The MoCA and ADL Items Separate Mild Cognitive Impairment and Dementia in Parkinson's Disease
Degree GrantorUniversity of Canterbury
Degree NameMaster of Science
The aim of this study is to establish a brief screening tool to classify PD patients as PD with normal cognition (PD-N), PD patients with mild cognitive impairment (PD-MCI) and PD patients with dementia (PD-D). There has been emerging evidence that the MoCA (Montreal Cognitive Assessment) shows potential for the brief assessment of cognition to differentiate among PD patients. One possible solution to further improve the discrimination among PD-D, PD-MCI and PD-N groups is to examine Instrumental Activities of Daily Living (IADL) measures in conjunction with the MoCA. A convenience sample of 162 patients suffering from PD and 53 volunteer control subjects were examined in a movement disorders center. Extensive neuropsychological testing was done to classify the PD patients into PD-N, PD-MCI or PD-D. The 24 patients were diagnosed as PD-D based on the Movement Disorders Society Task Force criteria. For PD-MCI, two criteria were used: 1.5SD:2 in one-domain (1.5 SD below the norms on two measures in at least one of four cognitive domains) and 1.5SD:1 in two-domains (1.5 SD below normative data in at least one measure but in two domains) which made a diagnosis of 34 and 39 PD-MCI patients respectively. The remaining patients were classified as PD-N. For both the MCI criteria, the results suggest that 1) for discriminating PD-MCI from PD-N, the MoCA is a sufficiently suitable screening measure that is not improved by adding ADL measures, 2) for distinguishing PD-D from PD-MCI, the MoCA and the full ADL-IS questionnaire can be administered to a patient suffering from PD. When time is limited and depending on the possibility of answering the questions regarding the ADL-IS items, the MoCA along with the Muddled and Complex Medication ADL-IS items should be administered. When no scores are obtained for Muddled, then MoCA along with Complex Medication ADL-IS item is sufficient to discriminate PD-D from PD-MCI. However, if no scores are obtained for Complex Medication item, then an average of four ADL-IS items should be taken along with the MoCA. This attractive brief screening tool helps in detection of cognitive impairment in the elderly.