Magnetic resonance imaging study of the brain in aged volunteers: T2 high intensity lesions and higher order cortical function

Neuropsychological correlates of magnetic resonance imaging-defined subcortical ischemic depression

OBJECTIVE

The goal of the current study was to examine the neuropsychological profile of magnetic resonance imaging (MRI)-defined subcortical ischemic depression (SID).

METHODS

Clinically depressed older adults with MRI-defined SID (n = 70) and depressed elders without SID (n = 75) were compared on neuropsychological performance, depression symptoms, and medical burden.

RESULTS

Group comparisons revealed that the SID was associated with worse performance on all neuropsychological measures, but also with greater age, higher cardiac illness burden, and greater deficits in the depression symptoms of self-initiation and concentration. In multivariate regression models, auditory working memory and nonverbal memory remained worse among the SID group after controlling for contributions of age, cardiovascular risk, and depression symptoms.

CONCLUSIONS

Although auditory working memory span and nonverbal memory appear to be specifically associated with the ischemic pathology that defines SID, the typical individual with SID is also likely to have a broader profile of neuropsychological deficits than those without SID because they are typically older and have specific depression symptoms that predispose them to compromised neurocognitive performance.

Diagnosing dementia and normal aging: clinical relevance of brain ratios and cognitive performance in a Brazilian sample

The main objective of the present study was to evaluate the diagnostic value (clinical application) of brain measures and cognitive function. Alzheimer and multi-infarct patients (N = 30) and normal subjects over the age of 50 (N = 40) were submitted to a medical, neurological and cognitive investigation. The cognitive tests applied were Mini-Mental, word span, digit span, logical memory, spatial recognition span, Boston naming test, praxis, and calculation tests. The brain ratios calculated were the ventricle-brain, bifrontal, bicaudate, third ventricle, and suprasellar cistern measures. These data were obtained from a brain computer tomography scan, and the cutoff values from receiver operating characteristic curves. We analyzed the diagnostic parameters provided by these ratios and compared them to those obtained by cognitive evaluation. The sensitivity and specificity of cognitive tests were higher than brain measures, although dementia patients presented higher ratios, showing poorer cognitive performances than normal individuals. Normal controls over the age of 70 presented higher measures than younger groups, but similar cognitive performance. We found diffuse losses of tissue from the central nervous system related to distribution of cerebrospinal fluid in dementia patients. The likelihood of case identification by functional impairment was higher than when changes of the structure of the central nervous system were used. Cognitive evaluation still seems to be the best method to screen individuals from the community, especially for developing countries, where the cost of brain imaging precludes its use for screening and initial assessment of dementia.