OTOLITH FUNCTION-TESTS IN PATIENTS WITH UNILATERAL VESTIBULAR LESIONS

This study was designed to assess the utility of otolith-ocular reflex testing in patients with complete unilateral peripheral vestibular de ficits. Ten subjects were given a clinical vestibular test battery (EN G & vertical rotation) and research oriented tests of otolith function including dynamic posturography with head tilt and earth-horizontal a xis rotation with otolith,visual interactions. Clinical tests confirme d the presence of a vestibular deficit and the side of the lesion. The results suggested the following: posturography during head tilt is no t a reliable means of detecting unilateral peripheral vestibular dysfu nction, while earth-horizontal axis rotation is a reliable means of as sessing asymmetric otolith function. The Bias response during earth-ho rizontal axis rotation was significantly less during rotation ipsilate ral to the lesioned ear compared to contralateral rotation while the M od response was normal. The optokinetic test results in these subjects were normal while otolith-visual interactions were symmetrically redu ced in these patients.