Parkinson's Kinetigraph Provides Clues for Better Therapy

Daniel M. Keller, PhD     October 17, 2018

Hong Kong — Use of the Parkinson's Kinetigraph (PKG) (Global Kinetics Corp) changed patient management for about one third of a cohort attending a hospital-based movement disorder clinic.

The PKG contains an accelerometer that measures activity and motor function and also gives medication dose alerts and records medication use. An open question is whether the added quantitative monitoring from the device produces better treatment outcomes than standard of care alone involving patient diaries, clinical rating scales and observation, and questioning of patients.

In keeping with this year's theme of Technology in the Diagnosis, Monitoring, and Management of Movement Disorders at the International Congress of Parkinson's Disease and Movement Disorders (MDS) 2018, several presentations involved devices such as this one, as well as smart phones or other electronic technology potentially beneficial for patient management.

In this study from the University Hospital of Wales in Cardiff, United Kingdom, patients wore the PKG for 6 to 10 days in the home and while engaged in normal activities. The device recorded information on motor patterns, impulsiveness, periods of sleep, and response to medications.

Lead author Shoned Jones, MBBS, told Medscape Medical News that the aim of the study was to see whether adding information from the PKG influenced clinical management of the 70 patients in their cohort. All of the patients had reported severe or worsening symptoms, or their clinicians had asked about next treatment options after an uncertain response to a treatment change. The researchers asked the clinicians managing the patients what their management plan would be before using the PKG and then after PKG results were sent to them.

"It did alter our clinical management in a third of our patients, and the most significant finding is that patients who were not previously being considered for advanced therapies were identified as being candidates, based on the PKG data," she said. In addition, patients who were being considered for advanced therapies before using the PKG were subsequently identified as "potentially having their medications optimized" after using the PKG.

For 80% of the patients, the results from the PKG were consistent with clinical findings. However, it did add further information in the form of data on symptoms, medication compliance, and response to medication. "So essentially, it's improved our identification of patients that should be referred for therapies while also avoiding some referrals by suggesting medical optimization of therapies," Jones noted. If a change in therapy was recommended, it happened without resistance from the patients or their physicians.

The median age of the patients (N = 70; n = 40 male) was 72 years (range, 44 - 91 years); the median time since diagnosis was 6.9 years (range, 1 - 24 years). The majority were in modified Hoehn and Yahr stages 2 to 3. The main reason (54%) for requesting PKG was increasing symptoms, followed by wearing off (14%), enhancing clinical confidence (10%), uncontrolled bradykinesia, uncontrolled dyskinesia, or both (7% each), or to assess response to levodopa (1%).

PKG results caused a change in clinical management for a total of 24 patients (34%). Medication was titrated for three patients who had been considered for advanced therapies of apomorphine or levodopa-carbidopa intestinal gel (Duopa, AbbVie) before PKG.

Six patients were recommended for advanced therapies of apomorphine or deep brain stimulation when such therapies had not been previously considered. In two patients, the PKG found a poor response to therapy and caused clinicians to question the diagnosis of Parkinson's disease.

In 12 patients (17%), the PKG evaluation differed from the clinical evaluation (see Table). Where the PKG data correlated with the clinical examination, in 18 patients, the PKG yielded additional clinically relevant information: additional symptoms (7/18), questions about compliance (6/18), and medication information (5/18).

Table 1. Difference Between PKG Findings and Clinical Evaluation

Clinical Evaluation	PKG Evaluation	Number of Patients
Wearing off	Uncontrolled bradykinesia	5
Uncontrolled dyskinesia	Uncontrolled bradykinesia	2
Uncontrolled bradykinesia and dyskinesia	Wearing off	1
Uncontrolled bradykinesia and dyskinesia	High fluctuations	1
Enhance clinical confidence	Medication ineffective	3

Jones described the PKG process. First, a clinician fills out a request form, which is sent to the manufacturer, Global Kinetics Corp (Melbourne, Australia). The company then sends the device to the patient. The patient wears it for a period, sends it back to the company, and within 48 hours, the clinician receives a report. The system is secure, and the company has only anonymized data, because only the clinic has patient codes.

Coauthor Consultant Physician Biju Mohamed, also at University Hospital of Wales and St. David's Hospital, said the technology is available internationally. A next step in development will be to make the information available to individual patients so "the patients themselves can see the graphs, and that then empowers them to have the information to hand."

A potential advantage of the PKG is that in a system with a large patient load, "it's difficult for us to keep patients' appointments every 6 months, for example, and this would allow us to fill that huge gap wherein we could have virtual clinics instead of the patient having to travel far away to see a specialist."

An important remaining question that this study did not address is whether the additional data and resulting changes to patient management produces better outcomes of treatment and for quality of life. "Yes. That's the ultimate goal and the next step that we're going to be looking at," Jones said.

Alberto Espay, MD, of the University of Cincinnati College of Medicine, Ohio, commented to Medscape Medical News that the utility of the PKG "is in the possibility that we might be getting data in terms of function by patients that we might be relatively insensitive to, number one. And number two, that this is collected in what's referred to as an ecologically valid setting, meaning the patient's home and when the patients are in other circumstances and so forth. So I see that the point here is to try to get data that we think is relevant."

What hasn't been done, he said, is finding out whether further questioning of patients about how they were doing would have produced similarly useful information to improve patients' quality of life.

"This is the problem in general with all studies that are open label and that begin with devices," Espay said. There may be a bias in the patient as well as the physician in that they expect the device to yield information that will have a positive outcome for the patient, "and lo and behold, you demonstrate it, and it begins a self-fulfilling prophecy." So he stressed the need for control groups for these kinds of studies "because they are the only way for us to truly claim that they make a difference in terms of patient care."

He proposed that an appropriate control would be a sham device that patients wear, and even further, that the control group should have a different physician, who, knowing that the device is a sham, might ask questions that the first group's physician would not. He said that would be a better test of whether the device yields better actionable information than just an experienced physician asking questions of the patients.

There was no commercial funding for the study. Dr Jones and Dr Mohamed have disclosed no relevant financial relationships. Dr Espay has received research support from Great Lakes Neurotechnology and is the chair of the Technology Task Force of the Movement Disorder Society.

International Congress of Parkinson's Disease and Movement Disorders (MDS) 2018. Abstract 1103, presented October 8, 2018.

https://www.medscape.com/viewarticle/903560?src=rss#vp_1