Affective symptoms in focal epilepsy: A scoping review of localization and lateralizing findings

Emotional experiences during focal seizures are often misinterpreted as psychiatric disorders. We aimed to evaluate symptoms involving affective symptoms at seizure onset. We aimed to identify the most prevalent affective symptoms at seizure onset and characterize their localizing and lateralizing value. We performed a scoping review based on Preferred Reporting Items for Systematic reviews and Meta-Analyses-extension for Scoping Reviews guidelines. A systematic search identified records from 4 databases: PubMed, Embase, CINAHL (via EBSCOhost), and Web of Science. Two reviewers independently screened titles/abstracts and full texts; discrepancies were resolved by consensus. This review focused on patients with focal seizures, as affective symptoms may occur in generalized epilepsies. The affective symptoms: fear, anxiety, panic, sadness, mystic, ecstatic, sexual, and mirth were identified, and semiology was evaluated in accordance with ILAE guidelines. Symptom onset, frequency, brain localization, and video-EEG monitoring technique were evaluated to assess localization and lateralization of regional networks. Scalp EEG, invasive EEG recordings, and electrical stimulation were analyzed. A total of 1276 documents were identified, with 98 studies included for review. Fear was the most frequently reported ictal emotion, identified in 274 patients (66%), predominantly in temporal lobe epilepsy. Sadness and sexual, ecstatic symptoms were also consistently associated with temporal networks. Mirth was more frequently reported with frontal onset seizures. Evidence, primarily from Class IV studies, reported right hemispheric predominance for ecstasy, mystic, and sexual symptoms at seizure onset. Ictal affective symptoms at seizure onset yield localizing information. The limbic system, especially the temporal lobe, followed by the frontal lobe, was the most common site of origin. Fear was the most common spontaneous and electrically elicited symptom, followed by anxiety. While bi-hemispheric lateralization occurred, right lateralization predominated. Recognizing paroxysmal affective symptoms as ictal phenomena may reduce misdiagnosis and aid presurgical evaluation in drug-resistant focal epilepsy.