Abstract

Magnetic Resonance Imaging Findings in Kenyans and South Africans with Active Convulsive Epilepsy: An Observational Study

Kariuki SM, Wagner RG, Gunny R, D'Arco F, Kombe M, Ngugi AK, White S, Odhiambo R, Cross JH, Sander JW, Newton Crjc
Epilepsia. 2023;65

Permenent descriptor

OBJECTIVE: Focal epilepsy is common in low- and middle-income countries. The frequency and nature of possible underlying structural brain abnormalities have, however, not been fully assessed. METHODS: We evaluated the possible structural causes of epilepsy in 331 people with epilepsy (240 from Kenya and 91 from South Africa) identified from community surveys of active convulsive epilepsy. Magnetic Resonance Imaging (MRI) scans were acquired on 1.5-tesla scanners to determine the frequency and nature of underlying lesions. We estimated the prevalence of these abnormalities using Bayesian priors (from an earlier pilot study) and observed data (from this study). We used a mixed-effect modified Poisson regression approach with the site as a random effect to determine the clinical features associated with neuropathology. RESULTS: MRI abnormalities were found in 140/240 (modelled prevalence=59% (95%CI:53%-64%)) of people with epilepsy in Kenya, and in 62/91 (modelled prevalence=65% (95%CI:57%-73%)) in South Africa, with a pooled modelled prevalence of 61% (95%CI:56%-66%). Abnormalities were common in those with a history of adverse perinatal events (15/23 (65% (95%CI:43%-84%))), exposure to parasitic infections (83/120 (69% (95%CI:60%-77%))) and focal electroencephalographic (EEG) features (97/142 (68% (95%CI:60%-76%))), but less frequent in individuals with generalized EEG features (44/99 (44% (95%CI:34%-55%))). Most abnormalities were potentially epileptogenic (167/202 (82%)), of which mesial temporal sclerosis (43%) and gliosis (34%) were most frequent. Abnormalities were associated with co-occurrence of generalised non-convulsive seizures (relative risk (RR)=1.12 (95%CI:1.04-1.25)), lack of family history of seizures (RR=0.91 (0.86-0.96), status epilepticus (RR=1.14 (1.08-1.21)), frequent seizures (RR=1.12 (1.04-1.20)) and reported use of anti-seizure medication (RR=1.22 (1.18-1.26)). SIGNIFICANCE: MRI identified pathologies common in people with epilepsy in Kenya and South Africa. MTS, the most common abnormality, may be amenable to surgical correction. MRI may have a diagnostic value in rural Africa, but future longitudinal studies should examine the prognostic role.