Table 1.

Summary of studies investigating the impact of vestibular hypofunction on perceptual thresholds.

Study	Subjects	Stimuli	Findings
Valko et al. (32)	• 3 complete bilateral loss (aged 24–58) • 14 healthy controls (mean age 36, SD: 10)	Single cycle of sinusoidal acceleration	• Yaw rotations (1, 2, and 5 Hz), z-translations (0.3, 0.5, 1, 2, and 5 Hz), y-translations (1, 2, and 5 Hz), and roll tilt (0.05, 0.1, 0.2, 0.5, 1, 2, 5 Hz) thresholds were significantly higher in vestibular loss patients. • Yaw rotations at 0.2 and 0.5 Hz and y-translations at 0.3 and 0.5 Hz could not be completed by loss patients at the highest level generated by the motion platform.
Priesol et al. (40)	• 4 bilateral weakness (reduced calorics, reduced time constant) • 14 healthy controls (mean age 36, SD: 10)	Single cycle of sinusoidal acceleration	• Yaw rotation thresholds (0.2, 0.5, 1, 2, and 5 Hz) were significantly higher in bilateral hypofunction; y-translation: (0.3, 0.5, 1, 2, and 5 Hz) were statistically higher, however, the effect was limited to unspecified “lower frequencies.” • Z-translation (0.3, 0.5, 1, 2, and 5 Hz) and roll tilt (0.05, 0.1, 0.2, 0.5, 1, 2, 5 Hz) thresholds were not significantly different between groups.
Shayman et al. (60)	• 3 bilateral weakness (reduced calorics, 35–55 years) • 13 healthy controls (23–49 years)	Single cycles of raised cosine velocity	• Yaw rotation (1 Hz) thresholds were significantly higher in patiens with bilateral weakness.
Agrawal et al. (20)	• 33 bilateral weakness (reduced calorics or HIT, 24–83 years) • 42 healthy controls (15–72 years)	Raised cosine velocity profile	• Z-translation (0.5 Hz), y-translation (0.5 Hz), x-translation (0.5 Hz) thresholds were significantly higher in patients with bilateral vestibular loss.
Bringoux et al. (61)	• 4 bilateral vestibular loss (37–60 years) • 12 healthy controls (mean age: 29 ± 6 years)	Tilts from upright at 0.05 deg/s	• Roll and pitch tilt thresholds were not significantly different between groups.
Gianna et al. (56)	• 5 bilateral vestibular loss (31–64 years) • 8 health controls (24–49 years)	Acceleration steps	• Y-translation thresholds were not significantly different between groups.
Cousins et al. (58)	• 25 VN patients, (mean age: 46) • 30 healthy controls (mean age: 42)	Acceleration at 0.5 deg/s/s, increasing 0.5 deg/s/s every 3 s	• Ipsilesional and contralesional yaw rotation thresholds were significantly higher in VN patients at acute (1–5 days) and recovered (6–16 weeks) time points.
Cutfield et al. (59)	• 12 patients with VN (mean age: 50.0) • 12 healthy controls (mean age: 46.0)	Acceleration at 0.5 deg/s/s, increasing 0.5 deg/s/s every 3 s	• Ipsilesional and contralesional yaw rotation thresholds were significantly higher in VN patients.

HIT, head impulse test; VN, vestibular neuritis.