ABSTRACT The Atahualpa Project includes a Neuroimaging sub-study, which consists in the practice of MRIs and MRAs to all participants aged ≥60 years, as well as those presenting with specific neurological complains. Likewise, all participants aged ≥20 years have been invited for the practice of a head CT. MRIs and MRAs have been performed with the use of a Philips Intera 1.5T MRI machine, and TCs with the use of a Philips Brilliance 64 CT scanner, following established protocols. All exams have been independently reviewed by a neurologist and a neuroradiologist, with adequate kappa coefficients for inter-rater agreement. MRIs studies have been focused on the evaluation of global cortical atrophy, posterior parietal atrophy, bicaudate index, Evans index, hippocampal atrophy, signatures of cerebral small vessel disease, and lesions consistent with ischemic or hemorrhagic strokes. By the use of MRI, we have assessed the prevalence of intracranial artery stenosis, intracranial dolichoectasia and variations in the configuration of the circle of Willis. Using CT, we have focused on the diagnosis of neurocysticercosis, pineal gland calcifications, as well as in variations and characteristics of skull bones, cerebellar atrophy, and severity of carotid siphon calcifications. In the present study, we focused on the description of basic protocols used for assessment of previously mentioned lesions of interest.

RESUMEN Como parte del Proyecto Atahualpa se diseñó el sub-estudio de neuroimagen, el cual incluye la práctica de IRM y angio-resonancias a toda la población ≥60 años, así como a participantes con padecimientos que ameriten estos exámenes. De igual manera, toda la población de ≥20 años ha sido invitada para la práctica de TC de cerebro. Las IRMs y angio-resonancias han sido realizadas en un equipo marca Philips, modelo Intera, de 1.5 Tesla, y las TC en un equipo helicoidal marca Philips, modelo Brilliance 64, siguiendo protocolos de investigación internacionalmente establecidos. Todos los exámenes han sido interpretados de manera independiente por un neurólogo y un neuroradiólogo. Hasta el momento, la mayoría de lecturas han tenido coeficientes de correlación (kappa) satisfactorio (excelente o muy bueno) y las discrepancias se han solucionado por consenso. Los estudios de IRM se han enfocado en estimación de atrofia cortical global, atrofia parietal posterior, atrofia de núcleo caudado, índice de Evans, atrofia de hipocampo, marcadores de enfermedad de pequeño vaso cerebral, y en la búsqueda de lesiones compatibles con infartos y hemorragias cerebrales. Utilizando angio-resonancia hemos valorado la presencia de estenosis de arterias intracraneales, dolicoectasia basilar y configuración del polígono de Willis. En TC, nos hemos enfocado en el diagnóstico de calcificaciones cisticercosas, en la presencia y severidad de las calcificaciones de la glándula pineal, en las variaciones en grosor, heterogeneidad de los huesos del diploe, en la atrofia de cerebelo, y en la estimación del grado de calcificación de los sifones carotideos. En el presente artículos se describen los protocolos básicos utilizados para la valoración de cada una de las lesiones of interés mencionadas previamente.

ABSTRACT Stroke burden is on the rise in rural regions of South America. We evaluated prevalence, pattern of subtypes and pathogenetic mechanisms underlying stroke in Atahualpa. In a three-phase epidemiologic study, suspected cases were detected by a door-to-door survey. Then, neurologists evaluated suspected cases and randomly selected negative persons, and confirmed patients underwent complementary exams. We found 20 stroke patients among 642 persons aged ≥ 40 years. Stroke prevalence was 31.15‰ that increased with age. Hypertensive arteriolopathy was the most likely mechanism underlying strokes (55% patients). Extracranial atherosclerotic lesions or cardiac sources of emboli were not found in any case. Comparison of our findings with a previous survey performed in the same village showed an alarming increase in stroke prevalence (from 14.08‰ in 2003 to 31.15‰ in 2012, p=0.03). Thereafter, we conducted an incidence study. For this, first-ever strokes occurring over four years were identified from yearly door-to-door surveys and other overlapping sources. Of 807 stroke-free individuals prospectively enrolled in the Atahualpa Project, follow-up was achieved in 718 (89%), contributing 2,499 years of follow-up (average 3.48±0.95 years). Stroke incidence rate was 2.97 per 100 person-years of follow-up (95% C.I.: 1.73-4.2), which increased to 4.77 (95% C.I.: 1.61-14.1) when only persons aged ≥57 years were considered. Poisson regression models, adjusted for relevant confounders, showed that high blood pressure (IRR: 5.24; 95% C.I.: 2.55-7.93) and severe edentulism (IRR: 5.06; 95% C.I.: 2.28-7.85) were the factors independently increasing stroke incidence. Stroke incidence in Atahualpa is comparable to that reported from the developed world. Besides age and high blood pressure, severe edentulism is a major factor independently predicting incident strokes.

RESUMEN El impacto de la enfermedad cerebrovascular (ECV) está en aumento en las regiones rurales de América del Sur. Evaluamos la prevalencia, subtipos y mecanismos patogénicos de la ECV en Atahualpa. En un estudio de tres fases, los casos sospechosos fueron detectados por una encuesta puerta-a-puerta. Luego, los neurólogos evaluaron casos sospechosos y seleccionaron al azar personas negativas, y los pacientes confirmados se sometieron a exámenes. Se encontraron 20 pacientes con ECV entre 642 personas ≥40 años. La prevalencia fue 31,15‰ y aumentó con la edad. La arteriolopatía hipertensiva fue el mecanismo más probable de los ECV (55% de los pacientes). En ningún caso se encontraron lesiones ateroscleróticas extracraneales o fuentes cardíacas de embolia. La comparación de nuestros hallazgos con una encuesta anterior realizada en Atahualpa mostró un aumento alarmante en la prevalencia de ECV (14,08‰ en 2003 a 31,15‰ en 2012, p=0,03). Posteriormente, se realizó un estudio de incidencia. Para ello, todos los eventos nuevos ocurridos a lo largo de cuatro años se identificaron. De 807 individuos sin ECV ingresados prospectivamente en el Proyecto Atahualpa, el seguimiento se logró en 718 (89%), contribuyendo con 2.499 años de seguimiento (promedio de 3,48 ± 0,95 años). La incidencia de ECV fue de 2,97 por 100 años-persona de seguimiento (95% C.I.: 1,73-4,2), que aumentó a 4,77 (95% C.I.: 1,61-14,1) cuando se consideraron las personas mayores de 57 años. Los modelos de regresión de Poisson, ajustados para los factores de confusión relevantes, mostraron que la presión arterial alta (IRR: 5,24; 95% C.I.: 2,55-7,93) y el edentulismo (IRR: 5,06; 95% C.I.: 2,28-7,85). La incidencia de ECV en Atahualpa es comparable a la reportada en el mundo desarrollado. Además de la edad y la presión arterial alta, el edentulismo es un factor importante que predice independientemente los ECV.

O teste cognitivo Leganés (TCL) é um instrumento para o rastreio rápido de demência em idosos com baixo nível educacional. OBJETIVO: Tivemos como objetivo avaliar se o TCL associa-se com medidas de atrofia cortical global (ACG) e pode ser usado como um substituto para a lesão cerebral estrutural. MÉTODOS: Residentes de Atahualpa com idade ≥ 60 anos identificados durante um levantamento porta-a-porta foram submetidos a ressonância magnética para avaliar a intensidade da ACG. Usando modelos lineares generalizados multivariados, avaliamos se escores TCL contínuos correlacionavam com a intensidade da ACG após ajustes para a dados demográficos, educação, saúde cardiovascular (CVH), depressão e edentulismo. Em um estudo caso-controle aninhado, avaliamos a gravidade da ACG em pessoas com escores no TCL abaixo do nível de corte para demência (≤ 22 pontos) e em pessoas pareados sem demência. RESULTADOS: Dentre as 311 pessoas elegíveis, 241 (78%) foram selecionadas. A média de idade foi de 69,2±7,5 anos, 59% eram mulheres, 83% tinham o ensino primário, 73% tinham mau estado CVH, 12% apresentaram sintomas de depressão e 43% tinham edentulismo. Pontuações médias no TCL foram 26,7±3 e 23 (9,5%) pessoas tinham ≤ 22 pontos. ACG foi leve em 108, moderada em 95 e grave em 26 pessoas. No modelo multivariado, a média de pontuação no TCL não foi associada com a gravidade da ACG (β=0,06, SE=0,34, p=0,853). ACG grave foi observada em 6 de 23 pacientes e em 8 de 23 controles (OR: 0,67; IC 95%: 0,14-2,81, p=0,752, teste de McNemar). CONCLUSÃO: O TCL não se associa com a gravidade da ACG após o ajuste para possíveis fatores de confusão e não deve ser usado como uma estimativa confiável de dano cerebral estrutural.

OBJECTIVE: We aimed to evaluate whether the Leganés cognitive test (LCT) correlates with global cortical atrophy (GCA) and can be used as a surrogate for structural brain damage. METHODS: Atahualpa residents aged ≥ 60 years identified during a door-to-door survey underwent MRI for grading GCA. Using multivariate generalized linear models, we evaluated whether continuous LCT scores correlated with GCA, after adjusting for demographics, education, cardiovascular health (CVH) status, depression and edentulism. In a nested case-control study, GCA severity was assessed in subjects with LCT scores below the cutoff level for dementia (≤ 22 points) and in matched controls without dementia. RESULTS: Out of 311 eligible subjects, 241 (78%) were enrolled. Mean age was 69.2±7.5 years, 59% were women, 83% had primary school education, 73% had poor CVH status, 12% had symptoms of depression and 43% had edentulism. Average LCT score was 26.7±3, and 23 (9.5%) subjects scored ≤ 22 points. GCA was mild in 108, moderate in 95, and severe in 26 individuals. On the multivariate model, mean LCT score was not associated with GCA severity (β=0.06, SE=0.34, p=0.853). Severe GCA was noted in 6 / 23 case-patients and in 8 / 23 controls (OR: 0.67, 95% CI: 0.14-2.81, p=0.752, McNemar's test). CONCLUSION: The LCT does not correlate with severity of GCA after adjusting for potential confounding variables, and should not be used as a reliable estimate of structural brain damage.