Fig. 2

Recordings from peripheral autonomic nerve and ganglion to demonstrate seizure-induced increases in both divisions of the ANS. a Increases in vagus nerve activity during a single discrete seizure (shown divided into for sequential segments where each segment shows arterial blood pressure, hippocampal EEG, and vagus nerve multi-unit activity). Note that the massive vagal activity increases by the second and third segments. b Increases in multi-unit activity recorded in superior cervical ganglion, even during a very brief seizure. a and b were taken from [36] with permission. c Percent change in mean activity (EEG autonomic peripheral nerve or ganglion) and hear rate from the beginning of bradycardic and tachycardic seizures to the peak autonomic activity during the seizure. The peak-to-peak amplitude of seizure EEG (black) tended to be larger when seizures were associated with bradycardia in ECG (green). Parasympathetic (blue) and sympathetic (red) activity was always increased, but the relative levels of the sympathetic and parasympathetic activity changes (and the starting heart rate—not shown) contribute to the final condition of bradycardia or tachycardia. Adapted from the doctoral thesis of Isaac Naggar with permission (Stewart, mentor). d Portion of a schematic diagram (full diagram is shown in Fig. 9) to emphasize the sequence of events: seizure activity changes autonomic activity; seizure ends; autonomic activity returns to pre-seizure levels. EEG electroencephalogram, ECG electrocardiogram