[Etiology analysis and vestibular assessment of bilateral vestibular vestibulopathy]

Objective:To define clinical and laboratory characteristics of bilateral vestibulopathy(BVP) and to propose diagnostic criteria of this disorder based on clinical and laboratory vestibular function test findings.Method:Forty-two case series with a clinical suspicion of BVP were retrospectively analyzed, in an attempt to determine etiology. Presenting auditory-vestibular symptoms, bedside dynamic visual acuity tests and laboratory test were reviewed, including bithermal caloric test, rotatory chair tests, video head impulse test (vHIT), vestibular-evoked myogenic potentials (VEMP).Result:Among these 42 patients, dizziness was seen in 42 cases(100%), oscillopsia was seen in 21 cases(50%), hearing loss was seen in 30(71.4%). Eight cases(19%) had tinnitus. Twenty-five cases showed vestibular loss in dynamic visual acuity test (69.4%). Definite diagnosis of complete BVP was made in 36 patients when the patients showed abnormal findings on caloric test, rotatory chair test and vHIT in addition to the symptoms. Whereas probable diagnosis of partial BVP was obtained in 6 patients with abnormal caloric test and rotatory chair test but no pathological vHIT. VEMP (ocular or cervical) could be recorded in 20 patients. Fourteen cases were caused by ototoxic drugs while no causes could be determined in 6 cases among these 42 cases.Conclusion:The diagnosis of BVP is a challenge. Vestibular laboratory test battery which reflect full frequency function of VOR has great value to confirming the diagnosis and differentiate complete BVP to partial BVP. Diagnosis standard shall be made combining clinical history, characteristic symptoms and the results of auditory-vestibular function testing. Ototoxic drugs contribute most considering etiology.