Postural disturbance in patients with normal pressure hydrocephalus

Area of Science:

• Neurology
• Biomechanics
• Geriatrics

Background:

• Normal pressure hydrocephalus (NPH) and subcortical arteriosclerotic encephalopathy (SAE) are neurological conditions affecting gait and balance.
• Postural control is crucial for daily activities and is often impaired in patients with these conditions.

Purpose of the Study:

• To analyze and compare the postural function in patients with NPH and SAE.
• To evaluate the effect of shunt surgery on postural function in NPH patients.
• To investigate the role of visual input in postural control for these patient groups.

Main Methods:

• Bedside assessment of postural function in 52 NPH and 19 SAE patients.
• Force platform analysis in 17 NPH, 10 SAE patients, and 23 healthy individuals (HI).
• Comparison of postural sway, center of pressure velocity, and body inclination in sagittal plane.

Main Results:

• No significant difference in bedside postural function between NPH and SAE patients.
• NPH patients showed greater improvement in postural function compared to motor function after shunt surgery.
• NPH patients exhibited larger sway areas and increased backward center of pressure velocity compared to HI.
• NPH and SAE patients had neutral or forward body inclination, unlike the backward inclination in HI.
• Postural function was better with eyes open across all groups, but significantly less so in NPH patients.

Conclusions:

• NPH patients demonstrate distinct postural deficits, including impaired visual sensory integration in the brainstem postural center.
• Shunt surgery can effectively improve postural instability in NPH.
• Postural control mechanisms are differentially affected in NPH and SAE, with visual input playing a critical role.