Cross-Cultural Cognitive Examination performance in patients with Parkinson's disease and Alzheimer's disease.

Performance profiles of patients with different dementia syndromes (Alzheimer's disease and Parkinson's disease) were compared with each other and with those of neurologically impaired and healthy individuals without dementia on a new instrument for screening dementia, the Cross-Cultural Cognitive Examination (CCCE). The CCCE measures discriminated reliably between nondemented and demented patients, regardless of etiology. Comparisons between dementia groups found that dementia patients with Parkinson's disease (PD) showed more severe psychomotor slowing and depression, compared with patients with Alzheimer's disease, who showed more impaired recall of recently learned verbal information and verbal abstract reasoning. The CCCE also distinguished between the motor and affective symptoms that are common to all PD patients and the dementia symptoms that occur in some PD patients. These results provide further support for the clinical utility of the CCCE for discriminating dementia from normal cognitive functioning and for initial identification of different dementia syndromes.