Functional neural correlates of the WAIS‐IV Block Design Test in older adult with mild cognitive impairment and Alzheimer’s disease dementia

Abstract

AbstractBackgroundWhile the Wechsler Adult Intelligence Scale IV (WAIS‐IV) Block Design Test (BDT) has is widely used in both research and clinical setting as a measure of cognitive decline in the aging population, its functional neural substrates has not been clearly identified. Hence, the aim of the current study is to identify the functional neural correlates of the BDT in older adults with mild cognitive impairment (MCI) and Alzheimer’s disease (AD) dementia patients.MethodThe current study includes 213 cognitively impaired (135 MCI and 78 AD dementia) middle and old‐aged adults. All participants underwent comprehensive clinical and neuropsychological assessments and 18F‐fluorodeoxyglucose (FDG) Positron Emission Tomography (PET) scans. The BDT performance was assessed using the Wechsler Adult intelligence scale‐IV Korean version. Voxel‐wise analyses were used to investigate the correlation between regional cerebral glucose metabolism and BDT performance. The same analyses were conducted on the subgroups categorized by clinical severity based on the Clinical Dementia Rating.ResultThe participants had a mean age of 73.1 (SD = 7.4) years, mean years of education of 9.8 (SD = 4.9), mean BDT score of 20.9 (SD = 9.1), and 67.1% were female. Significant positive correlations between the BDT performance and regional cerebral glucose metabolism were found bilaterally in the inferior parietal lobule and thalamus, the right superior temporal gyrus and left occipital precuneus.ConclusionThe findings indicated that BDT performance in MCI and AD dementia patients functionally relies on the brain regions known to be associated with motor and executive functions as well as visuospatial functions.