Atypical PC-BPPV - Cupulolithiasis and Short-Arm Canalithiasis: A Retrospective Observational Study.
Janet O Helminski
PMID 39656163WHAT IT FOUND
Two atypical posterior canal BPPV variants were identified in 15 patients.
Cupulolithiasis showed persistent downbeat nystagmus in Dix-Hallpike and straight head hang. Short-arm canalithiasis showed upbeat nystagmus only upon sitting up. Mechanism-specific repositioning resolved symptoms in most cases.
Key findings
01Cupulolithiasis (pc-BPPV-cu) presented with persistent downbeat or downbeat/torsional nystagmus in the provoking positions (Dix-Hallpike and straight head hang) and no nystagmus upon return to sitting.
02Short-arm canalithiasis (pc-BPPV-ca) presented with no or variable nystagmus in the provoking positions but transient upbeat or upbeat/torsional nystagmus toward the involved side upon return to sitting.
03Canal- and mechanism-specific repositioning procedures led to complete resolution in 69% of cupulolithiasis cases and 50% of short-arm canalithiasis cases, with the remainder showing partial improvement.
STILL TO COME
How it was doneWhat they foundWhat it means for PTsWhat it means for OTs
Read the rest of this summary
You get three full summaries a month, free, and we do not ask for a card. Search, the TL;DRs and your library stay unlimited either way.
What it does not show
Small sample size (15 persons) limits generalizability. Retrospective design with no control group or comparison of intervention types. Diagnostic tests like video head impulse test and neuroimaging were not consistently performed, so central causes were ruled out clinically rather than objectively in all cases. The mechanisms of atypical BPPV remain hypothetical, and differential diagnosis is difficult due to subtle differences in nystagmus patterns.
Declared interests
The authors declared no conflicts of interest. The study was conducted at Midwestern University’s Multispecialty Clinic.
The easy way to misread this
Do not assume standard Epley maneuvers will resolve these atypical variants. The study shows that correct identification of the specific debris location (cupula vs. short arm) via specialized positional testing is required to select the appropriate repositioning procedure, as typical BPPV treatments may not work or could cause canal switches.