Background: Epidemiological data on Creutzfeldt-Jakob disease (CJD) from Latin America are limited. We present a comprehensive epidemiological survey on CJD patients in Argentina based on systematic surveillance between 1997 and 2008. Methods: A CJD Surveillance Referral Center (SRC) was established in Argentina in 1997; previously a Neuropathology Referral Center was used from 1983 to 1996. All suspected cases referred to the SRC were classified using established criteria on the basis of information derived from the following: clinical data form, EEG, MRI (both for central review), cerebrospinal fluid (CSF) for protein 14-3-3 Western blot (WB), autopsy or biopsy material for neuropathology, prion protein (PrP) immunohistochemistry and PrP WB, as well as blood for DNA studies (when brain tissue was not available). Results: Of the 517 patients referred to the SRC between 1997 and 2008, 211 (40.8%) had CJD or other transmissible spongiform encephalopathies (TSEs) (definite or probable). Possible cases totaled 14.5%, while cases with no WHO criteria accounted for 16.4%. Non-CJD cases excluded by biopsy/autopsy or during follow-up corresponded to 28.2% of the 517 referrals. Main differential diagnoses included neurodegenerative diseases such as Alzheimer’s disease, frontotemporal dementia, vascular, metabolic or viral encephalopathy, and Hashimoto’s disease. Five percent of referred patients ultimately recovered. Eighty-three percent of TSE cases were sporadic CJD; 17% were genetic, mainly E200K (15.6%); the remaining 1.4% included an octarepeat insertion and two Gerstmann-Sträussler-Scheinker cases (P102L). Seventy-four of 100 definite cases had frozen tissue available for molecular subtyping (PrP^Sc/codon 129). CSF protein 14-3-3 WB sensitivity was 72.3% and specificity was 92.1%. Clinical diagnostic criteria for probable CJD when compared to definite diagnosis by neuropathology showed 71.3% sensitivity, 86.2% specificity, 94.4% positive predictive value and 48% negative predictive value. Country incidence increased over time and reached 0.85 cases per million in 2008, with the highest rate detected in the city of Buenos Aires (1.8). Districts with 6% of the total population have never reported suspected cases. Conclusion: In spite of an increase in incidence observed over time, the difference between Buenos Aires city, where the incidence is comparable to that of smaller European countries with higher population density, and the incidence observed in the rest of the country suggests underreporting in nonmetropolitan areas, probably due to a lack of access to specialized medical facilities. CSF WB sensitivity results for protein 14-3-3 were probably linked to the fact that testing was not routinely repeated during the course of the disease, when earlier test results had been negative. The spectrum of molecular CJD subtypes observed did not differ from other countries in Europe. No iatrogenic or variant CJD cases were identified. The sensitivity and negative predictive value of clinical diagnostic criteria...

Background: Most studies carried out in Latin America have shown greater rates of epilepsy and generalized seizures than those observed in developed countries, in spite of lower numbers of patients receiving treatment. To date, studies in Argentina have been insufficient to establish true prevalence. Objective: To determine the prevalence of epilepsy in primary school children in Buenos Aires, together with rates of different seizure types, treatments prescribed, diagnoses made and number of inadequate therapies administered, as well as the relationship between epilepsy and learning difficulties. Design and Method: A cross-sectional study was carried out on 10% of the entire primary school population of Buenos Aires through randomized, systematic, representative and conglomerate sampling of public and private school students. A total of 26,270 responses were received (83.1% of the population) to a specially designed questionnaire, with 96.4% sensitivity and 41.5% specificity, respectively. Interviews were conducted in all probable epilepsy cases as well as in a random sample of probable negative ones. Results: Eighty-four children with epilepsy were detected (lifetime prevalence 3.2‰; active prevalence 2.6‰), in whom generalized seizures predominated (57.1%). Ninety-three percent of cases diagnosed were currently under, or had previously received antiepileptic drug (AED) therapy. Almost 1% of the primary school population studied had a prior diagnosis and/or received AED for dysrhythmia or epilepsy. The percentage of grade repeaters in the general population and in children with epilepsy was 8.4 and 26.2%, respectively. Conclusions: (1) The prevalence of epilepsy in primary school children in Buenos Aires is similar to that reported for developed countries; (2) a slight prevalence for generalized seizures was observed; (3) 93% of cases received AEDs; (4) misdiagnoses and unnecessary treatments exceeded correct diagnoses and adequate therapy, and (5) disease presence and/or treatment were associated with poorer school performance.

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Background: Previous studies in special schools have shown a high prevalence of epilepsy, which is strongly associated with cerebral palsy and severe mental retardation. The conditions regulating school placement have also been described in those studies. In the City of Buenos Aires, information is known only for mainstream schools. Objective: To determine the prevalence and characteristics of epilepsy in special schools and to compare results with common primary education settings. Design and Methods: A cross-sectional study was carried out in special schools in the City of Buenos Aires, by adopting the same definitions, diagnostic criteria and questionnaire as those used in a previous study in the common primary school population. Responses from 1,682 children, aged 6–16 years, residing in the City of Buenos Aires, with mental retardation, visual or hearing impairment, psychiatric disorders and motor disabilities were analyzed. Results: A total of 121 children with epilepsy were detected. Lifetime prevalence was 71.9‰ and active prevalence was 64.8‰ (22–25 times greater than rates in mainstream schools). Prevalence was highest in girls and generalized seizures prevailed over other seizure types. Ninety-two percent of cases received antiepileptic drugs, 57.9% as a single drug treatment and 85.1% in adequate doses. Only 56% of the children with a diagnosis of epilepsy proved to be true-positive cases, and almost 40% received antiepileptic drugs for nonepileptic disorders. Malformations/degenerative disease were the most common etiology. Conclusions: Special schools contain clusters of children with epilepsy as a comorbid condition. False high frequency is due to misdiagnoses and unnecessary treatments. These schools are an important target for educational interventions.

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