Background: Bradykinesia is the defining motor feature of Parkinson’s disease (PD). There are limitations to its assessment using standard clinical rating scales, especially in the early stages of PD when a floor effect may be observed. Objective: To develop a quantitative method to track repetitive tapping movements and to compare people in the early stages of PD, healthy controls, and individuals with idiopathic anosmia. Methods: This was a cross-sectional study of 99 participants (early-stage PD = 26, controls = 64, idiopathic anosmia = 9). For each participant, repetitive finger tapping was recorded over 20 seconds using a smartphone at 240 frames per second. From each video, amplitude between fingers, frequency (number of taps per second), and velocity (distance travelled per second) was extracted. Clinical assessment was based on the motor section of the MDS-UPDRS. Results: People in the early stage of PD performed the task with slower velocity (p <  0.001) and with greater frequency slope than controls (p = 0.003). The combination of reduced velocity and greater frequency slope obtained the best accuracy to separate early-stage PD from controls based on metric thresholds alone (AUC = 0.88). Individuals with anosmia exhibited slower velocity (p = 0.001) and smaller amplitude (p <  0.001) compared with controls. Conclusion: We present a simple, proof-of-concept method to detect early motor dysfunction in PD. Mean tap velocity appeared to be the best parameter to differentiate patients with PD from controls. Patients with anosmia also showed detectable differences in motor performance compared with controls which may suggest that some are in the prodromal phase of PD.

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Background: Bradykinesia is the defining motor feature of Parkinson′s disease (PD). There are limitations to its assessment using standard clinical rating scales, especially in the early stages of PD when a floor effect may be observed. Objectives: To develop a quantitative method to track repetitive finger tapping movements and to compare people in the early stages of PD, healthy controls, and individuals with idiopathic anosmia. Methods: This was a cross-sectional study of 99 participants (early-stage PD=26, controls=64, idiopathic anosmia=9). For each participant, repetitive finger tapping was recorded over 20 seconds using a smartphone at 240 frames per second. Three parameters were extracted from videos: amplitude between fingers, frequency (number of taps per second), and velocity (distance travelled per second). Clinical assessment was based on the motor section of MDS-UPDRS. Results: People in the early stage of PD performed the task with slower velocity (p<0.001) and with greater decrement in frequency than controls (p=0.003). The combination of slower velocity and greater decrement in frequency obtained the best accuracy to separate early-stage PD from controls based on metric thresholds alone (AUC = 0.88). Individuals with anosmia exhibited slower velocity (p=0.001) and smaller amplitude (p<0.001) compared with controls. Conclusions: We present a new simple method to detect early motor dysfunction in PD. Mean tap velocity appeared to be the best parameter to differentiate patients with PD from controls. Patients with anosmia also showed detectable differences in motor performance compared with controls which may be important indication of the prodromal phase of PD.

BackgroundParkinson disease (PD) is the second most common neurodegenerative disease and the burden appears to be growing fastest in middle-low and low income countries. In the majority of obser- vational studies of PD, White, well-educated and affluent participants are over-represented.AimsOur aim was to engage a diverse group of people with Parkinson disease (PwP) from East London and build a research platform for previously under-represented groups.MethodsWe created a register of PwP from the Royal London Hospital which includes approximately 400 patients. In parallel, we have recruited participants to the East London Parkinson’s disease (ELPD) project; a case-control study of phenotype, genotype and biomarker characteristics. Clinical manifes- tations, UPDRS scores, data on non-motor symptoms, as well as biospecimens (buccal and skin swabs, serum samples) have been obtained.Results145 patients and 80 controls have been recruited so far. The mean age of PwP was 67.81 (SD 10.4); 62% were male and 59% identified as being from South Asian or Black ethnicity. The most common presenting symptom was tremor (55.9%), followed by gait impairment (16.6%).ConclusionThe ELPD project is a platform study for under-represented patients with PD which provides important opportunities for collaboration and research to improve health inequalities.