Psychiatric disorders in patients with resistant temporal lobe epilepsy two years after undergoing elective surgery. A longitudinal study

Abstract

Purpose: Psychiatric morbidity in temporal lobe epilepsy (TLE) is frequent and negatively affects patients' life quality. Surgery is the procedure of choice when treating seizures, although the effects on psychiatric disorders remain unclear. We evaluate the effect of surgery on psychiatric disorders in patients with TLE two years after the intervention, to then shed light on how these are related to anxiety and depression symptoms, and Interictal Dysphoric Disorder (IDD).

Methods: We included data from 65 patients with TLE whose psychiatric evaluations were performed according to DSM-IV criteria. Anxiety and depression symptoms were assessed using the Hospital Anxiety and Depression Scale (HADS) test.

Results: At 2-year follow-up, anxiety and depressive disorders decreased, and psychotic disorders augmented without statistical significance. Baseline psychiatric disorders predisposed to psychiatric pathology at 2-year follow-up and did not correlate with epilepsy outcome after surgery. Postoperative psychiatric disorders correlated with the seizure incidence two years after the intervention, suggesting that epilepsy and psychiatric disorders were associated in processes such as surgery. De novo psychiatric disorders represented 52% of postoperative psychiatric pathology, 62% being psychotic disorders. De novo psychiatric disorders became more frequent from the first year of surgery, occurring mainly in patients free of seizures. The HADS test scores and IDD correlated with psychiatric disorders at 2-year follow-up.

Conclusions: Baseline psychiatric disorders did not influence surgery outcome, but correlated with psychiatric disorders' prevalence two years after surgery. Despite not finding statistical significance, surgery reduced the prevalence of psychiatric disorders, and de novo psychiatric disorders were associated with an improvement in the epilepsy course at 2-year follow-up.

Keywords: Interictal dysphoric disorder; Psychiatric disorders; Surgery; Temporal lobe epilepsy.