Clinical course of persistent geotropic direction-changing positional nystagmus with neutral position—Light cupula

Abstract

Conclusion: A short clinical course and frequent recurrence are common features of persistent geotropic direction-changing positional nystagmus with neutral position (positional nystagmus of light cupula: PNLC) and cupulolithiasis of the lateral semicircular canal. It is suggested that PNLC is caused by light debris attached to the cupula of the lateral semicircular canal. Objectives: PNLC is a sub-type of direction-changing positional nystagmus. It is thought to be caused by anti-gravitational deviation of the cupula of the lateral semicircular canal (light cupula); however, the exact mechanism is yet to be elucidated. To this end, the clinical features of PNLC were studied.

Method: Clinical charts of 27 patients (13 men and 14 women) with PNLC were reviewed. Results: The nystagmus had resolved within a week in 70% and within 30 days in 89% of the patients. The recurrence rate was 33%. The subjects did not have a history of alcohol intake, head trauma, or vestibular neuritis.

Keywords:

• Ampulla
• anti-gravitational deviation
• lateral semicircular canal
• light cupula

Declaration of interest

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.

This work was partially supported by a Grant-in-Aid from the Japan Agency for Medical Research and Development.