Head-impulse testing system HIT

The HIT – Head Impulse Test was designed for the daily work in the set up practice and the clinical application. It impres- ses by its great circumference of functions with intuitive handling. With HIT USB a complete system is available for you to examine the semicircular canals. The test was rst described in 1988 by Curthoys and Halmagyi. As now been shown in many studies, the head impulse test should be a standard test in vestibular diagnosis. The system offers the functionality of a complete one-off solution to you. Also, the stress for the patient is signi cantly reduced. The tested canal is always in the direction of rotation. This means at a rotation of the head to the right, the right canal is excited and vice versa. For the vertical semicircular canals, this also applies. The test uses the vertical planes of the canals in the front and rear, which are located at an angle of approximately 45° to the sagittal plane. The results are shown in realtime. The normal reaction to the stimulus is almost the complete opposite of the head movement with a smooth eye movement. The gain is calculated for each trial. The gain ratio between head an eye movement should nearly be 1. If there is an issue with a semicircular canal the patient loses the target and there will be compensation saccades. If the gain is in the grey area, there can be a disease. If only one side is affected there will be two seperated point clouds. Additional to the gain and movement display, the HIT USB software offers a 3D-depiction of the eye response.