Direction of Finger Displacement in Parkinson Disease (PD) May Predict the Onset of Dementia (P5.241)

OBJECTIVE: To study finger displacement in PD patients with and without dementia. BACKGROUND: In our initial study finger displacement distinguished patients with tremor preponderant PD from patients with Essential Tremor. In a subsequent study the direction of finger displacement suggested there might be a difference between cognitively intact (Mini Mental Status Examination, MMSE, 28- 30) and minimally cognitively impaired patients (MMSE of 25- 27). In this study we evaluated the direction of displacement in PD patients with dementia (MMSE < 24). DESIGN/METHODS- We examined 104 patients without dementia: 96 were cognitively intact, 8 were minimally impaired. We next examined 36 PD patients with dementia. All patients were evaluated using the motor part of the UPDRS. Displacement was tested by having the patient to point both his index fingers at the examiner’s index fingers and then asked to close both eyes. A “positive result” was displacement up, laterally or downward of at least 5 cm after 15 seconds of pointing. RESULTS: Among the 104 patients without cognitive or with minimal cognitive impairment mean age was 67.7 ±8.9 years, PD duration was 5.5 ±2.9 years, UPDRS motor score was 11.3 ±8.2, MMSE score was 28.9±0.8. Ninety six patients without cognitive impairment exhibited unilateral finger displacement either upward or laterally in the more affected hand. Eight patients with minimal cognitive impairment exhibited unilateral downward displacement. Among the 36 patients with dementia (MMSE 16.6 ± 6.9), mean age was 75± 7.3, PD duration was 5.9± 4.7 years, UPDRS score was 34.7± 18.6. 35/36 (97%) patients exhibited bilateral downward finger displacement of >5cm. One patient exhibited less than 5 cm downward displacement. CONCLUSIONS- The direction of finger displacement may provide insight, at the bedside, of the integrity of sub-cortical-cortical circuits. Downward finger displacement, especially bilateral downward displacement may signal extensive disruption of sub-cortical-cortical circuits as occurs in PD patients with dementia. Disclosure: Dr. Deep has nothing to disclose. Dr. Lieberman has nothing to disclose. Dr. Dhall has received personal compensation for activities with UCP Pharma, Impax Pharmaceuticals, and Teva Neuroscience. Dr. Tran has nothing to disclose. Dr. Liu has nothing to disclose. Dr. Saha has nothing to disclose. Dr. Salins has nothing to disclose. Dr. Sadreddin has nothing to disclose. Dr. Moguel-Cobos has nothing to disclose. Dr. Karis has nothing to disclose. Dr. Krishnamurthi has nothing to disclose.