Assessment of mental deterioration with the Cognitive Abilities Screening Instrument (CASI) and glucose hypometabolism in Alzheimer’s disease: The Osaki-Tajiri Project

The Cognitive Abilities Screening Instrument (CASI) is a screening test for dementia consisting of 9 domains. We investigated the relationships between CASI domain scores and cerebral glucose metabolism (CMRglc) as shown by positron emission tomography. Fifteen patients with very mild Alzheimer’s disease (AD) and 15 with mild AD were studied using the ¹⁸F]fluoro-deoxyglucose method. The 9 CASI domains were classified into four clusters (recent memory, frontal cortex cluster, posterior cortex cluster, and orientation). Using the region of interest method, the recent memory cluster was correlated with the bilateral hippocampal CMRglc, the frontal cortex cluster was correlated with the bilateral anterior and right inferior frontal CMRglc, the posterior cortex cluster was correlated with the bilateral temporo-parieto-occipital and occipital CMRglc, and the orientation cluster was correlated with the left anterior frontal CMRglc (Spearman’s correlations). The use of statistical parametric mapping showed that most CASI domains were correlated with CMRglc of the left frontal lobe, the temporal lobe, and the angular gyrus. These findings show that the mental dysfunction assessed using CASI in AD patients has a neurobiological basis.