A 35-year-old woman presents 72 hours after sudden-onset spinning vertigo with vomiting. She has spontaneous left-beating horizontal-torsional nystagmus. Hearing is preserved. Right horizontal vHIT gain is 0.4 with overt catch-up saccades.
RCT pattern
Three-panel SHA summary. Shaded green = published normal band. Solid marker = patient/archetype curve; dashed = overlaid reference if shown.