A novel in-home wireless radio device successfully monitors movement and gait speed, which can help assess disease severity, progression, and medication response in patients with Parkinson disease (PD), according to findings published in Science Translational Medicine.
The assessment of the clinical progression of PD and the effect of medications on symptoms is vital for drug development and providing medical care. However, as many as 40% of patients with PD have rarely seen a neurologist or a specialist since most PD specialists tend to be concentrated in urban areas. This limits the ability to travel for patients who may live in rural areas, have limited mobility, a decreased driving ability, impaired cognition, or are of older age. Therefore, it is essential to have a method that objectively, accurately, and continuously assesses PD at home.
For the study, researchers sought to evaluate the accuracy of an in-home wireless radio device that assesses PD severity, progression, and medication response at home, in an objective manner.
Researchers conducted a 2-part observational study at Boston University and University of Rochester in the United States. The first part of the study involved an observational period of 8 weeks. The second part is an ongoing the 2-year, longitudinal substudy funded by the National Institutes of Health (NIH).
A radio device installed in patients’ homes emitted wireless radio signals, gathered reflected radio waves as they bounced off a person’s body, and analyzed walking movements and trajectories allowing calculation of gait speed.
The researchers compared 34 patients with PD (mean age, 69.4 years; 26% women) with 16 age-matched people without primary or secondary PD in the control group. Approximately 40% underwent the 8-week observation period, while the remainder are receiving ongoing monitoring up to 1 year in the longitudinal study.
In-home gait speed strongly correlated with PD severity according to the gold-standard PD assessment, the Movement Disorder Society’s Unified Parkinson’s Disease Rating Scale (MDS-UPDRS) part III subscores (P <.001), and total scores (P <.001).
After 1 year of monitoring, gait speed of the patients with PD declined at a rate of -0.026 m/s (95% CI, -0.034 to -0.019; P <.001), while those in the control group demonstrated a rate of gait speed decline of -0.015 m/s (95% CI, -0.025 to -0.004); P =.007). This indicated slower gait speeds due to the aging process regardless of the presence of PD.
Nevertheless, the gait speed of those with PD deteriorated almost twice as fast as those without PD, indicating a positive correlation between PD disease progression and declining gait speed.
After 3 to 5 years of levodopa treatment, patients with PD experience motor fluctuations characterized by the “ON-OFF” effect, suggestive of altered response to medication. The researchers compared the patients’ self-reported daily “ON-OFF” states to gait speed as detected by the radio device.
Fluctuations in gait speed correlated with the timing of levodopa administration with gait speed deteriorating 1 to 2 hours following medication administration. This indicated a wearing off of the medication. Adjustments to medication plans resulted in changes to gait speed throughout the day.
“Our study provides important insight into medication response and the relationship between PD motor function status and in-home gait speed,” the researchers noted.
They added, “This indicates that in-home and in-clinic gait measurements can play a complementary role in PD assessment.”
Study limitations included the small sample size, the monitoring only of a limited space within range of the device in the patient’s home, and the dependence of the radio device’s accuracy on self-reported patient outcome measures and the gold standard PD assessment ratings. Additionally, other limitations included lack of consideration for other comorbid conditions causing decline in gait speed, and lack of assessment for other concerns within PD mobility, such as falls and freezing episodes, which the radio device might detect.
Disclosure: One study author declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.
Liu Y, Zhang G, Tarolli CG, et al. Monitoring gait at home with radio waves in Parkinson’s disease: a marker of severity, progression, and medication response. Sci Transl Med. Published online September 21, 2022. doi:10.1126/scitranslmed.adc9669