Examining the Epidemiology and Pharmacotherapy of Epilepsy in Northern Nigeria: A Population-Based Registry Study with Treatment Gap Analysis

Epilepsy is one of the most prevalent neurological disorders in sub-Saharan Africa, with Nigeria bearing a disproportionate burden concentrated in rural and northern communities. The treatment gap, defined as the proportion of people with active epilepsy who do not receive appropriate antiepileptic drug therapy, is estimated to exceed 80 percent in some Nigerian states, yet population-based registry data to substantiate and characterize this gap are largely absent. This study established a population-based epilepsy registry and conducted a comprehensive epidemiological and pharmacotherapy analysis with treatment gap quantification across four states in northern Nigeria encompassing Kano, Bauchi, Niger, and Borno. Over 30 months, community sensitization, health facility case ascertainment, and key informant referral networks identified 2,140 persons with active epilepsy. Standardized diagnostic confirmation, pharmacotherapy assessment, treatment gap calculation, and qualitative barrier exploration were undertaken. Point prevalence of active epilepsy was 7.2 per 1,000 population, with generalized tonic-clonic seizure the most prevalent syndrome. The treatment gap was 76 percent overall, rising to 89 percent in rural areas. Among those receiving therapy, phenobarbital monotherapy at subtherapeutic doses was documented in 58 percent, reflecting both access limitations and prescribing quality deficiencies. Barriers to treatment included stigma, traditional healer preference, antiepileptic drug unavailability, and cost. Pharmacist absence from epilepsy care teams was universal. This registry constitutes the first population-based epilepsy pharmacotherapy dataset from northern Nigeria and provides the evidentiary foundation for a pharmacist-integrated epilepsy treatment gap reduction strategy. Keywords: epilepsy, treatment gap, population-based registry, northern Nigeria, antiepileptic drugs