Change of Subjective Visual Vertical (SVV) in Patients of Vestibular Neuritis

ABSTRACT

BACKGROUND AND OBJECTIVES: Measurement of subjective visual vertical (SVV) in darkness with the head upright is one of the static function test of the otolithic system and is simple to perform in the patients. Changes of SVV were measured during the recovery period of vestibular neuritis to investigate the relation between SVV and the subjective improvements reported by the patients. MATERIAL AND METHODS:Sixty-two patients with unilateral vestibular neuritis were investigated. All the patients were diagnosed by physical examination with electronystagmography and the SVV were assessed during the acute period and sequentially followed during the recovery period. At the same time, the subjects were questioned in five scale of symptom improvement which were "Level 5 I am so dizzy to open my eyes", "Level 4 I am dizzy not moving my head", "Level 3 I am not dizzy if I don't move my head", "Level 2 I am not dizzy with head moving", "Level 1 I am not dizzy at all". RESULTS: The calibrated mean values were 5.72+/-4.77 degree in vertical deviated toward the lesion side. There was no relation between the canal paresis and the tilt of SVV. As the SVV reaches the normal value, the symptom scale improved to level 2 (p=0.018). The mean recovery time could be obtained by calculating the regression curve of the well compensated groups. CONCLUSION: These results show that SVV correlated with clinical improvement of dizziness symptoms in vestibular neuritis. Therefore, this method can be used to evaluate vestibular neuritis during the follow up.