Autonomic changes during paroxysmal EEG activity

Abstract

1. 1. Changes in skin resistance, heart rate, skin temperature, respiration and finger vasomotor activity during paroxysmal EEG discharges were evaluated in 54 epileptic patients and five non-epileptic photo-sensitive subjects. Simultaneous recording of autonomic variables and EEG enabled an evaluation to be made of the association of autonomic changes with seizure discharges. 2. 2. All discharges recorded were generalized, bilaterally synchronous, and symmetrical. They were evaluated as to type of wave form and organization, length of burst, whether spontaneous or photically induced, and whether they were accompanied by clinical phenomena. 3. 3. Analysis indicated that no autonomic responses were associated with slow wave bursts and few autonomic responses were present during “subclinical” spike and slow wave discharges. “Clinical” spike and slow wave bursts ( i.e. bursts associated with objective or subjective signs) were usually accompanied by autonomic involvement, the degree of which correlated with the extent of clinical phenomena. Changes in skin resistance and HR were most frequently associated with paroxysmal activity. A GSR and change in heart rate were present during nearly all petit mal discharges, but respiration and temperature responses were variable. 4. 4. The latency of the GSR differed significantly for spike and slow wave complexes and petit mal discharges. Regardless of duration of the burst the GSR usually occurred within 2 sec following the first spike of the atypical spike and wave bursts, whereas it occurred several seconds after onset, or more frequently, following the cessation of the petit mal discharge. These observations of the GSR suggest that awareness of the manifestations of the discharge may be an important determinant of autonomic response.