with implications for seizure forecasting, therapy, and mortality (i.e., sudden unexpected death in epilepsy).
Methods: We report the results from a non-interventional, observational cohort study, Tracking Seizure Cycles. This study sought to examine multiday cycles of heart rate and seizures in adults with diagnosed uncontrolled epilepsy (N=28) and healthy adult controls (N=14) using wearable smartwatches and mobile seizure diaries over at least four months (M=10.5, SD=4.8; control M=9.2, SD=6.2). In addition, we analysed the relationship between cycles of heart rate and epileptic activity in a cohort with continuous EEG recorded via an implantable sub-scalp recording system (N=6). Cycles in heart rate were detected using a continuous wavelet transform. Comodulation between heart rate and epileptic activity cycles and seizure occurrence were measured from the distributions of seizure likelihood with respect to underlying cycle phase.
Results: Heart rate cycles were found in all 42 participants (people with epilepsy and healthy controls), with circadian (N=42), about-weekly (N=25) and about-monthly (N=12) rhythms being the most prevalent (Figure 1 shows two example cases). Of the participants with epilepsy, 16 people had at least 20 reported seizures, and nine of these had seizures comodulated with their multiday heart rate cycles. Compared to cycles of epileptic activity measured from chronic EEG, heart rate cycles showed similar periodicities with patient-specific comodulation (Figure 2 shows an example case).
Conclusions: Heart rate cycles showed similarities to multiday epileptic rhythms and were comodulated with seizure likelihood. The relationship between heart rate and seizures is relevant for epilepsy therapy, including seizure forecasting. Intriguingly, the similarity of heart rate cycles in healthy controls suggests multiday rhythms are not limited to epileptic phenomenon. Understanding the link between multiday cycles in the heart and brain can shed new light on endogenous physiological rhythms in humans.
Funding: Please list any funding that was received in support of this abstract.: This research was funded by the Australian government National Health and Medical Research Council. This research was also supported by the American Epilepsy Foundation's My Seizure Gauge grant.
Translational Research