Natural history and mortality of chronic epilepsy in an untreated population of rural Bolivia: A follow-up after 10 years *Alessandra Nicoletti, *Vito Sofia, *Giuseppina Vitale, ySara Irene Bonelli, zVladimir Bejarano, yFilippo Bartalesi, xDuc-Si Tran, xPierre-Marie Preux, *Mario Zappia, and yAlessandro Bartoloni *Department of Neurosciences, University of Catania, Catania, Italy; yInfectious and Tropical Diseases Unit, University of Florence, Florence, Italy; zHealth District Cordillera Province, Bolivia; and xInstitute of Neuroepidemiology and Tropical Neurology (EA 3174), Limoges, France SUMMARY Purpose: To evaluate the natural history and mor- tality of chronic epilepsy in an untreated preva- lence cohort of people with epilepsy (PWE) in a rural area of Bolivia. Methods: During 1994–1996 we carried out an epidemiologic survey in a sample of 9,995 subjects in the Cordillera province. At the end of the survey we identified 130 PWE, of whom 118 were classified as having ‘‘active epilepsy.’’ We revisited this cohort 10 years after the prevalence survey. Results: We were able to trace 103 (87.3%) of the 118 PWE previously identified. Ten of the 103 subjects died during the follow-up period. Of the 93 PWE still alive, adequate information on the occurrence of seizures was available for 71 sub- jects, of whom 31 (43.7%) were seizure-free for more than 5 years; only 3 of these 31 subjects have taken an antiepileptic drug (AED) for more than 1 year. Generalized seizures were associ- ated with a better prognosis. Mortality rate in our prevalent cohort was 10.0/1,000 person-year at risk [95% confidence interval (CI) 5.5–18.3], without a significant increased risk respect to the general population [standardized mortality rate (SMR) 1.34; 95% CI 0.68–2.39]; a significant increased risk of death was found for patients with remote symptomatic epilepsy (SMR 3.0; 95% CI 1.2–6.3) but not with idiopathic epilepsy. Three of the 10 subjects died of causes possibly related to epilepsy. Discussion: Our data suggest that spontaneous remission of epilepsy occurs in a substantial pro- portion of untreated patients affected by chronic epilepsy; concerning mortality, we found a 3-fold increased mortality in patients with remote symp- tomatic epilepsy. KEY WORDS: Epilepsy, Mortality, Natural history. Epilepsy is the most common serious neurologic disorder and is one of the world’s most prevalent noncommunicable diseases. It is estimated that the condition affects approxi- mately 50 million people, about 40 million of them living in developing countries (Scott et al., 2001). Several epidemio- logic surveys have been carried out in tropical countries during the last 20 years reporting, on average, a prevalence of about 15% (Burneo et al., 2005; Preux & Druet-Cabanac, 2005; Mac et al., 2007); on the other hand, because of logis- tical problems, prospective studies are difficult to perform and few data on incidence and mortality are available in these populations (Carpio et al., 2005). During the past decade, several studies on mortality in epilepsy have been carried out in developed countries. In a population-based incidence cohort of epileptic subjects, up to a 3-fold increase in mortality was observed, compared to the general population [standardized mortality ratio (SMR) ranged from 1.6–3.0] (Forsgren et al., 2005). A higher increased risk is suspected in tropical countries where approximately 80–85% of PWE are not treated (Scott et al., 2001). Concerning the prognosis, even if it has been estimated that greater than 60% of newly diagnosed patients will Accepted April 16, 2009; Early View publication June 26, 2009. Address correspondence to Alessandra Nicoletti, Department of Neu- rosciences, University di Catania, Via S. Sofia n° 78, 95123 Catania, Italy. E-mail: anicolet@unict.it Wiley Periodicals, Inc. ª 2009 International League Against Epilepsy Epilepsia, 50(10):2199–2206, 2009 doi: 10.1111/j.1528-1167.2009.02174.x FULL-LENGTH ORIGINAL RESEARCH 2199