Pre-ictal heart rate changes: A systematic review and meta-analysis

Area of Science:

• Epilepsy research
• Cardiovascular monitoring in neurological disorders
• Biomedical signal analysis

Background:

• Epilepsy is a chronic neurological disorder characterized by recurrent seizures.
• Understanding pre-ictal phenomena, changes preceding a seizure, is crucial for seizure management.
• Heart rate (HR) variability is a potential biomarker for physiological changes during epilepsy.

Purpose of the Study:

• To determine the incidence of pre-ictal heart rate (HR) changes (increase and reduction) in individuals with epilepsy.
• To identify clinical and study-related factors influencing the observed incidence of pre-ictal HR manifestations.
• To assess the potential of HR monitoring for early seizure detection and intervention.

Main Methods:

• Systematic literature search for studies reporting concurrent pre-ictal electroencephalogram (EEG) and HR data in adults and children with epilepsy.
• Classification of pre-ictal HR changes into heart rate reduction (HRR) and heart rate increase (HRI).
• Random-effects meta-analysis and meta-regression to pool incidence rates and identify sources of heterogeneity.

Main Results:

• Thirty studies, encompassing 1110 participants and 2957 seizures, were included in the analysis.
• The pooled incidence of pre-ictal heart rate increase (HRI) was 36 per 100 seizures (95% CI 22-50).
• Higher HRI incidence was observed in temporal lobe epilepsy (44%), adult cohorts (55%), and studies including patients on antiepileptic drugs (35%). Pre-ictal HR reduction (HRR) was rare (0 per 100 seizures).
• Meta-regression identified age group, pre-ictal period length, ictal tachycardia incidence, and timing of HRI onset as significant modulators of incidence estimates.

Conclusions:

• Significant limitations exist in the current evidence base regarding pre-ictal HR changes.
• HR monitoring shows promise for identifying seizures before clinical manifestation, enabling timely interventions.
• Further research is needed to define optimal patient populations and elucidate the underlying mechanisms of pre-ictal cardiac alterations.