Brief spins on rolling over in bed, with normal VEMPs
A 35-year-old reports seconds-long bursts of vertigo triggered by lying down, sitting up, and rolling over in bed, with no hearing symptoms. A positional manoeuvre reproduces a brief, fatigable torsional-upbeat nystagmus.
Affected earContralateral ear
Both cVEMP traces are well-formed, symmetric and within normal limits — VEMP does not detect a canalith disorder.
Why are the VEMPs normal in this patient despite clear vertigo?