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

Abstract

Dr. Hampel is neurologist with special interest in autonomic function and epilepsy surgery. SUMMARYObjective: 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. Methods: Systemic arterial BP, HR, and peripheral capillary oxygen saturation (SPO 2 ) were continuously and noninvasively monitored using the ccNexfin device in those epilepsy patients undergoing video-electroencephalography (EEG) telemetry. Data are given as mean AE standard deviation (SD). Results: Forty-five seizures in 37 patients were included. In focal seizures (FS, n = 35), the mean arterial BP (MAP) increased by 33 AE 35% and the HR by 53 AE 44%, whereas the SPO 2 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 AE 14% and returned to a baseline slightly below preictal levels after 5 min, whereas the HR was increased by 77 AE 33% and remained elevated throughout the postictal phase. Significance: 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 SPO 2 . The potential clinical implications of these findings are discussed in the article. KEY WORDS: Systemic blood pressure, Syncope, Sudden unexpected death in epilepsy.Epileptic seizures affect the autonomic nervous system in many ways including modulation of the gastrointestinal (e.g., spitting, vomiting), cardiac (tachycardia, bradycardia), and respiratory (tachypnea, hypopnea and apnea) functions.1,2 Depending on their severity, cardiorespiratory alterations can lead to syncope or sudden unexpected death in epilepsy (SUDEP).3-5 In most of the previous studies addressing seizure-related cardiorespiratory function, the cardiac rhythm and oxygen saturation were assessed either separately or together. [6][7][8][9] The supply of oxygen and metabolites, however, critically depends on the blood perfusion of the different organs which is, in turn, tightly regulated in most organs and connected to systemic blood pressure (BP). In this context, a recent study has shown that during the interictal period, the diastolic BP for those individuals who subsequently died as a result of SUDEP, tended to be higher than for the epilepsy controls.10 This could be due to an epilepsy-related increase in the activity of the sympathetic branch of the autonomic nervous system. 11 To date, however, little is known about seizure-r...

Impaired Baroreflex Sensitivity after Bilateral Convulsive Seizures in Patients with Focal Epilepsy

“…In FS, BP, and HR both display a transient increase with a similar time course, probably due to an increase of the sympathetic activity through stimulation of central autonomic centers by epileptic activity (4). In BCS, systemic BP appears to display at least two different patterns.…”

“…Data on seizure-related HR and systemic BP of included patients were previously published (4). Epilepsies and seizures were classified according to the revised International League Against Epilepsy terminology (8).…”

“…In addition, pulse rate, oxygen saturation (LNCS DC-I ® reusable sensor, Masimo, Irvine, CA, USA), and arterial BP were continuously and non-invasively recorded from beat-to-beat using the ccNexfin ® device (BMEYE, Amsterdam, the Netherlands) for up to 8 h a day (maximum approved time span for the device applied at a single finger). The exact methodology for the data recording was described previously (4). For each seizure, consecutive values of systolic BP and HR obtained by the ccNexfin ® device at three different time periods (interictal, i.e., starting 5 min after the beginning of the recordings or starting 20 min before the end of the recording; preictal, i.e., up to the last 2 min before the seizure start; postictal, i.e., starting 2 min after seizure end) of 15 min duration each were considered.…”

“…The current knowledge points toward an early postictal autonomic failure after bilateral convulsive seizures (BCS) as the cause of death in most SUDEP cases (3). Recently, we found that heart rate (HR) and systemic blood pressure (BP) are differentially modulated in the early postictal phase after BCS, suggesting possible autonomic imbalance (4). While HR was elevated by 75% 2 min after BCS-cessation, the mean arterial BP was only increased by 15% and even dropped slightly below the preictal values 5 min after seizure termination.…”

Adaptive heart rate-based epileptic seizure detection using real-time user feedback

“…Figure 4 shows that the sensitivity changed for both seizure duration and seizure type. In order for a seizure to be accurately detectable using the heart rate, the seizure should indeed last long enough, so that the seizure HRIs can be sufficiently different from non-seizure HRIs (De Cooman et al 2017, Hampel et al 2016. Both reasons are however correlated in this database as shown in figure 4(c).…”