2.Vestibular Neuritis
2.Vestibular Neuritis
VESTIBULAR NEURITIS SYMPTOMS
Vestibular neuritis is a common cause of peripheral vertigo. It is a good example of the sudden unilateral suppression of vestibular information involved in the maintenance of balance and the steadying of the gaze.
Vestibular neuritis results in the sudden onset of rotational vertigo with nausea and vomiting. It is essential to note that when the patient is questioned, no auditory problems are detected (deafness, tinnitus
The videonystagmoscopy examination identifies a spontaneous peripheral nystagmus, which is horizontal and rotational, unidirectional, and less substantial and less frequent during ocular fixation. The rapid phase of this nystagmus is directed toward the healthy ear. The other aspects of the examination, in particular the neurological examination, are normal. As time goes on there is a regression in vestibular symptoms. In a few days, the rotational sensation and neurovegetative manifestations will improve. The sensation of imbalance will remain for some time.
CAUSES
The cause of the condition appears to be viral.
There are three arguments for this:
- The epidemiological context with the notion of occurrence in seasonal or family epidemics, an infection of the upper airways in the weeks before the incident, the existence of a concomitant cranial polyneuropathy.
- Serological tests that show a protein concentration suggestive of demyelination or antiviral antibodies. The virus responsible cannot be identified. However, the herpes simplex virus seems the most likely candidate.
- Histopathological studies of the pyramids that have found characteristic viral lesions. Following inaugural infection, the virus spreads in the body and remains dormant in the ganglia of certain cranial nerves including the vestibular ganglia. When the patient has an intercurrent condition, the virus is woken and induces an autoimmune reaction responsible for inflammation, oedema and demyelination.
In some cases, the cause may be vascular, particularly in hypertensive patients or those prone to vascular problems.