New Wearable Device Helps Detect Dyskinesia in Parkinson's

August 09, 2019

A new wearable device that assesses motor fluctuations may be a useful tool for detecting dyskinesia in patients with Parkinson's disease, a new study suggests.

"The device, which is worn on the wrist like a watch, can tease out wearing off and dyskinesia and identify patients who need to see a neuro-specialist or who may need a neurosurgical procedure," lead author, Echo E. Tan, MD, Cedars-Sinai Medical Center, Los Angeles, told Medscape Medical News.

She explained that at present, clinicians rely on taking a history to try and identify those patients with more serious symptoms, but many patients are unable to communicate their symptoms and cannot keep reliable records.

"Symptom diaries are usually filled out by caregivers and are generally not very accurate. We need a more quantitative system and this device may help with that."

"We found the device gave a more accurate assessment of symptoms than patient diaries, and the device was used more consistently than the diaries," Tan added.

The study was published in Functional Neurology.

In the paper, the authors note that Parkinson's disease patients typically respond well to medical therapy in the first few years of their disease. However, approximately 40% of patients develop fluctuations of response to levodopa and dyskinesia after 4-6 years of treatment, which increases to 70% after longer-term treatment.

The current device, which has the brand name Personal KinetiGraph, was developed to address the lack of objective measurement tools for movement disorders. It quantifies symptoms, including tremor, bradykinesia, and dyskinesia, and produces a motor fluctuation score.

For the study, Tan and colleagues assessed 60 patients attending the Movement Disorders Clinic at Cedars-Sinai Medical Center with detailed questionnaires — Wearing Off Questionnaire (WOQ9) and Movement Disorders Society-Unified Parkinson's Disease Rating Scale (MDS-UPDRS) Part IV scores — and assigned them into four disease categories: mild (no fluctuations); mild with minor fluctuations; moderate fluctuations, and severe bothersome fluctuations. These fluctuations included wearing off and dyskinesia.

"We wanted to see if the device could distinguish between these different types of patients," Tan said.

The patients then wore the Personal KinetiGraph for 6 days and they or their caregivers also completed symptom dairies.

Results from the 54 subjects who completed the study showed that the fluctuation score on the device significantly differentiated between early fluctuators and troublesome fluctuators (P = .01), as well as dyskinetic and non-dyskinetic subjects (P < .005).

In contrast, motor diaries could not distinguish the four study groups on the basis of average OFF time, while average time with dyskinesia distinguished non-fluctuators and moderate fluctuators but did not distinguish among all four groups.

The device also identified high levels of dyskinesia in some patients who denied having dyskinesia.

"We found that the device fluctuation score can distinguish between patients who do and do not have dyskinesia — ie the two milder groups and the two more severe groups. But it couldn't distinguish between the two milder groups," Tan reported.

"The fluctuator score appears to be a good triage tool — it can help physicians identify patients with these motor fluctuations without spending long periods of time at the clinic."

Tan pointed out that the device can also be a source of additional information for physicians. "As well as the fluctuator score it also gives other useful information including a bradykinesia score (how slow the patient has been during the day); tremor responses to medications; how long the patients has been asleep — which can help work out if the medication is making them drowsy. It also gives medication reminders."

"It does take a bit of training to interpret the graphical data so it will probably be used mainly by movement disorder specialists and neurologists treating more severe Parkinson's patients," she commented.

Tan believes it will be particularly useful for patients starting to develop more serious symptoms. "For those patients who start to complain about a bit of wearing off and the problem is not solved in one clinic visit or with one medication change, we can use this device to get a handle on what is happening."

Another group who may benefit are those who live a long distance from a specialist clinic. "They could just come to the clinic a couple of times a year and use this device in between to monitor symptoms. It would also be good for patients with cognitive impairment or for those who don't have caregivers that can give reliable information," Tan suggested.

The Personal KinetiGraph device has been approved in the United States and Europe. It is still undergoing post-marketing clinical evaluation, but reimbursement codes are now available so it can be prescribed in the United States where it has a list price of around $700, manufacturer Global Kinetics said. It is also available in the United Kingdom, the Netherlands, and Germany.

Commenting for Medscape Medical News, James Beck, PhD, the Parkinson's Foundation chief scientific officer, said: "This study is another example of how, over time, we can expect to see more technology being brought to bear for the clinical assessment of motor disorders. The sensitivity to distinguish the various degrees of motor fluctuations is not yet there, so, to me, the benefit of this device is not everyday clinical practice but for clinical trials to reduce participant burden and improve reporting. As sensitivity/accuracy increases — along with ease of interpretation — we can expect to see wider deployment of devices like these in a clinical setting."

The study was funded by Global Kinetics. Tan has disclosed no relevant financial relationships.

Funct Neurol. 2019;34:21-28. Full text

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