Persisting nystagmus following vestibular nerve section for Menière's disease

Unilateral vestibular nerve section (VNS) creates a state of acute dysequilibrium which resolves by a process of central compensation. This disturbance resolves quickly and central compensation is complete generally within a month with resolution of symptoms and signs. The course of central compensation following VNS will be similar to that seen after labyrinthectomy because the detachment of hemi-labyrinthine input that is achieved by both will be identical. Six patients are presented who have undergone VNS at least 2.7 years ago (Average 3.5 years); all of them have persisting spontaneous peripheral type horizontal jerk nystagmus, present with optic fixation in five. This is obvious clinically and was confirmed in each case by agreement of three independent observers and has been recorded by electronystagmography (ENG). They are free from marked vestibular symptoms. The explanations of mechanisms involved in central compensation are discussed with respect to this previously unrecorded clinical observation.