Electronystagmographic outcome in patients after peripheral vestibular loss
Abstract
The aim of this study was to compare the clinical and ENG outcome in different time in patients with peripheral vestibular loss diagnosed as a vestibular neuronitis in order to establish compensation degree.
Material and method. Clinical observations were made on 33 patients with peripheral vestibular loss diagnosed as a vestibular neuronitis in the last 4 years (from 1999 to 2003) in ENT Department Medical University of Lodz. Mean age of patients was 38,9 ± 3,7 years. In all of them clinical neurootolaryngological and audiological examination were performed. Balance system was evaluated by 4-channel ENG system during first two weeks after onset of the symptoms and later between 12-16 month. ENG tests like spontaneous and positional nystagmus, caloric and kinetic tests, smooth pursuit, optokinetic and saccadic tests were carried out. We compared clinical findings and ENG outcome applying modified vestibular index by Toth et al. which defines the extend of a lesion and recovery during follow-up.
Results. At the first examination vertigo was reported in 91% patients although spontaneous nystagmus was recorded in 73% patients. The ENG outcome showed canal paresis in 73% patients, abnormalities in smooth pursuit in 32%, optokinetic in 32%, directional preponderance in kinetic test in 60%. This index includes the degree of vertigo, spontaneous nystagmus, dysfunction of vestibulospinal reflex and caloric and postrotatory response. We classified patients according to vestibular index scores as remission stage – 3 patients, compensation stage – 18 patients, and acute- subacute stage -12 patients. We discuss usefulness of vestibular index in evaluating balance system disorders after peripheral vestibular loss.
