Practical suggestions on how to differentiate dementia with Lewy bodies from Alz

[Guest guest]

Practical suggestions on how to differentiate dementia with Lewy bodies from

Alzheimer's disease with common cognitive tests

February 2009

Abstract

Objective

Dementia with Lewy bodies (DLB) is the second most common neurodegenerative

dementia, but it is often underdiagnosed and mistaken for Alzheimer's disease

(AD) with sometimes lethal consequences. Over 35 studies have established the

differences between DLB and AD in neuropsychological tests, but none have

provided easy interpretations of common tests suitable for the clinician. The

aim of this study was to suggest practical interpretations of the Mini-Mental

State Examination (MMSE), clock drawing, and cube-copying to identify DLB and

differentiate it from AD.

Methods

Thirty-three DLB patients were matched according to gender, MMSE, and age with

66 AD patients. The median MMSE score was 24. Easy interpretations of the tests,

including the MMSE orientation subscore, were sought for.

Results

The identified criteria to separate DLB from AD were (1) the MMSE orientation

score × 3 the total MMSE score, (2) an impaired clock drawing, and (3) a non-3D

cube-copying. If (1) was fulfilled, the sensitivity and specificity were 100 and

57% in patients with MMSE 21-27. If (1) and (2) were fulfilled in patients with

MMSE 21-27, the sensitivity and specificity were 93 and 70%. If at least two of

the three criteria were fulfilled, the sensitivity was 85%, and the specificity

75% regardless of MMSE score.

Conclusion

If the orientation score × 3 the total MMSE score together with an impaired

clock drawing and possibly a non-3D cube-copying, the patient should be

thoroughly investigated according to the DLB consensus criteria. Copyright ©

2009 Wiley & Sons, Ltd.

http://tinyurl.com/y8cgp93