Differentiation of Alzheimer's Disease from Vascular Dementia Using the Modified Mini-Mental State Examination

Lee, Ae Young; Sohn, Eun Hee; Park, Hyun Ju

Abstract

BACKGROUND: Alzheimer's disease (AD) and vascular dementia (VaD) are the most frequently occurring dementia. Although accurate differentiation of dementia subtype is important in treatment perspective, it is not easy even using expensive and time-consuming devices. To evaluate diagnostic value of the Modified Mini-Mental State (3MS) examination as a dementia screening and whether the first recall (FR) and delayed recall(DR) of 3MS are helpful in differentiating AD from VaD.
METHODS
Patients comprised of 64 cases diagnosed for dementia at the Neurology department. Diagnosis of probable AD (n=34) and VaD (n=30) were made according to consensus criteria. Cognitive status was measured by the Mini-Mental State Examination (MMSE) and 3MS. Receiver operating characteristic (ROC) curves were used to identify the optimal FR and DR for differentiating AD from VaD. Ninety-three age- and education-matched controls were evaluated. The neuropsychologist was blind to clinical diagnosis.
RESULTS
Sensitivity (SN), specificity (SP), diagnostic accuracy (DA), and positive likelihood ratio (+LR) of 3MS (cutoff score=76) were 0.75, 0.68, 0.70 and 2.34. The optimal score of FR and DR to differentiate AD from VaD were 2 (SN=0.81, SP=0.76, and +LR=3.38) and 1 (SN=0.81, SP=0.71, and +LR=2.79), respectively.
CONCLUSIONS
The diagnostic value of 3MS is comparable to that of MMSE as well as covers broader cognitive functions and has wider difficulty levels. Among dementia patients, a low FR and DR scores on the 3MS produce small to moderate increases the post-test probability of AD.