Work

Cognitive Measure May Identify Atrophy in Brain Regions Associated With Posterior Cortical Atrophy

Year: 2017

Type: conference-abstract

Abstract: Posterior cortical atrophy (PCA) affects a small percentage of individuals with Alzheimer’s disease (AD) pathology and is characterized by significant visual-perceptual impairment. There are no consensus diagnostic criteria for PCA and misdiagnosis is common. This study tested whether a simple ratio score of visual-perceptual performance to memory performance was associated with MRI measures of visual association cortices in a subgroup of patients with suspected PCA. Analyses included 141 patients with AD dementia (M age = 74.4) from the Alzheimer’s Disease Neuroimaging Initiative. Ratio scores, reflecting constructional praxis performance (a measure of visual spatial ability) relative to immediate recall memory performance, were calculated for each patient using subscales of the ADAS-Cog. Atrophy was estimated using structural MRI measures (volume, thickness) of cortical regions involved in visual processing. Using ADAS-Cog ratio scores, 12 patients were classified as possible PCA subjects (M age = 69.9). Relative to the ‘typical’ AD group, the ‘PCA’ group had smaller volumes and lower thicknesses in several posterior cortical regions and a composite score of these brain regions (p <.05). Several MRI measures were significantly related to higher scores on the ADAS-cog based ratio in the ‘PCA’ subgroup but not in the ‘typical’ AD group (p<.05). Additionally, logistic regressions showed that the degree of atrophy in several regions predicted ‘PCA’ group status (p<.05). The results suggest that the ADAS-Cog based ratio of constructional praxis to memory recall is associated with significant atrophy in posterior cortical regions. This measure may be useful for identifying individuals with suspected PCA.

Source: Innovation in Aging

DOI: 10.1093/geroni/igx004.2060

Authors: E. Couser, M. Albert, C. Pettigrew, A. Soldan

Institutions: University of Maryland, Baltimore, Johns Hopkins University, Johns Hopkins Hospital

Language: English

Topic: Dementia and Cognitive Impairment Research

Subfield: Psychiatry and Mental health

Field: Medicine

Domain: Health Sciences

SDG: Good health and well-being

Open Access status: gold

Estimated APC paid: $3,977