Bilateral downward finger displacement in Parkinson disease may be a sign of worsening dementia and a bedside test to distinguish it from Alzheimer’s disease (P1.049)

Objective: To study finger displacement in patients with Parkinson disease dementia (PDD) and in patients with Alzheimer disease (AD) Background: One of the most disabling non-motor complications among patients with Parkinson disease (PD) is Parkinson disease dementia (PDD).There is no simple bedside test available that can measure the progression of dementia. Design/Methods: We examined 56 patients with PDD and 35 with AD. Finger displacement was examined by asking patients to point their index fingers toward the grid ruler. Patients were asked to maintain the pointing position for 15 seconds. After 15 seconds, patients were asked to close their eyes for another 15 seconds while maintaining the same position. A positive result was downward index finger displacement of ≥5 cm within the 15-second time window with eyes closed Results: The PDD group with MMSE ≤24 (n=56) comprised 14 female and 42 male patients. Mean age was 75.0±5.8 years, mean PD duration was 9.1±7.4 years, and mean onset of dementia was 3.1±1.6 years. For the PDD group, the mean MMSE score was 17.5±5.8 and the mean MDS-UPDRS score was 37±13.2. Results from the finger displacement test showed that among PDD patients, 53 of 56 (95%) exhibited bilateral downward drift of ≥5 cm and 3 (5%) exhibited Conclusions: The simple and inexpensive bedside test of finger displacement may be used to help distinguish PDD from AD and also the progression of dementia in PD. Disclosure: Dr. Deep has nothing to disclose. Dr. Lieberman has nothing to disclose. Dr. Aboud has nothing to disclose. Dr. Dhall has nothing to disclose. Dr. Shi has nothing to disclose.