Drug resistant epilepsy and associated factors among children with epilepsies in Tanzania: a cross-sectional study

Epilepsy contributes to high morbidity among children and adolescents in developing countries. A quarter of all children with epilepsy will be resistant to anti-seizure medications (ASMs), with associated neurocognitive impairments and risk of higher mortality. This study aimed to estimate and characterize drug-resistant epilepsy (DRE) (defined as failure to achieve sustained remission after adequate trials of two tolerated and appropriately chosen ASMs) and its associated factors among children and adolescents with epilepsies attending the pediatric neurology clinic at Muhimbili National Hospital (MNH), Dar es Salaam Tanzania.

This cross-sectional study was conducted from June 2020 to June 2021. Children with epilepsies and who had been treated with ASMs for at least 3 months were eligible for inclusion. Exclusion criteria included children whose caregivers denied consent and those who exhibited acute medical conditions necessitating admission on the scheduled visit day. Data on demographic characteristics, perinatal history, detailed history of the seizures semiology, drug history, magnetic resonance imaging (MRI), and electroencephalography (EEG) results were obtained from caregivers and medical records available during recruitment. Seizures and epilepsies were classified using the 2017 International League Against Epilepsy (ILAE) classification. Logistic regression was used to determine factors associated with DRE.

A total of 236 children and adolescents aged between 4 months and 15 years (Median age 72 months (IQR = 42–78)) were enrolled in this study. We found the proportion of DRE to be 14.8% in this cohort. Of the thirty-five patients with DRE, 60% had generalized epilepsy and almost 25% had a diagnosis of an epilepsy syndrome, the most common being Lennox-Gastaut syndrome (LGS). Structural abnormalities on brain MRI were seen in almost 80% of all patients with DRE, the most prevalent being cystic encephalomalacia, which was observed in 34% of patients. Patients using both ASMs and alternative therapies accounted for 9% of this cohort. The onset of seizures during the first month of life (aOR = 1.99; 95%CI 1.7–4.6; p = 0.031) and high initial seizure frequency (aOR = 3.6; 95%CI 1.6-8;p = 0.002) were found to be independently associated with DRE.

The proportion of DRE in Tanzania is high. Patients with neonatal onset seizures and high initial seizure frequency should be followed up closely to ensure early diagnosis of DRE.