VESTIBULAR NEURITIS

ACUTE UNILATERAL VESTIBULOPATHY (Sudden One-Sided Loss of Balance Nerve Function)

 

In Brief

Vestibular neuritis is an inflammatory reaction of the vestibular nerve (the balance nerve), associated with a viral infection. It presents with sudden, severe spinning sensation (rotatory vertigo) lasting for days, nausea and vomiting, and difficulty standing (postural instability); hearing is preserved. It is the most common peripheral (inner-ear) cause of acute vestibular syndrome (sudden-onset, continuous dizziness). The prognosis (expected course) is generally good: thanks to the brain’s ability to make up for the loss (central compensation), most patients return to normal daily life within a few weeks to a few months.

 

EMERGENCY: If sudden vertigo comes with slurred speech (dysarthria), double vision (diplopia), numbness or weakness in the face, arm or leg, inability to sit or stand without support, or a new severe headache, call 112. This picture can mimic a stroke of the brainstem or cerebellum (cerebrovascular event); telling them apart is vital, especially in people with vascular risk factors such as high blood pressure, diabetes or heart rhythm disorders. If vertigo is accompanied by sudden hearing loss, see an ENT specialist the same day.

 

How Does It Develop? (Pathophysiology)

The balance organs of both inner ears (vestibular labyrinth) send the brain a symmetrical, continuous stream of information about head movement. When the balance nerve on one side loses function, this symmetry is broken, and the brain interprets the imbalance as a strong spinning sensation with involuntary rhythmic eye movements (nystagmus). The most widely accepted explanation is reactivation of herpes simplex virus type 1 lying dormant in the nerve ganglion (vestibular ganglion). Some patients have had an upper respiratory infection beforehand. The upper branch of the nerve (superior vestibular nerve) is affected far more often than the lower branch (inferior vestibular nerve); this matters when interpreting tests and anticipating possible complications.

 

Symptoms (Clinical Findings)

• Sudden, continuous spinning sensation (rotatory vertigo), often noticed on waking

• The worst period is the first 24–72 hours, after which it gradually eases

• Marked nausea and vomiting (autonomic nervous system response)

• Veering towards the affected side and imbalance that worsens with head movement (postural instability)

• Involuntary eye movements beating towards the healthy side, whose intensity changes with gaze direction (spontaneous nystagmus)

• Hearing loss and ringing (tinnitus) are not expected. If they are present, the condition is called labyrinthitis (inflammation of both the hearing and balance parts of the inner ear)

 

How Common Is It? (Epidemiology)

The annual incidence is about 3.5 per 100,000. It is most common between the ages of 30 and 60, with no clear difference between women and men. Recurrence in the same or the other ear is rare (2–11%).

 

Diagnosis

The diagnosis is clinical; the main goal is to distinguish an inner-ear (peripheral) cause from a brain (central) cause, especially stroke.

• Bedside examination (HINTS protocol): Consists of the head impulse test, the characteristics of the nystagmus and assessment of vertical eye alignment (skew deviation); in experienced hands it can identify stroke in the first hours more sensitively than MRI.

• vHIT (Video Head Impulse Test): Shows which semicircular canals and which nerve branch are affected.

• VNG (Videonystagmography) and caloric test: Warm and cool stimulation of each ear quantifies one-sided loss of balance function.

• VEMP (Vestibular Evoked Myogenic Potentials): Assesses the lower branch of the nerve and the otolith organs (inner-ear structures that sense gravity and linear motion).

• Audiometry (hearing test): Performed to distinguish labyrinthitis and other inner-ear diseases.

• MRI (Magnetic Resonance Imaging): Requested if there are central findings, a high vascular risk or an atypical course.

 

Treatment

• Medicines for dizziness and nausea (vestibular suppressants and antiemetics): Used only in the acute phase, usually for the first 1–3 days. Long-term use is not recommended because it delays the brain’s compensation process (central compensation).

• Cortisone (corticosteroid) treatment: A short course started within the first 72 hours has been shown to help recovery of the measured response of the balance organ; its effect on long-term clinical outcome is debated, so the decision is made individually.

• Early movement (mobilisation): Getting out of bed and staying active as soon as the acute phase is over is the strongest stimulus for compensation.

• Balance exercises (vestibular rehabilitation): A structured programme of eye, head and body movements is the cornerstone of treatment; it improves both the speed of recovery and the risk of lasting symptoms.

 

Course and Possible Complications

The severe vertigo usually settles within a few days. Imbalance felt during rapid head movements and in situations with fewer visual cues (darkness, uneven ground) decreases over weeks to months. Even if the nerve does not fully recover, the brain largely compensates for the loss. Two complications are known:

• Ear crystals (BPPV – Benign Paroxysmal Positional Vertigo): The posterior canal type may develop, particularly when the lower branch of the nerve has been spared.

• Persistent perceptual dizziness (PPPD – Persistent Postural-Perceptual Dizziness): A condition in which compensation is disrupted by anxiety and avoidance of movement; early rehabilitation reduces this risk.

 

Frequently Asked Questions

How is it told apart from a stroke? The symptoms can be similar; bedside examination findings are decisive. Because the two can look very alike in the first hours, examination should not be delayed in sudden, continuous dizziness.

Does it come back? Rarely. If attacks keep recurring, other diagnoses such as vestibular migraine or Ménière’s disease should be considered.

When can I return to work and driving? Most patients return to work within a few days to a few weeks after the acute phase. Avoid driving and working at heights until imbalance with head movement has clearly resolved.

Is it contagious? No.

 

Detailed information and diagnostic criteria for physicians: the Vestibology link at the top of the page (vestibology.com).

Last updated: November 2026 · Editor: Assoc. Prof. Mehmet Sürmeli · Source: Bárány Society diagnostic criteria for acute unilateral vestibulopathy / vestibular neuritis (2022). This page is for general information and does not replace examination and diagnosis.