This 2004 medical journal article is about differentiating Dementia with Lewy Bodies (DLB) from Alzheimer’s Disease (AD) and normal aging. The lead author of this article is on the Scientific Advisory Council of the Lewy Body Dementia Association. I’ve copied the abstract below.
The abstract notes that “four characteristics of fluctuations were found to significantly differentiate AD from DLB, (including) daytime drowsiness and lethargy, daytime sleep of 2 or more hours, staring into space for long periods, and episodes of disorganized speech.”
If your eyes glaze over on the abstract, read the Science Daily article from January 16, 2004 on this research!
Specific features that reliably differentiate DLB from AD and normal aging
T. J. Ferman, PhD, G. E. Smith, PhD, B. F. Boeve, MD, R. J. Ivnik, PhD, R. C. Petersen, MD PhD, D. Knopman, MD, N. Graff-Radford, MBBCh MRCP, J. Parisi, MD and D. W. Dickson, MD
From the Department of Psychiatry and Psychology (Dr. Ferman), Mayo Clinic and Foundation, Jacksonville, FL; and Departments of Psychiatry and Psychology (Drs. Smith and Ivnik), Neurology (Drs. Boeve, Petersen, Knopman, and Graff-Radford), and Pathology (Drs. Parisi and Dickson), Mayo Clinic and Foundation, Rochester, MN.
Objective: To determine whether certain aspects of fluctuations reliably distinguish dementia with Lewy bodies (DLB) from Alzheimer’s disease (AD) and normal aging.
Methods: Participants included 200 community-dwelling cognitively normal elderly persons, 70 DLB patients, and 70 AD patients with collateral informants. A 19-item questionnaire was administered to the informants that queried about symptoms of fluctuations and delirium.
Results: Fluctuations occur infrequently in nondemented elderly persons aged 58 to 98 years. In contrast, four characteristics of fluctuations were found to significantly differentiate AD from DLB. These composite features include daytime drowsiness and lethargy, daytime sleep of 2 or more hours, staring into space for long periods, and episodes of disorganized speech. The presence of three or four features of this composite occurred in 63% of DLB patients compared with 12% of AD patients and 0.5% of normal elderly persons. Informant endorsement of three or four of these items yielded a positive predictive value of 83% for the clinical diagnosis of DLB against an alternate diagnosis of AD. Endorsement of fewer than three items had a negative predictive value of 70% for the absence of a clinical diagnosis of DLB in favor of AD. The authors present evidence of test-retest reliability, convergent validity, and empirical verification with a separate cross-validation sample. Fluctuations were not associated with any particular combination of hallucinations, parkinsonism, or REM sleep behavior disorder.
Conclusions: Based on informant report, disturbed arousal and disorganized speech are specific aspects of fluctuations in dementia with Lewy bodies that reliably distinguish dementia with Lewy bodies from Alzheimer’s disease and normal aging.
PubMed ID #: 14745051 (see pubmed.gov for this abstract only)