SVV test will be done.

SVV test will be done with virtual reality glasses.

For commercially available VR Subjective Visual vertical(SVV), VIRTUALIS® PHYSIO VR[SVV and Dynamic SVV](Virtualis, France) was used. The bar angles are given in a random order. The system consists of glasses, computer and hand control. When patients wear their glasses, they can see only a light bar in Static SVV, and points rotating left or right on the background of the light bar in Dynamic SVV. No light can enter the glasses. The glasses have a sensor that detects the angle of the head. The starting point of the bar can be adjusted randomly to different angles by the computer. The visual background rotation rate for dynamic SVV was determined as ±30°/sec. The subject should adjust the bar in the vertical position using the right/left arrows on the controller. When verticality is confirmed by pressing the set button in the middle of the control unit, the computer records the angle of the bar and the position of the head.

For commercially available VR Subjective Visual vertical(SVV), VIRTUALIS® PHYSIO VR[SVV and Dynamic SVV](Virtualis, France) was used. The bar angles are given in a random order. The system consists of glasses, computer and hand control. When patients wear their glasses, they can see only a light bar in Static SVV, and points rotating left or right on the background of the light bar in Dynamic SVV. No light can enter the glasses. The glasses have a sensor that detects the angle of the head. The starting point of the bar can be adjusted randomly to different angles by the computer. The visual background rotation rate for dynamic SVV was determined as ±30°/sec. The subject should adjust the bar in the vertical position using the right/left arrows on the controller. When verticality is confirmed by pressing the set button in the middle of the control unit, the computer records the angle of the bar and the position of the head.