Hallpike-Dix: Which statement defines a positive result?

• A. Nystagmus immediately upon lying down
• B. Vertigo that persists after movement
• C. Dizziness worsens with eye movement
• D. Nystagmus after 2-5 seconds and stopping within 30 seconds

Answer: (D)

The test is looking for the pattern that defines a positive Dix-Hallpike result, which points to benign paroxysmal positional vertigo from the posterior semicircular canal. A positive result is the appearance of nystagmus after a brief delay—about 2 to 5 seconds—when the patient is moved into the provocative position, with the nystagmus and vertigo then lasting for a short period, typically less than 30 seconds, and it tends to fatigue with repeated testing. This combination of delayed onset, short duration, and fatigability is classic for canalithiasis–type BPPV and distinguishes it from other causes of vertigo that may cause immediate nystagmus or symptoms that persist longer than a minute or more, or dizziness that worsens with eye movements rather than with specific positional changes. The nystagmus in posterior canal BPPV is often torsional and upbeating, aligning with the usual canal involvement.