Determining the Affected Ear in Positional Vertigo

Diagnostic Approach

The American Academy of Otolaryngology-Head and Neck Surgery recommends the supine roll test as the preferred diagnostic maneuver to determine which ear is affected when head turning causes vertigo 1, 3
The supine roll test involves positioning the patient supine with head in neutral position, quickly rotating the head 90° to one side and observing for nystagmus, returning to neutral position after nystagmus subsides, and rotating the head 90° to the opposite side and again observing for nystagmus 2, 3

The American Academy of Otolaryngology-Head and Neck Surgery states that two types of nystagmus patterns may occur during the supine roll test: geotropic type, where horizontal nystagmus beats toward the ground, and apogeotropic type, where horizontal nystagmus beats toward the uppermost ear 1, 4
In geotropic lateral canal BPPV, the affected ear is the one where rotation produces the most intense nystagmus, while in apogeotropic lateral canal BPPV, the affected ear is typically opposite to the side with the strongest nystagmus 1, 4, 5

Direction-changing positional nystagmus is the hallmark of lateral canal BPPV, where nystagmus direction changes with changes in head position 1
In geotropic lateral canal BPPV, debris is likely located in the long arm of the semicircular canal, while in apogeotropic lateral canal BPPV, debris is likely adherent to or near the ampulla of the semicircular canal 1
Despite careful testing, determining the affected side remains unclear in about 20% of cases 1, 5

When standard testing is inconclusive, additional methods to determine the affected ear include the lying-down nystagmus test, head pitch test, and bow and lean test 5

The American Academy of Otolaryngology-Head and Neck Surgery advises against assuming the side to which head turning triggers vertigo is automatically the affected ear 1, 2
Exercise caution when performing diagnostic maneuvers in patients with cervical stenosis, limited cervical range of motion, severe kyphoscoliosis, cervical radiculopathies, ankylosing spondylitis, spinal cord injuries, or morbid obesity 3