Abstracts

Rationale: Over the last few years there has been a breakthrough in diagnostic methods for the etiological work-up of patients with epilepsy and intellectual disability (ID), especially in the genetic field. However, these advances have not reached the entire population in the same manner. The objective of this study is to evaluate the access to advanced diagnostic tests in patients with epilepsy and ID, with special focus on genetics. Methods: Patients with epilepsy and ID evaluated between 2016 and 2018 at the Epilepsy Program of two tertiary care hospitals were included. The main inclusion criterion was an undetermined etiological diagnosis after clinical assessment, basic neuroimaging, and routine electroencephalogram. Demographic and clinical variables, as well as whether the diagnostic work-up had been complete or incomplete, were analyzed. Statistical analysis was performed using R 3.1.2 and the epicalc and optimalcutpoints packages. Results: 124 patients (53.2% male; mean age 33.9 years) were included. 39.5% were institutionalized due to their ID. The degree of intellectual disability was mild (32.3%), moderate (20.2%), or severe-profound (47.6%). Regarding the etiological work-up, magnetic resonance imaging, prolonged video-EEG monitoring, and any type of genetic test had been performed in 58%, 41%, and 40% (7% array-CGH, 9% epilepsy gene panel, 15% single gene test), respectively. An etiological diagnosis had been reached in 18.5% of the cases, and the work-up was considered incomplete in 67%. Variables that showed the highest association with an incomplete diagnostic work-up in the multivariate analysis were current age (p<0.001) and institutionalization (p<0.001; see table 1). Conclusions: Despite the prognostic and therapeutic implications of genetic testing in the management of epilepsy associated with ID, there is a large proportion of patients who do not have access to them. In our study, older age and institutionalization were associated with the highest diagnostic gap. This barrier may be related to the lack of awareness and hope, as well as family support, in this population. Funding: Gmp Foundation for Neuroscience research, Madrid (Spain)