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Alzheimer's disease (AD) is a dementia that affects a large contingent of the elderly population characterized by the presence of neurofibrillary tangles and senile plaques. Traumatic brain injury (TBI) is a non-degenerative injury caused by an external mechanical force. One of the main causes of TBI is diffuse axonal injury (DAI), promoted by acceleration-deceleration mechanisms., Objective: To understand the electroencephalographic differences in functional mechanisms between AD and DAI groups., Methods: The study included 20 subjects with AD, 19 with DAI and 17 healthy adults submitted to high resolution EEG with 128 channels. Cortical sources of EEG rhythms were estimated by exact low-resolution electromagnetic tomography (eLORETA) analysis., Results: The eLORETA analysis showed that, in comparison to the control (CTL) group, the AD group had increased theta activity in the parietal and frontal lobes and decreased alpha 2 activity in the parietal, frontal, limbic and occipital lobes. In comparison to the CTL group, the DAI group had increased theta activity in the limbic, occipital sublobar and temporal areas., Conclusion: The results suggest that individuals with AD and DAI have impairment of electrical activity in areas important for memory and learning., Competing Interests: Disclosure: The authors report no conflicts of interest.

Objective: We evaluated quantitative EEG measures to determine a screening index to discriminate Alzheimer's disease (AD) patients from normal individuals., Methods: Two groups of individuals older than 50 years, comprising a control group of 57 normal volunteers and a study group of 50 patients with probable AD, were compared. EEG recordings were obtained from subjects in a wake state with eyes closed at rest for 30 min. Logistic regression analysis was conducted., Results: Spectral potentials of the alpha and theta bands were computed for all electrodes and the alpha/theta ratio calculated. Logistic regression of alpha/theta of the mean potential of the C3 and O1 electrodes was carried out. A formula was calculated to aid the diagnosis of AD yielding 76.4% sensitivity and 84.6% specificity for AD with an area under the ROC curve of 0.92., Conclusion: Logistic regression of alpha/theta of the spectrum of the mean potential of EEG represents a good marker discriminating AD patients from normal controls.

The relationship between social class and nutritional status, although frequently presumed true, has scarcely ever been studied empirically. The health and nutritional status of a sample of children from different social classes in the city of S. Paulo (Brazil) are studied by means of an on operational classification of social class. Through the analysis of the height for age distribution normal growth--and, therefore, favourable health status--as found only among the burgeoisie and the small-burgeoisie, these two classes together constituting about 30% of the total population. Significant divergences from an expected anthropometric standard were found among all the segments of the working-class population. Differences in income and schooling among the classes corroborate the empirical link found between social class and health and nutritional status.