Vestibular Neuritis: Clinical-Pathologic Correlation

Cross-Sectional Vestibular Nerve Analysis in Vestibular Neuritis

Objectives:

We examined the association between the size and cross-sectional area of the superior vestibular nerve as measured on constructive interference in steady-state (CISS) parasagittal magnetic resonance imaging (MRI) and the vestibular nerve function as measured by electronystagmography.

Methods:

The retrospective observational cohort study took place at an academic tertiary referral center. Twenty-six patients who met established clinical and electronystagmographic criteria for vestibular neuritis and who underwent parasagittal CISS MRI were identified. Two blinded investigators measured vestibular nerve height and width bilaterally at the level of the fundus of the internal auditory canal and calculated the cross-sectional nerve areas. The inter-rater reliability and agreement were analyzed. Symptom duration, age, and gender were also examined.

Results:

A statistically significant decrease was observed in both vestibular nerve cross-sectional area and height as compared to the contralateral vestibular nerve. A non–statistically significant trend was observed for a relative decreased cross-sectional nerve area with increased age, as well as a decrease in nerve area with an increase in symptom duration.

Conclusions:

Decreases in both vestibular nerve cross-sectional area and height are observed in patients with unilateral vestibular neuritis as measured on parasagittal CISS MRI.

Oval Window Transport of Gd-DOTA from Rat Middle Ear to Vestibulum and Scala Vestibuli Visualized by in vivo Magnetic Resonance Imaging

Objectives:

We tested our hypothesis that the oval window (OW) potentially functions as a route to carry substances from the middle ear to the vestibulum and then the scala vestibuli through the annular ligament across the stapediovestibular joint.

Methods:

Gd-DOTA was either injected into the lateral attic compartment of rats with a high-performance polyimide tube in a selective OW delivery group, or administered to the middle ear cavity of two groups of rats in which the OW was either sealed or not sealed. The dynamic uptake of Gd-DOTA in the inner ear was visualized with a 4.7-T magnetic resonance imaging machine.

Results:

In the selective OW delivery group, Gd-DOTA appeared in the vestibulum and in the basal turn of the scala vestibuli but not in the scala tympani on T1-weighted images acquired at 10 minutes after Gd-DOTA administration (the earliest available time point of magnetic resonance imaging). In the sealed-OW group, immediate uptake of Gd-DOTA was absent in the vestibulum and scala vestibuli. Measurement of the signal ratio of the vestibulum to that of the scala tympani showed that selective OW delivery induced the greatest signal ratio and that sealing of the OW induced the lowest signal ratio.

Conclusions:

The OW is a genuine and efficient pathway to transport Gd-DOTA from the middle ear to the vestibulum.

Acute vestibulopathy

The presentation of acute vertigo may represent both a common benign disorder or a life threatening but rare one. Familiarity with the common peripheral vestibular disorders will allow the clinician to rapidly "rule-in" a benign disorder and recognize when further testing is required. Key features of vertigo required to make an accurate diagnosis are duration, chronicity, associated symptoms, and triggers. Bedside tests that are critical to the diagnosis of acute vertigo include the Dix-Hallpike maneuver and canalith repositioning manuever, occlusive ophthalmoscopy, and the head impulse test. The goal of this review is to provide the clinician with the clinical and pathophysiologic background of the most common disorders that present with vertigo to develop a logical differential diagnosis and management plan.

The three faces of vestibular ganglionitis

We present temporal bone and clinical evidence that common syndromes of recurrent vertigo are caused by a viral infection of the vestibular ganglion. In the present series, histopathologic and radiologic changes in the vestibular ganglion and meatal ganglion were consistent with a viral inflammation of ganglion cells in cases of Meniere's disease, benign paroxysmal positional vertigo, and vestibular neuronitis. Clinical observations of multiple neuropathies involving cranial nerves V, VII, and VIII on the same side in patients with recurrent vertigo are best explained by a cranial polyganglionitis caused by a neurotrophic virus, which is reactivated by a stressful event later in life. The reactivation of the latent virus may manifest as one of the above vertigo syndromes, depending on the part of the vestibular ganglion that is inflamed, the type and strain of the virus, and host resistance.

Isolated vestibular areflexia after blunt head trauma

The sudden unilateral loss of vestibular function is a frequent cause of vertigo. This condition is called vestibular neuronitis or vestibular neuritis. Its cause remains unknown, but many authors consider it to be a sequel of vestibular viral infection. We report the history and clinical findings of 5 patients in whom a unilateral vestibular loss occurred after head trauma. None of these patients complained of hearing loss. In all cases, the vertigo gradually subsided over days or weeks. The follow-up showed the partial recovery of vestibular function in 2 cases, while vestibular areflexia persisted in 3. The clinical course and findings were similar in every respect to those in patients with classic idiopathic vestibular neuronitis.

Molecules, Motion, and Man

The application of cell and molecular biology techniques to vestibular research is resulting in rapid changes in our understanding of the fundamental mechanisms of vestibular function. The clinical problems encountered in space travel together with the acute and chronic vestibular dysfunction affecting many of the patients otolaryngologists care for have driven this research at a rapid pace. A review of these methods and highlights of the major advances are discussed. (Otolaryngol Head Neck Surg 1998;118:S16-S24.)