Subjective visual vertical test: Normative values in healthy population

Abstract

INTRODUCTION Subjective Visual Vertical test (SVV test) can be applied to measure one of the functions of the vestibular apparatus, its afferent pathways and nuclei within the brain stem. The test is based on the subjective assessment of verticality. The possibility of perceived visual vertical in healthy subjects can show deviation with accuracy of ±2° at most. OBJECTIVE The goal of the study is to present the results of the SVV test developed at our department. METHOD Two kinds of testing procedures were applied; the static test during which the subjects evaluated the verticality on a static background; the dynamic test during which the subjects evaluated the verticality after 20 seconds of rotation of the background to the right or to the left. Ninety-five healthy subjects aged between 21 and 79 years were tested. The whole group was divided into smaller groups according to age criterium. RESULTS The results showed statistically significant bigger SVV tilt in the subjects aged over 45 years than in the younger subjects. The arithmetic mean of the tilt to the left or tilt to the right in the group younger than 45 years was 0.42 degrees during the static test and 0.49 degrees during the dynamic test. The arithmetic mean for the group older than 45 years was 0.67 during the static test and 0.68 during the dynamic test. CONCLUSION The testing indicated that SVV perception showed a bigger tilt according to age. This should be taken into consideration in individual testing and evaluation of functional ability.

Keywords

• Subjective Visual Vertical test
• vestibular apparatus
• vestibular afferent pathways
• healthy volunteers