The study is still in the planning stage, undergoing protocol reconsideration.

Benign Paroxysmal Positional Vertigo (BPPV) is a benign inner ear disease that causes the patient to experience short episodes of vertigo when there are changes in head position. The current theory on the causes of BPPV is the displacement of the otoconia from the otolith organ to the semicircular canal organs. BPPV's current treatments consist of repositioning maneuvers to readjust the location of the otoconia back to its original place. Even though the treatments are highly successful in many cases, this study, if proven successful, will help confirm this theory and will help diagnose complicated cases where BPPV is recurrent and treatment has been unsuccessful.

Benign Paroxysmal Positional Vertigo (BPPV) is a benign inner ear disease that causes the patient to experience vertigo when there are changes in head position. The prevalence is estimated to account for 20-30% of all vertigo diagnoses in a specialized clinic (von Brevern et al., 2007). The current theory on the cause of BPPV is the displacement of otoconia from the otolith organ to the semicircular canal organs due to gravitational forces.

Current treatments for BPPV consist of repositioning maneuvers to readjust the location of the otoconia back to its original place (von Brevern et al., 2015). Even though the treatment is highly successful in many cases patients still have recurrent (26%) or persistent (4%) symptoms (Dorigueto et al., 2009), and objective confirmation of the disease is warranted. Until now, visualization and confirmation of the presence of otoliths have not been successful in clinical practice. This is largely due to the very small size of the otoliths in a small inner ear structure, requiring sensitive and ultra-high-resolution imaging.

In 2021, a study was performed in Japan using 3 Dimensional Computed Tomography (3D CT) scans to detect the otoconia inside the horizontal canal. It compared scans of people with BPPV in the horizontal canal and healthy individuals (Yamane et al., 2021). The authors were able to visualize otoconia-like substance inside the canal in all 10 out of 10 affected patients and 6 out of 10 of the healthy participants in at least one ear (Yamane et al., 2021). In this study, the investigators will image the patients temporal bone with an ultra-high-resolution CT-scan (Benson et al.2022). They will focus on imaging the posterior canal for BPPV, and compare it with the imaging of individuals who do not have BPPV. In addition, they will compare the imaging of the canal pre and post-treatment using the Epley maneuver.

Inclusion Criteria:

Experimental Group:

• Diagnosed with Posterior canal BPPV.
• Age 18 or older.
• Clear nystagmus consistent with canal direction and stimulation.
• Mild or greater complaints (none, mild, moderate, severe).
• Crescendo decrescendo nystagmus pattern.
• Slow phase eye velocity ≥ 15 deg/sec.

Control Group:

• Scheduled for CI implantation CT scan.
• Age 18 or older.

Exclusion Criteria:

Experimental Group:

• Anterior or lateral canal BPPV.
• Inability to undergo CRM and DH maneuvers.
• Central vestibular disorders.
• Multi-canal BPPV or subjective BPPV.
• Pregnancy.

Control Group:

• BPPV, central vestibular disorders, multicanal BPPV, subjective BPPV.
• Ossifying labyrinthitis, DFNA9, obstructive vestibular schwannoma on MRI.
• Normal VHIT or history of meningitis.
• Pregnancy or other vestibular pathologies.
• Past history of BPPV.

The radiologist assessing the CT imaging will be blinded to which participants have positive posterior canal BPPV.