Abstracts

Rationale: Ictal and postictal tachycardia have been shown to distinguish complex-partial (CPS) or generalized seizures from psychogenic nonepileptic seizures (PNES). Recent evidence has emerged for autonomic dysfunction in PNES. We reinvestigated pre-ictal, ictal, and post-ictal heart rate (HR) changes in CPS and PNES. Methods: We screened 205 consecutive elective admissions to the epilepsy monitoring unit (EMU) at our tertiary hospital between January 2008 and 2010 for video EEG confirmed CPS and/or PNES. In cases where multiple seizures were captured in one patient, only the first event of each type was analyzed. PNES was diagnosed, if there was alteration of consciousness and/or bilateral motor elements without epileptiform abnormalities on surface EEG. HR was calculated by an average of three consecutive R-R intervals at 30 sec prior to seizure onset (pre-ictal), maximal HR during the seizure (ictal) and one minute after the seizure (post-ictal) for each event and normalized to the baseline HR of each patient. If determination of HR was obscured by artifacts, this measurement did not go into analysis. Mean, standard deviation (SD) and Student t-tests were performed for each time point to determine differences between CPS and NES. This study was approved by the hospital internal review board. Results: A total of 44 pre-ictal, 46 ictal, and 44 post-ictal HR measurements in CPS and 41 pre-ictal, 42 post-ictal, and 39 postictal HR measurements in PNES went into the analysis. Mean and SD of the HR for CPS were 104 /- 20 beats per minute (bpm) pre-ictally, 159 /- 43 bpm ictally, and 129 /- 34 bpm post-ictally and for PNES 116 /- 21 bpm pre-ictally, 157 /- 37 bpm ictally, and 114 /- 20 bpm post-ictally. P-values of Student t-tests between CPS and PNES were 0.006 (pre-ictal), 0.493 (ictal) and 0.015 (post-ictal). Comparison of HR pre-ictal vs. ictal and ictal vs. post-ictal within the group of CPS and PNES patients revealed p-values < 0.001 throughout (see Figure 1). Conclusions: Maximal ictal HR showed tachycardia for both CPS and PNES without significant difference in contrast to prior reports. Compared to CPS, PNES are associated with a greater pre-ictal HR and lower HR post-ictally.