Executive dysfunction and periventricular diffusion tensor changes in amnesic mild cognitive impairment and early Alzheimer's disease

• Published in: Human brain mapping Vol. 30; no. 11; pp. 3826 - 3836
• Main Authors: Chen, Ta-Fu, Chen, Ya-Fang, Cheng, Ting-Wen, Hua, Mau-Sun, Liu, Hon-Man, Chiu, Ming-Jang
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 01.11.2009; Wiley-Liss
• Subjects: Aged; Aged, 80 and over; Alzheimer Disease - pathology; Alzheimer Disease - physiopathology; Alzheimer's disease; Analysis of Variance; Anisotropy; Biological and medical sciences; Brain Mapping; Cerebral Ventricles - pathology; Cognition Disorders - pathology; Cognition Disorders - physiopathology; Degenerative and inherited degenerative diseases of the nervous system. Leukodystrophies. Prion diseases; Dementia - pathology; Dementia - physiopathology; Diffusion Magnetic Resonance Imaging - methods; diffusion tensor imaging; executive function; Executive Function - physiology; Female; Humans; Imaging, Three-Dimensional - methods; Investigative techniques, diagnostic techniques (general aspects); Male; Medical sciences; Middle Aged; mild cognitive impairment; Nervous system; Neurology; Neuropsychological Tests; periventricular white matter; Radiodiagnosis. Nmr imagery. Nmr spectrometry; Statistics as Topic; Executive function; Nervous system diseases; Radiodiagnosis; Alzheimer disease; Diffusion imaging; White matter; Cerebral disorder; Diffusion tensor; Dysfunction; periventricular white matter; Central nervous system disease; diffusion tensor imaging; Degenerative disease; mild cognitive impairment; Alzheimer's disease
• ISSN: 1065-9471; 1097-0193; 1097-0193
• DOI: 10.1002/hbm.20810

Our aim in this study was to explore the neural substrates of executive function in frontal and nonfrontal white matter using diffusion tensor imaging (DTI). We studied the relationship between executive dysfunction and DTI measurements on 13 subjects with amnesic mild cognitive impairment (aMCI), 11 subjects with early Alzheimer's disease (AD), and 16 control subjects. All participants underwent an examination of their intelligence, memory, and executive function and were subjected to DTI. Both aMCI and early AD subjects showed executive function impairment with differential performance in frontal‐related behaviors. Both aMCI and early AD subjects showed increased mean diffusivity in the genu of the corpus callosum and left frontal periventricular white matter (PVWM), whereas subjects with early AD showed an additional decrease in the fractional anisotropy of bilateral frontal PVWM and in the genu of the corpus callosum. The frontal PVWM was associated with performance on the Verbal Fluency Test, the Wisconsin Card Sorting Test (WCST), and Part B of the Trail Making Test. The parietal PVWM was associated with perseverative errors on the WCST and Part A of the Trail Making Test. In summary, executive function was impaired in subjects with aMCI and early AD and was associated with frontal and parietal PVWM changes. These changes may be due to early AD degeneration of the lateral cholinergic projections or to early change of the superior longitudinal fasciculus. Hum Brain Mapp, 2009. © 2009 Wiley‐Liss, Inc.