Subjective visual vertical in vestibular disorders measured with the bucket test

Abstract

Conclusion: The ‘bucket test' may indicate that patients with known vestibular disorders have spatial orientation deficits but due to the low receiver operating characteristics (ROC) values it is not useful for screening people for vestibular impairments. Objectives: 1) to verify that patients with unilateral peripheral vestibular weakness (UW) differ from normal subjects on the bucket test, 2) to determine if patients with unilateral benign paroxysmal positional vertigo (BPPV) differ from normal subjects, 3) to determine the sensitivity and specificity of the test. Methods: Patients with UW (n = 25) and BPPV (n = 25) were compared to normals (n = 50). Subjects looked into a clean bucket with a vertical line on the bottom, which rested on a table. It was rotated, clockwise or counterclockwise, for three trials per direction until the subject indicated that the line was vertical. The dependent measure was the mean absolute value of the deviations from the true vertical. Results: Some, but not all, patients' responses differed from normal subjects but responses also differed by age and sex. ROC values were all weak, i.e. < 0.8. No good cut-off points differentiated controls from patients. Thus, although the bucket test is useful for describing spatial deficits in patients this test is not useful for screening people for possible vestibular impairments.

Keywords::

• Spatial orientation
• benign paroxysmal positional vertigo
• unilateral weakness
• visual perception

Acknowledgments

Supported by NIH grants R01DC003602 and R01DC009031. The authors thank the staff of the Center for Balance Disorders for 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.