Positional vertigo is the experience of sudden spinning or dizziness triggered by head movement. Healthcare providers use the Dix-Hallpike maneuver as the standard diagnostic procedure. This test determines the underlying cause and locates the affected inner ear, allowing for targeted treatment.
What the Dix-Hallpike Test Is
The Dix-Hallpike test is primarily used to diagnose Benign Paroxysmal Positional Vertigo (BPPV). BPPV is a common inner ear disorder that causes brief episodes of vertigo triggered by changes in head position. The condition is caused by the displacement of tiny calcium carbonate crystals, known as otoconia.
These crystals naturally reside in the utricle, but they can sometimes break loose and float into the three fluid-filled semicircular canals. When the head is moved, gravity pulls on these loose crystals, causing the fluid inside the canal to move improperly. This movement sends confused signals to the brain, resulting in the characteristic spinning sensation of vertigo. The Dix-Hallpike maneuver is designed to provoke this specific movement and confirm BPPV.
Performing the Dix-Hallpike Maneuver
The procedure begins with the patient sitting upright on an examination table. The clinician first turns the patient’s head 45 degrees toward the side they intend to test. This specific angle aligns the posterior semicircular canal to best capture the effect of gravity.
While maintaining the 45-degree head rotation, the clinician quickly guides the patient backward into a lying position. The patient’s head is allowed to hang slightly below the edge of the table, extended approximately 20 to 30 degrees past the horizontal plane. This rapid change in position forces any loose crystals to move within the inner ear canals. The position is held for at least thirty seconds while the clinician observes the patient for reactions.
The test is performed on both the left side and the right side to compare the patient’s physical response to each movement. The clinician looks for two main signs of a positive result: the patient reporting a sudden onset of vertigo and the observation of nystagmus. After the first side is tested, the patient is returned to the sitting position for a short rest before the maneuver is repeated on the opposite side.
Interpreting Results to Identify the Side
Identifying the affected ear relies on observing the involuntary eye movements, or nystagmus, that occur during the test. A positive result is confirmed when both nystagmus and vertigo are triggered upon lying down. Crucially, the affected ear is the one closest to the ground when the nystagmus is observed. For example, if symptoms appear when the patient is laid back with their head turned to the right, the right ear is identified as the problem side.
The nystagmus associated with the most common form of BPPV (posterior canal) has a specific pattern. The eye movement is a combination of up-beating and torsional, rotating with the top of the eye twisting toward the affected, downward ear. This reaction occurs after a brief latency period, usually two to five seconds, as the displaced crystals begin moving through the fluid. The direction and characteristics of this eye movement allow the provider to confirm BPPV and which specific semicircular canal is involved.
Next Steps After Diagnosis
Once the Dix-Hallpike maneuver identifies the affected ear and the specific canal, treatment can often begin immediately. The primary treatment for posterior canal BPPV is the Epley maneuver, also called a canalith repositioning procedure. This maneuver is a therapeutic extension of the diagnostic test itself.
The Epley maneuver uses a sequential series of deliberate head and body position changes to manipulate the inner ear. The goal is to use gravity to guide the displaced otoconia out of the sensitive semicircular canal. These movements shepherd the crystals back into the utricle, where they naturally belong and will no longer cause positional vertigo. Localizing the problem ear with the Dix-Hallpike maneuver dictates the starting position and direction of the therapeutic Epley maneuver.