Gait analysis in PSP and NPH: Dual-task conditions make the difference

Area of Science:

• Neurology
• Biomechanical Engineering
• Gait Analysis

Background:

• Progressive supranuclear palsy (PSP) and idiopathic normal-pressure hydrocephalus (iNPH) are neurological conditions that affect gait.
• Differential diagnosis between PSP and iNPH can be challenging.
• Quantitative gait analysis offers a potential tool for distinguishing these conditions.

Purpose of the Study:

• To evaluate the utility of quantitative gait analysis under single- and dual-task conditions for the differential diagnosis of PSP and iNPH.
• To identify specific gait parameters that differentiate between PSP and iNPH patients.

Main Methods:

• A cross-sectional study involving 38 PSP patients, 27 iNPH patients, and 38 healthy controls.
• Gait analysis using a pressure-sensitive carpet under single-task (preferred, slow, maximal speed) and dual-task (cognitive, motor) conditions.
• Measurement of temporal and spatial gait parameters.

Main Results:

• Both PSP and iNPH patients showed significant gait dysfunction compared to controls, with iNPH patients exhibiting broader-based gait.
• Stride time variability was increased in both groups, more so in PSP.
• Cognitive dual tasks reduced gait velocity more in PSP patients, while motor dual tasks led to worsening in PSP but improvement in iNPH patients.

Conclusions:

• Patients with PSP demonstrate higher sensitivity to dual-task perturbations compared to iNPH patients.
• Increased step width and differential responses to cognitive versus motor dual tasks are potential diagnostic markers for iNPH.