Postural Reflexes in Conditions of Visual Disturbance

Summary

Introduction:
Tests of balance are routine elements of neurological and otolaryngological examination. What follows is a general study of the effectiveness of balance control when visual-vestibular integrity is disturbed, conducted by means of ascertaining the influence of vertical and horizontal visual stimulation on postural reflexes as measured by craniocorpography.

Goal:
The purpose of the study was to observe the effect of visual, horizontal and vertical optokinetic and sinusoidal stimulation on postural reflexes.

Material and method:
A group of 40 healthy subjects (20 female, 20 male) aged 18–52 with no pathological otoneurologial history or signs was tested. Horizontal and vertical optokinetic and sinusoidal stimulation was administered in order to observe balance disturbances, as measured by craniocorpography in the course of a Romberg test.

Results:
It was revealed that visual stimulation (optokinetic and sinusoidal) in the horizontal plane induced stronger postural disturbances than visual stimulation in the vertical plane. Both horizontal and vertical optokinetic stimulation resulted in high longitudinal body sway. Lateral body displacement was better controlled during vertical visual disturbances. The authors observed that the differences in postural reflexes were dependent on the direction of both horizontal and vertical visual stimulation. Balance control was better when the optokinetic incitement was directed to the left and downward. Increased intensity of visual stimulus (target velocity) did not worsen balance.

Key words:
postural reflexes – balance –
craniocorpography – visual stimulation – 
otoliths

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