RESUMO
Resumen La reserva cognitiva (RC) se refiere al nivel de adaptabilidad de la cognición frente a cambios cerebrales. Varios estudios la han considerado un factor de protección de la enfermedad de Alzheimer (EA). En la región argentina no se cuenta con un instrumento validado que permita medir este constructo. El objetivo del presente trabajo es adaptar el Cuestionario de Reserva Cognitiva (CRC) a la población argentina, establecer puntajes de corte para determinar desde niveles bajos a superiores de RC y analizar qué variables predicen el puntaje total de la reserva. Las modificaciones introducidas a la adaptación fueron evaluadas a través de un proceso de juicio de expertos. Un total de 177 sujetos sanos completaron el Cuestionario de Reserva Cognitiva en su adaptación argentina (CRC-a). Mediante la medida de cuartiles, se establecieron puntajes de corte para determinar niveles bajos, medios, altos y superiores de la reserva. Se realizó una regresión lineal para evaluar si el sexo, la edad y la escolaridad predicen el nivel de RC. En la adaptación argentina del CRC se modificaron 3 de las 8 dimensiones totales y 16 de los 33 ítems totales con respecto al cuestionario original. La media del puntaje total obtenido por la muestra a partir del cuestionario fue de 15.06 con DS = 3.42. Puntajes menores a 13 reflejaron niveles bajos de RC, puntajes entre 13 y 16, niveles medios, puntajes entre 16 y 20, niveles altos, y puntajes superiores a 20, niveles superiores. La escolaridad resultó ser la única variable de predicción del nivel de RC. Si bien se encontraron diferencias entre grupos respecto a la variable sexo, esta no demostró ser predictiva. El CRC-a es el primer instrumento desarrollado en esta región para medir el nivel de RC. Contar con su validación abriría futuras líneas de investigaciones sobre posibles intervenciones para la prevención de enfermedades, tales como la EA.
Abstract Cognitive reserve (CR) refers to the level of adaptability of cognition after brain changes. It is based on processes that allow the activation of new synaptic connections after neurodegeneration, which permits to better withstand the consequences. This reserve is constituted by the interaction of innate individual characteristics (intrauterine or genetically determined) and the exposure to different life experiences. It begins its development in early stages of life and continues its transformation up to advances ages. The sociodemographic variables reported as the main ones to build the reserve are education, leisure activities, lifestyle, socioeconomic level and intelligence. Several studies have considered it as a protective factor for Alzheimer's Disease (AD). Subjects with high levels of CR have lower prevalence and incidence of AD in comparison to those with low levels of reserve. CR would lead to a late onset of symptoms, despite not having any effect on the underlying pathophysiological process of the disease. The reserve would not prevent AD from developing, but it would compensate the symptoms and, therefore, delay their onset. In some cases, there is such compensation that the symptoms do not manifest. There is no validated instrument available for the Argentinian region that allows to measure this construct. The aim of this study is to adapt the Cognitive Reserve Questionnaire to the Argentinian population, to establish cut-off scores to distinguish between low, medium, high and superior levels of CR and analyze which variables could predict the total reserve score. The modifications introduced in the adaptation were evaluated through an expert judgment process. A total of 177 healthy subjects completed the Cognitive Reserve Questionnaire in its Argentinian adaptation (CRQ-a). Through the measure of quartiles, cut-off scores were established to determine low, medium, high and superior levels of the reserve. A lineal regression was made to evaluate if age, education, and sex might predict the level of CR. Three of the eight total dimensions and 16 of the 33 total items that make up the original questionnaire were modified. The mean of the total score obtained by the sample from the questionnaire was 15.06 with SD = 3.42. Scores under 13 reflected low CR levels, scores between 13 and 16 reflected medium levels, scores between 16 and 20 reflected high levels, and scores above 20 reflected superior levels. Education turned out to be the only predictor variable for the level of CR. Although differences were found between groups of different sex, this variable turned out to be not predictive. The CRQ-a is the first instrument for the Argentinian population to measure the level of the reserve. It allows to quickly explore different dimensions, considered as the most relevant for its formation. These are: formal education, courses, parents' formal education, employment, musical training, languages, reading activity and intellectual games. In patients with AD, is particularly important to have a measure for CR to prepare interventions for those subjects whose reserve levels are perceived as low, aiming to delay and, when possible, prevent the clinical manifestation of the disease. Its validation would open future lines of research on possible interventions for the prevention of diseases such as AD.
RESUMO
INTRODUCTION: Dissociative amnesia (DA) is a retrograde amnesia characterized by an alteration in episodic memory. AIM: Establish the neural bases which underlie the development of dissociative amnesia. METHODS: Systematic and evaluative bibliographic review of qualitative type. RESULTS: The bibliography found suggested functional inhibition in the hippocampus, amygdala, temporal lobes, prefrontal cortex and thalamus. Also, hypoglycemia was observed in right cerebral cortex, at the fronto-temporal junction. An inhibition in the potential action P300 was also stated. CONCLUSIONS: There is enough evidence to say that dissociative amnesia is an objectifiable biologically based pathology. There is a need to review the current conceptualization of this syndrome and to establish new criteria that would allow us to distinguish DA from organic amnesias.