Intracranial volume in mild cognitive impairment, Alzheimer's disease and vascular dementia: evidence for brain reserve?

• Published in: International journal of geriatric psychiatry Vol. 19; no. 10; pp. 995 - 1007
• Main Authors: Wolf, Henrike, Julin, Per, Gertz, Hermann-Josef, Winblad, Bengt, Wahlund, Lars-Olof
• Format: Journal Article
• Language: English
• Published: Chichester, UK John Wiley & Sons, Ltd 01.10.2004; Wiley; Wiley Subscription Services, Inc
• Subjects: Adult; Aged; Alzheimer Disease - pathology; Alzheimer Disease - psychology; Alzheimer's disease; Biological and medical sciences; Brain; Brain - pathology; brain reserve; brain volume; Cognition & reasoning; Cognition Disorders - pathology; Cognition Disorders - psychology; Degenerative and inherited degenerative diseases of the nervous system. Leukodystrophies. Prion diseases; Dementia; Dementia, Vascular - pathology; Dementia, Vascular - psychology; Female; Fundamental and applied biological sciences. Psychology; Geriatric psychiatry; Geriatrics; hippocampal atrophy; Humans; intracranial volume; Magnetic Resonance Imaging; Male; Medical sciences; Middle Aged; mild cognitive impairment; Neurology; Neuropsychological Tests; Psychology. Psychoanalysis. Psychiatry; Psychology. Psychophysiology; Psychopathology. Psychiatry; Risk Factors; stereology; vascular dementia; Human; Intracranial; Nervous system diseases; Alzheimer disease; Cardiovascular disease; Cerebral disorder; Vascular disease; Gerontology; Volume; Central nervous system disease; Degenerative disease; mild cognitive impairment; Elderly; Geriatrics
• ISSN: 0885-6230; 1099-1166
• DOI: 10.1002/gps.1205

Objective The possibility of brain volume reserve effects was examined in a sample of geriatric outpatients with mild cognitive impairment (MCI), Alzheimer's disease (AD) and vascular dementia (VaD). The total intracranial volume (ICV) served as an estimate of the maximum attained brain volume in life. Methods Subjects (n = 181, mean age 60.7) were consecutive referrals to a geriatric outpatients clinic (n = 96) and a group of age‐matched healthy control subjects (n = 85). ICV and brain volume were attained from T1‐weighted magnetic resonance images using a stereological method. Hippocampal atrophy was assessed with a visual rating scale. Results ICV was significantly smaller in patients with AD and VaD than in control subjects, but effect size was small. After adjusting for age and gender, having ICV in the smallest quartile significantly increased the risk of cognitive impairment (either MCI or dementia). In patients with dementia, but not in MCI, severity of cognitive impairment and ICV were moderately correlated. The effect of ICV on cognition was not mediated by hippocampal atrophy. Conclusions These findings are compatible with volume reserve effects that modify the clinical expression of symptoms in both AD and VaD. They may have implications for the design of neuroimaging studies that use ICV for normalization procedures. Copyright © 2004 John Wiley & Sons, Ltd.