{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,12]],"date-time":"2026-10-12T21:41:02Z","timestamp":1791841262899,"version":"4.3.4"},"reference-count":41,"publisher":"SAGE Publications","issue":"4","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["JPD"],"published-print":{"date-parts":[[2021,10,12]]},"abstract":"<jats:p>Background: Bradykinesia is the defining motor feature of Parkinson\u2019s 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\u200a=\u200a26, controls\u200a=\u200a64, idiopathic anosmia\u200a=\u200a9). 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\u200a&lt;\u200a0.001) and with greater frequency slope than controls (p\u200a=\u200a0.003). 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\u200a=\u200a0.88). Individuals with anosmia exhibited slower velocity (p\u200a=\u200a0.001) and smaller amplitude (p\u200a&lt;\u200a0.001) 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 were in the prodromal phase of PD.<\/jats:p>","DOI":"10.3233\/jpd-212683","type":"journal-article","created":{"date-parts":[[2021,6,22]],"date-time":"2021-06-22T14:40:58Z","timestamp":1624372858000},"page":"1901-1915","source":"Crossref","is-referenced-by-count":17,"title":["Slow Motion Analysis of Repetitive Tapping (SMART) Test: Measuring Bradykinesia in Recently Diagnosed Parkinson\u2019s Disease and Idiopathic Anosmia"],"prefix":"10.1177","volume":"11","author":[{"given":"Cristina","family":"Simonet","sequence":"first","affiliation":[{"name":"Preventive Neurology Unit, Wolfson Institute of Preventive Medicine, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Miquel A.","family":"Galmes","sequence":"additional","affiliation":[{"name":"Physical and Analytical Chemistry Department, Jaume I University, Castell\u00f3 de la Plana, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Christian","family":"Lambert","sequence":"additional","affiliation":[{"name":"Wellcome Centre for Human Neuroimaging, London, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Richard N.","family":"Rees","sequence":"additional","affiliation":[{"name":"Department of Clinical and Movement Neuroscience, UCL Institute of Neurology, London, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tahrina","family":"Haque","sequence":"additional","affiliation":[{"name":"Preventive Neurology Unit, Wolfson Institute of Preventive Medicine, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jonathan P.","family":"Bestwick","sequence":"additional","affiliation":[{"name":"Preventive Neurology Unit, Wolfson Institute of Preventive Medicine, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Andrew J.","family":"Lees","sequence":"additional","affiliation":[{"name":"Reta Lila Weston Institute of Neurological Studies, University College London Queen Square Institute of Neurology, London, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Anette","family":"Schrag","sequence":"additional","affiliation":[{"name":"Preventive Neurology Unit, Wolfson Institute of Preventive Medicine, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, UK"},{"name":"Department of Clinical and Movement Neuroscience, UCL Institute of Neurology, London, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Alastair J.","family":"Noyce","sequence":"additional","affiliation":[{"name":"Preventive Neurology Unit, Wolfson Institute of Preventive Medicine, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, UK"},{"name":"Department of Clinical and Movement Neuroscience, UCL Institute of Neurology, London, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"179","reference":[{"key":"10.3233\/JPD-212683_ref1","doi-asserted-by":"crossref","first-page":"140","DOI":"10.1001\/archneur.1993.00540020018011","article-title":"A clinicopathologic study of 100 cases of Parkinson\u2019s disease","volume":"50","author":"Hughes","year":"1993","journal-title":"Arch Neurol"},{"key":"10.3233\/JPD-212683_ref2","doi-asserted-by":"crossref","first-page":"181","DOI":"10.1136\/jnnp.55.3.181","article-title":"Accuracy of clinical diagnosis of idiopathic Parkinson\u2019s disease: A clinico-pathological study of 100 cases","volume":"55","author":"Hughes","year":"1992","journal-title":"J Neurol Neurosurg Psychiatry"},{"key":"10.3233\/JPD-212683_ref4","doi-asserted-by":"crossref","first-page":"1005","DOI":"10.1136\/jnnp.74.7.1005","article-title":"How valid is the clinical diagnosis of Parkinson\u2019s disease in the community?","volume":"74","author":"Jellinger","year":"2003","journal-title":"J Neurol Neurosurg Psychiatry"},{"key":"10.3233\/JPD-212683_ref5","doi-asserted-by":"crossref","first-page":"2131","DOI":"10.1093\/brain\/124.11.2131","article-title":"Pathophysiology of bradykinesia in Parkinson\u2019s disease","volume":"124","author":"Berardelli","year":"2001","journal-title":"Brain"},{"key":"10.3233\/JPD-212683_ref6","doi-asserted-by":"crossref","first-page":"727","DOI":"10.1093\/brain\/awz344","article-title":"Evolving concepts on bradykinesia","volume":"143","author":"Bologna","year":"2019","journal-title":"Brain"},{"key":"10.3233\/JPD-212683_ref7","doi-asserted-by":"crossref","first-page":"1600","DOI":"10.1002\/mds.26431","article-title":"MDS research criteria for prodromal Parkinson\u2019s disease","volume":"30","author":"Berg","year":"2015","journal-title":"Mov Disord"},{"key":"10.3233\/JPD-212683_ref8","doi-asserted-by":"crossref","first-page":"1223","DOI":"10.1136\/jnnp.2009.193391","article-title":"Accuracy of clinical diagnosis in tremulous parkinsonian patients: A blinded video study","volume":"81","author":"Bajaj","year":"2010","journal-title":"J Neurol Neurosurg Psychiatry"},{"key":"10.3233\/JPD-212683_ref9","doi-asserted-by":"crossref","first-page":"1859","DOI":"10.1002\/mds.23740","article-title":"The modified bradykinesia rating scale for Parkinson\u2019s disease: Reliability and comon with kinematic measures","volume":"26","author":"Heldman","year":"2011","journal-title":"Mov Disord"},{"key":"10.3233\/JPD-212683_ref10","doi-asserted-by":"crossref","first-page":"627","DOI":"10.1002\/mds.24973","article-title":"Motor signs in the prodromal phase of Parkinson\u2019s disease","volume":"27","author":"Maetzler","year":"2012","journal-title":"Mov Disord"},{"key":"10.3233\/JPD-212683_ref11","doi-asserted-by":"crossref","first-page":"65","DOI":"10.3233\/JPD-160878","article-title":"Technologies assessing limb bradykinesia in Parkinson\u2019s disease","volume":"7","author":"Hasan","year":"2017","journal-title":"J Parkinsons Dis"},{"key":"10.3233\/JPD-212683_ref12","doi-asserted-by":"crossref","first-page":"429","DOI":"10.3233\/JPD-191781","article-title":"Systematic review looking at the use of technology to measure free-living symptom and activity outcomes in Parkinson\u2019s disease in the home or a home-like environment","volume":"10","author":"Morgan","year":"2020","journal-title":"J Parkinsons Dis"},{"key":"10.3233\/JPD-212683_ref13","doi-asserted-by":"crossref","first-page":"2099","DOI":"10.1007\/s00415-019-09642-0","article-title":"The motor prodromes of Parkinson\u2019s disease: From bedside observation to large-scale application","volume":"268","author":"Simonet","year":"2021","journal-title":"J Neurol"},{"key":"10.3233\/JPD-212683_ref14","doi-asserted-by":"crossref","first-page":"738","DOI":"10.1002\/mds.10473","article-title":"The Unified Parkinson\u2019s Disease Rating Scale (UPDRS): Status and recommendations","volume":"18","author":"Movement Disorder Society Task Force on Rating Scales for Parkinson\u2019s Disease","year":"2003","journal-title":"Mov Disord"},{"key":"10.3233\/JPD-212683_ref15","doi-asserted-by":"crossref","first-page":"31","DOI":"10.1136\/jnnp-2013-305420","article-title":"PREDICT-PD: Identifying risk of Parkinson\u2019s disease in the community: Methods and baseline results","volume":"85","author":"Noyce","year":"2014","journal-title":"J Neurol Neurosurg Psychiatry"},{"key":"10.3233\/JPD-212683_ref18","doi-asserted-by":"crossref","first-page":"261","DOI":"10.1038\/s41592-019-0686-2","article-title":"SciPy 1.0: Fundamental algorithms for scientific computing in Python","volume":"17","author":"Virtanen","year":"2020","journal-title":"Nat Methods"},{"key":"10.3233\/JPD-212683_ref19","doi-asserted-by":"crossref","first-page":"357","DOI":"10.1038\/s41586-020-2649-2","article-title":"Array programming with NumPy","volume":"585","author":"Harris","year":"2020","journal-title":"Nature"},{"key":"10.3233\/JPD-212683_ref20","doi-asserted-by":"crossref","first-page":"155","DOI":"10.1177\/8756479308317006","article-title":"Measures of association: How to choose?","volume":"24","author":"Khamis","year":"2008","journal-title":"J Diagnostic Med Sonogr"},{"key":"10.3233\/JPD-212683_ref21","first-page":"1","article-title":"A validation study of a smartphone-based finger tapping application for quantitative assessment of bradykinesia in Parkinson\u2019s disease","volume":"11","author":"Lee","year":"2016","journal-title":"PLoS One"},{"key":"10.3233\/JPD-212683_ref22","doi-asserted-by":"crossref","first-page":"118","DOI":"10.1016\/j.parkreldis.2016.05.009","article-title":"Tests of manual dexterity and speed in Parkinson\u2019s disease: Not all measure the same","volume":"28","author":"R\u016f\u017ei\u010dka","year":"2016","journal-title":"Parkinsonism Relat Disord"},{"key":"10.3233\/JPD-212683_ref23","doi-asserted-by":"crossref","first-page":"117003","DOI":"10.1016\/j.jns.2020.117003","article-title":"The discerning eye of computer vision: Can it measure Parkinson\u2019s finger tap bradykinesia?","volume":"416","author":"Williams","year":"2020","journal-title":"J Neurol Sci"},{"key":"10.3233\/JPD-212683_ref24","doi-asserted-by":"crossref","first-page":"657","DOI":"10.1002\/mds.27671","article-title":"A roadmap for implementation of patient-centered digital outcome measures in Parkinson\u2019s disease obtained using mobile health technologies","volume":"34","author":"Espay","year":"2019","journal-title":"Mov Disord"},{"key":"10.3233\/JPD-212683_ref25","doi-asserted-by":"crossref","first-page":"1563","DOI":"10.1002\/mds.25161","article-title":"A study of subtle motor signs in early Parkinson\u2019s disease","volume":"27","author":"Schneider","year":"2012","journal-title":"Mov Disord"},{"key":"10.3233\/JPD-212683_ref26","doi-asserted-by":"crossref","first-page":"1927","DOI":"10.1007\/s00415-019-09348-3","article-title":"Does the MDS-UPDRS provide the precision to assess progression in early Parkinson\u2019s disease? Learnings from the Parkinson\u2019s progression marker initiative cohort","volume":"266","author":"Regnault","year":"2019","journal-title":"J Neurol"},{"key":"10.3233\/JPD-212683_ref27","doi-asserted-by":"crossref","first-page":"18","DOI":"10.1186\/s40035-018-0124-x","article-title":"Objective assessment of bradykinesia in Parkinson\u2019s disease using evolutionary algorithms: Clinical validation","volume":"7","author":"Gao","year":"2018","journal-title":"Transl Neurodegener"},{"key":"10.3233\/JPD-212683_ref28","doi-asserted-by":"crossref","first-page":"559","DOI":"10.1109\/TEVC.2013.2281532","article-title":"Evolving classifiers to recognize the movement characteristics of Parkinson\u2019s disease patients","volume":"18","author":"Lones","year":"2014","journal-title":"IEEE Trans Evol Comput"},{"key":"10.3233\/JPD-212683_ref29","doi-asserted-by":"publisher","DOI":"10.3233\/JPD-202402"},{"key":"10.3233\/JPD-212683_ref30","doi-asserted-by":"crossref","first-page":"320","DOI":"10.1111\/ejn.14269","article-title":"The prodromes of Parkinson\u2019s disease","volume":"49","author":"Rees","year":"2019","journal-title":"Eur J Neurosci"},{"key":"10.3233\/JPD-212683_ref31","doi-asserted-by":"crossref","first-page":"1441","DOI":"10.1212\/WNL.0000000000004382","article-title":"Olfaction and incident Parkinson disease in US white and black older adults","volume":"89","author":"Chen","year":"2017","journal-title":"Neurology"},{"key":"10.3233\/JPD-212683_ref32","doi-asserted-by":"crossref","first-page":"102","DOI":"10.1111\/j.1468-1331.2012.03798.x","article-title":"The PRIPS study: Screening battery for subjects at risk for Parkinson\u2019s disease","volume":"20","author":"Berg","year":"2013","journal-title":"Eur J Neurol"},{"key":"10.3233\/JPD-212683_ref33","doi-asserted-by":"crossref","first-page":"3673","DOI":"10.1007\/s00415-020-10048-6","article-title":"Prodromal Parkinson disease in patients with idiopathic hyposmia","volume":"267","author":"Marrero","year":"2020","journal-title":"J Neurol"},{"key":"10.3233\/JPD-212683_ref34","doi-asserted-by":"crossref","first-page":"1739","DOI":"10.1212\/WNL.0000000000000960","article-title":"Imaging prodromal Parkinson disease: The Parkinson Associated Risk Syndrome Study","volume":"83","author":"Jennings","year":"2014","journal-title":"Neurology"},{"key":"10.3233\/JPD-212683_ref35","doi-asserted-by":"crossref","first-page":"933","DOI":"10.1001\/jamaneurol.2017.0985","article-title":"Conversion to Parkinson disease in the PARS hyposmic and dopamine transporter\u2013 deficit prodromal cohort","volume":"74","author":"Jennings","year":"2017","journal-title":"JAMA Neurol"},{"key":"10.3233\/JPD-212683_ref36","doi-asserted-by":"crossref","first-page":"3753786","DOI":"10.1155\/2019\/3753786","article-title":"Hyposmia as a predictive marker of Parkinson\u2019s disease: A systematic review and meta-analysis","volume":"2019","author":"Sui","year":"2019","journal-title":"Biomed Res Int"},{"key":"10.3233\/JPD-212683_ref37","first-page":"4693019","article-title":"Evaluation of wearable sensor devices in Parkinson\u2019s disease: A review of current status and future prospects","volume":"2020","author":"Lu","year":"2020","journal-title":"Parkinsons Dis"},{"key":"10.3233\/JPD-212683_ref38","doi-asserted-by":"crossref","first-page":"97","DOI":"10.1016\/0028-3932(71)90067-4","article-title":"The assessment and analysis of handedness: The inventory, Neuropsychologia","volume":"9","author":"Oldfield","year":"1971","journal-title":"Neuropsychologia"},{"key":"10.3233\/JPD-212683_ref39","doi-asserted-by":"crossref","first-page":"1977","DOI":"10.1093\/brain\/awx104","article-title":"Tremor stability index: A new tool for differential diagnosis in tremor syndromes","volume":"140","author":"Di Biase","year":"2017","journal-title":"Brain"},{"key":"10.3233\/JPD-212683_ref40","first-page":"719167","article-title":"Confirmatory factor analysis of the motor unified Parkinson\u2019s disease rating scale","volume":"2012","author":"Vassar","year":"2012","journal-title":"Parkinsons Dis"},{"key":"10.3233\/JPD-212683_ref41","doi-asserted-by":"crossref","first-page":"2490","DOI":"10.1093\/brain\/awaa181","article-title":"Natural history of motor symptoms in Parkinson\u2019s disease and the long-duration response to levodopa","volume":"143","author":"Cilia","year":"2020","journal-title":"Brain"},{"key":"10.3233\/JPD-212683_ref42","doi-asserted-by":"crossref","first-page":"440","DOI":"10.1016\/j.parkreldis.2008.11.003","article-title":"Opening velocity, a novel parameter, for finger tapping test in patients with Parkinson\u2019s disease","volume":"15","author":"Yokoe","year":"2009","journal-title":"Parkinsonism Relat Disord"},{"key":"10.3233\/JPD-212683_ref43","doi-asserted-by":"crossref","first-page":"e96260","DOI":"10.1371\/journal.pone.0096260","article-title":"Bradykinesia-Akinesia Incoordination Test: Validating an online keyboard test of upper limb function","volume":"9","author":"Noyce","year":"2014","journal-title":"PLoS One"},{"key":"10.3233\/JPD-212683_ref44","doi-asserted-by":"crossref","first-page":"129","DOI":"10.1016\/j.parkreldis.2020.09.007","article-title":"Objective measurement of limb bradykinesia using a marker-less tracking algorithm with 2D-video in PD patients","volume":"81","author":"Hwan","year":"2020","journal-title":"Parkinsonism Relat Disord"}],"container-title":["Journal of Parkinson's Disease"],"original-title":[],"link":[{"URL":"https:\/\/content.iospress.com\/download?id=10.3233\/JPD-212683","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,5,1]],"date-time":"2026-05-01T04:50:17Z","timestamp":1777611017000},"score":1,"resource":{"primary":{"URL":"https:\/\/journals.sagepub.com\/doi\/full\/10.3233\/JPD-212683"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,10,12]]},"references-count":41,"journal-issue":{"issue":"4"},"URL":"https:\/\/doi.org\/10.3233\/jpd-212683","relation":{"has-preprint":[{"id-type":"doi","id":"10.1101\/2021.03.24.21254234","asserted-by":"object"}]},"ISSN":["1877-7171","1877-718X"],"issn-type":[{"value":"1877-7171","type":"print"},{"value":"1877-718X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,10,12]]}}}