The Neuroepidemiology Branch, is conducting a study to define the prevalence of neurocysticercosis (NCC) in populations hyperendemic for taeniasis. As seizures and headaches have been correlated with NCC, the NEB is studying the prevalence of epilepsy and headache in Naulinco, Veracruz, Mexico, to determine the frequency of NCC. This study will determin the natural history of NCC in endemic regions of Mexico and Ecuador.