The Influence Of Interrupting Visual And Somatosensory Cues To The Static Posture Of Normal Subjects And The Patients With Unilateral Vestibular Hypofunction

Objective To investigate the static posturography(SPG)of normal individuals and the patients with unilateral vestibular hypofunction(UVH) when the visual or somatosensory input was interrupted, and discuss the difference strategies of normal individuals and the patients with UVH.Method 60 normal subjects and 28 patients with UVH were taken the computerized posturography under these different upright stance condition:â‘ the firm surface with eyes open(T1);â‘¡the firm surface with eyes closed(T2);â‘¢the foam surface with eyes open(T3). standing for 30 seconds under the 3 conditions and recording the sway velocity(SV) respectively. Closing eyes was to interrupt the visual input and standing on the foam surface was to interrupt the somatosensory input in the postural stability.Resultâ‘ For the two groups, both of the SV increased when the visual or somatosensory input was interrupted(P<0.01).â‘¡The SV of the normal group was higher when the somatoseneory input was interrupted compared with the visual cue was interrupted(P<0.001); but the SV of the UVH patients group have no difference between the two sensory input were interrupted(P=0.051).â‘¢The SV of the 2 groups have no difference when they standed on the firm surface with eyes open(P=0.257),and also when the somatosensory cue was interrupted(P=0.232); when the visual cue was interrupted, the SV of the UVH patients group was higher than the normal group(P<0.05).Conclusion The static balance function of the normal individuals and the UVH patients decreased when the visual or somatosensory cue was interrupted, and the degrees of the influences are difference; the normal group was apt to depended on the somasensory cue, while the UVH patients depended on the visual input much more. This maybe indicate that the normal ones and the UVH patients use the difference strategies when they keep balance.