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Lying Down Nystagmus in Lateral Canal Paroxysmal Positional Vertigo
Mauro Gufoni1, Nicola Ducci1, Davide Bernacca1
1Department of Otorhinolaryngology, Pisa University Hospital, 56122 Pisa, Italy.
Audiology Research
|January 21, 2026
Summary
This study on horizontal canal benign paroxysmal positional vertigo (HC-BPPV) found that analyzing nystagmus direction during lying down and the supine roll test helps pinpoint otoconial debris location. This aids in selecting the correct treatment maneuver for canal jams.
Area of Science:
- Otolaryngology
- Neurology
- Vestibular System Disorders
Background:
- Benign paroxysmal positional vertigo (BPPV) is a common cause of dizziness.
- Horizontal canal BPPV (HC-BPPV) involves otoconial debris in the lateral semicircular canal.
- Accurate localization of debris is crucial for effective treatment.
Purpose of the Study:
- To determine the precise location of otoconial debris in lateral canalithiasis.
- To differentiate between ampullar and non-ampullar canalolithiasis.
- To correlate nystagmus findings with debris position for guiding treatment.
Main Methods:
- Analysis of nystagmus direction upon lying down.
- Positional nystagmus evoked by the supine roll test.
- Comparison of theoretical results with 170 HC-BPPV patients (141 geotropic, 29 apogeotropic).
Main Results:
- Significant differences in supine nystagmus were observed between geotropic and apogeotropic forms.
- 52.9% of patients showed no nystagmus in the supine position.
- Specific nystagmus patterns correlated with debris location (e.g., GT+, AGT+).
Conclusions:
- The Supine Roll Test is a key diagnostic maneuver for HC-BPPV.
- Combining lying-down and supine roll test findings accurately identifies debris location.
- This localization guides the selection of appropriate liberatory maneuvers and distinguishes canal-side from utricular-side jams.
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