Test · 1
Positional manoeuvres
BPPV is the commonest cause of recurrent vertigo and the most reliably bedside- diagnosed vestibular disorder. Three manoeuvres test the three canals — and the shape of the nystagmus locates the otoconia.
The Dix-Hallpike — posterior canal BPPV
The Dix-Hallpike drops the patient's head into a hanging position with the tested ear down. If otoconia are loose in that ear's posterior canal, you see a brief burst of rotating-upward nystagmus and the patient feels vertiginous. Treat with the Epley right then.
Posterior-canal BPPV is by far the most common variant, ~85% of all BPPV.1A positive Dix-Hallpike on the dependent side gives torsional-upbeat nystagmus with short latency (5–15 s), a crescendo–decrescendo course, and fatigue on repeat — all peripheral hallmarks. Sensitivity 79–88%, specificity 75–100%.1
Persistent, non-fatiguing, purely vertical, or direction-changing nystagmus instead points to a central cause and warrants imaging. The fall onto the head- hang must be brisk — too slow and the otoconia don't migrate.
Cautions: cervical spine instability, vertebrobasilar disease and severe cardiopulmonary disease. The side-lying variant is a useful substitute. False negatives occur when the manoeuvre is performed too slowly or when otoconia have migrated to a different canal; repeat after a short rest. A negative Dix-Hallpike with a clear history of positional vertigo should provoke a Supine Roll for horizontal-canal involvement.
Posterior canal
Debris resting in the vestibule
Eye view
Quiet — within latency
Patient sits upright on the table edge. Explain the manoeuvre, warn about a transient burst of vertigo, obtain consent.
The Supine Roll — horizontal canal BPPV
Horizontal-canal BPPV (about 15–20% of cases) is caught by the Supine Roll Test: the head turns 90° each way while the patient lies supine. The direction of the resulting horizontal nystagmus identifies the affected ear AND the type of debris.
Geotropic nystagmus — beating toward the lower ear in both head positions — indicates canalithiasis; the side with the stronger response is affected. Treat with the Lempert (barbecue) roll. Apogeotropic nystagmus — beating away from the ground — indicates cupulolithiasis; the side with the weaker response is affected. Treat with Gufoni manoeuvres.2 The Bow and Lean test can resolve lateralisation when the supine roll is ambiguous.
Frenzel goggles or video-oculography sharpen the call when fixation suppresses a subtle response. Treat aggressively — HC-BPPV is often more disabling than PC-BPPV. Refractory cases benefit from forced prolonged position on the unaffected side overnight.
Canalithiasis (geotropic): horizontal nystagmus beats toward the dependent ear in both head-turn positions. The stronger side is the affected ear — here the right . Treat with the Lempert (barbecue) or Gufoni manoeuvre.
Anterior-canal BPPV and the Straight Head Hanging Test
The rarest variant (~3%) is anterior-canal BPPV. The diagnostic manoeuvre is the Straight Head Hanging Test: supine, the head dropped 30–45° below the horizontal in the midline. A brief downbeating-torsional nystagmus with fatigue points to AC-BPPV.
Persistent, non-fatiguing downbeat (rather than transient) instead suggests a craniocervical-junction or cerebellar lesion, even if the head-hang elicits it.3Always image when in doubt.
Repositioning strategies for AC-BPPV are less standardised than for PC- or HC-BPPV; the Yacovino manoeuvre is widely used and does not require knowing the affected side.4 Recurrent or refractory cases should prompt a careful look for an alternative diagnosis.
Anterior canal
Debris at the canal's superior end
Eye view
Quiet — within latency
Patient seated. No 45° head rotation: SHHT uses the midline plane so the anterior canal is best aligned with gravity on descent.
Peripheral vs central positional nystagmus
The whole point of the positional manoeuvre is to catch the rare central case. Five features separate them at the bedside.
Direction-changing positional nystagmus, sustained downbeat on head-hanging, or persistence beyond the BPPV time-course should prompt MRI of the posterior fossa.