Errors produced on the Mini-Mental State Examination and neuropsychological test performance in Alzheimer's disease, ischemic vascular dementia, and Parkinson's disease

The authors investigated whether MMSE indices designed to measure temporal and physical orientation, declarative memory, language, working memory, and motor/constructional function could differentiate patients with different dementia diagnoses: Alzheimer's disease (AD), ischemic vascular dementia (IVD), or Parkinson's disease (PD). MMSE summary scores did not differ (AD, 21.4; IVD, 27.1; PD, 22.3). The AD group scored lower than IVD or PD on temporal orientation and declarative memory, IVD lower than AD on motor/constructional and working memory. The IVD and PD groups made more errors in writing a sentence and copying intersecting pentagons. Significant correlations were found between the orientation indices and neuropsychological tests of naming and memory, and between the working memory and motor/constructional indices and tests of executive control. Such analyses of MMSE performance could assist in formulating referral questions for cognitive assessment and in tracking the course of dementing illnesses.