Quantitative Assessment of Bradykinesia in Parkinson's Disease (PD) (P04.192)

Abstract

OBJECTIVE: 1) Determine whether quantitative motor function tests can distinguish between subjects with and without parkinsonism. 2) Correlate findings from quantitative motor testing with standard measures of motor function (Unified Parkinson's Disease Rating Scale-UPDRS-III).

BACKGROUND: Ordinal rating scales (e.g., UPDRS) that measure motor function in PD can be subjective and may lack sensitivity to detect subtle features. Automated quantitative assessments are of interest for both their objectivity and sensitivity.

DESIGN/METHODS: 40 subjects (21 patients with parkinsonism and 19 patients with other neurological disorders) were assessed with the UPDRS and MovAlyzeR, a digital writing tablet able to measure velocity and amplitude during upper extremity movements (quickly drawing lines between targets). Subjects were tested under single and dual task (saying the days of the week backwards) conditions. Group means were compared using Mann-Whitney U-tests. Relationships between UPDRS-III and quantitative motor function test scores were assessed using partial correlations.

RESULTS: Stroke velocity was significantly slower in parkinsonian subjects under single and dual task conditions (p=.041 for both tasks). The differences persisted for single task stroke velocity when controlling for subject age. Absolute stroke size did not vary between groups (p=.147). Total UPDRS motor scores negatively correlated with stroke velocity (single task r=-.368, p=.027; dual task r=-.495, p=.002), consistent with slowing in more advanced parkinsonism. Among UPDRS domains, the strongest correlation was with bradykinesia items (single task r=-.383, p=.021; dual task r=-.495., p=.002). Associations were also observed with rigidity and Postural Instability and Gait Disorder items. Tremor items did not correlate with stroke velocity.

CONCLUSIONS: MovAlyzeR quantitative testing distinguished between subjects with parkinsonism and controls, and stroke velocity correlated well with UPDRS motor scores, particularly with measures of bradykinesia rather than tremor. Future studies will assess whether quantitative testing can evaluate parkinsonism and changes associated with progression or treatment more sensitively than UPDRS.

Supported by: PVAMC PADRECC Pilot Grant (Morley PI).

Disclosure: Dr. Pantelyat has nothing to disclose. Dr. Freedman has nothing to disclose. Dr. Pawlowski has nothing to disclose. Dr. Kesari has nothing to disclose. Dr. Duda has received personal compensation for activities with the Delaware Media Group. Dr. Duda holds stock and/or stock options in Celgene Corporation. Dr. Morley has nothing to disclose.