Objective assessment of bradykinesia in Parkinson’s disease using evolutionary algorithms: clinical validation

Chao Gao, Stephen Leslie Smith, Michael Lones, Stuart Jamieson, Jane Alty, Jeremy Cosgrove, Pingchen Zhang, Jin Liu, Yimeng Chen, Juanjuan Du, Shishuang Cui, Haiyan Zhou, Shengdi Chen

Research output: Contribution to journalArticlepeer-review


Background: There is an urgent need for developing objective, effective and convenient measurements to help clinicians accurately identify bradykinesia. The purpose of this study is to evaluate the accuracy of an objective approach assessing bradykinesia in finger tapping (FT) that uses evolutionary algorithms (EAs) and explore whether it can be used to identify early stage Parkinson’s disease (PD).

Methods: One hundred and seven PD, 41 essential tremor (ET) patients and 49 normal controls (NC) were recruited. Participants performed a standard FT task with two electromagnetic tracking sensors attached to the thumb and index
finger. Readings from the sensors were transmitted to a tablet computer and subsequently analyzed by using EAs. The
output from the device (referred to as "PD-Monitor") scaled from − 1 to +1 (where higher scores indicate greater
severity of bradykinesia). Meanwhile, the bradykinesia was rated clinically using the Movement Disorder Society-
Sponsored Revision of the Unified Parkinson’s Disease Rating Scale (MDS-UPDRS) FT item.

Results: With an increasing MDS-UPDRS FT score, the PD-Monitor score from the same hand side increased correspondingly. PD-Monitor score correlated well with MDS-UPDRS FT score (right side: r = 0.819, P = 0.000; left side: r = 0.783, P = 0.000). Moreover, PD-Monitor scores in 97 PD patients with MDS-UPDRS FT bradykinesia and each PD subgroup (FT bradykinesia scored from 1 to 3) were all higher than that in NC. Receiver operating characteristic (ROC) curves revealed that PD-Monitor FT scores could detect different severity of bradykinesia with high accuracy (≥89.7%) in the right dominant hand. Furthermore, PD-Monitor scores could discriminate early stage PD from NC, with area under the ROC curve greater than or equal to 0.899. Additionally, ET without bradykinesia could be differentiated from PD by PD-Monitor scores. A positive correlation of PD-Monitor scores with modified Hoehn and Yahr stage was found in the left hand sides.

Conclusions: Our study demonstrated that a simple to use device employing classifiers derived from EAs could not only be used to accurately measure different severity of bradykinesia in PD, but also had the potential to differentiate early stage PD from normality.
Original languageEnglish
Article number18
Pages (from-to)18
Number of pages8
JournalTranslational Neurodegeneration
Issue number1
Early online date16 Aug 2018
Publication statusPublished - 16 Aug 2018

Bibliographical note

© The Author(s). 2018


  • Bradykinesia
  • Clinical validation
  • Evolutionary algorithms
  • Objective assessment
  • Parkinson's disease

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