Ocular counter-rollingを用いたBPPV患者の耳石器機能評価

抄録

Benign paroxysmal positional vertigo (BPPV) due to peripheral vestibular lesions is the most common type of vertigo encountered in clinical practice. The purpose of this study was to compare the otolith organ function of patients with BPPV with that in healthy volunteers, and evaluate otolith organ dysfunction.

Video-oculography goggles were used to measure ocular counter-rolling (OCR) in 15 patients with BPPV and 21 healthy volunteers. For all subjects, the otolith-ocular function of both ears was tested separately by the measurement of OCR under a 30° head tilt. The R-L side asymmetry ratio for OCR values (%OCRA) was compared with the patients’ OCR values under static conditions. We also performed subjective visual vertical (SVV) testing in both groups of subjects.

The %OCRA differed significantly between patients with BPPV and the healthy volunteers (p < 0.01). However, there was no significant difference in the SVV value between the two groups. In most of patients with BPPV, when the head was tilted toward the healthy ear side, the OCR value tended to become lower.

It has been reported that in patients with utricular organ dysfunction, a head tilt toward the healthy ear side leads to a decrease of the OCR value. In general, BPPV is considered as being caused by detachment of the otolith from the utricular macula. We consider measurement of OCR as a useful testing method to evaluate otolith organ, especially utricular organ function, in patients with BPPV.