2 Psychiatric comorbidity and quality of life in drug-resistant epilepsy

Abstract

Objective Epilepsy is a brain disorder characterised by an enduring predisposition to develop seizures. While most patients achieve seizure control with antiepileptic drug (AED) treatment, some develop refractory epilepsy. These patients have been known to present with important psychiatric comorbidity and to be negatively impacted by the disease in their quality of life. The reported prevalence of psychiatric disorders and assessment of quality of life in patients with refractory epilepsy varies greatly due to methodological differences between studies and the lack of use of adequate measurement instruments. Also, treatment efforts often focus on seizure control, when several other factors have been shown to significantly influence the quality of life of these patients. The aim of the present study is to determine the point-prevalence of psychiatric disorders in a homogenous group of patients with drug-resistant epilepsy and to analyse possible predictors of psychopathology and quality of life. Method This was a retrospective medical records review. The sample were adult patients with drug-resistant mesial temporal lobe epilepsy associated with hippocampal sclerosis being considered for epilepsy surgery at the Hospital of Egas Moniz in Lisbon, from January 2014 to July 2016. Psychiatric diagnoses were based on the Mini-International Neuropsychiatric Interview and health-related quality of life was assessed with the Quality-of-Life in Epilepsy Inventory. Point-prevalence ratios for each psychiatric diagnosis were calculated. Predictors of psychiatric comorbidity and of quality of life were analysed with multiple logistic regression models and stepwise, backward-elimination linear regression models, respectively. Results A total of 26 records were included. Point-prevalence ratio of psychiatric disorders was 31%. Absolute frequencies were: generalised anxiety disorder (3), agoraphobia (2), adjustment disorder (2), social phobia (1) and major depressive episode (1). No significant predictor of psychiatric comorbidity was identified. The female gender, AED polypharmacy and a diagnosis of a mood disorder were significant predictors of a lower overall quality of life. Seizure frequency only predicted lower scores in the seizure worry and social function scales, while right-sided hippocampal sclerosis predicted a better score in those domains. Conclusion Point-prevalence of psychiatric comorbidity was in line with previous research. The high prevalence of anxiety disorders, which are often under-recognised and undertreated, should alert clinicians to actively screen and treat these conditions. The concurrent association of various AED can lower the patient’s overall quality of life, while seizure frequency showed only a modest impact on well-being. Therapeutic decisions should reflect this reality and not focus solely on seizure control. While the precise relationship between neuropathology and psychosocial variables remains elusive, the observed asymmetric effect of HS laterality on some of the quality of life domains should be further studied.