Introduction

Benign paroxysmal positional vertigo (BPPV) is the most common cause of positional vertigo. It arises from displaced otoconia that migrate into one of the semicircular canals. The posterior canal is involved in the vast majority of cases, while the lateral canal is less common. The anterior (superior) canal is the rarest subtype, accounting for only 1–3% of all BPPV cases. This article presents a typical case of anterior canal BPPV, highlighting its distinctive clinical features and management.

Case Presentation

A 46-year-old woman presented with a two-week history of brief episodes of vertigo triggered by rolling over in bed, especially when turning onto her right side. She also noted a sense of imbalance when bending forward to tie her shoes or when reaching for an object on a high shelf. There was no hearing loss, tinnitus, or headache. She had no significant past medical history and took no regular medications.

Physical examination was unremarkable except for positional testing. The Dix-Hallpike maneuver was performed with the patient seated, head turned 45° to the right, and then quickly brought into the supine position with the head hanging slightly below the horizontal. After a short latency of about three seconds, the patient reported vertigo and reproduction of her symptoms. Observation of the eyes revealed a prominent downbeating nystagmus with a subtle torsional component. The nystagmus was transient, lasting approximately 15 seconds, and fatigued with repeated testing. No nystagmus was provoked on the left Dix-Hallpike position or during the supine roll test.

Diagnosis

The findings were consistent with right anterior canal BPPV. The downbeating nystagmus is characteristic because the anterior canal ampulla is located anteriorly and superiorly; when debris moves within this canal, the resulting eye movement is predominantly downward. The absence of nystagmus on the left side further supported the diagnosis, as anterior canal involvement often produces a stronger response when the affected ear is positioned inferiorly during the Dix-Hallpike maneuver.

The differential diagnosis for positional downbeating nystagmus includes central positional vertigo, such as a cerebellar lesion or Chiari malformation. The short latency, limited duration, fatigability, and the reproduction of the patient's typical vertigo helped distinguish peripheral anterior canal BPPV from central causes. In many clinical settings, however, neuroimaging may be warranted if the nystagmus is persistent, not fatigable, or accompanied by other neurologic signs.

Treatment

The patient was treated with the Yacovino maneuver, a canalith repositioning procedure specifically designed for anterior canal BPPV. The maneuver involves a sequence of head and body movements that guide the displaced otoconia out of the anterior canal and back into the utricle. The patient was instructed to remain upright for 48 hours after the procedure to prevent immediate recurrence.

She was also given a home exercise program for residual imbalance, consisting of gait stabilization exercises. At the two-week follow-up, the positional vertigo had resolved, and repeat Dix-Hallpike testing revealed no nystagmus. The patient reported a complete return to normal daily activities.

Discussion

Anterior canal BPPV remains a diagnostic challenge due to its low incidence and overlapping features with central positional nystagmus. Clinicians should be aware of the characteristic downbeating nystagmus and the typical triggers, such as looking up or bending forward. The Yacovino maneuver is an effective treatment and can be performed with good patient outcomes. As with any BPPV, accurate identification of the involved canal is essential for successful treatment. Although rare, anterior canal BPPV should be considered in the differential diagnosis of positional vertigo, especially when downbeating nystagmus is observed.