Otolaryngology & Neurology & Family Medicine
Vestibular neuritis
Vestibular neuritis - also known as vestibular neuronitis, acute vestibular neuritis or, in its historically broader forms, labyrinthitis (a term now reserved for forms associating hearing loss) - is an acute inflammation of the vestibular nerve, most often of presumed viral origin, representing the second most common cause of acute vertigo after benign paroxysmal positional vertigo (BPPV), and the leading cause of persistent acute vestibular syndrome in adults. It manifests itself as a single episode of intense, sudden-onset rotatory vertigo, associated with severe nausea and vomiting and marked postural instability, lasting several days to several weeks before gradual improvement through central compensation. Unlike BPPV, whose attacks last seconds to minutes and are triggered by changes in position, vertigo in vestibular neuritis is continuous and spontaneous, peaking in the first 24 to 48 hours. The etiology is probably viral in the majority of cases - a reactivation of herpes simplex virus type 1 (HSV-1) in the vestibular ganglion of Scarpa has been proposed as the main mechanism, based on post-mortem and virological studies - but this hypothesis has yet to be formally confirmed. The fundamental clinical issue in vestibular neuritis is its distinction from a cerebellar or brainstem stroke, which can present clinically identically at the patient's bedside - a misdiagnosis leading to failure to perform thrombolysis or thrombectomy can leave severe neurological sequelae. The HINTS rule (Head Impulse - Nystagmus type - Test of Skew), applied at the patient's bedside, is the most effective clinical tool for making this critical distinction, surpassing diffusion brain MRI in the first 24 hours for detecting posterior fossa stroke. Management is based on oral methylprednisolone, which accelerates functional recovery, symptomatic antivertigo drugs limited to the first 48 hours, and above all early vestibular rehabilitation, which is the most important modifiable prognostic factor for the quality of long-term central compensation.
Pathophysiology and etiology
- Inflammation of the superior vestibular nerve In the majority of cases (around 75-80% %), vestibular neuritis affects only the superior branch of the vestibular nerve (innervating the horizontal and anterior semicircular canals + the utricle), sparing the inferior branch (innervating the posterior canal + the saccule) → asymmetry of left-right vestibular afferents to the vestibular nuclei of the brainstem → slow drift of the eyes toward the affected side (hypofunction) + horizontal nystagmus beating toward the healthy side + postural deviation toward the lesioned side
- Presumed viral etiology: probable reactivation of HSV-1 in Scarpa's ganglion (analogous to herpes zoster oticus / Ramsay Hunt syndrome for the facial nerve) + HSV-1 RNA detected post-mortem in vestibular ganglia of patients who died of vestibular neuritis + clinical context of a viral upper respiratory tract episode preceding the dizzying episode by 1 to 2 weeks in 50 to 60 % of cases + theoretical rationale for the use of antivirals (valacyclovir), but the VESTIGES clinical trial (Strupp 2004) did not demonstrate a benefit of the combination of methylprednisolone + valacyclovir versus methylprednisolone alone → antivirals are not routinely recommended
- Decompensation and central compensation The sudden unilateral destruction or hypofunction of the vestibular nerve creates a tonic asymmetry between the two vestibular nuclei, leading to intense vertigo, spontaneous nystagmus, and instability. In the following days to weeks, neuronal plasticity mechanisms in the cerebellum and brainstem (central compensation) progressively restore the balance of vestibular signals, resulting in the disappearance of symptoms at rest. This is followed by compensation during exertion, and finally, complete compensation with head movement. Vestibular rehabilitation accelerates and completes this compensation.
- Risk of secondary BPPV: 10 to 15 % of patients develop ipsilateral posterior canal BPPV in the weeks to months following vestibular neuritis - likely related to otolith denaturation by the inflammatory process + should be systematically screened for using the Dix-Hallpike maneuver during follow-up if positional vertigo recurs
Clinical presentation
| Clinical features | Description | Diagnostic value |
|---|---|---|
| Intense spontaneous rotatory vertigo | Sudden onset (sometimes upon waking) + sensation of the environment or body spinning (subjective or objective vertigo) + continuous and persistent (non-positional) + maximal in the first 24–48 hours + gradually subsides over 3 to 7 days + oscillopsia (objects seem to move or vibrate) with head movements | Continuous and spontaneous character distinguish vestibular neuritis from BPPV (brief paroxysmal positional vertigo) — a major diagnostic element |
| Severe nausea and vomiting | Often very severe in the first few hours + sometimes uncontrollable vomiting requiring IV hydration if dehydrated + associated autonomic dysfunction (paleness + sweating + bradycardia) | Frequent in severe but non-specific peripheral vestibular disorders |
| Postural instability and falls to the affected side | Inability to stand without assistance in severe forms + Romberg test deviation to the affected side + star excursion gait (deviation to the affected side when walking with eyes closed) + falling to the affected side | Instability toward a side consistent with the nystagmus side favors a peripheral origin |
| Unilateral horizontal nystagmus | Spontaneous horizontal or horizontational nystagmus banging towards the healthy side (opposite side to the lesion) + unidirectional (same direction regardless of gaze position) + inhibited by visual fixation + worsened by Frenzel glasses or in darkness | Unidirectional nystagmus inhibited by fixation = peripheral signature + pure or bidirectional vertical nystagmus points to a central cause (stroke) |
| Absence of auditory signs | Strictly normal hearing - no hearing loss + no tinnitus + no ear fullness + hearing loss associated with labyrinthitis or Ménière's disease rather than pure vestibular neuritis. | The absence of auditory symptoms is an important negative diagnostic criterion—it distinguishes vestibular neuritis from Meniere's disease and infectious labyrinthitis. |
| Absence of focal neurological signs | Neurological examination rigorously normal — no diplopia + no dysarthria + no limb ataxia (cerebellar dysmetria) + no Babinski sign + no limb sensory or motor deficit + no dysphagia | Any focal neurological sign associated with vertigo immediately requires an urgent brain MRI to rule out a posterior fossa stroke. |
HINTS rule — distinction between vestibular neuritis/posterior fossa stroke
The HINTS (Head Impulse — Nystagmus type — Test of Skew) rule is the gold standard clinical tool for distinguishing a benign peripheral acute vestibular syndrome from a cerebellar or brainstem stroke at the bedside:
| HINTS Component | Reassuring result (peripheral) | Alarming result (central — stroke) |
|---|---|---|
| Head Impulse Test | Positive — Catch-up nystagmus visible after rapid head impulse towards the lesioned side → Impaired vestibulo-ocular reflex (VOR) on the affected side → Confirms unilateral peripheral vestibular hypofunction | Negative — no visible catch-up saccades after head impulse in either direction → RVO intact bilaterally → intense vertigo with negative HIT is the most powerful central alarm sign → brainstem stroke until proven otherwise |
| N — Nystagmus type | Unidirectional horizontal — same direction regardless of viewing position (e.g.: always beating to the left) → peripheral signature | Bidirectional (changes direction based on gaze direction) or purely vertical (down-beat or up-beat) → central signature - never observed in peripheral pathology |
| T — Test of Skew (Alternating Vertical Deviation) | Absent — no vertical deviation on alternate cover test | Present — skew deviation: vertical misalignment of one eye relative to the other during the cover test → vertical oculomotor misalignment → lesion of central otolithic pathways → highly specific central sign |
ℹ️
The HINTS rule is more sensitive than diffusion-weighted imaging (DWI) MRI in the first 24 hours for detecting posterior fossa stroke in a patient with acute vestibular syndrome — DWI MRI sensitivity for cerebellar and brainstem strokes is only 80–90 % in the first 24–48 hours (frequent false negatives for small brainstem infarcts). A central HINTS profile (negative HIT + bidirectional or vertical nystagmus + skew) mandates hospitalization and a follow-up brain MRI at 48–72 hours even if the initial MRI is negative.
Treatment
| Treatment | Protocol and dosage | Level of evidence and remarks |
|---|---|---|
| Oral methylprednisolone — etiological treatment | Validated protocol (Strupp 2004 — NEJM): methylprednisolone 100 mg/day × 3 days + gradual reduction of 20 mg every 3 days over a total of 22 days + to be started within the first 3 days of the episode for optimal benefit | Significantly accelerates vestibular function recovery (measured by caloric testing at 12 months) + randomized controlled trial by Strupp 2004 (NEJM): methylprednisolone superior to placebo for vestibular recovery + no additional benefit from valaciclovir + corticosteroids do not alter the duration of subjective symptoms but improve long-term objective functional recovery |
| Symptomatic anti-vertigo medication — acute phase only | Metopimazine (Vogalene®) 15 mg orally or as a suppository + or prochlorperazine + or dimenhydrinate (Gravol®) 50 mg orally or IV + to be used for a maximum of 48 to 72 hours in severe cases with uncontrollable vomiting | Effective symptomatic relief of nausea and vomiting + do not prolong beyond 48-72 hours – anti-vertiginous drugs suppress central compensation by reducing activity in the vestibular nuclei → their prolonged use delays functional recovery + benzodiazepines (diazepam) should be avoided for the same reason |
| IV hydration for intractable vomiting | Isotonic solution (0.9% NaCl % or Ringer's lactate) + fluid loss correction + until the patient tolerates oral intake + short hospitalization if dehydration or uncontrolled vomiting as an outpatient | Necessary in severe forms within the first 24-48 hours + short hospitalization (1 to 3 days) possible for very debilitating cases before returning home with vestibular rehabilitation |
| Vestibular Rehabilitation — Fundamental Treatment | Gaze stabilization exercises (fixating on a target during head movements) + progressive balance exercises (standing + eyes closed + on an unstable surface) + walking exercises with sensory perturbations + to begin as soon as vomiting is controlled (Day 2 to Day 5) + gradually increasing intensity + vestibular specialist physiotherapist recommended | The most important long-term prognostic treatment is vestibular rehabilitation, which accelerates central compensation, reduces the risk of anxiety and postural avoidance (phobias), and improves quality of life at 3 months and 1 year. Evidence level A (Cochrane 2015 — Hillier). It should be widely favored over prolonged anti-vertigo medications. |
Course and prognosis
- Subjective recovery: the majority of patients see their symptoms improve significantly in 1 to 3 weeks + complete disappearance of spontaneous vertigo in 4 to 6 weeks in typical forms + residual instability during rapid head movements + in dim light or on unstable ground may persist for several months in 30 to 50 % of patients
- Objective vestibular functional recovery normalization of the caloric test (measurement of each labyrinth's function separately) in 30 to 40 % of cases at 12 months + 60 to 70 % maintain asymptomatic residual unilateral hypofunction compensated by central plasticity + methylprednisolone improves this rate of functional recovery
- Risk of secondary BPPV: 10 to 15 % of patients develop ipsilateral BPPV in the weeks to months following neuritis + to suspect if recurrence of brief positional vertigo + Dix-Hallpike maneuver + treatment with Epley maneuver
- Factors for poor functional prognosis: Advanced age (slower central compensation) + sedentary lifestyle and postural avoidance + prolonged use of antivertigo medications + absence of vestibular rehabilitation + anxiety and phobic fear of vertigo (development of PPPD — persistent postural-perceptual dizziness) in 15 to 25 % of patients + neurological comorbidities (multiple sclerosis)
- Recidivism Vestibular neuritis generally does not recur on the same side. An ipsilateral recurrence after complete recovery should raise suspicion for Meniere's disease or another etiology.
Situations requiring a 911 call or immediate urgent evaluation
Call 911 or go to the ER immediately if severe acute vertigo is accompanied by any of the following neurological signs: difficulty walking or falling and being unable to get up + double vision + slurred speech or hoarse voice + difficulty swallowing + limb weakness + numbness or loss of sensation on one side of the face or body + sudden, severe headache (the worst of your life) + loss of consciousness — these signs suggest a stroke in the cerebellum or brainstem requiring emergency thrombolysis or thrombectomy, where every minute counts for the neurological outcome.
Sudden, severe vertigo in a patient over 60 with vascular risk factors (hypertension + diabetes + atrial fibrillation + smoking + history of stroke) should always lead to an urgent medical evaluation in the emergency department, even in the absence of obvious neurological signs, as posterior fossa strokes can present with a clinically identical picture to vestibular neuritis.
For the evaluation of acute vertigo, including the head impulse test and HINTS rule, prescribing methylprednisolone, and referral to vestibular rehabilitation, Clinique Omicron offers medical consultations at its service points in Quebec and via telemedicine. To book an appointment, visit cliniqueomicron.ca.
Consult at Clinique Omicron
Clinique Omicron's physicians and Nurse Practitioners (NPs) assess patients with acute vertigo, apply the HINTS rule to differentiate vestibular neuritis from a posterior fossa stroke, prescribe methylprednisolone according to the validated protocol, refer to the emergency room for suspicious central presentations, and refer to specialized vestibular rehabilitation for long-term functional recovery. Consultations are available at several service points throughout Quebec and via telemedicine. To book an appointment, visit cliniqueomicron.ca.
The content of this page is for informational purposes only and does not replace the advice of a doctor or a specialist in Otolaryngology or Neurology. Any intense acute vertigo associated with focal neurological signs constitutes a neurological emergency requiring immediate hospital evaluation to rule out a posterior fossa stroke.
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