Subjective Head Vertical Test Reveals Subtle Head Tilt in Unilateral Peripheral Vestibular Loss

Utricular dysfunction has been indirectly measured with subjective visual horizontal or vertical testing. Video-oculography equipment with integrated head position sensor allows direct evaluation of head tilt. The aim was to assess head tilt after peripheral vestibular lesion by recording tilting of the head after excluding visual cues (static test condition), and after three lateral head tilts to both sides [subjective head vertical (SHV)]. Thirty patients with unilateral, peripheral vestibular loss were measured in the acute state, and 3 months later. Twenty healthy, age- and sex-matched subjects served as controls. Mean static tilt of 2.6 ± 1.1° in patients with acute vestibular loss differed significantly from that of 1.0 ± 0.4° in healthy subjects (p = 0.004), and from that of 1.1 ± 0.5° during the follow-up visit (p = 0.008). The mean SHV of 3.4 ± 0.7° in patients with acute vestibular loss was significantly more than that of 1.2 ± 0.5° in controls (p < 0.001). The SHV towards the lesion was 4.9 ± 1.0° while returning from the lesion side and 2.0 ± 1.0° while returning from the healthy side. The SHV was definitely abnormal in 60%, moderately abnormal in 20% and normal in 20% of the patients in acute state. Abnormal SHV persisted in only 20% of the patients indicating that recovery of the peripheral utricular function is occurring within months. In summary, head tilts slightly towards acute peripheral lesion, and this tilting is reinforced, when the head is actively moved on the lesion side.