Seizure-related modulation of systemic arterial blood pressure in focal epilepsy

Cardiorespiratory function alterations are commonly observed with epileptic seizures and may lead to syncope and sudden unexpected death in epilepsy (SUDEP). Although most previous research has focused on controlling heart rate (HR) and respiration, little is known about seizure-related regulation of systemic blood pressure (BP). Herein, we have investigated whether the periictal modulation of systemic BP and HR depends on seizure characteristics.

Systemic arterial BP, HR, and peripheral capillary oxygen saturation (SPO₂ ) were continuously and noninvasively monitored using the ccNexfin device in those epilepsy patients undergoing video-electroencephalography (EEG) telemetry. Data are given as mean ± standard deviation (SD).

Forty-five seizures in 37 patients were included. In focal seizures (FS, n = 35), the mean arterial BP (MAP) increased by 33 ± 35% and the HR by 53 ± 44%, whereas the SPO₂ remained unaltered. The MAP and HR increases were significantly greater in FS with alterations in consciousness than in those without. For those FS that evolved to bilateral convulsive seizures (BCS, n = 10), all of the ictal recordings were compromised by artifacts. However, 2 min after seizure cessation, the MAP was enhanced by only 16 ± 14% and returned to a baseline slightly below preictal levels after 5 min, whereas the HR was increased by 77 ± 33% and remained elevated throughout the postictal phase.

Periictal regulation of systemic BP and HR displays distinct patterns depending on the type of seizure with focal onset. These changes were unrelated to alterations in SPO₂ . The potential clinical implications of these findings are discussed in the article.