Neurocysticercosis and its impact on crude prevalence rate of epilepsy in an Indian community

Background : Community-based studies of epilepsy in India have reported variable prevalence rates, 5 10/1000 population. Reasons for this wide variation in the prevalence rates are uncertain. Most of the earlier studies had not done appropriate investigations to establish the possible etiology. Aim : To study the prevalence and etiological profile of active epilepsy in the rural population of Uttarakhand. Material and Methods : In this rural community-based study in the state of Uttarakhand, a door-to-door survey was conducted using validated questionnaire. All the suspected cases of epilepsy were examined by a neurologist to confirm the diagnosis of epilepsy and all the confirmed cases underwent contrast computed tomography (CT) scan and electroencephalography (EEG). Epilepsy and epilepsy syndromes were classified using the classifications proposed by the International League Against Epilepsy. Results : Of the 14,086 population studied, 141 cases of active epilepsy were detected giving a crude prevalence rate of 1%. After clinical evaluation and scanning, 35 (24.8%) were found to have seizure disorder active neurocysticercosis (NCC) and 14 (9.9%) had remote symptomatic seizures related to calcified granuloma. After excluding acute and remote symptomatic cases related to NCC, prevalence rate of epilepsy was 6.5/1000. Conclusion : The study suggests that the region-specific prevalence rates of epilepsy in India are partly dependent on the prevalence of NCC in the given community. To some extent, this may be responsible for variable rates of epilepsy prevalence reported from different regions of the country.