Physiological Changes During Conscious and Unconscious Emotional Reactions in Persons with Temporal Lobe Epilepsy: A Pilot Study

Objective: To find out if there are subjective, autonomic and EEG differences between the emotional responses of patients with TLE and controls. Secondary objectives are to establish which modality is the most sensitive. Do implicit of explicit emoticons evoke stronger reactions, and does epilepsy surgery alter these responses.

Methods: We compared the emotional response to implicitly and explicitly induced emotions through movie clips of 12 patients with TLE, before and after epilepsy surgery, with those of controls. We looked at changes in EEG, heart rate and subjective experiences.

Results: Patents showed a greater arousal and a smaller dominance on subjective SAM scores, a greater variation in heart rate together with a reduced variation of parasympathetic activity and a greater increase in rhythmical activity in the EEG. Post-surgery changes consisted of a decrease in autonomic dynamics and a further increase in rhythmical activity in the EEG. The responses between the various types of explicit and implicit emotion start already before the specific movie clip begins, a reaction which can be interpreted as PAA. This PAA effect was more pronounced in controls than in patients.

Significance: This pilot emphasizes the importance of provoked changes in HRV in interpreting differences in activity of the autonomic system and its clinical consequences between patients with TLE and controls. It emphasizes also the importance of considering the -usually neglected- pre stimulus part of the trajectory in analyses of emotional responses.

Keywords:Temporal lobe epilepsy; Epilepsy surgery; Emotion; Autonomic nervous system; Heart rate variability; Predictive anticipatory activity

Abbreviations:AED: Anti Epileptic Drug; ANS: Autonomic Nervous System; FFT: Fast Fourier Transform; HR(V): Heart Rate (Variability); HF: High Frequency band; LF: Low Frequency band; MM: Mixed Model; PAA: Predictive Anticipatory Activity; PNES: Psychogenic Non-Epileptic Seizure; SAM: Self-Assessment Manikin; SUDEP: Sudden Unexpected Death in Epilepsy; TLE: Temporal Lobe Epilepsy