Ictal fear is associated with anxiety symptoms and interictal dysphoric disorder in drug-resistant mesial temporal lobe epilepsy

Abstract

Interictal dysphoric disorder (IDD) is a poorly understood psychiatric disorder of epilepsy patients. Interictal dysphoric disorder is characterized by depressive, somatoform, and affective symptoms observed in up to 5.9% of drug-resistant mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS). This study aimed to evaluate the association between ictal fear (IF) and the psychiatric symptoms and diagnosis in MTLE-HS patients. We included 116 (54.3% male) consecutive adult patients (36 ± 11 years) with MTLE-HS. Anxiety and depression symptoms were evaluated by the Hospital Anxiety and Depression Scale (HADS) and the psychiatric diagnosis were according to Fourth Edition of the Diagnosis and Statistical Manual of Mental Disorders (DSM-IV). The independent association between the occurrence of IF aura and the psychiatric diagnosis was determined by binary regression. When compared to those with other auras or without aura, patients reporting IF have higher HADS anxiety, but not HADS depression, scores. Ictal fear was independently associated with the diagnosis of interictal dysphoric disorder (OR, IC 95% = 7.6, 1.3–43.2, p = 0.02), but not with the diagnosis of anxiety (OR, CI 95% = 0.72, 0.08–6.0, p = 0.73), depression (OR, CI 95% = 0.94, 0.19–4.8, p = 0.94) or psychotic disorders (p = 0.99). Only patients with drug-resistant MTLE-HS were included and the small number of cases with DD diagnosis in the sample. In MTLE-HS patients, the occurrence of IF is associated with higher levels of anxiety symptoms and IDD. The results provide insights about fear-related neural network connections with anxiety symptoms and the IDD in MTLE-HS.