Electroencephalographic features of convulsive epilepsy in Africa: A multicentre study of prevalence, pattern and associated factors

OBJECTIVE: We investigated the prevalence and pattern of electroencephalographic (EEG) features of epilepsy and the associated factors in Africans with active convulsive epilepsy (ACE). METHODS: We characterized electroencephalographic features and determined associated factors in a sample of people with ACE in five African sites. Mixed-effects modified Poisson regression model was used to determine factors associated with abnormal EEGs. RESULTS: Recordings were performed on 1426 people of whom 751 (53%) had abnormal EEGs, being an adjusted prevalence of 2.7 (95% confidence interval (95% CI), 2.5-2.9) per 1000. 52% of the abnormal EEG had focal features (75% with temporal lobe involvement). The frequency and pattern of changes differed with site. Abnormal EEGs were associated with adverse perinatal events (risk ratio (RR)=1.19 (95% CI, 1.07-1.33)), cognitive impairments (RR=1.50 (95% CI, 1.30-1.73)), use of anti-epileptic drugs (RR=1.25 (95% CI, 1.05-1.49)), focal seizures (RR=1.09 (95% CI, 1.00-1.19)) and seizure frequency (RR=1.18 (95% CI, 1.10-1.26) for daily seizures; RR=1.22 (95% CI, 1.10-1.35) for weekly seizures and RR=1.15 (95% CI, 1.03-1.28) for monthly seizures)). CONCLUSIONS: EEG abnormalities are common in Africans with epilepsy and are associated with preventable risk factors. SIGNIFICANCE: EEG is helpful in identifying focal epilepsy in Africa, where timing of focal aetiologies is problematic and there is a lack of neuroimaging services.