From the Guidelines
The side-lying test is a diagnostic procedure used to evaluate benign paroxysmal positional vertigo (BPPV), particularly when it affects the horizontal semicircular canals, and is performed by having the patient lie on their back and then quickly turning their head 90 degrees to one side while remaining in the supine position, with the examiner observing for nystagmus and asking about vertigo symptoms, as recommended by the American Academy of Otolaryngology-Head and Neck Surgery 1.
Diagnostic Procedure
To perform the side-lying test, the patient lies on their back and then quickly turns their head 90 degrees to one side while remaining in the supine position. The examiner observes for nystagmus (involuntary eye movements) and asks about vertigo symptoms. The test is then repeated with the head turned to the opposite side. A positive test occurs when the patient experiences vertigo and the examiner observes horizontal nystagmus, with the direction and intensity of nystagmus helping to determine which ear is affected.
Purpose of the Test
The side-lying test is particularly useful for diagnosing horizontal canal BPPV, which accounts for about 10-30% of BPPV cases. If positive, treatment typically involves canalith repositioning maneuvers such as the Lempert (BBQ roll) maneuver or Gufoni maneuver to guide the displaced crystals back to their proper location in the vestibule of the inner ear.
Importance of Accurate Diagnosis
Accurate diagnosis of BPPV is crucial to prevent unnecessary tests and treatments, and to improve patient outcomes. The American Academy of Otolaryngology-Head and Neck Surgery recommends that clinicians diagnose posterior semicircular canal BPPV when vertigo associated with nystagmus is provoked by the Dix-Hallpike maneuver, and that clinicians perform a supine roll test to assess for lateral semicircular canal BPPV if the Dix-Hallpike test is negative 1.
Treatment Options
Treatment options for BPPV include canalith repositioning maneuvers, vestibular rehabilitation, and observation. The choice of treatment depends on the severity of symptoms, the presence of underlying medical conditions, and the patient's overall health status. Clinicians should reassess patients within 1 month after an initial period of observation or treatment to confirm symptom resolution, and should evaluate patients with persistent symptoms for underlying peripheral vestibular or central nervous system disorders 1.
From the Research
Side Lying Test for Vertigo
- The side-lying test is a diagnostic maneuver used to identify posterior canal benign paroxysmal positional vertigo (PC-BPPV) 2, 3, 4.
- The test is often used as an alternative to the Dix-Hallpike test, particularly for patients who have mobility limitations 2, 3, 4.
- Studies have shown that the side-lying test has a high sensitivity and specificity in diagnosing PC-BPPV, with estimated sensitivity ranging from 79% to 95.1% and specificity ranging from 75% to 96.97% 2, 3.
Comparison with Dix-Hallpike Test
- The Dix-Hallpike test is the standard test for diagnosing posterior semicircular canal BPPV, but the side-lying test can be used as an alternative when the Dix-Hallpike test is not possible 2, 4.
- Studies have compared the diagnostic accuracy of the side-lying test with the Dix-Hallpike test, and found that the side-lying test has comparable sensitivity and specificity to the Dix-Hallpike test 3, 4.
- The side-lying test may be safer and easier to perform in patients with range-of-motion limitations, such as spondylosis 4.
Diagnostic Value
- The side-lying test has been shown to have the same diagnostic value as the Dix-Hallpike test in determining PC-BPPV 4.
- The test can be used to diagnose PC-BPPV, and can also be used to determine whether a patient has combined BPPV of the horizontal semicircular canal (HC-BPPV) 4.
- The diagnostic value of the side-lying test is supported by studies that have found a high positive rate and association between the side-lying test and the Dix-Hallpike test 4.