Direction-fixed paroxysmal nystagmus lateral canal benign paroxysmal positioning vertigo (BPPV): another form of lateral canalolithiasis

L Califano, A Vassallo, M G Melillo, S Mazzone, F Salafia
Acta Otorhinolaryngologica Italica 2013, 33 (4): 254-60
Benign paroxysmal positioning vertigo (BPPV) is the most frequent vertiginous syndrome. It is caused either by free-floating otoliths in the semicircular canals (canalolithiasis) or by otoconial debris adhering to a canal cupula (cupulolithiasis). The posterior canal is the most frequently involved (80%), while the lateral canal is involved less frequently (15%), and the rarest conditions are anterior canalolithiasis and apogeotropic posterior canalolithiasis (5%). The main diagnostic sign of lateral canal BPPV is paroxysmal horizontal bidirectional positioning nystagmus evoked through Pagnini-McClure's test (head roll in the yaw plane in supine position). In the geotropic variant, which is more frequent, the fast phase of the nystagmus is directed towards the lowermost ear, when the patient lies on the affected side or on the healthy side; in the apogeotropic variant, which is less frequent, the fast phase is directed always toward the uppermost ear, regardless of which side the patient lies on. Paroxysmal nystagmus is more intense on the affected side in the geotropic form, and more intense on the healthy side in the apogeotropic form. The authors describe five cases of another primitive and rare form of lateral BPPV, defined as "direction-fixed paroxysmal nystagmus lateral canal BPPV", which has previously been described by other authors as a transitory step observed during the transformation from an apogeotropic into a geotropic form. It is characterized by typical BPPV symptoms and diagnosed by the presence of a paroxysmal horizontal unidirectional positioning nystagmus, evoked through Pagnini-McClure's test, which is apogeotropic on the affected side and geotropic on the healthy side. In the reported cases, direction-fixed horizontal paroxysmal nystagmus was always transformed into a typical geotropic form. The clinical features and pathophysiology of direction-fixed nystagmus lateral canal BPPV are discussed.

Full Text Links

Find Full Text Links for this Article


You are not logged in. Sign Up or Log In to join the discussion.

Related Papers

Remove bar
Read by QxMD icon Read

Save your favorite articles in one place with a free QxMD account.


Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"