MRI confirms mild cognitive impairments prodromal for Alzheimer's, vascular and Parkinson-Lewy body dementias.
OBJECTIVE
MRI assessments were correlated with serial Combined Mini-Mental Cognitive Capacity Screening Examinations (CMC). Vascular-MCI (VMCI), Neurodegenerative MCI (NMCI) and Parkinson-Lewy body MCI (PLB-MCI) were compared during conversions to dementia. Mild cognitive impairments (MCI) are identifiable prodromes for all dementia subtypes. MRI abnormalities are characterized among MCI subjects prodromal for dementia of Alzheimer's disease (DAT), vascular dementia (VaD) and Parkinson-Lewy body dementia (PLBD).


METHODS
Aging volunteers (n=166) were recruited from ongoing longitudinal studies of aging, stroke, cerebrovascular disease and dementia. Cognitively normal (CN, n=52), MCIs of neurodegenerative (N-MCI, n=30), vascular (V-MCI, n=35) and Parkinson-Lewy Body (PLB-MCI, n=8) subtypes, plus converted DAT (n=19), VaD (n=17) and PLBD (n=5) were all diagnosed according to established protocol recommendations. Cerebral MRI abnormalities were likewise intercorrelated utilizing quantitative volumetric measurements.


RESULTS
V-MCI and converted VaD showed extensive leukoaraiosis with more lacunar infarcts than subjects with N-MCI or PLB-MCI. N-MCI, prodromal for DAT, showed medial temporal atrophy, greater enlargement of temporal horns, and fewer vascular lesions. PLB-MCI, prodromal for PLBD, displayed third ventricular enlargement greater than N-MCI and V-MCI, with similar but less severe atrophy of medial temporal lobe than N-MCI and fewer vascular lesions than V-MCI. Cognitive Impairments due to PLB with vascular features (V-PLB-CI) showed more lacunar and microvascular lesions involving both white matter and basal ganglia with greater frontal horn enlargement.


CONCLUSIONS
This study confirms different MCI subtypes prior to conversion to different dementias listed, recognizable by specific MRI abnormalities.
Meyer
John Stirling
JS
Department of Neurology, Baylor College of Medicine, and Cerebrovascular Research Laboratories, Michael E. DeBakey Veterans Administration Medical Center, Houston, Texas 77098, USA. johnstirlingmeyer@yahoo.com
Huang
Juebin
J
Chowdhury
Munir H
MH
D000368:Aged; D000544:Alzheimer Disease / Q000175:diagnosis / Q000503:physiopathology / Q000523:psychology; D001284:Atrophy / Q000209:etiology / Q000473:pathology / Q000503:physiopathology; D001921:Brain / Q000098:blood supply / Q000473:pathology* / Q000503:physiopathology; D002536:Cerebral Arteries / Q000473:pathology / Q000503:physiopathology; D003072:Cognition Disorders / Q000175:diagnosis* / Q000503:physiopathology / Q000523:psychology*; D003704:Dementia / Q000175:diagnosis* / Q000503:physiopathology / Q000523:psychology*; D015140:Dementia, Vascular / Q000175:diagnosis / Q000503:physiopathology / Q000523:psychology; D003937:Diagnosis, Differential; D018450:Disease Progression; D005260:Female; D006801:Humans; D020961:Lewy Body Disease / Q000175:diagnosis / Q000503:physiopathology / Q000523:psychology; D008279:Magnetic Resonance Imaging / Q000379:methods* / Q000592:standards; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D011237:Predictive Value of Tests; D011379:Prognosis