Is Functional Decline Necessary for a Diagnosis of Alzheimer’s Disease?

• Published in: Dementia and geriatric cognitive disorders 2007-01, Vol.24 (5), p.375-379
• Main Authors: Park, Kyung Won, Pavlik, Valory N., Rountree, Susan D., Darby, Eveleen J., Doody, Rachelle S.
• Format: Article
• Language: English
• Subjects: Activities of Daily Living; Aged; Aged, 80 and over; Alzheimer Disease - complications; Alzheimer Disease - diagnosis; Alzheimer Disease - physiopathology; Analysis of Variance; Biological and medical sciences; Chi-Square Distribution; Cognition Disorders - complications; Cognition Disorders - diagnosis; Cognition Disorders - physiopathology; Degenerative and inherited degenerative diseases of the nervous system. Leukodystrophies. Prion diseases; Development. Senescence. Regeneration. Transplantation; Female; Fundamental and applied biological sciences. Psychology; Humans; Male; Medical sciences; Mental Status Schedule; Neurology; Neuropsychological Tests; Oculomotor disorders; Ophthalmology; Original Research Article; Severity of Illness Index; Vertebrates: nervous system and sense organs
• ISSN: 1420-8008; 1421-9824
• DOI: 10.1159/000109268

Background: The purpose of this study is to examine baseline differences and annualized cognitive and functional change scores in mild Alzheimer’s disease (AD) patients with and without impaired activities of daily living (ADL). Methods: We recruited 267 mild probable AD patients with at least 1 year of follow-up (NINCDS-ADRDA criteria, MMSE ≧20). Based on initial ADL scores, they were divided into 2 groups: unimpaired (n = 40) and impaired (n = 227). We compared the differences in annualized change scores on MMSE, Alzheimer’s Disease Assessment Scale-cognitive subscale (ADAS-cog), ADL and Clinical Dementia Rating sum of box score (CDR-SB) for patients with and without functional impairment at baseline. Results: The group with unimpaired ADL at baseline had a significantly shorter symptom duration (p = 0.01) and better neuropsychological test scores at baseline (p < 0.001) than those with impaired ADL. The annualized cognitive and functional change of each group from baseline to 1-year follow-up was not significantly different on the MMSE, ADAS-cog, CDR-SB, Physical Self-Maintenance Scale and Instrumental Activities of Daily Living. After 1 year, 56% of the initially unimpaired group and 6% of the initially impaired group reported no ADL impairment. Conclusions: Our study suggests that functional decline should not be required for the diagnosis of mild AD.