Vestibular Neuritis
Vestibular neuritis is one of the most common causes of acute prolonged vertigo, accounting for approximately 5–9% of all vertigo presentations to emergency departments. It results from acute inflammation — most likely viral or post-viral — of the vestibular nerve, producing a sudden and profoundly disabling episode of sustained vertigo lasting hours to days. When cochlear function is also affected, the condition is called labyrinthitis. Understanding the distinction between vestibular neuritis and its dangerous imitator — posterior circulation stroke — is among the most important skills in acute vestibular medicine.
Table of Contents
- What Is Vestibular Neuritis?
- Anatomy: The Vestibular Nerve
- Etiology: Viral Inflammation and HSV-1
- Labyrinthitis: When Hearing Is Also Affected
- Symptoms and Clinical Course
- Physical Examination: Bedside Tests
- The HINTs Exam: Ruling Out Stroke
- Diagnosis and Investigations
- Acute Treatment
- Vestibular Rehabilitation and Recovery
- References & Research
- Featured Videos
1. What Is Vestibular Neuritis?
Vestibular neuritis is an acute unilateral loss of vestibular function caused by inflammation of the vestibular nerve — the vestibular division of cranial nerve VIII. The cochlear nerve is spared, which means there is no hearing loss; this absence of hearing loss is a key clinical feature that distinguishes vestibular neuritis from labyrinthitis and from cochlear pathology.
The condition has an incidence of approximately 3.5 per 100,000 people per year, with a peak age of onset between 30 and 60 years and a slight female predominance. It is the second most common cause of peripheral vertigo after benign paroxysmal positional vertigo (BPPV). Most patients experience a single episode; recurrence is uncommon but possible, and bilateral involvement is rare.
The diagnosis is entirely clinical, based on the characteristic presentation combined with the absence of central neurological signs. The superior vestibular nerve division is most commonly affected. This vulnerability is explained by anatomy: the anterior vestibular artery supplying the superior division is an end artery with limited collateral circulation, making it more susceptible to ischemia and inflammatory compromise. Involvement of the inferior vestibular nerve division is less common and more often associated with preservation of horizontal canal function.
2. Anatomy: The Vestibular Nerve
The vestibular apparatus is the sensory end-organ of balance, housed within the inner ear (membranous labyrinth). It consists of two functional units: the three semicircular canals (horizontal, anterior/superior, and posterior), which detect rotational acceleration, and the two otolith organs (utricle and saccule), which detect linear acceleration and gravity.
The superior vestibular nerve innervates the horizontal semicircular canal, the anterior semicircular canal, and the utricle. The inferior vestibular nerve innervates the posterior semicircular canal and the saccule. Both divisions unite to form the vestibular nerve, which travels through the internal auditory canal (IAC) alongside the cochlear nerve and the facial nerve (cranial nerve VII).
Scarpa's ganglion is the vestibular nerve ganglion located within the internal auditory canal. It is the site of herpes simplex virus type 1 (HSV-1) latency and reactivation — a fact central to the leading etiological hypothesis for vestibular neuritis.
The vestibulo-ocular reflex (VOR) is the critical functional pathway affected in vestibular neuritis. The VOR stabilizes gaze during head movement by generating compensatory eye movements in the opposite direction of head rotation. When one vestibular nerve is inflamed and functionally impaired, the VOR becomes asymmetric: head movements toward the affected side produce a characteristic corrective "catch-up" saccade — the clinical basis of the head impulse test.
3. Etiology: Viral Inflammation and HSV-1
The majority of cases are believed to be caused by viral infection or post-viral immune-mediated inflammation, although direct pathological proof is difficult to obtain because labyrinthectomy specimens are rarely available in living patients. The evidence most strongly implicates herpes simplex virus type 1 (HSV-1) as the primary causative agent.
Supporting evidence includes: seasonal clustering with spring and summer peaks (consistent with viral reactivation patterns), a preceding upper respiratory tract infection in approximately 50% of cases, detection of HSV-1 DNA in vestibular ganglia at autopsy by Arbusow and colleagues (1999/2000), and elevation of anti-HSV antibody titers in some patients. The mechanism parallels HSV-1 reactivation from the trigeminal ganglion in herpes labialis — with Scarpa's ganglion serving as the vestibular equivalent.
Ramsay Hunt syndrome (herpes zoster oticus) is a distinct but closely related condition in which varicella-zoster virus (VZV) reactivates in the geniculate ganglion of the facial nerve, producing vestibular neuritis combined with facial nerve palsy and characteristic auricular vesicles. Its recognition is important because antiviral therapy (valacyclovir) combined with corticosteroids significantly improves facial nerve outcomes.
A post-infectious immune-mediated mechanism — in which molecular mimicry against vestibular nerve proteins drives inflammatory damage — is also proposed and may explain cases without identifiable viral prodrome. A vascular hypothesis (occlusion of the anterior vestibular artery, analogous to a mini-stroke in the AICA territory) cannot be excluded, particularly in older patients with cardiovascular risk factors. Rare autoimmune causes typically present with bilateral vestibular involvement and are associated with systemic autoimmune diseases.
4. Labyrinthitis: When Hearing Is Also Affected
Labyrinthitis is defined as vestibular neuritis with the addition of cochlear involvement. The patient presents with both acute vertigo and unilateral sensorineural hearing loss (SNHL) occurring simultaneously — the simultaneous onset is the key distinguishing feature. Hearing loss may be partial or complete (total deafness in the affected ear).
The spectrum of labyrinthitis includes several subtypes. Serous labyrinthitis results from mild perilymph irritation caused by adjacent otitis media; hearing typically recovers fully. Suppurative (bacterial) labyrinthitis results from bacterial spread from bacterial otitis media or meningitis; it is severe, often produces permanent deafness, and is now rare in developed countries in the post-antibiotic era. Viral labyrinthitis shares the same presumed etiology as vestibular neuritis, with variable hearing recovery depending on the degree of cochlear damage.
A critical clinical imperative: acute unilateral sensorineural hearing loss combined with vertigo can also represent an AICA (anterior inferior cerebellar artery) stroke. The AICA supplies both the inner ear labyrinth via the labyrinthine artery and portions of the lateral pons and cerebellum. An AICA stroke can present identically to viral labyrinthitis. MRI with diffusion-weighted imaging (DWI) is essential when any central nervous system signs are present or when significant cardiovascular risk factors exist, recognizing that early MRI may be falsely negative in the first 24–48 hours of a posterior fossa infarct.
5. Symptoms and Clinical Course
The clinical course of vestibular neuritis unfolds in three characteristic phases:
Acute Phase (hours 0–72): Onset is typically sudden, often upon waking or with a change in head position. Most patients describe the worst vertigo of their lives — a constant, violent spinning sensation that does not resolve with stillness. They are usually unable to stand or walk without assistance. Nausea and vomiting are severe and persistent. The characteristic nystagmus is horizontal with a torsional component, direction-fixed (fast phase always beating away from the affected ear, toward the healthy ear), and suppressed by visual fixation (Alexander's law — it intensifies when fixation is removed, such as in darkness or with Frenzel goggles). Intensity peaks within the first 24–48 hours, then begins to decline.
Subacute Phase (days 3–7): The severe constant vertigo resolves as the vestibular system begins central compensation. Significant residual imbalance and motion-provoked dizziness persist. Nystagmus diminishes and becomes detectable only with provocative testing or removal of fixation. The patient can typically ambulate with support.
Recovery Phase (weeks to months): Central vestibular compensation occurs as the brain recalibrates, progressively relying on the intact contralateral vestibular input, visual input, and proprioception. Most patients achieve functional recovery within 3–6 months. Older patients, those with more severe initial attacks, those who delay rehabilitation, and those with comorbid anxiety tend to have slower or incomplete recovery.
Persistent Postural-Perceptual Dizziness (PPPD) develops in a subset of patients as a chronic central sensitization syndrome — dizziness persisting beyond 3 months, characteristically worsened in visually complex environments (crowds, supermarkets) or with upright posture. PPPD requires vestibular rehabilitation combined with cognitive behavioral therapy (CBT) and, in many cases, SSRI medication (sertraline).
6. Physical Examination: Bedside Tests
The bedside examination of a patient with suspected vestibular neuritis is systematic and highly informative:
Spontaneous Nystagmus: The most fundamental finding. In vestibular neuritis, nystagmus is horizontal-torsional and direction-fixed — the fast phase always beats toward the healthy (unaffected) ear. Observation is enhanced by removing visual fixation using Frenzel goggles or having the patient fix gaze in darkness. Direction-changing nystagmus (fast phase changes with direction of gaze) is a central alarm sign.
Romberg Test: The patient stands with feet together and eyes closed. In vestibular neuritis, there is characteristic falling or swaying toward the affected (lesioned) side, due to the asymmetric vestibular input perceived as real motion.
Head Shaking Test: The examiner shakes the patient's head horizontally for 20 seconds, then observes the eyes. In vestibular neuritis, a brief burst of nystagmus beating toward the healthy ear is provoked — this head-shaking nystagmus indicates an asymmetric vestibular lesion. Vertical nystagmus after horizontal head-shaking is a central sign.
Vertical Skew Deviation: The examiner alternately covers and uncovers each eye while the patient fixes gaze straight ahead. A corrective vertical eye movement on uncovering (vertical skew) indicates a central lesion. Peripheral lesions typically produce no skew or only trivial skew.
Past-Pointing Test: The patient extends an arm and points to the examiner's finger with eyes open, then repeats with eyes closed. In vestibular neuritis, the outstretched arm consistently deviates toward the affected side.
Fukuda Stepping Test: The patient marches in place for 50 steps with eyes closed and arms extended. A vestibular lesion produces progressive rotation toward the affected side — typically more than 45 degrees in significant unilateral peripheral loss.
7. The HINTs Exam: Ruling Out Stroke
The HINTs examination (Head Impulse, Nystagmus, Test of Skew) is a three-component bedside oculomotor test battery developed specifically to distinguish acute peripheral vestibular syndrome (vestibular neuritis) from central pathology — most critically, posterior circulation stroke — at the bedside. Landmark research by Kattah et al. (2009) demonstrated that HINTs performed by a trained examiner is more sensitive than early MRI for detecting posterior fossa stroke, because diffusion-weighted MRI misses approximately 12–20% of posterior fossa strokes in the first 24–48 hours.
H — Head Impulse Test (Halmagyi-Curthoys Test)
The patient fixates on the examiner's nose. The examiner rapidly and unpredictably rotates the patient's head approximately 10–15 degrees to one side. The examiner watches for a corrective saccade.
- Abnormal (catch-up saccade present): When the head is rotated toward the affected side, the eyes initially move with the head (impaired VOR) and then make a small corrective saccade back to the target. This finding indicates impaired VOR on the side of the head impulse — a peripheral vestibular lesion (vestibular neuritis). This is REASSURING — it is the expected finding in a benign condition.
- Normal (no saccade): The eyes maintain fixation throughout the head impulse — the VOR is intact. When a patient has acute vertigo AND a normal head impulse, this is an ALARMING sign indicating a central lesion (posterior circulation stroke) that has disrupted the central vestibular pathways without impairing the VOR.
N — Nystagmus Type
- Direction-fixed nystagmus (fast phase always in the same direction regardless of gaze direction) = peripheral vestibular lesion → Reassuring
- Direction-changing nystagmus (fast phase reverses with changes in gaze direction) = central lesion → Alarming — emergent workup required
T — Test of Skew
The alternate cover test is performed. If uncovering a covered eye produces a corrective vertical eye movement (vertical skew deviation), this indicates a central lesion disrupting the otolith-ocular pathways. No correction (or symmetric alignment) is expected in peripheral lesions.
Interpreting HINTs Results
Peripheral pattern (benign — consistent with vestibular neuritis): Abnormal head impulse (catch-up saccade present) AND direction-fixed nystagmus AND no skew deviation.
Central pattern (dangerous — urgent stroke workup required): Normal head impulse (no catch-up saccade) OR direction-changing nystagmus OR positive skew deviation. Any one of these three alarm signs mandates emergent neuroimaging.
The sensitivity of HINTs for detecting stroke in acute vestibular syndrome reaches 96–100% in studies performed by trained examiners. CT of the head should not be relied upon to exclude posterior fossa stroke — it misses approximately 80% of posterior fossa infarcts. Early MRI (within 24–48 hours) misses 12% of posterior fossa strokes due to restricted diffusion artifact; if clinical suspicion is high, MRI should be repeated at 48–72 hours.
8. Diagnosis and Investigations
In a classic case — acute sustained vertigo with unilateral peripheral nystagmus pattern, abnormal head impulse test, no hearing loss, and no neurological signs — the diagnosis is clinical and no investigations are immediately required beyond careful bedside examination.
Video Head Impulse Test (vHIT): An objective, quantitative measurement of the vestibulo-ocular reflex using high-speed video goggles that record eye movements during rapid head impulses. In vestibular neuritis, the VOR gain on the affected side is typically less than 0.8 (normal >0.8), with covert or overt catch-up saccades. vHIT can localize the lesion to the superior or inferior vestibular nerve based on which semicircular canals are hyporesponsive.
Caloric Testing: Irrigation of the external auditory canal with warm and cool water provokes convective endolymph flow, creating a controlled vestibular stimulus. Canal paresis — defined as more than 25% asymmetry between ears — confirms unilateral peripheral vestibular hypofunction. Caloric testing remains the gold standard for documenting the degree and laterality of vestibular loss, and is used to monitor recovery.
Audiometry: Pure-tone audiometry is normal in vestibular neuritis (by definition). Sensorineural hearing loss on audiometry indicates labyrinthitis and should prompt consideration of AICA stroke if cardiovascular risk factors are present.
MRI with Gadolinium: Indicated in the following circumstances: atypical presentation, normal head impulse test (no catch-up saccade), direction-changing nystagmus, vertical nystagmus, associated hearing loss, new cranial nerve signs, headache, gait ataxia out of proportion to vertigo, or significant cardiovascular risk factors. Gadolinium enhancement of the vestibular nerve on MRI has been reported in vestibular neuritis, though this is not a routine finding. Crucially, MRI may be normal or falsely negative in the first 24–48 hours of a posterior fossa stroke — if suspicion is high, repeat imaging at 48–72 hours.
Blood Tests: Full blood count, ESR, CRP (to exclude systemic infection or inflammatory cause); autoimmune screen (anti-nuclear antibody, ANCA, anti-Ro/La) if the presentation is recurrent or bilateral; fasting glucose and lipids in older patients where vascular etiology is a concern.
9. Acute Treatment
Treatment in the acute phase serves two goals: symptom relief during the most distressing initial hours, and supporting the process of central vestibular compensation.
Vestibular Suppressants (maximum 3 days):
- Meclizine 25 mg three times daily, dimenhydrinate, or promethazine 25 mg — antihistamines that reduce the intensity of acute vertigo and nausea
- Benzodiazepines (diazepam 2–5 mg as needed) for severe acute vestibular crises when other agents are insufficient
- Critical caveat: vestibular suppressants must not be continued beyond 72 hours. These agents suppress the vestibular system centrally, which directly interferes with the neural plasticity required for central compensation. Prolonged use is one of the most common causes of delayed and incomplete recovery.
Antiemetics: Ondansetron (4–8 mg orally or intravenously, a 5-HT3 antagonist) is preferred for vomiting as it does not suppress the vestibular system. Metoclopramide is an alternative. Adequate hydration should be maintained, with intravenous fluids if oral intake is impossible due to persistent vomiting.
Corticosteroids (controversial): Methylprednisolone 100 mg/day tapered over three weeks was shown in a landmark randomized controlled trial by Strupp et al. (2004) to significantly improve canal paresis recovery at 12 months compared to placebo. However, no study has demonstrated a benefit in reducing the duration of acute vertigo or improving quality-of-life outcomes. Current practice varies by clinician preference: many prescribe a corticosteroid course if the patient presents within 72 hours of symptom onset and has no contraindications (diabetes, immunosuppression, active peptic ulcer disease).
Antivirals: Despite the strong circumstantial evidence for HSV-1 involvement, a Cochrane systematic review found no additional benefit of acyclovir or valacyclovir over corticosteroids alone in vestibular neuritis. Antivirals are therefore not routinely recommended in isolated vestibular neuritis. The exception is Ramsay Hunt syndrome, where combined corticosteroids and valacyclovir are the standard of care.
Avoid prolonged bed rest: Immobilization actively delays central vestibular compensation. Patients should begin cautious mobilization as soon as the acute vomiting phase permits, which is typically within 24–48 hours of onset.
10. Vestibular Rehabilitation and Recovery
Vestibular rehabilitation therapy (VRT) is the single most important intervention for achieving full recovery from vestibular neuritis — more impactful than any pharmacological treatment. The goal is to accelerate and optimize central vestibular compensation, the process by which the brain recalibrates its balance processing to account for the asymmetric vestibular input.
Mechanism of central compensation: Following unilateral vestibular loss, the brain undergoes progressive adaptation over weeks to months. It learns to suppress the erroneous resting asymmetry, recalibrates the VOR using visual and proprioceptive feedback, and progressively redistributes balance reliance toward the intact contralateral vestibular system, visual input, and somatosensory (proprioceptive) input from the feet and ankles.
Gaze Stabilization Exercises: The patient fixes gaze on a stationary target (such as a letter on the wall) and moves the head side-to-side and up-and-down at progressively faster speeds while maintaining a stable clear image. This specifically drives VOR recalibration and is the most potent stimulus for reducing pathological nystagmus and gaze instability.
Balance Exercises: Progressively challenging static and dynamic balance training — tandem walking, single-leg stance, standing on foam pads (which reduce proprioceptive input, forcing vestibular and visual reliance), and walking with head turns. The principle of progressive challenge drives neural adaptation.
Walking: Early resumption of ambulation — as soon as safely possible, with support from a wall or assistant if needed — is essential. Walking provides the complex multi-sensory stimulation required for compensation that is impossible to replicate in bed or a chair.
Supervised versus home-based VRT: A Cochrane review by Hillier and McDonnell (2011) confirmed that supervised VRT by a qualified physiotherapist produces superior outcomes compared to unsupervised home exercises, particularly for patients with more severe initial deficits or comorbid anxiety.
Timeline: Most patients with vestibular neuritis achieve functional recovery — return to work and daily activities — within 4–6 weeks. Full neurological compensation, with resolution of subtle balance deficits detectable on formal testing, may take 3–6 months. A minority of patients, particularly older individuals and those with more complete initial vestibular loss, have residual deficits detectable on caloric testing even after clinical recovery.
Persistent Postural-Perceptual Dizziness (PPPD): When dizziness persists beyond 3 months in the absence of ongoing peripheral vestibular pathology, PPPD should be diagnosed and treated. PPPD is a central sensitization syndrome characterized by chronic dizziness provoked by upright posture, head movement, and visually complex environments. Treatment is multimodal: continued VRT (with cognitive components), SSRIs (sertraline 50–100 mg/day has the strongest evidence base), and cognitive behavioral therapy targeting the maladaptive attentional and avoidance behaviors that perpetuate the syndrome.
Return to work and driving: When the acute phase has resolved, nystagmus has subsided, and the patient can safely perform the demands of the activity. For sedentary desk work this is typically 1–3 weeks from onset; physically demanding occupations or those involving driving or operating machinery require formal assessment of balance and visual stability, typically at 3–6 weeks.
11. References & Research
- Strupp M, Zingler VC, Arbusow V, et al. Methylprednisolone, valacyclovir, or the combination for vestibular neuritis. N Engl J Med. 2004;351(4):354–361. PMID: 15269315
- Kattah JC, Talkad AV, Wang DZ, Hsieh YH, Newman-Toker DE. HINTS to diagnose stroke in the acute vestibular syndrome: three-step bedside oculomotor examination more sensitive than early MRI. Stroke. 2009;40(11):3504–3510. PMID: 19762709
- Newman-Toker DE, Kerber KA, Hsieh YH, et al. HINTS outperforms ABCD2 to screen for stroke in acute continuous vertigo and dizziness. Acad Emerg Med. 2013;20(10):986–996. PMID: 24127701
- Arbusow V, Schulz P, Strupp M, et al. Distribution of herpes simplex virus type 1 in human geniculate and vestibular ganglia: implications for vestibular neuritis. Ann Neurol. 1999;46(3):416–419. PMID: 10482273
- Halmagyi GM, Curthoys IS. A clinical sign of canal paresis. Arch Neurol. 1988;45(7):737–739. PMID: 3390028
- Brandt T, Huppert D, Hecht J, Karch C, Strupp M. Benign paroxysmal positioning vertigo: a long-term follow-up (6–17 years) of 125 patients. Acta Otolaryngol. 2006;126(2):160–163. PMID: 16428204
- Staab JP, Eckhardt-Henn A, Horii A, et al. Diagnostic criteria for persistent postural-perceptual dizziness (PPPD). J Vestib Res. 2017;27(4):191–208. PMID: 29036855
- Hillier SL, McDonnell M. Vestibular rehabilitation for unilateral peripheral vestibular dysfunction. Cochrane Database Syst Rev. 2011;(2):CD005397. PMID: 21328283
- Bhattacharyya N, Gubbels SP, Schwartz SR, et al. Clinical Practice Guideline: Benign Paroxysmal Positional Vertigo (Update). Otolaryngol Head Neck Surg. 2017;156(3_suppl):S1–S47. PMID: 28248609
- Lee H, Sohn SI, Cho YW, et al. Cerebellar infarction presenting isolated vertigo: frequency and vascular topographical patterns. Neurology. 2006;67(7):1178–1183. PMID: 17030747
- Fishman JM, Burgess C, Waddell A. Corticosteroids for the treatment of idiopathic acute vestibular dysfunction (vestibular neuritis). Cochrane Database Syst Rev. 2011;(5):CD008607. PMID: 21563170
- Strupp M, Brandt T. Vestibular neuritis. Semin Neurol. 2009;29(5):509–519. PMID: 19834860
PubMed Topic Searches
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- PPPD persistent postural-perceptual dizziness treatment
- Acute vestibular syndrome emergency diagnosis
Featured Videos
Educational videos on vestibular neuritis, the HINTs exam, and vestibular rehabilitation from neurologists and ENT specialists.