Abstracts

Rationale: Epilepsy is one of the most common neurological disorders in the world, and 80% of people with epilepsy live in low- and middle-income countries (1). The Central Hospital in San Luis Potosi, Mexico attends the lowest income people of the central region in Mexico, most from the state (1,500,000 inhabitants) but also from the population of nine states around. Access to diagnostic procedures (Magnetic Resonance Imaging (MRI)), electroencephalogram (EEG)) is often limited in this population. We aimed to describe the characteristics, antiepileptic drugs (AEDs) prescribed, and potential applicability of the ILAE 2017 classification2 in this representative population. Methods: All patients with epilepsy seen at the Central Hospital Neurology service were prospectively included from Mar 31, 2016, to Dec 3, 2018. Seizure types, etiology, MRI findings, EEG findings, AEDs prescribed and drug resistance were registered. Central tendency measures, number, and percentage of patients using AEDs, and drug-resistant epilepsy patients described. Results: From 1774 office visits, 959 patients were included in the study — 55.2 % women and 44.8% men, mean age 34 years old. Etiology was presumed genetic in 26.4% of patients, structural in 47.2%, and the rest was unknown or without enough data to be determined. The most common seizure type was focal with impaired awareness to bilateral tonic-clonic, followed by generalized in 22.7%, and then focal (15.2%). Most EEG studies present focal findings (32.1%), followed by generalized (14.1%) and dysfunction (14.1%). Almost a third (29.1%) have normal EEG, and 16.4% does not have an EEG performed. The most common abnormal finding in brain MRI is hippocampal asymmetry/mesial temporal sclerosis (24.5%), while 20.9% have MRI without apparent brain abnormalities and 39.1% does not have at least one MRI performed. CBZ is the most commonly used AED (40.45%). While VPA use (30.97%) and PHT (5.74%) has been decreasing, LEV has been prescribed more often (30.45%). 34.03% have drug-resistant epilepsy. Only 9.2% required more than 2 AEDs combined. Conclusions: Clinical characteristics in this sample are similar to other populations. AEDs prescription has been changing, decreasing PHT and VPA use and increasing LEV use. CBZ is still the most used AED. While the ILAE 2017 classification might help homogenize epilepsy definitions across the world, determination of etiology might be complicated due to limited access to diagnostic procedures in at least a third of patients. Funding: No funding