Lying down nystagmus in horizontal semicircular canal benign paroxysmal positional vertigo (HSC-BPPV)

Abstract

Objective

Determining the lateralizing value of lying-down nystagmus (LDN) in horizontal semicircular canal benign paroxysmal positional vertigo (HSC-BPPV).

Methods

The authors prospectively investigated LDN in 35 consecutive patients of HSC-BPPV (28 geotropic and 7 apogeotropic variants) attending an Otoneurology Centre in South Rajasthan India over a period of 20 months.

Results

LDN was present in 45.7% (16/35) patients of HSC-BPPV; 50% in those with geo-HSC-BPPV (14/28), and 28.6% (2/7) with apo-HSC-BPPV. When present, LDN directs contralaterally in 93% of geo-HSC-BPPV (13/14) and ipsilaterally in 100% of apo-HSC-BPPV (2/2). Only in 1 out of the 35 patients (2.9%), LDN was solitarily decisive in lateralizing the affected canal as the supine roll test elicited nystagmus of symmetric strength on the lateral head roll to either side.

Conclusion

LDN is an important secondary sign of lateralization (SSL) in patients with HSC-BPPV (both geotropic and apogeotropic variants). LDN direction is mainly corroborative, but rarely when the lateral head rolls to either side elicits horizontal positional nystagmus of symmetric strength to either side, it can be solitarily relied on for lateralization.

Keywords:

• Supine roll test
• lying down nystagmus
• geotropic
• apogeotropic
• HSC-BPPV

Correction Statement

This article has been corrected with minor changes. These changes do not impact the academic content of the article.

Acknowledgments

Thank you Renith Kurian, videographer, for volunteering his time to make video recordings of the diagnostic and therapeutic maneuvers and precisely capturing the nystagmus during the entire diagnostic and treatment period.

Disclosure statement

The authors whose names are listed above certify that they have no affiliations with or involvement in any organization or entity with any financial interest (such as honoraria; educational grants; participation in speakers’ bureaus; membership, employment, consultancies, stock ownership, or other equity interest; and expert testimony or patent-licensing arrangements), or non-financial interest (such as personal or professional relationships, affiliations, knowledge or beliefs) in the subject matter or materials discussed in this manuscript.

Supplemental material

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