Abstract: ObjectiveTo investigate the characteristic and the function of the eye movements system of the patients with vertebral-basilar insufficiency (VBI).Methods83 patients with VBI and 57 healthy controls were tested with electronystagmogram instrument,include saccade test, Eye Tracking Test (ETT) and optokinetic test(OKN).Results and ConclusionDelay lower accuracy of saccade test, decreased gain of OKN, asymmetry of horizontal ETT were showed in the patients with VBI.

Key words: vertebral-basilar insufficiency(VBI), electronystagmography(ENG), eye movements system