Follow-up Changes of Eye Movements by Caloric Stimulation in Patients With Vestibular Neuritis

ABSTRACT

BACKGROUND AND OBJECTIVES: A significant recovery of resting activity in the vestibular nuclei ipsilateral to the unilateral labyrinthectomy has been reported by the time symptoms such as spontaneous nystagmus and roll head tilt have largely disappeared. However, the dynamic vestibular response after unilateral vestibular loss to passively imposed vestibular stimuli does not recover. MATERIALS AND METHODS: We investigated changes of the caloric responses in 32 patients with vestibular neuritis during in- and out-patient visits separated by 2 months in an attempt to identify changes brought about by peripheral and/or central compensation processes. RESULTS: The slow-phase eye velocities stimulated by warm caloric stimulation at acute and follow-up stage were 6.6+/-6.6 degrees/s, 9.5+/-9.9 degrees/s in the lesioned side; 28.4+/-19.1 degrees/s, 24.5+/-11.6 degrees/s in the intact side. The slow-phase eye velocities stimulated by cold caloric stimulation at acute and follow-up stage were 5.9+/-7.7 degrees/s, 10.3+/-8.2 degrees/s in the lesioned side; 19.8+/-10.3 degrees/s, 18.8+/-9.9 degrees/s in the intact side. CONCLUSION: Our findings show that the recovery of caloric responses comes mostly from the recovery of the eye responses to the caloric stimulation in the lesioned side and the eye responses to the caloric stimulation in the intact side does not change over time after vestibular neuritis.