Neurological disorders in children and adolescents.

OBJECTIVE: To ascertain the prevalence of active epilepsy, febrile seizures (FS), cerebral palsy (CP) and tic disorders (TD) in aged 19 years or less. METHODS: This was a cross-sectional observational study conducted as a two-stage door-to-door survey of a stratified randomly selected population in 2003-04. Trained field workers screened the population followed by case examination by the field neurologist. RESULTS: A total of 16979 (male 8898, female 8081) subjects aged <or= 19 years were surveyed. The prevalence rates per 100,000 population of active epilepsy, FS, CP and TD with 95% confidence intervals are 700.87 (580.60-838.68), 1113.14 (960.07-1283.59), 282.70 (CI 208.43-374.82) and 35.34 (12.96-76.92) respectively. Active epilepsy prevalence shows a rising trend and that of other disorders a declining trend with age. Of the epileptics who had brain CT scans, 23.4% showed single or multiple lesions suggestive of neurocysticercosis. Regarding treatment, 23.5% of the epileptics never received any antiepileptic drugs. Among those with history of FS, 9.5% developed epilepsy later on. The prevalence of FS among slum dwellers is lower than in the non-slum population. Among CP cases, 39.6% gave history of birth anoxia, 16.7% kernicterus and 31.3% epilepsy. Prevalence of CP is significantly associated with lower education status. CONCLUSION: The prevalence of CP and TD is lower than reported from western countries. CP prevalence is also comparatively lower than in many community studies from India. Compared to western nations, higher proportion of FS cases develops epilepsy. A third of the CP cases have seizures which is higher than in many Indian studies. Birth anoxia is a common cause of CP and educational underachievement is frequent.

A random sample survey for prevalence of major neurological disorders in Kolkata.

BACKGROUND & OBJECTIVES: Large scale epidemiological studies on neurological disorders are very few in India. We therefore planned to conduct a cross-sectional population-based epidemiological study on a stratified randomly selected sample from the city of Kolkata to study the prevalence of major neurological disorders such as epilepsy, stroke, dementia and Parkinsonism. METHODS: The method of case ascertainment was two- stage house-to-house survey; the first stage was undertaken by a field team consisting of four field workers and a neuropsychologist. Screening questionnaire based on National Institute of Mental Health and Neuro Sciences (NIMHANS) protocol was used. In the second stage a neurologist examined all the screened positive cases. RESULTS: A total of 52,377 subjects participated in the study. The crude prevalence rates (per 100,000 population) of major neurological disorders with 95 per cent confidence intervals (95% CI) and age adjusted rates (AAR) based on US 2000 population were 557.5 (95% CI 496.17-624.40 and AAR - 516.77) in epilepsy, 486.85 (95% CI 377.0 to 551.11 and AAR-765.68) in stroke, 87.82 (95% CI 64.02-117.50 and AAR-168.4) in dementia and 45.82 (95% CI 29.64-67.63 and AAR-71.64) in Parkinsonism. The weighted prevalence rates (per 100,000) of the whole population based on re-screening of 10 per cent of negative samples were 763.89 (95% CI 690.55- 842.57) in epilepsy, 624.32 (95% CI 555.64-699.24) in stroke and 139.37 (95% CI 108.71-176.06) in dementia. INTERPRETATION & CONCLUSION: A high rate of stroke and overall lower prevalence of Parkinsonism and dementia was recorded as compared to western studies. High prevalence rate of stroke emphasizes the need to study incidence, morbidity and mortality profile of stroke including its socio-economic impact and also case-control analysis to determine the underlying risk factors.