Positional testing in a 61-year-old woman elicits nystagmus that begins immediately on assuming the provoking position, persists as long as the position is maintained, does not fatigue with repetition, and changes direction depending on gaze. This pattern should prompt investigation for:
- A Canalolithiasis of the lateral semicircular canal
- B Meniere's disease in the active stage
- C A central nervous system lesion such as a cerebellar tumour or craniocervical junction anomaly ✓
- D Vestibular neuritis of the superior division
Correct answer: C. A central nervous system lesion such as a cerebellar tumour or craniocervical junction anomaly
Explanation
Genuine BPPV nystagmus has a latent period of a few seconds, is transient, fatigues with repetition, and has a fixed direction for a given canal and head position. Nystagmus that appears immediately, persists without fatigue, and reverses direction with change of gaze violates all peripheral rules and is a red flag for a central positional nystagmus from posterior fossa disease. Such patients need neuroimaging rather than repositioning manoeuvres.
Reference: Dhingra's Diseases of Ear, Nose and Throat, 8th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.