Diagnóstico precoz de la enfermedad de Alzheimer: fase prodrómica y preclínica / Early diagnosis of Alzheimer’s disease: the prodromal and preclinical phase

Introducción. Debido a la necesidad de tratamientos para la enfermedad de Alzheimer (EA) en fases muy iniciales, su detección precoz se ha convertido en uno de los principales focos de investigación en el campo de las enfermedades neurodegenerativas. Desarrollo. El intento de caracterizar las fases incipientes de la enfermedad ha evolucionado desde la aparición del heterogéneo concepto de deterioro cognitivo leve a finales del siglo pasado hasta los actuales criterios diagnósticos de investigación propuestos para la EA. Estos criterios permiten realizar un diagnóstico precoz de la EA, en fase prodrómica, y etiológico, al estar sustentado en marcadores biológicos objetivos, que se describirán a lo largo de este trabajo. Se revisará, además, el concepto de EA preclínica, que se sustenta en la evidencia de que el proceso patológico de la EA empieza años antes de la manifestación clínica de la enfermedad. Conclusiones. Por el momento, la fase preclínica es la menos estudiada, aunque el desarrollo de técnicas complejas de imagen con nuevos trazadores supone un inicio prometedor del camino soñado hacia el diagnóstico preclínico de la enfermedad (AU)

Introduction. Because Alzheimer’s disease (AD) needs to be treated as soon as possible after onset, its early detection has become one of the core areas of research in the field of neurodegenerative diseases. Development. Attempts to characterise the incipient phases of the disease have evolved from the appearance of the heterogeneous concept of mild cognitive impairment in the last twentieth century to the diagnostic criteria proposed for AD by current research. These criteria make it possible to perform an early diagnosis of AD (in the prodromal phase) that is at the same time aetiological, since it is backed up by objective biological markers which will be discussed in this work. Additionally, the article will also review the concept of preclinical AD, which is supported by evidence showing that the pathological process of AD begins years before the clinical manifestation of the disease. Conclusions. To date, this preclinical phase is the one that has received less attention from researchers, although the development of complex imaging techniques with new tracers appears to be a promising beginning to the coveted path towards the preclinical diagnosis of the disease (AU)

Validez discriminativa y asociación del test minimental (MMSE) y del test de alteración de memoria (T@M) con una batería neuropsicológica en pacientes con deterioro cognitivo leve amnésico y enfermedad de Alzheimer / Discriminatory validity and associationof the mini-mental test (MMSE) and the memory alteration test (M@T) with a neuropsychological battery in patients with amnestic mild cognitive impariment and alzeimer´s disease

Objetivos. Establecer la validez discriminativa del test minimental (MMSE) y del test de alteración de memoria (T@M) para el diagnóstico del deterioro cognitivo leve amnésico (DCLa) y la enfermedad de Alzheimer (EA) probable, y estudiarla asociación entre los resultados obtenidos en pruebas de cribado, una batería neuropsicológica y un cuestionario funcional en personas sanas y en pacientes con DCLa y EA. Sujetos y métodos. Se evaluó a 27 controles normales, 27 pacientes con DCLa y 35 pacientes con EA con el MMSE y con un test de cribado de memoria, el T@M, una batería neuropsicológica y un cuestionario de actividades funcionales de la vida diaria. Los coeficientes de correlación de Pearson se utilizaron para evaluar las relaciones entre las puntuaciones del T@M y el MMSE y los test neuropsicológicos. Se calcularon las áreas bajo la curva, la sensibilidad y la especificidad para los test de cribado. Resultados. En los pacientes con DCLa, las puntuaciones en el T@M y el MMSE resultaron estar fuertemente asociadas con el rendimiento de test de memoria episódica de las pruebas frontales y con las puntuaciones del cuestionario funcional, pero no con pruebas que evaluaban praxias y funciones perceptivas. En los pacientes con EA, las puntuaciones en el T@M y el MMSE se asociaron con resultados en memoria semántica, lenguaje, funciones ejecutivas y praxias, pero no con pruebas perceptivas y cuestionarios funcionales. Conclusiones. En pacientes con DCLa y EA, la asociación entre el MMSE y el T@M solamente correlaciona con algunas funciones cognitivas, sin que exista asociación con otras funciones cognitivas. Por lo tanto, los test de cribado no pueden utilizarse como único instrumento para evaluar el estado cognitivo en pacientes con sospecha de demencia (AU)

Aims. To establish the discriminatory validity of the mini-mental test (MMSE) and the memory alteration test (M@T) for the diagnosis of amnestic mild cognitive impairment (aMCI) and probable Alzheimer’s disease (AD), and also to study the association between the results obtained in screening tests, a neuropsychological battery and a functional questionnaire in healthy persons and in patients with aMCI and AD. Subjects and methods.We evaluated 27 normal controls, 27 patients with aMCI and 35 patients with AD using the MMSE and a memory screening test, the M@T, a neuropsychological battery and a questionnaire on functional activities of daily living. Pearson correlation coefficients were used to evaluate the relations between the scores on the M@T and the MMSE and the neuropsychological tests. The area below the curve, the sensitivity and the specificity were calculated for the screening tests. Results. In patients with aMCI, the scores on the M@T and the MMSE were strongly associated with the performance in the episodic memory tests in frontal tests and with the scores on the functional questionnaire, but not with tests that evaluated praxias and perceptive functions. In patients with AD, the scores on the M@T and the MMSE were associated with results in semantic memory, language, executive functions and praxias, but not with perceptive tests and functional questionnaires. Conclusions. In patients with aMCI and AD, the association between MMSE and M@T only correlate with some cognitive functions, without there being any association with other cognitive functions. Therefore, screening tests cannot be used as the only instrument for evaluating the cognitive status in patients with suspected dementia (AU)

[Discriminatory validity and association of the mini-mental test (MMSE) and the memory alteration test (M@T) with a neuropsychological battery in patients with amnestic mild cognitive impairment and Alzheimer's disease]. / Validez discriminativa y asociación del test minimental (MMSE) y del test de alteración de memoria (T@M) con una batería neuropsicológica en pacientes con deterioro cognitivo leve amnésico y enfermedad de Alzheimer.

AIMS: To establish the discriminatory validity of the mini-mental test (MMSE) and the memory alteration test (M@T) for the diagnosis of amnestic mild cognitive impairment (aMCI) and probable Alzheimer's disease (AD), and also to study the association between the results obtained in screening tests, a neuropsychological battery and a functional questionnaire in healthy persons and in patients with aMCI and AD. SUBJECTS AND METHODS: We evaluated 27 normal controls, 27 patients with aMCI and 35 patients with AD using the MMSE and a memory screening test, the M@T, a neuropsychological battery and a questionnaire on functional activities of daily living. Pearson correlation coefficients were used to evaluate the relations between the scores on the M@T and the MMSE and the neuropsychological tests. The area below the curve, the sensitivity and the specificity were calculated for the screening tests. RESULTS: In patients with aMCI, the scores on the M@T and the MMSE were strongly associated with the performance in the episodic memory tests in frontal tests and with the scores on the functional questionnaire, but not with tests that evaluated praxias and perceptive functions. In patients with AD, the scores on the M@T and the MMSE were associated with results in semantic memory, language, executive functions and praxias, but not with perceptive tests and functional questionnaires. CONCLUSIONS: In patients with aMCI and AD, the association between MMSE and M@T only correlate with some cognitive functions, without there being any association with other cognitive functions. Therefore, screening tests cannot be used as the only instrument for evaluating the cognitive status in patients with suspected dementia.