Neurology & ENT & Emergency Medicine & Family Medicine
Labyrinthitis
Labyrinthitis is an inflammation of the membranous labyrinth of the inner ear, a complex anatomical structure comprising both the organs of hearing (cochlea) and balance (vestibule: utricle + saccule + semicircular canals). It is manifested by the combination of intense vertigo (rotatory type + peripheral character) and cochlear damage (hypoacusis + tinnitus), which distinguishes it from vestibular neuritis (or vestibular neuronitis) in which only the vestibular system is affected, with no cochlear component. In clinical practice, the distinction between labyrinthitis and vestibular neuritis is based primarily on the presence or absence of auditory symptoms - in the absence of auditory deficit, the condition is referred to as vestibular neuritis. However, both entities share the same acute vestibular presentation (AVS - Acute Vestibular Syndrome) and respond to the same symptomatic treatments. The most frequent etiology is viral (herpes viruses : HSV-1 + VZV zoster + EBV + CMV + enterovirus + urlian viruses) in the context of acute post-infectious or directly infectious labyrinthitis. Bacterial labyrinthitis - although rare in developed countries thanks to vaccination and early treatment of otitis - is the most serious, resulting either from direct extension of suppurative acute otitis media (AOM) or mastoiditis, or from bacterial meningitis (meningogenic labyrinthitis). Bacterial labyrinthitis is a medical emergency, as it frequently leads to permanent deafness, and can be complicated by meningitis if not treated promptly.
Pathophysiology, etiologies and clinical presentation
- Anatomy of the labyrinth and pathophysiological mechanisms of labyrinthitis: functional anatomy of the labyrinth: the osseous labyrinth (labyrinthus osseus) - a cavity in the rock of the temporal bone - contains the membranous labyrinth (labyrinthus membranaceus) made up of: cochlea (organ of Corti): transduction of sound vibrations into nerve signals (cochlear nerve = cochlear branch of VIII) + vestibule : utricle + saccule (otoliths - linear accelerations) + 3 semicircular canals (angular accelerations - each in one plane of space) + vestibular nerve (vestibular branch of VIII = stato-acoustic nerve) → the entire membranous labyrinth is filled with endolymph + the perilymphatic space (between the two labyrinths) is filled with perilymph → inflammation of the membranous labyrinth → disruption of endolymphatic flows + damage to cochlear hair cells + vestibular hair cells → cochlear lesions produce hypoacusis + vestibular lesions produce vertigo ; etiological mechanisms according to the type of labyrinthitis : viral labyrinthitis (most frequent - 85-90 % of labyrinthitis): reactivation of a latent virus in the geniculate or spiral ganglion (HSV-1 in the spiral ganglia of the cochlea) → or viremic infection with damage to the endothelium of labyrinthine vessels → endolymphatic edema → internal pressure + damage to hair cells → the mechanism is similar to that of vestibular neuritis (whose viral etiology is strongly suspected but not proven with certainty - Gacek 2002 - Annals of Otology Rhinology and Laryngology : HSV-1 in vestibular ganglia) + bacterial labyrinthitis: 3 routes of extension: 1/ tympanogenic (via round or oval window from AOM or chronic otitis with cholesteatoma) → 2/ meningogenic (from subarachnoid spaces via cochlear nerve or labyrinth aqueducts → most often secondary to pneumococcal or meningococcal meningitis) → 3/ hematogenous (rarer - bacteremia) + autoimmune labyrinthitis: anti-cochlear antibodies (anti-hair cell proteins) → fluctuating + bilateral hypoacusis + responsive to corticosteroids + toxic labyrinthitis: aminoglycosides (gentamicin + streptomycin) → accumulation in endolymph → ototoxicity (outer hair cells) → hypoacusis + particularly in high frequencies → cisplatin + quinine + high-dose aspirin → tinnitus + reversible hypoacusis at low dose.
- Clinical Presentation and Differential Diagnosis of Labyrinthitis symptoms of acute labyrinthitis : intense vertigo of the rotatory type (sensation of rotation of the environment) → abrupt or sudden onset + nausea + severe vomiting (vegetative reflex) + gait instability + unilateral hypoacusis (hearing loss on the affected side) → key cochlear component that distinguishes labyrinthitis from vestibular neuritis + unilateral tinnitus (buzzing + whistling) + sensation of a blocked ear + horizontal-spontaneous rotatory nystagmus (beating on the side contralateral to the lesion - healthy side) → nystagmus attenuates with ocular fixation + positive HIT test (Head Impulse Test - Halmagyi) on injured side + HINTS test : in emergency to distinguish a peripheral cause from a central cause (stroke): H = Head Impulse Test + I = Nystagmus type (direction) + T = Test of Skew → unidirectional nystagmus + positive HIT + no skew deviation → peripheral cause + multidirectional nystagmus + negative HIT + skew deviation → Stroke → Kattah 2009: HINTS superior to early MRI for detecting brainstem stroke in acute vestibular syndrome + evolution: acute phase (J1-J14): intense vertigo + instability + difficulty walking → compensation phase (J15-J60): progressive reduction of vertigo thanks to central compensation → residual phase: residual instability + persistent hypoacusis if severe cochlear lesion; differential diagnosis: vestibular neuritis (neuronitis): identical to labyrinthitis BUT without auditory involvement → no hypoacusis + no tinnitus + BPPV (benign paroxysmal positional vertigo): brief vertigo (<1 min) + triggered by changes in head position → positive Dix-Hallpike test → treatment with repositioning maneuver (Epley) + brainstem stroke (AICA infarct): may simulate labyrinthitis → HINTS emergency → MRI if doubt + HINTS test negative central side → Meniere's disease: recurrent episodes of vertigo + fluctuating hypoacusis + tinnitus + auricular fullness → auricular herpes zoster (Ramsay Hunt syndrome): VZV + ENT shingles → pinna vesicles + facial paralysis + vertigo + hypoacusis + intense auricular pain
Treatment and care
| Treatment / appearance | Data, modalities, and protocols | Key studies and recommendations |
|---|---|---|
| Symptomatic treatment — dizziness and vomiting Antivertigo — dimenhydrinate Gravol — prochlorperazine — metoclopramide — ondansetron — meclizine — betahistine — duration of suppressive treatment — vestibular rehabilitation — hydration — rest |
Symptomatic treatment of acute phase (J1-J5): aim: relieve vertigo + nausea + vomiting → allow hydration and feeding → facilitate safe ambulation → allow central compensation + antivertiginous and antiemetic : dimenhydrinate (Gravol) 50 mg PO or IM → H1 antagonist + anticholinergic → reduces vertigo + nausea → 50 mg PO × 4-6/d → or 50 mg IM if severe vomiting → side effect: somnolence → prochlorperazine (Stemetil) 5-10 mg PO or IM → antidopaminergic + potent antiemetic → effective for severe vomiting → risk: extrapyramidal effects (dystonia) → promethazine (Phenergan) 25 mg IM → sedative + antiemetic + meclizine (Antivert - not available in Canada but used in USA) → dimenhydrinate analog → ondansetron (Zofran) 4-8 mg PO or IV → 5-HT3 receptor antagonist → antiemetic → little sedation → useful if persistent vomiting → metoclopramide (Maxeran) 10 mg IV/IM → prokinetic + antiemetic → extrapyramidal risk + IMPORTANT: vestibular suppressants (dimenhydrinate + prochlorperazine + benzodiazepines) should be used as little as possible (maximum 3-5 days) → they mask symptoms but slow central compensation → prolong beyond-beyond 5 days → delayed healing → betahistine (Serc) 16-24 mg × 3/d → histamine analogue → reduces endolymphatic pressure → indicated especially in Meniere's disease + probably useful in labyrinthitis → may reduce vertigo + improve compensation + corticoids in viral labyrinthitis : prednisone 40-60 mg/d × 5-7 days → controversy → Strupp 2004 - Lancet : methylprednisolone IV + vestibular neuritis → improved vestibular recovery at 12 months → data transposed to viral labyrinthitis + benefit on hypoacusis if started early + corticosteroids recommended if sudden significant hypoacusis (sudden deafness) → prednisone 1 mg/kg/d × 7-14 days → or intratympanic methylprednisolone if insufficient systemic route → hydration: IV if severe vomiting prevents oral hydration → bed rest in acute phase + avoid sudden head movements | Strupp 2004 — Lancet: IV methylprednisolone + vestibular neuritis → improved vestibular recovery at 12 months → reference for corticosteroids in acute vestibular syndromes + Gacek 2002 — Annals of Otology Rhinology and Laryngology: HSV-1 + vestibular ganglia + viral pathophysiology → Kattah 2009 — Stroke: HINTS + acute vestibular syndrome → superior to early MRI for stroke + AAO-HNS (American Academy of Otolaryngology — Head and Neck Surgery) 2019: sudden hearing loss → oral corticosteroids → strong recommendation + NICE 2017: dizziness + labyrinthitis → symptomatic treatment + Bhattacharyya 2017 — Otolaryngology Head and Neck Surgery: vestibular neuritis + labyrinthitis → guidelines + corticosteroids + Government of Quebec + MSSS + INESSS: dimenhydrinate + prochlorperazine + ondansetron reimbursed + RAMQ: betahistine Serc reimbursed |
| Bacterial labyrinthitis and antibiotic therapy Bacterial labyrinthitis — AOM extension — meningitis — ceftriaxone — amoxicillin-clavulanate — surgical emergency — mastoidectomy — paracentesis — permanent hearing loss — cochlear implant — vaccination prevention |
Bacterial labyrinthitis - medical and surgical emergency: etiology and context: extension of untreated or inadequately treated suppurative AOM (acute otitis media) → fever + otalgia + anterior otorrhea → then vertigo + hypoacusis → sign of complication + extension of mastoiditis → extension of chronic otitis with cholesteatoma → meningogenic extension (pneumococcal bacterial meningitis ++ ) → agents: Streptococcus pneumoniae ++ + Haemophilus influenzae + Staphylococcus aureus + gram-negative bacilli (less frequent) → urgent workup: CBC + CRP + blood cultures × 3 + lumbar puncture if meningitis suspected → CT scan of rocks + mastoids → urgent ENT consultation → MRI of posterior fossa if stroke suspected; antibiotic treatment of bacterial labyrinthitis: emergency IV antibiotic therapy: ceftriaxone (Rocéphine) 2 g IV × 1/d → broad coverage + penetration into inner ear → if associated meningitis → ceftriaxone 2 g IV × 2/d + dexamethasone IV 0.15 mg/kg × 4/d × 2-4 days → reduction of meningeal inflammation → reduction of risk of auditory sequelae → Van de Beek 2010 - NEJM : dexamethasone + bacterial meningitis → reduced neurological + auditory sequelae → if allergic to cephalosporins → chloramphenicol or vancomycin + rifampicin → meningitis: see standard protocol + if suppurative AOM with labyrinthitis + mastoiditis: myringotomy + tympanic paracentesis (drainage of AOM) → or mastoidectomy if extensive mastoiditis → double drainage: middle ear + mastoid → IV antibiotic therapy × 7-14 days → then oral relay according to antibiogram → amoxicillin-clavulanate 875/125 mg × 2/d → or amoxicillin if susceptible pneumococcus → auditory sequelae of bacterial labyrinthitis: severe to profound permanent hypoacusis in 20-40 % of bacterial labyrinthitis → cochlear ossification (ossified labyrinth) if severe bacterial labyrinthitis → compromises cochlear implant insertion → early cochlear implantation (before ossification if possible - within weeks of labyrinthitis) → prevention: pneumococcal vaccination (Prevnar 13 + Prevnar 20 + Pneumovax 23) → meningococcal vaccination → early and complete treatment of AOM → no use of insufficient antibiotics + ENT follow-up of any complicated AOM. | Van de Beek 2010 — NEJM: dexamethasone + bacterial meningitis → reduced neurological + auditory sequelae → reference + Van de Beek 2016 — NEJM (meta-analysis): corticosteroids + bacterial meningitis → reduced mortality + sequelae + AAO-HNS 2019 + IDSA 2019 (Tunkel): bacterial meningitis → treatment + ceftriaxone + dexamethasone → Bhattacharyya 2017 — Otolaryngology Head and Neck Surgery: bacterial labyrinthitis → treatment → ENT emergency + SOGC + MSSS + INSPQ Quebec: pneumococcal + meningococcal vaccination → Health Canada: Prevnar 13 + Prevnar 20 + Pneumovax 23 → Quebec vaccination programs + cochlear implant: early discussion after severe bacterial labyrinthitis → RAMQ + MSSS: cochlear implant covered if criteria met |
| Vestibular rehabilitation and long-term recovery Central vestibular compensation — vestibular rehabilitation — Cawthorne-Cooksey exercises — vestibular physiotherapy — residual instability — chronicity — vestibular neuritis — residual hearing loss — prognosis — return to work |
Recovery and central vestibular compensation: mechanism of central compensation: the central nervous system (cerebellum + brainstem) detects the asymmetry of vestibular signals (injured side vs. healthy side) → progressive compensation → reduction of vertigo → improvement of balance → this process takes 4 to 8 weeks for resting vertigo + several months for instability on walking and exertion → vestibular suppressants (dimenhydrinate + benzodiazepines) slow down this process by reducing vestibular input → hence the importance of stopping them quickly (maximum 3-5 days) + vestibular rehabilitation (specialized physiotherapy) : specific exercises to stimulate and accelerate central compensation: Cawthorne-Cooksey exercises (historical): progressive head + eye + trunk movements → progressive sensitization → adaptation + gaze stabilization exercises (VOR - Vestibulo-Ocular Reflex): head rotations with target fixation → reinforcement of residual VOR + balance + walking exercises + vestibular rehabilitation results: Yardley 1998 - Quarterly Journal of Medicine: vestibular physiotherapy + chronic vertigo → significant improvement vs. control group → Hillier 2011 - Cochrane: vestibular rehabilitation + vestibular neuritis + labyrinthitis → well-established efficacy → recommended → start: as soon as patient can mobilize (often D3-J5 post-start) → reference in vestibular physiotherapy → trained professionals + available in Quebec + viral labyrinthitis prognosis: vertigo: complete resolution in 80-90 % of cases in 6-8 weeks + residual instability: 20-30 % of patients retain mild instability on exertion or fatigue → vestibular physiotherapy helps → residual hypoacusis: if viral labyrinthitis → often partial and stable → if bacterial labyrinthitis → severe to profound deafness possible → cochlear implant + return to work: usually 2-4 weeks for non-physical professions + longer if risky work (height + driving vehicles) → Meniere's disease in differential: if recurrent vertigo (≥2 episodes >20 min) + fluctuating hypoacusis + tinnitus + auricular fullness → diagnostic criteria (AAO-HNS 1995 + 2020) → betahistine + diuretics (hydrochlorothiazide-triamterene) + low-salt diet → intratympanic gentamicin injection if refractory (chemical ablation of vestibule) | Hillier 2011 — Cochrane: vestibular rehabilitation + vestibular neuritis + labyrinthitis → effectiveness → strong recommendation + Yardley 1998 — Quarterly Journal of Medicine: vestibular physiotherapy + chronic vertigo → significant improvement + Strupp 2004 — Lancet: methylprednisolone + vestibular neuritis → recovery + Bhattacharyya 2017 — Otolaryngology Head and Neck Surgery: vestibular neuritis + labyrinthitis + rehabilitation + Kattah 2009 — Stroke: HINTS + acute vestibular syndrome + stroke vs. peripheral + Newman-Toker 2021 — Stroke: HINTS + MRI + vestibular syndrome + NICE 2017: labyrinthitis + vertigo → vestibular rehabilitation + AAO-HNS 1995 + 2020: Meniere's disease criteria + Ordre professionnel de la physiothérapie du Québec (OPPQ): physiotherapists trained in vestibular rehabilitation + INESSS Québec + RAMQ: vestibular physiotherapy partially reimbursed + betahistine Serc reimbursed |
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Vestibular suppressants (dimenhydrinate + prochlorperazine) should not be used for more than 3-5 days—they slow central compensation and delay recovery: Vestibular rehabilitation (specialized physical therapy with Cawthorne-Cooksey exercises and gaze stabilization) is the most effective treatment for accelerating recovery from day 3–5. The HINTS test (Head Impulse + Nystagmus type + Test of Skew) is more accurate than early MRI for distinguishing labyrinthitis from a brainstem stroke—multidirectional nystagmus or a negative HIT in acute vestibular syndrome warrants an urgent MRI.
Situations requiring urgent consultation or a call to 911
Acute vestibular syndrome (severe vertigo + nausea + instability) + multidirectional nystagmus (changes direction with gaze) + negative HIT + skew deviation + associated neurological signs (dysphagia + dysarthria + diplopia + severe ataxia + sudden headache) Brainstem stroke (AICA or PICA) - not labyrinthitis - call 911 - emergency diffusion MRI - stroke management.
Child or adult with acute otitis media (ear pain + ear discharge + fever) + onset of intense dizziness + sudden hearing loss + nystagmus + stiff neck Bacterial labyrinthitis + possible meningitis → medical emergency → call 911 → lumbar puncture if meningitis → ceftriaxone IV 2 g + dexamethasone IV → urgent ENT consultation → myringotomy + paracentesis + or mastoidectomy as indicated.
Patient with Ramsay Hunt syndrome (vesicles on auricle + ear canal) + facial paralysis + intense vertigo + hearing loss → Ramsay Hunt syndrome (VZV) → geniculate herpes zoster → ENT + neurological emergency → valacyclovir 1 g TID for 7-10 days + prednisone 60 mg daily for 5 days → to reduce the risk of facial and auditory sequelae → ENT consultation within 72 hours.
Patient with a history of severe bacterial labyrinthitis (<4-6 weeks) + persistent unilateral profound hearing loss → ongoing cochlear ossification → urgent cochlear ENT consultation to discuss early cochlear implant BEFORE ossification → each week of delay increases the risk of inability to insert the cochlear electrode.
Consult at Clinique Omicron
Clinique Omicron's doctors diagnose viral labyrinthitis (vertigo + hypoacusis + tinnitus + unilateral horizontal nystagmus + positive HIT), use the HINTS test to rule out stroke, prescribe symptomatic treatment (dimenhydrinate + prochlorperazine + corticosteroids if significant hypoacusis), refer urgently if the presentation is atypical or central, and refer for vestibular physiotherapy as soon as the patient can mobilize. Consultations are available at several points of service in Quebec, and via telemedicine. To book an appointment, visit cliniqueomicron.ca.
The content of this page is for informational purposes only and does not substitute for the advice of a physician, neurologist, or ENT. Acute vestibular syndrome with associated neurological signs or atypical nystagmus requires urgent evaluation to rule out a brainstem stroke.
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