Prevalence, Incidence, and Etiology of Epilepsies in Rural Honduras: The Salamá Study

Abstract

Determination of epilepsy etiology in population-based studies is difficult because of the high cost of diagnostic tests. However, cost-effectiveness may be proven if preventive public-health strategies can be established from the test results. We report an epilepsy population-based study using clinical and laboratory techniques. A medical team administered an epilepsy survey to 88% of the residents by census in the rural county of Salamá, Honduras. Ninety of 100 participants identified with active epilepsy underwent a neurologic examination, video-electroencephalography (video-EEG), brain computed tomography (CT) scan, and serum enzyme-linked immunoelectrotransfer blot (EITB) for cysticercosis. Final diagnoses were based on the International League Against Epilepsy classifications for seizures and epilepsy syndromes. Combined epidemiologic, clinical, video-EEG, neuroimaging, and serum EITB assays were used for the diagnosis of epilepsy etiologies. Among 6,473 residents surveyed, 151 persons with epilepsy (prevalence rate, 23.3/1,000) were identified, 100 of whom had active epilepsy (15.4/1,000) on the prevalence day. Incidence was determined to be 92.7/100,000. Partial seizures with or without secondary generalization were common (92.2%). Symptomatic epilepsy (62%) was primarily due to neurocysticercosis (37%), perinatal brain damage (8%), post-traumatic (3%), and poststroke (2%). Eight percent were idiopathic, and 30% were cryptogenic (unknown cause). Symptomatic epilepsies primarily explained the high prevalence and incidence of epilepsy in Salamá. Integration of video-EEG and brain CT scan with clinical-epidemiologic evaluation was critical for determination of epilepsy etiology. Establishment of specific programs for continuation of epidemiologic surveillance, education, intervention, and long-term follow-up will benefit the Salamá region.