Comorbid psychosis in temporal lobe epilepsy is associated with auditory emotion recognition impairments

Abstract

Temporal lobe epilepsy (TLE), characterized by recurrent unprovoked seizures originating from the temporal lobe, is the most common form of focal epilepsy and is frequently associated with brain lesions (i.e. hippocampal sclerosis) involving the medial temporal lobe region (Monti and Meletti, 2015). Psychiatric comorbid disorders are very frequent among patients with drug-resistant TLE; psychosis affects about 8?13 % and depression approximately 30?50 % of patients (Nadkarni et al., 2007; D´Alessio et al., 2020). The pathogenesis of this association is still unknown, but it has been proposed that recurrent epileptic discharges acting on medial temporal lobe structures (hippocampus-amygdala) may induce neurotransmitters changes, neurogenesis alterations and inflammation, increasing the vulnerability to stressors (Sachdev, 2007; D´Alessio et al., 2020). These brain areas play a central role in emotion recognition (ER), the brain function by which the emotions expressed by others are recognized (Yovel and Belin, 2013).Many reports demonstrated a lower performance of visual and auditory ER among patients with TLE, but only a few studies analyzed anxiety and depression symptoms with no reference to psychosis (Fowler et al., 2006; Brand et al., 2009; Monti and Meletti, 2015). Epileptic psychosis has been classified by temporal ictal relationship in postictal, interictal and alternating psychosis, nonetheless it has been considered a unified pathogenic process related to epilepsy (Sachdev, 2007; D´Alessio et al., 2020; Kanemoto et al., 2012). However, since other schizophrenia-spectrum disorders showed ER deficits (Ruocco et al., 2014), comorbid psychosis in patients with TLE may affect ER performance.The aim of the present study was to explore the ER in a cohort of patients with drug-resistant TLE diagnosed by Video-Electroencephalography (VEEG), using visual (faces) and auditory (prosody) stimuli, focusing on the main comorbid psychiatric disorders (depression and psychosis).