cupulolithiasis

Cupulolithiasis is a variant of benign paroxysmal positional vertigo (BPPV) in which otoconia adhere to the cupula of a semicircular canal, most often the posterior canal and less commonly the horizontal canal. The attached debris makes the cupula heavier and susceptible to gravity, producing vertigo and nystagmus when the head is in certain positions.

Clinical features typically include vertigo and a direction-fixed nystagmus that begins with a position change and can persist as long as the head remains in the provoking position, sometimes for minutes. In posterior canal cupulolithiasis, the nystagmus is usually upbeating with a torsional component toward the affected ear; horizontal canal involvement can produce geotropic or apogeotropic nystagmus depending on the variant. Symptoms may be more pronounced and longer-lasting than in canalithiasis.

Diagnosis relies on history and positional testing. Dix-Hallpike testing for the posterior canal and the supine roll test for the horizontal canal often reveal a persistent, non-fatigable nystagmus in the provocative position, distinguishing cupulolithiasis from canalithiasis. Imaging and other laboratory tests are not diagnostic.

Treatment aims to detach the otoconia from the cupula and reposition them within the canal. Maneuvers designed to liberate debris from the cupula and reposition it are used, including liberatory or Semont-type maneuvers for posterior canal involvement and the Gufoni or barbecue roll maneuvers for horizontal canal cupulolithiasis. Repositioning procedures are commonly repeated over multiple sessions, and vestibular rehabilitation may be considered if symptoms persist. The prognosis with appropriate maneuvers is generally favorable, though recurrence can occur.