Abstract: We performed a retrospective study on 30 patients diagnosed with persistent postural-perceptual dizziness (PPPD). Upon data analysis, we determined that 1) unilateral centrifugation (UC-dynamic SVV) may be more sensitive at detecting isolated otolith dysfunction in PPPD patients and 2) there may a much higher probability of otolith dysfunction in patients (at least 50%) with PPPD than previously reported. Upon completion, learners will be able to analyze the effectiveness of UC in assessing otolith organ function in patients with PPPD and describe this specific type of PPPD patient.
Summary: This work was marked as "Advanced" because it requires a detailed understanding of inner-ear structures and clinical vestibular testing methods.
Objective Previous studies had demonstrated isolated otolith dysfunction as a precipitating factor in patients with persistent postural-perceptual dizziness (PPPD). Otolith dysfunction is often measured through ocular and cervical vestibular evoked myogenic potential (oVEMP/cVEMP), and subjective visual vertical (SVV) tests. Here we investigate the effectiveness of unilateral centrifugation (UC) testing in conjunction with SVV and oVEMP/cVEMP in assessing otolith organ function in patients with PPPD.
Methods The study includes 30 patients diagnosed with PPPD and who consented to advanced battery vestibular testing including unilateral centrifugation (UC-dynamic SVV), static SVV, oVEMP/cVEMP, vHIT, caloric testing, rotary chair (RC), and computerized dynamic posturography (CDP). Caloric testing, RC, vHIT, and CDP were used to differentiate other peripheral vestibular disorders from otolith dysfunction.
Results Among the 30 PPPD patients, 15 (50%) showed otolith dysfunction. Of those 15 patients, 6 (20%) exhibited abnormal UC results only, 4 (13.3%) exhibited abnormal VEMP results only, 3 (10%) exhibited abnormal UC and VEMP results, 1 (3.33%) exhibited abnormal UC and vHIT results, and 1 (3.33%) exhibited abnormal VEMP and vHIT results. 10/16 (62.5%) patients who had UC testing on both sides showed either unilateral or bilateral otolith dysfunction. 14/30 (46.7%) patients were unable to perform the UC due to dizziness and/or fear of dizziness. Of those 14 patients, 4 showed abnormal oVEMP/cVEMP results. The remaining 10/14 patients who had normal SVV, vHIT and oVEMP/cVEMP results may have a higher probability to exhibit abnormal than normal findings had they been tested.
Conclusion
UC-dynamic SVV may be more sensitive in detecting isolated otolith dysfunction in PPPD patients.
The study suggests a much higher probability of otolith dysfunction in patients (at least 50%) with PPPD than previously reported
Learning Objectives:
Upon completion, participants will be able to explain the clinical utility and sensitivity of UC testing in diagnosing otolith dysfunction in PPPD patients.
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