Neuropsychological Assessment for Early Detection and Diagnosis of Dementia: Current Knowledge and New Insights.

Dementia remains an underdiagnosed syndrome, and there is a need to improve the early detection of cognitive decline. This narrative review examines the role of neuropsychological assessment in the characterization of cognitive changes associated with dementia syndrome at different states. The first section describes the early indicators of cognitive decline and the major barriers to their identification. Further, the optimal cognitive screening conditions and the most widely accepted tests are described. The second section analyzes the main differences in cognitive performance between Alzheimer's disease and other subtypes of dementia. Finally, the current challenges of neuropsychological assessment in aging/dementia and future approaches are discussed. Essentially, we find that current research is beginning to uncover early cognitive changes that precede dementia, while continuing to improve and refine the differential diagnosis of neurodegenerative disorders that cause dementia. However, neuropsychology faces several barriers, including the cultural diversity of the populations, a limited implementation in public health systems, and the adaptation to technological advances. Nowadays, neuropsychological assessment plays a fundamental role in characterizing cognitive decline in the different stages of dementia, but more efforts are needed to develop harmonized procedures that facilitate its use in different clinical contexts and research protocols.

Systemic inflammatory impact of periodontitis on cognitive impairment.

OBJECTIVES: The role in dementia of systemic inflammation derived from periodontal disease is not fully elucidated. The objective of our study was to examine the impact of inflammation on the relationship between periodontitis and cognitive impairment. METHODS: We have designed a case (n = 171) and control (n = 131) study to determine the periodontal health status, grade of cognitive impairment/dementia and systemic inflammation level, the last being measured by analysis of 29 inflammatory biomarkers using multiplex techniques. RESULTS: At the time of sampling, 11 of the 29 inflammatory biomarkers were associated with cognitive impairment in patients with more severe periodontitis. However, the inflammatory response to severe periodontitis was more reduced (lower biomarker concentrations) in cases (with cognitive impairment or dementia) than in (cognitively healthy) controls, an unexpected finding. CONCLUSIONS: Based on these results, we cannot confirm that systemic inflammation derived from periodontal disease plays a relevant role in the aetiology of cognitive impairment.

Effective diagnosis of Alzheimer's disease by means of large margin-based methodology.

BACKGROUND: Functional brain images such as Single-Photon Emission Computed Tomography (SPECT) and Positron Emission Tomography (PET) have been widely used to guide the clinicians in the Alzheimer's Disease (AD) diagnosis. However, the subjectivity involved in their evaluation has favoured the development of Computer Aided Diagnosis (CAD) Systems. METHODS: It is proposed a novel combination of feature extraction techniques to improve the diagnosis of AD. Firstly, Regions of Interest (ROIs) are selected by means of a t-test carried out on 3D Normalised Mean Square Error (NMSE) features restricted to be located within a predefined brain activation mask. In order to address the small sample-size problem, the dimension of the feature space was further reduced by: Large Margin Nearest Neighbours using a rectangular matrix (LMNN-RECT), Principal Component Analysis (PCA) or Partial Least Squares (PLS) (the two latter also analysed with a LMNN transformation). Regarding the classifiers, kernel Support Vector Machines (SVMs) and LMNN using Euclidean, Mahalanobis and Energy-based metrics were compared. RESULTS: Several experiments were conducted in order to evaluate the proposed LMNN-based feature extraction algorithms and its benefits as: i) linear transformation of the PLS or PCA reduced data, ii) feature reduction technique, and iii) classifier (with Euclidean, Mahalanobis or Energy-based methodology). The system was evaluated by means of k-fold cross-validation yielding accuracy, sensitivity and specificity values of 92.78%, 91.07% and 95.12% (for SPECT) and 90.67%, 88% and 93.33% (for PET), respectively, when a NMSE-PLS-LMNN feature extraction method was used in combination with a SVM classifier, thus outperforming recently reported baseline methods. CONCLUSIONS: All the proposed methods turned out to be a valid solution for the presented problem. One of the advances is the robustness of the LMNN algorithm that not only provides higher separation rate between the classes but it also makes (in combination with NMSE and PLS) this rate variation more stable. In addition, their generalization ability is another advance since several experiments were performed on two image modalities (SPECT and PET).

Usefulness of a 15-item version of the Boston Naming Test in neuropsychological assessment of low-educational elders with dementia.

The purpose of this study was to validate a reduced version (15 items) of the Boston Naming Test (BNT) in a sample of 78 low-educational elderly persons with or without dementia, as determined by independent assessment with a battery of cognitive tests. The reduced version was found to be equivalent to the complete BNT, and to have criterion validity with respect to other measures of dementia. We conclude that the reduced version is a useful instrument for assessing patients who require shorter testing methods because of severe cognitive deterioration or their low level of education.

Trastornos somáticos funcionales / Functional somatic disorders

Los autores contemplan una serie de trastornos cuya incidencia contrasta con las dificultades diagnósticas. En cada grupo de patología se muestra un caso clínico característicos; se proponen a continuación una serie de medidas terapéuticas generales para cada uno de los casos y se expone finalmente un cuadro resumen en el que se trata de sintetizar la clínica y los factores circunstanciales