Autonomic nervous system functioning associated with psychogenic nonepileptic seizures: Analysis of heart rate variability

Sylvie J M van der Kruijs; Kristl E J Vonck; Geert R Langereis; Loe M G Feijs; Nynke M G Bodde; Richard H C Lazeron; Evelien Carrette; Paul A J M Boon; Walter H Backes; Jacobus F A Jansen; Albert P Aldenkamp; Pierre J M Cluitmans

doi:10.1016/j.yebeh.2015.10.014

Autonomic nervous system functioning associated with psychogenic nonepileptic seizures: Analysis of heart rate variability

Epilepsy Behav. 2016 Jan:54:14-9. doi: 10.1016/j.yebeh.2015.10.014. Epub 2015 Nov 25.

Affiliations

¹ Kempenhaeghe, P.O. Box 61, 5590AB Heeze, The Netherlands; School for Mental Health and Neuroscience, Maastricht University, P.O. Box 616, 6200MD Maastricht, The Netherlands. Electronic address: kruijss@kempenhaeghe.nl.
² Reference Centre for Refractory Epilepsy, Department of Neurology, Ghent University Hospital, De Pintelaan 185, 9000 Ghent, Belgium.
³ University of Technology, P.O. Box 513, 5600MB Eindhoven, The Netherlands.
⁴ Kempenhaeghe, P.O. Box 61, 5590AB Heeze, The Netherlands; School for Mental Health and Neuroscience, Maastricht University, P.O. Box 616, 6200MD Maastricht, The Netherlands.
⁵ Kempenhaeghe, P.O. Box 61, 5590AB Heeze, The Netherlands; Department of Neurology, Maastricht University Medical Centre, P.O. Box 5800, 6202AZ Maastricht, The Netherlands.
⁶ Kempenhaeghe, P.O. Box 61, 5590AB Heeze, The Netherlands; Reference Centre for Refractory Epilepsy, Department of Neurology, Ghent University Hospital, De Pintelaan 185, 9000 Ghent, Belgium.
⁷ School for Mental Health and Neuroscience, Maastricht University, P.O. Box 616, 6200MD Maastricht, The Netherlands; Department of Radiology, Maastricht University Medical Centre, P.O. Box 5800, 6202AZ Maastricht, The Netherlands.
⁸ Kempenhaeghe, P.O. Box 61, 5590AB Heeze, The Netherlands; School for Mental Health and Neuroscience, Maastricht University, P.O. Box 616, 6200MD Maastricht, The Netherlands; Reference Centre for Refractory Epilepsy, Department of Neurology, Ghent University Hospital, De Pintelaan 185, 9000 Ghent, Belgium; University of Technology, P.O. Box 513, 5600MB Eindhoven, The Netherlands; Department of Neurology, Maastricht University Medical Centre, P.O. Box 5800, 6202AZ Maastricht, The Netherlands.
⁹ Kempenhaeghe, P.O. Box 61, 5590AB Heeze, The Netherlands; University of Technology, P.O. Box 513, 5600MB Eindhoven, The Netherlands.

PMID: 26615481
DOI: 10.1016/j.yebeh.2015.10.014

Abstract

Objective: Psychogenic nonepileptic seizures (PNESs) resemble epileptic seizures but originate from psychogenic rather than organic causes. Patients with PNESs are often unable or unwilling to reflect on underlying emotions. To gain more insight into the internal states of patients during PNES episodes, this study explored the time course of heart rate variability (HRV) measures, which provide information about autonomic nervous system functioning and arousal.

Methods: Heart rate variability measures were extracted from double-lead electrocardiography data collected during 1-7days of video-electroencephalography monitoring of 20 patients with PNESs, in whom a total number of 118 PNESs was recorded. Heart rate (HR) and HRV measures in time and frequency domains (standard deviation of average beat-to-beat intervals (SDANN), root mean square of successive differences (RMSSD), high-frequency (HF) power, low-frequency (LF) power, and very low-frequency (VLF) power) were averaged over consecutive five-minute intervals. Additionally, quantitative analyses of Poincaré plot parameters (SD1, SD2, and SD1/SD2 ratio) were performed.

Results: In the five-minute interval before PNES, HR significantly (p<0.05) increased (d=2.5), whereas SDANN (d=-0.03) and VLF power (d=-0.05) significantly decreased. During PNES, significant increases in HF power (d=0.0006), SD1 (d=0.031), and SD2 (d=0.016) were observed. In the five-minute interval immediately following PNES, SDANN (d=0.046) and VLF power (d=0.073) significantly increased, and HR (d=-5.1) and SD1/SD2 ratio (d=-0.14) decreased, compared to the interval preceding PNES.

Conclusion: The results suggest that PNES episodes are preceded by increased sympathetic functioning, which is followed by an increase in parasympathetic functioning during and after PNES. Future research needs to identify the exact nature of the increased arousal that precedes PNES.

Keywords: Autonomic nervous system; Conversion disorder; Heart rate variability; Psychogenic nonepileptic seizures; Vagal tone.

MeSH terms

Adult
Arousal / physiology
Autonomic Nervous System / physiopathology*
Electrocardiography
Emotions / physiology
Female
Heart Rate / physiology*
Humans
Male
Middle Aged
Psychophysiologic Disorders / physiopathology*
Psychophysiologic Disorders / psychology
Seizures / physiopathology*
Seizures / psychology
Young Adult