Peri-ictal Prone Position Is Associated With Independent Risk Factors For Sudden Unexpected Death In Epilepsy: A Controlled Video-EEG Monitoring Unit Study

Abstract

Introduction: Sudden unexpected death in epilepsy (SUDEP) is a major cause of death in patients with chronic drug-resistant epilepsy, and peri-ictal prone position has been elucidated as a risk factor for SUDEP. We aimed to investigate consecutive patients in peri-ictal prone positions in our video EEG monitoring (VEM) unit and compare patients with and without peri-ictal prone position to emphasize its relationship with other independent risk factors for SUDEP.

Methods: We retrospectively screened all patients with peri-ictal prone position who underwent VEM for a 10-year period and these patients constituted the prone (+) group. All patients without peri-ictal prone position who underwent VEM in the past 2 years constituted the prone (-) control group. Sequences of peri-ictal positions and interventions were evaluated. Clinical and laboratory features and SUDEP-7 scores were compared between the groups.

Results: A total of 21 seizures were identified with peri-ictal prone position from 16 patients. SUDEP-7 scores were significantly higher in the prone (+) group. Longer duration of epilepsy, early age at seizure onset, mental retardation, and frequency of seizures of any type (>50 seizures per month for the past year) were found significantly different between the prone (+) and prone (-) groups.

Conclusion: Peri-ictal prone position in the VEM unit may relate with other independent risk factors of SUDEP, especially with mental retardation. Nocturnal supervision becomes important to reduce SUDEP risk, especially in patients with mental retardation.

Keywords: mental retardation; nocturnal supervision; prone position; sudden unexpected death in epilepsy (SUDEP); video EEG monitoring (VEM).