Effect of white matter hyperintensity on medial temporal lobe atrophy in Alzheimer's disease.
BACKGROUND
Medial temporal atrophy (MTA) is a recognized marker of Alzheimer's disease (AD), and white matter hyperintensities (WMH) are frequently observed on MRI of AD. The purpose of this study was to understand the role of WMH in MTA.


METHODS
Subjects were 94 probable AD patients and 51 cognitively normal subjects. WMH was assessed based on the severity of deep WMH (DWMH) and periventricular WMH (PWMH). Each structural volume was evaluated using the Individual Brain Atlases from the Statistical Parametric Mapping Toolbox.


RESULTS
There were no significant differences between subjects with and without WMH in terms of general cognitive function scales. Subjects with AD with WMH had decreased volume in the bilateral orbital frontal gyrus, frontal rectus gyrus, and olfactory gyrus, but not in the medial temporal lobes. After correcting for differences in DWMH, age and Clinical Dementia Rating Scale (CDR), AD with PWMH showed decreased volumes in the bilateral hippocampi. AD with PWMH showed worse scores on the Clinical Dementia Rating-Sum of Boxes and Barthel-ADL, and some frontal executive function tests. Those with DWMH did not show any reductions in the medial temporal lobes.


CONCLUSIONS
WMH in AD is not associated with medial temporal lobe atrophy, but PWMH is independently correlated with hippocampal volume reduction.
Department of Neurology, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seoul, South Korea.
Jae-Won
JW
Jang
Sangyun
S
Kim
Hye Yeon
HY
Na
Seha
S
Ahn
Sang Jin
SJ
Lee
Ki-Hyeon
KH
Kwak
Min-A
MA
Lee
Ging-Yuek Robin
GY
Hsiung
Byung-Sun
BS
Choi
Young Chul
YC
Youn
D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000150:complications* / Q000473:pathology*; D001284:Atrophy / Q000209:etiology / Q000473:pathology; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008609:Mental Status Schedule; D008875:Middle Aged; D009413:Nerve Fibers, Myelinated / Q000473:pathology*; D009483:Neuropsychological Tests; D013702:Temporal Lobe / Q000473:pathology*