Time-dependent changes in postural control in early Parkinson's disease: what are we missing?

Area of Science:

• Biomedical Engineering
• Neuroscience
• Movement Science

Background:

• Impaired postural control (PC) is a hallmark of Parkinson's disease (PD).
• Objective measurement of PC using accelerometers is valuable.
• Optimal testing protocols for PC in PD are not yet established.

Purpose of the Study:

• To characterize time-dependent changes in PC during standing in individuals with PD and controls.
• To identify PC outcomes most sensitive to PD pathology.
• To evaluate the utility of short-duration analysis windows for PC assessment.

Main Methods:

• Accelerometer-based PC measurement in 26 PD patients and 31 controls over 2 minutes.
• Time series analysis using 2-second windows and piecewise linear regression.
• Analysis focused on the initial 30 seconds and subsequent 90 seconds of standing.

Main Results:

• PC outcomes demonstrated significant time-dependent changes, primarily within the first 30 seconds of standing.
• Individuals with PD exhibited reduced dynamic changes in PC compared to controls.
• Jerk, a measure of the rate of change of acceleration, was identified as a discriminative outcome for PD pathology.

Conclusions:

• Standard PC assessments may overlook crucial time-dependent variations.
• Analyzing short, dynamic intervals (e.g., 2-second windows) provides sensitive insights into PC deficits in PD.
• This approach can enhance the understanding of PC in PD and inform intervention strategies.