Vestibular Neuritis – Inflammation of the vestibular nerve accompanied by rotational vertigo

Vestibular neuritis can cause persistent or intermittent severe vertigo. It is an inflammation of the vestibular nerve (nervus vestibularis). As a result, the nerve can no longer correctly transmit impulses from the vestibular system in the inner ear to the brain’s balance center.

This results in completely uncontrollable sensations of movement, which typically include severe and persistent rotational vertigo.

Our vestibular system consists of three semicircular canals, each about 6 millimeters in size, which are filled with a special lymphatic fluid.

The three semicircular canals are arranged perpendicular to one another. Each semicircular canal corresponds to one of the three directions of rotation around the vertical, horizontal, and longitudinal axes in three-dimensional space. The three semicircular canals transmit actual rotational accelerations to the vestibular nerve.

A small ampulla at the base of the semicircular canals detects and measures linear accelerations—such as those we feel in a car during acceleration and braking.

The vestibular system is one of the sensory organs @ Henrie /AdobeStock

An episode of rotational vertigo is usually very unpleasant for those affected and can last up to seven days or longer. These episodes are often accompanied by severe nausea, vomiting, and nystagmus.

Rotational vertigo is a specific type of vertigo in which the sensation of rotation is counterclockwise @ dragonstock /AdobeStock

Affected individuals usually experience a more pronounced sense of illness. In addition, there is often a tendency to fall toward the affected side. If the sense of balance in the left inner ear is affected, there is a tendency to fall to the left.

Doctors refer to nystagmus as a specific type of uncontrollable eye movement (eye tremor). During a rapid rotation around the vertical axis, the surroundings become blurry. The eyes reflexively try to follow the rotation and then jerk back (vestibulo-ocular reflex, VOR).

This allows us to better focus on our surroundings during a rapid rotation. Nystagmus usually goes completely unnoticed. Vertigo caused by rotation can also trigger nystagmus, which, however, can be just as pronounced as the severity of the vertigo attack.

In these cases, the motion center in our brain does not realize that the intense sensation of rotation is not real. Therefore, it responds by initiating “true” nystagmus (as it would during actual rotational acceleration).

Medical professionals suspect that the cause is a viral infection or a reactivation of Herpes simplex type 1 viruses. This hypothesis is supported by the detection of genetic material (DNA) from this virus type in degenerative inflammation of the vestibular nerve. Statistically, there is a noticeable clustering of the condition among people between the ages of 50 and 60.

Of all patients who seek medical treatment for rotational vertigo, only 7 percent suffer from vestibular neuritis. In the remaining patients, their episodes of rotational vertigo have other causes. There are no known risk factors that predispose individuals to vestibular neuritis.

The typical, usually prolonged episodes of rotational vertigo are not sufficient for a definitive diagnosis of the condition. There are too many other causes of vertigo attacks, so further diagnostic procedures are necessary.

Even modern imaging techniques such as CT and MRI do not provide a definitive diagnosis.

Simple tests (head impulse test) and a rotational and thermal examination of the vestibular system, along with a few exclusion criteria, however, allow for a definitive diagnosis.

The head impulse test can be performed very easily without any special equipment. The doctor instructs the patient to fix their gaze on a distant point.

The doctor takes the patient’s head in both hands and turns it abruptly to the right and then to the left. Based on the reflexive eye movements, the doctor can reliably determine whether—and which of the two balance organs—is not functioning properly.

It is important to note that vestibular neuritis never occurs in conjunction with tinnitus. Furthermore, an audiogram—if performed—will show no abnormalities. A disorder of the vestibular system does not impair hearing. The condition also does not trigger tinnitus.

The head impulse test checks whether the patient can fixate on a point with their eyes while tilting their head @ Halfpoint /AdobeStock

Accompanying symptoms of vestibular neuritis, such as frequent vomiting, initially require treatment of the symptoms and their associated manifestations. This means that, in most cases, the treating physician will first administer medications to prevent further vomiting (antiemetics). 

If vomiting leads to severe fluid and electrolyte loss, an intravenous infusion is administered.

Anticholinergics, antihistamines, and benzodiazepines are available to alleviate vertigo. These medications inhibit the transmission of nerve impulses; however, their effect is not limited to the affected vestibular nerve. 

A short-term course of corticosteroids may also be considered. This involves a brief treatment with cortisone or cortisone-like drugs (corticosteroids). Patients should take these for a period of about three days. Cortisone has an anti-inflammatory effect.

Patients should combine all forms of therapy with movement and balance exercises (physical therapy). The recommended physical therapy also includes eye exercises such as gaze stabilization and training of the vestibulo-ocular reflex.

With medication as described above, the acute phase subsides after 3 to 4 days. Patients can then walk again without assistance. 

It can take up to 7 weeks for symptoms to disappear completely and for fitness to be restored. In general, the prognosis is considered good. 

If the vestibular system or the vestibular nerve does not fully regenerate, the brain has compensatory mechanisms. Therefore, there are usually no residual impairments of the sense of balance.

Vestibular neuritis is an inflammatory disease of the vestibular nerve or the vestibular system in the inner ear. Certain herpes viruses are highly likely to trigger the disease. 

The main symptom is severe rotational vertigo, which can last up to seven weeks.

Accompanying symptoms usually include:

• Nausea with vomiting
• A tendency to fall, as well as
• Reflexive eye movements (nystagmus)

Hearing is not affected by the condition.

Treatment typically involves medication in combination with physical therapy. The prognosis is generally favorable.

What is vestibular neuritis?
Vestibular neuritis is a vestibular dysfunction or inflammation of the vestibular nerve. It causes acute, severe vertigo, often accompanied by nausea and vomiting. The condition is also known as vestibular neuropathy or vestibular neuronitis.

What are the symptoms of vestibular neuritis?
Typical symptoms include persistent rotational vertigo, spontaneous nystagmus, unsteadiness while walking, and a tendency to fall toward the affected side. Many patients also complain of nausea and vomiting. Hearing loss or tinnitus tends to rule out a diagnosis of vestibular neuritis alone.

How is the condition diagnosed?
Diagnosis is made clinically through neurological and vestibular examinations of eye movements and the vestibular system. Nystagmus toward the healthy side and hyporesponsiveness of the inner ear are typical findings. It is important to rule out a central cause such as a stroke.

What treatment is effective for vestibular neuritis?
During the acute phase, bed rest, anti-vertigo medications such as dimenhydrinate, and medications for dizziness are helpful. Corticosteroids such as 250 mg of prednisolone or methylprednisolone are often used as well. Physical therapy and rehabilitation promote vestibular compensation.

What is the difference between positional vertigo and Meniere’s disease?
In benign paroxysmal positional vertigo, symptoms occur only briefly during certain movements. Meniere’s disease also causes hearing problems and tinnitus. Vestibular neuritis, on the other hand, usually leads to acute, prolonged unsteadiness due to a failure of the vestibular system.