[The subjective visual vertical in vestibular disease]

Area of Science:

• Neuroscience
• Ophthalmology
• Vestibular System

Background:

• Accurate perception of visual verticality is crucial for maintaining balance and spatial orientation.
• Vestibular disorders, both peripheral and central, can impair the ability to perceive visual verticality.
• Assessing vestibular function often involves evaluating visual-motor coordination and spatial orientation.

Purpose of the Study:

• To compare the accuracy of visual verticality perception in patients with peripheral or central vestibular disease.
• To evaluate the effect of frontal plane trunk-head tilt (30 degrees) on visual verticality perception.
• To determine if trunk-head tilt enhances the diagnostic utility of visual verticality tests.

Main Methods:

• Thirty-eight patients with vestibular disease (23 peripheral, 15 central) and 40 healthy controls participated.
• Participants adjusted a motorized bar to perceived verticality using a joystick.
• Testing was conducted in both upright and 30-degree tilted (bilateral) trunk-head positions.

Main Results:

• Healthy subjects estimated true vertical with less than 2 degrees of error.
• Patients with peripheral vestibular disease and nystagmus showed the largest verticality tilt errors in upright posture.
• Accuracy in estimating true vertical decreased significantly (p < 0.05) in all patients with trunk-head tilt.
• Frontal plane trunk-head tilt increased test sensitivity from 34% to 85% and efficacy from 68% to 93% (p < 0.05).

Conclusions:

• Frontal plane trunk-head tilt diminishes the accuracy of visual verticality perception in individuals with vestibular disease.
• This finding highlights that incorporating head-trunk tilt improves the sensitivity and efficacy of tests used for vestibular function assessment.