Vestibular neuritis can affect the superior and inferior vestibular nerves together or can selectively affect the superior vestibular nerve.

No abstract

Sudden, spontaneous, unilateral loss of vestibular function without simultaneous hearing loss or brain stem signs is generally attributed to a viral infection involving the vestibular nerve and is called acute vestibular neuritis. The clinical hallmarks of acute vestibular neuritis are vertigo, spontaneous nystagmus, and unilateral loss of lateral semicircular function as shown by impulsive and caloric testing. In some patients with vestibular neuritis the process appears to involve only anterior and lateral semicircular function, and these patients are considered to have selective superior vestibular neuritis. Here we report on two patients with acute vertigo, normal lateral semicircular canal function as shown by both impulsive and caloric testing, but selective loss of posterior semicircular canal function as shown by impulsive testing and of saccular function as shown by vestibular evoked myogenic potential testing. We suggest that these patients had selective inferior vestibular neuritis and that contrary to conventional teaching, in a patient with acute spontaneous vertigo, unilateral loss of lateral semicircular canal function is not essential for a diagnosis of acute vestibular neuritis.

Glucocorticoids administered within 3 days after onset of vestibular neuronitis improves long-time recovery of vestibular function and reduces length of hospital stay.

Patients with suspected cervicogenic dizziness have some musculoskeletal findings in common. Treatment based on these findings reduces neck pain as well as dizziness long-term but some patients might need a maintenance strategy.

Vibration is an excitatory stimulus for both vestibular and proprioceptive afferents. Vibration applied either to the skull or to the neck muscles of subjects after unilateral vestibular deafferentation induces nystagmus and a shift of the subjective visual horizontal. Previous studies have ascribed these effects to vibratory stimulation of neck muscle proprioceptors. Using scleral search coils, we recorded three-dimensional eye movements during unilateral 92 Hz vibration of the mastoid bone or of the sternocleidomastoid (SCM) muscle in 18 subjects with chronic unilateral vestibular deficits after vestibular neurectomy or neuro-labyrinthitis. Nine subjects had lost function of all three semicircular canals (SSCs) on one side, and the other nine had lost function of only the anterior and lateral SSCs. Vibration of the mastoid bone or of the SCM muscle on either side induced an ipsilesional tonic shift of torsional eye position of up to 6.5 degrees during visual fixation, as well as a nystagmus with horizontal, vertical and torsional components in darkness. Subjects who had lost function of all three SSCs on one side showed a larger shift in ocular torsion in response to SCM vibration than did subjects who had lost function of only two SSCs. The difference between ocular torsion produced by ipsilesional muscle or bone vibration was not significantly different from that produced by contralesional bone or muscle vibration. The vibration-induced nystagmus rotation axis tended to align with the pitch (y) axis of the head in subjects who had lost only anterior and lateral SSC function, and with the roll (x) axis of the head in subjects who had lost function of all three SSCs. We propose that the previously described vibration-induced shift of the subjective visual horizontal can be explained by the vibration-induced ocular torsion, and that the magnitude of ocular torsion is related to the extent of the unilateral vestibular deficit. While altered proprioceptive inputs from neck muscles might be important in the mechanism of vibration-induced ocular torsion and nystagmus after unilateral vestibular deafferentation, vibratory stimulation of vestibular receptors in the intact labyrinth also appears to have an important role.

Both devices are reliable and showed good agreement. We conclude that the two techniques can be used interchangeably. Our study supports the continued use of the Myrin-a gravity-reference goniometer in routine clinical orthopedic work. The more sophisticated three-dimensional method adds information and allows evaluation of combined motion in two and three dimensions and is suitable for research.

There was a loss of caloric reactions and loss of impulses. In two patients the hearing deteriorated and in one hearing improved. All subjects were vestibulary compensated before surgery and no patient complained of dizziness or vertigo after surgery.