Nystagmus parameters and subtypes of benign paroxysmal positional vertigo

Abstract

Conclusion: Although computational models suggest the existence of canalithiasis and cupulolithiasis subtypes of benign paroxysmal positional vertigo (BPPV), these subtypes cannot be distinguished from each other based on characteristics of nystagmus. Therefore, although the subtypes probably exist more information is needed from each patient than is available without invasive procedures. Also, some patients may have clinical syndromes that include both canalithiasis and cupulolithiasis subtypes. Objective: To determine if the parameters of nystagmus provide sufficient information to determine the subtype of nystagmus in a patient with BPPV. Methods: Patients (n = 118) had unilateral BPPV of the posterior canal; 15 patients also had BPPV of the lateral canal. The main outcome measures were parameters of nystagmus in response to the Dix-Hallpike maneuver: latency to onset of nystagmus, maximum slow phase velocity, and maximum duration. Results: Correlations between pairs of variables showed minimal or no relationships. Also, cluster analyses showed no significant subtypes. The contralateral eye moved significantly faster than the ipsilateral eye.

Keywords::

• Dizziness
• vestibular
• canalithiasis
• cupulolithiasis

Acknowledgments

Supported by NIH grant DC003602. We thank the staff of the Center for Balance Disorders for invaluable technical assistance.

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