Bilateral Vestibulopathy

Vestibular Function Testing

• Video Head Impulse Test (vHIT):
  Primary bedside test showing bilaterally reduced horizontal VOR gain (< 0.6) with overt and/or covert catch-up saccades (Strupp et al., 2017; Starkov et al., 2021; van Stiphout et al., 2023).
• Rotational Chair Test:
  Gold standard for confirming diagnosis. Markedly reduced VOR gain across frequencies (< 0.1–0.2) with phase lead indicating bilateral canal loss (Hain et al., 2013; Strupp et al., 2017).
• Caloric Testing:
  Bilaterally reduced or absent responses (total SPV < 6°/s), indicating loss of low-frequency horizontal canal function (Lucieer et al., 2016; Strupp et al., 2017).

Balance and Gait Findings

• Balance Testing:
  Patients exhibit instability or falls when visual and surface cues are reduced—such as with eyes closed, on foam, or during tandem stance and dynamic posturography (conditions 5–6)—indicating loss of vestibular input and compensatory reliance on vision and proprioception (Strupp et al., 2017; Hain et al., 2013; Lucieer et al., 2016; van Stiphout et al., 2023).

• Gait Observation:
  Patients exhibit broad-based, cautious gait, difficulty walking in the dark, and unsteadiness when turning or looking around while walking (Strupp et al., 2017; Piper et al., 2023).

• Functional Balance Scales:
  Dynamic Gait Index (DGI) and Berg Balance Scale scores are often reduced, reflecting impaired mobility and increased fall risk (Herdman et al., 2015; Piper et al., 2023).