ILIAD 2 STUDY - IDEOMOTOR LIMB APRAXIA IN ALZHEIMER'S DISEASE: DEVELOPMENT OF A SHORT STAGING TOOL IN ALZHEIMER'S DISEASE

Abstract

Introduction The Mini-Mental State Exam (MMSE) is currently the gold standard tool for staging the severity of Alzheimer's Disease (AD) into mild, moderate, and severe. In the ILIAD Phase 1 study, the Postural Knowledge Test (PKT) - developed by Mozaz et al for identifying limb apraxia - was determined to be significantly correlated with the severity of dementia in (AD) as measured by the (MMSE). However, the PKT is a lengthy tool to administer. This study investigates the correlation between the shortened PKT-Transitive (PKT/T) and the MMSE. The ultimate objective would be to assess the efficacy of the PKT/T as a shorter, easier and more practical clinical staging tool for AD. Methods Right-handed participants with either an established or suspected clinical diagnosis of AD were enrolled in our study. Exclusion criteria included concomitant diagnosis of Major Depressive Disorder, Parkinson's Disease, or other neurodegenerative disorders. These participants were administered the MMSE then the PKT/T by two blinded examiners. Participants were staged as normal vs mild, moderate, or severe AD based on their MMSE scores. Results To date, the tests were administered to 65 eligible subjects. Results demonstrate a strong correlation (Pearson's coefficient = 0.763) between the PKT/T and the MMSE. The ROC curve had an area of 0.869 (95% CI: 0.776-0.962). The coordinates of the ROC curve showed the optimum cutoff between normal and cognitive impairment at a PKT/T score of 8/10 with a sensitivity of 0.900 and a specificity of 0.745 Conclusions The significant correlation between both tests supports the PKT/T as a possible staging tool. The ROC curve shows a score of 8/10 to be an appropriate cutoff between normal and cognitively impaired participants. Further data still needs to be collected for sub-stratifying into mild, moderate, and severe AD accurately. This research was funded by: Not Applicable