Gait Analysis in Progressive Supranuclear Palsy Phenotypes.

Area of Science:

• Neurology
• Movement Disorders
• Biomechanical Analysis

Background:

• Progressive supranuclear palsy (PSP) encompasses diverse phenotypes with overlapping early symptoms.
• Differentiating PSP phenotypes and Parkinson's disease (PD) is crucial for accurate diagnosis and management.
• Gait disturbances are a hallmark of PSP, but their specific characteristics across phenotypes require detailed investigation.

Purpose of the Study:

• To characterize early-stage gait parameters in distinct PSP phenotypes.
• To evaluate the efficacy of gait analysis in discriminating between PSP phenotypes (Richardson's syndrome, PSP-parkinsonism, PSP-progressive gait freezing) and variant PSP (vPSP).
• To assess the ability of gait analysis to differentiate vPSP from Parkinson's disease (PD).

Main Methods:

• Nineteen PSP patients (categorized into Richardson's syndrome, PSP-parkinsonism, and PSP-progressive gait freezing) and nine PD patients underwent computerized gait analysis.
• Gait assessments were performed under both single-task and dual-task conditions.
• Statistical models were employed to analyze gait parameters and diagnostic accuracy.

Main Results:

• Richardson's syndrome exhibited significantly worse gait parameters compared to other vPSP subtypes, despite similar demographics.
• Gait analysis achieved nearly 90% diagnostic accuracy in differentiating conditions during dual-tasking.
• PSP-Richardson's syndrome showed a strong correlation between gait parameters and cognitive functions (visuo-spatial, praxic, attention).
• Variant PSP demonstrated poorer gait parameters than PD patients.

Conclusions:

• Computerized gait analysis is a highly effective tool for differentiating early-stage PSP phenotypes.
• Richardson's syndrome presents with greater gait dynamic instability from the earliest stages compared to other PSP phenotypes.
• Gait analysis can reliably distinguish between vPSP and PD, aiding in differential diagnosis.