Vestibular Function in Different Otoneurological Patients

Objectives The first objective was to evaluate feasibility of head tilt testing and the motorized head impulse test (mHIT) for the quantification of vestibular function and its possible change in different otoneurological patient groups. The second objective was to compare these objective findings with symptoms and other signs for these patients. Methods Head tilt was measured by using a commercially available video-oculography (VOG) mask-integrated head position sensor in complete darkness in static and dynamic (subjective head vertical, SHV) conditions. The head tilt was measured in 20 healthy subjects, and in 30 patients with acute unilateral vestibular loss in the acute stage and at a mean of three months later. Head tilt was also measured in 43 patients with vestibular schwannoma preoperatively and at a mean of four months postoperatively. The mHIT was used for quantifying the function of the horizontal angular vestibulo-ocular reflex (aVOR) in 30 patients with acute unilateral vestibular loss in the acute stage and at a mean of three months later. mHIT was also used to measure aVOR in 44 patients with cochlear implant (CI) preoperatively and at a mean of two months and 19 months postoperatively. The aVOR was assessed by gain and asymmetry in gain. The patients completed a structured questionnaire during their visits to the vestibular laboratory to assess hearing, dizziness, and quality of life. Results Those patients with acute unilateral vestibular loss exhibited a slight head tilt towards the ipsilateral side, which significantly differed from that of controls, and which significantly recovered during the follow-up period. The mean head tilt in patients with VS was ipsilateral both preand postoperatively, and significantly larger than in controls. No significant change in head tilt after three months was encountered. In both patient groups the head tilt reinforced after returning from an ipsilateral head tilt. In patients with acute unilateral vestibular loss, the initially low mean ipsilateral aVOR gain and high asymmetry improved significantly during the follow-up, whereas the contralateral gain remained normal and showed no significant change. During the follow-up visit a high symptom score correlated moderately with low gain and with high asymmetry. The preoperative aVOR was deficient in the majority of the CI recipients. The