Balance Control Impairments in Usher Syndrome

Area of Science:

• Neurology
• Ophthalmology
• Audiology

Background:

• Usher Syndrome (USH) is a leading cause of inherited deafblindness.
• Understanding balance control in USH is crucial for managing functional deficits.

Purpose of the Study:

• To investigate postural control in USH patients using posturography.
• To elucidate sensory compensation strategies in deafblind individuals.
• To correlate the Activities-specific Balance Confidence (ABC) scale with balance parameters.

Main Methods:

• Temporal posturographic analysis (classical and wavelet) of center of pressure (CoP).
• Study included 34 USH patients (USH1, USH2, USH4) and 35 controls.
• Assessment of balance using static/dynamic platforms, varying visual conditions, and the ABC scale.

Main Results:

• USH patients exhibited significantly increased postural sway and angular velocity on unstable surfaces compared to controls.
• Visual impairment was the primary factor affecting postural deficits; vestibular and somatosensory systems showed no significant differences.
• USH patients demonstrated reduced visual dependence, suggesting a reliance on other sensory inputs for balance.

Conclusions:

• USH patients, particularly USH1, have poorer balance control, especially with eyes open on unstable surfaces.
• Patients appear to suppress visual input and rely more on proprioception.
• USH2 patients may employ distinct multisensory balance strategies not fully captured by the ABC scale.