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The PKG wearable was able to more effectively and objectively assess motor fluctuations in patients with Parkinson disease than standard patient-reported motor diaries.
Echo E. Tan, MD
The Personal KinetiGraph (PKG) watch has been deemed to provide a more effective, and objective, approach to evaluating motor fluctuations in patients with Parkinson disease compared to patient-reported motor diaries, according to new study results.1
Using the PKG production score resulted in a significant differentiation of patients who were early fluctuators and troublesome fluctuators (P = .01), as well as those who were dyskinetic and non-dyskinetic (P <.005), whereas the use of motor diaries could not identify the 4 patient categories—non-fluctuators (n = 14), early fluctuators (n = 14), moderate fluctuators (n = 15), and troublesome fluctuators (n = 10)—to which patients were pre-stratified. Nor could diaries distinguish among the groups via average time with dyskinesia, due to their limitations.
Additionally, patients in the trial displayed a higher tendency to return the PKG (88%) to their clinician over the motor diary (65%), and PKG identified high levels of dyskinesia in those who had denied having dyskinesia.
“Motor fluctuations, including 'wearing-off' and dyskinesia, are associated with increased disease severity and disability, and PD patients experience decreased quality of life as their response to medical therapy becomes less predictable,” said lead author Echo E. Tan, MD, neurologist, Cedars-Sinai Medical Center, in a statement. Tan noted that the management of patient motor fluctuations can be complicated, and thus less effective, by this lack of objective assessment tools. In turn, this can lead to the reliance on direct observation by the physician during clinic visits or patient reports, which Tan said can be “unrevealing, incomplete and unreliable.”2
“The results of our study demonstrate that the fluctuation score calculated by the PKG system provides objective quantification of motor fluctuations,” she said. “This may help improve routine management of PD patients and enable more objective assessments in clinical trials of PD therapies.”
In the study, 53 patients completed the 6-day study period with the PKG watch, of which 39 also returned 2 completed motor diaries. Of those 39, fluctuator score analysis showed an average increase in score from non-fluctuator to troublesome fluctuator (7.3 to 9.6; P = .012). Five patients reported ‘wearing-off’ in the motor diaries that was not reported on the pre-trial Wearing Off Questionnaire, though none reported dyskinesia in the motor diaries that was not reported in the Movement Disorders Society-Unified Parkinson’s Disease Rating Scale Part IV.
The motor diaries identified 9 non-fluctuators, 14 early fluctuators, 9 moderate fluctuators, and 5 troublesome fluctuators. In comparison, the PKG watch identified 12, 14, 12, and 9, respectively. Although, half of the patients in the troublesome fluctuator group were excluded due to incorrect diary completion, but compliance with the motor diary improved with decreasing severity of fluctuations.
Previous study results suggested that the PKG is able to provide novel additional information about patients with Parkinson disease beyond what is regularly captured in routine clinic visits. The PKG provided information significant enough to result in a change in the medical management of almost one-third of patients in the study, and ultimately, 41% (n = 46) of physicians surveyed indicated that the device provided relevant additional information considered sufficient enough to consider a therapeutic management plan adjustment. 3,4
The device was developed by Global Kinetics in conjunction with the Florey Institute of Neuroscience and Mental Health in Melbourne, Australia.
“The results of this study add to the growing body of data supporting the clinical benefit of PKG as an objective tool for guiding treatment decisions that overcomes the limitations of physician observation and patient reporting,” John Schellhorn, CEO of Global Kinetics Corporation, said in a statement. “We believe that increasing adoption of the PKG will help to standardize and improve treatment for [Parkinson] patients, and enable evidence-based approaches to optimizing care and outcomes for [Parkinson] patients when they are first diagnosed and as their symptoms evolve over time.”
1. Tan EE, Hogg EJ, Tagliati M. The role of Personal KinetiGraph fluctuator score in quantifying the progression of motor fluctuations in Parkinson’s diease. Funct Neurol. 2019;34(1):21-28.
2. Data Published in Functional Neurology Demonstrate that Global Kinetics’ Personal KinetiGraph® (PKG®) is Uniquely Positioned to Enable Objective Assessment of Motor Fluctuations in Parkinson’s Disease Patients [press release]; ]. Portsmouth, NH; London, UK; Melbourne, Australia: Global Kinetics Corporation; Published July 23, 2019. globenewswire.com/news-release/2019/07/23/1886449/0/en/Data-Published-in-Functional-Neurology-Demonstrate-that-Global-Kinetics-Personal-KinetiGraph-PKG-is-Uniquely-Positioned-to-Enable-Objective-Assessment-of-Motor-Fluctuations-in-Park.html. Accessed July 25, 2019.
3. Data Published in the Journal of Parkinson’s Disease Demonstrate Real-World Clinical Benefit of Global Kinetics’ Personal KinetiGraph® in Optimizing Parkinson’s Disease Therapy [press release]. Portsmouth, NH; London, UK; Melbourne, Australia: Global Kinetics Corporation; Published February 4, 2019. globenewswire.com/news-release/2019/02/04/1709868/0/en/Data-Published-in-the-Journal-of-Parkinson-s-Disease-Demonstrate-Real-World-Clinical-Benefit-of-Global-Kinetics-Personal-KinetiGraph-in-Optimizing-Parkinson-s-Disease-Therapy.html. Accessed July 25, 2019.
4. Santiago A, Langston JW, Rita G, et al. Qualitative evaluation of the Personal KinetiGraph movement recording system in a Parkinson’s clinic. J Parkinson Dis. Published pre-press November 8, 2018. content.iospress.com/articles/journal-of-parkinsons-disease/jpd181373. Accessed July 25, 2019.