Head tilt is pronounced after an ipsilateral head roll in patients with vestibular schwannoma.

ABSTRACT

The study aimed to measure utricular function by directly quantifying head tilt in vestibular schwannoma (VS) patients using regular video-oculography (VOG) equipment with integrated head-position sensor, and to correlate the results with patients' symptoms and signs. We recorded head tilting after exclusion of visual cues (static head tilt), and after returning to the centre following lateral head rolls towards each side [subjective head vertical (SHV)]. Head tilt in 43 patients was measured preoperatively and approximately 4 months postoperatively, and compared to that of 20 healthy subjects. Symptoms were assessed with a structured questionnaire. Static head tilt in patients was significantly greater than in controls (1.0° ± 0.9°) preoperatively (1.6° ± 1.5°, p = 0.04) and postoperatively (1.7° ± 1.5°, p = 0.01). Mean SHV in patients was significantly greater than in controls (1.2° ± 1.0°) preoperatively (2.0° ± 1.9°, p = 0.03) and postoperatively (2.5° ± 1.8°, p = 0.001), increasing non-significantly after surgery (p = 0.3). Side-specific SHV after ipsilateral head rolls was significantly greater than after contralateral head rolls preoperatively (2.8° ± 3.3° vs. -0.5° ± 3.0°, p = 0.001) and postoperatively (3.3° ± 3.0° vs. 0.6° ± 3.2°, p < 0.001). The intensity of dizziness increased postoperatively (p = 0.04), but its effect on quality of life remained unchanged. In conclusion, commercial VOG equipment including a head-position sensor allows direct evaluation of head tilt in VS patients. The slight head tilt towards the ipsilateral side becomes most evident after returning from an ipsilateral head roll.