Side-lying Test
Fundamentals
The side-lying test is a validated alternative to the Dix-Hallpike, assessing for ipsilateral posterior and contralateral anterior canal benign paroxysmal positional vertigo (BPPV). It is particularly beneficial for patients with physical or medical comorbidities such as pregnancy, low back pain, and mobility limitations that would make using a Dix-Hallpike test difficult or impossible. The patient begins seated with the head turned 45° away from the posterior canal side being tested and is then (if possible) quickly brought into side lying with the tested posterior canal ear down (toward the floor).
A 2025 study reported the side-lying test has a sensitivity of 95.1% and a specificity of 96.97% for detecting posterior canal BPPV, which is comparably similar to the sensitivity and specificity of the Dix-Hallpike test.
History
Dr. Helen S. Cohen, EdD, OTR, FAOTA
The side-lying test was introduced in the early 2000s as a modification of the Dix-Hallpike test. In 2004, Dr. Helen S. Cohen, published a study titled “Side-lying as an alternative to the Dix-Hallpike test of the posterior canal,” which evaluated the efficacy of the side-lying test in diagnosing BPPV. The study found that patients who received both the Dix-Hallpike and side-lying tests (regardless of order of testing) presented with the same nystagmus, which was consistent with posterior canal BPPV, as measured by VNG.
Dr. Cohen’s work as a researcher and Professor in the Department of Otolaryngology–Head and Neck Surgery at Baylor College of Medicine in Houston, Texas established the value of considering alternative testing methods for BPPV to accommodate diverse patient conditions.
Instructions
The purpose of the side-lying test is to identify ipsilateral posterior or contralateral anterior canal BPPV by transitioning the patient into a side-lying position, provoking symptoms and nystagmus due to gravitational movement of otoconia within the vertical semicircular canal(s). The right and the left sides must be tested individually.
Right Ear
- Explain the procedure to the patient and obtain consent.
- Seat the patient on the edge of the exam table.
- Turn the patient’s head 45° towards left and instruct the patient to keep their eyes open throughout test
- Quickly (if possible) assist the patient to lie down on the right side while maintaining the head rotation to left.
- Keep the head turned (nose pointed toward ceiling) and the patient in the sidelying position for 30- 60 sec
- Observe the eyes for nystagmus and ask the patient about any symptoms.
- Return the patient to a seated position slowly, maintaining head support and continuing to guard the patient.
Left Ear
- Explain the procedure to the patient and obtain consent.
- Seat the patient on the edge of the exam table.
- Turn the patient’s head 45° towards right and instruct the patient to keep their eyes open throughout test
- Quickly (if possible) assist the patient to lie down on the left side while maintaining the head rotation to the right.
- Keep the head turned (nose pointed toward ceiling) and the patient in the sidelying position for 30- 60 sec
- Observe the eyes for nystagmus and ask the patient about any symptoms.
- Return the patient to a seated position slowly, maintaining head support and continuing to guard the patient.
Test Interpretation
An abnormal side-lying test is characterized by a brief latency (approximately 1–5 seconds) followed by a burst of torsional and upbeating nystagmus lasting less than one minute, typically accompanied by symptoms. This pattern is consistent with posterior canal BPPV affecting the downward ear being tested. Absence of nystagmus or symptoms may indicate a negative result or suggest involvement of a different canal or vestibular disorder.
This is an example of an abnormal right side-lying test. Although the test is typically performed quickly, patient-specific precautions required the test to be performed slowly.
Related Pathology
- Posterior Canalithiasis
- Posterior Cupulolithiasis
- Anterior Canalithiasis
- Posterior Cupulolithiasis
The side-lying test is best done with infrared video goggles due the risk of otherwise missing about 2/3 of abnormal eye movements when testing in room light or with traditional thickened lens Frenzels. See what you’re missing – access a free virtual demo (on-demand or live with a clinician) today.
Sources
- Bhattacharyya N, Gubbels SP, Schwartz SR, et al. Clinical practice guideline: benign paroxysmal positional vertigo (update). Otolaryngol Head Neck Surg. 2017;156(3_suppl):S1–S47. https://aaohnsfjournals.onlinelibrary.wiley.com/doi/10.1177/0194599816689667
- Cohen HS. Side-lying as an alternative to the Dix-Hallpike test of the posterior canal. Otol Neurotol. 2004 Mar;25(2):130-4. doi: 10.1097/00129492-200403000-00008. PMID: 15021771. https://pubmed.ncbi.nlm.nih.gov/15021771/
- Dhiman NR, Raj D, Gyanpuri V, Kumar A, Singh VK, Pathak A, Chaurasia RN, Mishra VN, Joshi D. Evaluating the Diagnostic Accuracy of the Side-Lying Test for Posterior Canal BPPV: Sensitivity and Specificity Analysis. Otol Neurotol. 2025 Apr 17. https://pubmed.ncbi.nlm.nih.gov/40307982/