Objective measure of freezing of gait for PD patients using Physilog®
Freezing of gait (FoG), is defined as a brief, episodic absence or marked reduction of forward progression of the feet despite the intention to walk. It is one of the most debilitating motor symptoms in patients with Parkinson’s disease (PD) as it may lead to falls and a loss of independence.
This study developed an objective measure of FoG severity based on inertial sensor data (Physilog®) worn on the shins and at the lumbar level. FoG-ratio was calculated during a 2-minute turning task, in which individuals with PD made 360° turns on the spot. 70 individuals (27 freezers, 22 non-freezers and 21 HC) performed the test. Analysis was based on power spectral density from the anteroposterior acceleration data. Subjective FoG measurement was also performed via NFoGQ, which is a useful and comprehensive tool to subjectively assess the severity of FoG and its impact on activities of daily living and quality of life.
Significant correlations were only found for freezers between loss of presynaptic inhibition (PSI) and FoG‐ratio, suggesting that loss of PSI for step initiation in freezers may be due to FoG.
Using body-worn accelerometers during a clinically popular mobility test and provide objective assessment of the FoG events, as suggested in this publication, could help not only to understand better FoG but also to evaluate the effect of rehabilitation or new therapies for patients with Parkinson disease.
Read the complete study: “Loss of presynaptic inhibition for step initiation in parkinsonian individuals with freezing of gait” (Lira et al, 2020)