THE CHARACTERISTICS OF EPILEPSY IN A LARGELY UNTREATED POPULATION IN RURAL ECUADOR

A house-to-house survey of epileptic seizures covering a population of 72 121 persons was carried out in a rural area of northern Ecuador. A cascade system of diagnosis was used to identify all cases of epilept ic seizures in this population. 1029 cases were found, of whom 881 wer e considered to be definite cases and 148 were possible cases. Of the 1029 cases, 56% had active epilepsy. The lifetime prevalence rate was found to lie between 12.2 and 19.5/1000 and the prevalence of active c ases between 6.7 and 8.0/1000. An annual incidence rate of between 122 /100 000 and 190/100 000 was estimated. Seizure type was classified wi thout EEG data and almost half of the cases had partial seizures. In 2 7% of cases an aetiology was proposed on clinical grounds. This is one of few reported studies of a population that has been largely unexpos ed to antiepileptic drugs, providing an opportunity to study the natur al history of the untreated condition. It has been suggested that trea tment in newly developing epilepsy will prevent its development to a c hronic condition. Only 37% of the 1029 cases had received antiepilepti c drugs. and 12% of the cases were taking them at the time of the surv ey. Despite this, a high rate of inactivity was observed, with 44% of all cases free of seizures. Nearly two thirds of the inactive cases id entified had never received treatment with antiepileptic drugs. In a s ubgroup of untreated cases with an active condition, treatment with an tiepileptic drugs was initiated and was highly effective even in cases with a long previous history. Thus the findings from this study sugge st that the development of epilepsy resistant to therapy is not always associated with a long duration of untreated epilepsy.