6.2 Ear, Hearing & Vestibular Disorders
Key Takeaways
- Sudden sensorineural hearing loss is defined as a loss of at least 30 decibels across three contiguous frequencies within 72 hours and is an otologic emergency requiring corticosteroids and audiometry within days, not weeks.
- In the Weber test, sound lateralizes to the affected ear in conductive hearing loss and to the better-hearing ear in sensorineural loss; the Rinne test shows bone conduction greater than air conduction only in conductive loss.
- Benign paroxysmal positional vertigo produces brief positional vertigo with upbeating torsional nystagmus on Dix-Hallpike that has a latency of a few seconds and fatigues, and it is treated with the Epley canalith repositioning maneuver rather than with medication.
- Necrotizing (malignant) otitis externa should be suspected in an older adult with diabetes who has severe otalgia and granulation tissue on the floor of the ear canal, and it requires urgent otolaryngology referral with systemic antipseudomonal therapy.
- Aminoglycoside-containing otic drops such as neomycin are contraindicated when the tympanic membrane is perforated or tympanostomy tubes are present because of ototoxicity; use a fluoroquinolone otic preparation instead.
Ear, Hearing & Vestibular Disorders
Hearing loss affects roughly two-thirds of adults over age 70 and is independently associated with social isolation, depression, falls and accelerated cognitive decline. Dizziness is one of the most common presenting complaints in adults over 65 and one of the most frequently mismanaged, because the reflex is to prescribe meclizine before the mechanism is established.
1. Bedside Differentiation: Conductive vs. Sensorineural
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| WEBER AND RINNE: THE 2 x 2 THAT GETS TESTED |
| |
| WEBER (512 Hz fork on the vertex/forehead midline) |
| - Normal ........................ Midline, heard equally |
| - CONDUCTIVE loss ............... Lateralizes TO the AFFECTED ear |
| - SENSORINEURAL loss ............ Lateralizes AWAY, to the BETTER ear |
| |
| RINNE (fork on mastoid, then beside the ear canal) |
| - Normal ........................ AC > BC (positive Rinne) |
| - SENSORINEURAL loss ............ AC > BC (still positive - both are |
| reduced proportionally) |
| - CONDUCTIVE loss ............... BC > AC (negative Rinne) IN THAT EAR |
| |
| Memory hook: the Rinne only "flips" in CONDUCTIVE loss. Weber does the |
| work of telling you which side. |
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Conductive causes sit in the canal or middle ear: cerumen impaction, otitis externa with canal edema, otitis media with effusion, tympanic membrane perforation, cholesteatoma, otosclerosis. Sensorineural causes sit in the cochlea or the eighth nerve: presbycusis, noise-induced loss, ototoxicity, Meniere disease, vestibular schwannoma, sudden sensorineural hearing loss.
Presbycusis is the prototype: bilateral, symmetric, gradual, high-frequency sensorineural loss with disproportionate difficulty understanding speech in noisy environments and with high-pitched voices. Asymmetry is the red flag - unilateral or markedly asymmetric sensorineural loss requires audiometry and MRI to exclude a vestibular schwannoma.
Ototoxic medications to know: aminoglycosides (gentamicin, tobramycin - both cochleotoxic and vestibulotoxic), loop diuretics at high dose or rapid infusion, cisplatin, high-dose salicylates (reversible tinnitus and hearing loss), quinine, and vancomycin in combination.
[!IMPORTANT] Sudden sensorineural hearing loss is an otologic emergency. Defined as a loss of >= 30 dB over at least 3 contiguous frequencies occurring within 72 hours, usually unilateral, often noticed on waking, and frequently accompanied by aural fullness and tinnitus. The critical bedside step is a Weber test: it lateralizes to the unaffected ear, which distinguishes it from the far more common cerumen impaction, where Weber lateralizes to the blocked ear. Management is urgent audiometry and otolaryngology referral within days plus systemic (or intratympanic) corticosteroids, ideally started within 2 weeks; MRI is obtained to exclude retrocochlear pathology. Attributing sudden unilateral loss to "wax" without examining the canal is the classic miss.
Screening. The USPSTF concluded that evidence is insufficient (Grade I) to assess screening for hearing loss in asymptomatic adults 50 years and older. Nonetheless, ask about hearing at every visit in older adults, and refer for formal audiometry when the patient or family reports difficulty, since untreated hearing loss is a modifiable dementia risk factor and hearing aids are now available over the counter for perceived mild to moderate loss in adults.
2. External and Middle Ear Disease
| Condition | Hallmark | Management |
|---|---|---|
| Cerumen impaction | Conductive loss, fullness; obscured tympanic membrane | Cerumenolytic, irrigation or manual removal. Do not irrigate if there is a known or suspected perforation, tympanostomy tubes, prior ear surgery, or an immunocompromised or diabetic patient at risk of malignant otitis externa. |
| Acute otitis externa ("swimmer's ear") | Pain on tragal traction or auricular pull, canal edema and debris, normal hearing early | Aural toileting plus topical therapy: ciprofloxacin-dexamethasone or ofloxacin drops for 7 days. Keep the ear dry. Systemic antibiotics only if infection extends beyond the canal or the patient is immunocompromised or diabetic. |
| Necrotizing (malignant) otitis externa | Older adult with diabetes or immunocompromise; severe deep otalgia out of proportion, granulation tissue on the floor of the canal at the bony-cartilaginous junction, possible cranial nerve VII palsy | Urgent otolaryngology referral. Pseudomonas aeruginosa skull-base osteomyelitis. Imaging (CT/MRI, nuclear scan) and prolonged systemic antipseudomonal therapy such as ciprofloxacin. |
| Acute otitis media | Bulging, opaque, immobile tympanic membrane with otalgia and fever | Uncommon in adults, and adults are less likely to resolve spontaneously. Treat with amoxicillin or amoxicillin-clavulanate; consider a nasopharyngeal source if unilateral and recurrent in an adult. |
| Otitis media with effusion | Retracted or neutral membrane, air-fluid level or bubbles, conductive loss without acute inflammation | Observe. Persistent unilateral effusion in an adult mandates nasopharyngoscopy to exclude nasopharyngeal carcinoma or another obstructing mass. |
| Tympanic membrane perforation | Sudden pain relief after severe otalgia, or trauma; visible defect | Keep dry, avoid irrigation and ototoxic drops, most heal spontaneously; refer if not healed at 3 months or if hearing loss persists. |
[!WARNING] The otic-drop rule. Neomycin-containing preparations (for example neomycin-polymyxin B- hydrocortisone) are contraindicated when the tympanic membrane is perforated or tympanostomy tubes are in place, because aminoglycoside entry into the middle ear is ototoxic. Use a fluoroquinolone otic drop (ofloxacin or ciprofloxacin), which is safe across an open membrane.
3. The Dizzy Patient
Start by making the patient describe the sensation without using the word "dizzy." Four categories emerge: vertigo (an illusion of movement), presyncope, disequilibrium (unsteadiness on the feet) and non-specific lightheadedness. Then ask about timing and triggers, which is more discriminating than the quality of the sensation.
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| PERIPHERAL VERTIGO: TIMING AND TRIGGERS |
| |
| SECONDS TO < 1 MINUTE, TRIGGERED BY HEAD POSITION |
| -> BENIGN PAROXYSMAL POSITIONAL VERTIGO (BPPV) |
| Otoconia in the posterior semicircular canal. NO hearing loss. Rolling over in bed, |
| looking up to a shelf, or lying back at the dentist. Dix-Hallpike is diagnostic. |
| |
| 20 MINUTES TO 12 HOURS, EPISODIC AND SPONTANEOUS |
| -> MENIERE DISEASE |
| The tetrad: episodic vertigo + FLUCTUATING LOW-frequency sensorineural hearing loss + |
| tinnitus + aural fullness. Endolymphatic hydrops. Low-sodium diet, thiazide diuretic, |
| vestibular rehabilitation; refer to otolaryngology. |
| |
| DAYS, CONTINUOUS, SINGLE EPISODE |
| -> VESTIBULAR NEURITIS (no hearing loss) |
| -> LABYRINTHITIS (same, PLUS hearing loss) |
| Often post-viral. Short course of vestibular suppressant for <= 3 days ONLY, then early |
| vestibular rehabilitation - prolonged meclizine prevents central compensation. |
| |
| MINUTES TO HOURS WITH HEADACHE, PHOTOPHOBIA, PHONOPHOBIA |
| -> VESTIBULAR MIGRAINE (a common and underdiagnosed cause in adults) |
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Dix-Hallpike maneuver. With the patient seated, turn the head 45 degrees toward the test side, then rapidly lay the patient supine with the head extended about 20 degrees below horizontal. A positive posterior-canal BPPV response is upbeating torsional nystagmus that begins after a latency of 2 to 20 seconds, lasts less than a minute, and fatigues on repetition. Treatment is the Epley canalith repositioning maneuver, which is effective in roughly 80 percent of patients after one or two sessions. Vestibular suppressants do not treat BPPV and increase fall risk; meclizine, promethazine and scopolamine all carry anticholinergic burden and appear on the Beers Criteria for older adults.
Distinguishing central from peripheral: the HINTS examination. In a patient with acute continuous vertigo with nystagmus (the acute vestibular syndrome), three bedside tests together outperform early MRI for detecting stroke:
| Component | Peripheral (reassuring) | Central (dangerous) |
|---|---|---|
| Head Impulse test | Abnormal - a corrective saccade is present | Normal - no corrective saccade |
| Nystagmus | Unidirectional, horizontal, suppressed by fixation | Direction-changing with gaze, or vertical/torsional |
| Test of Skew (alternate cover) | Absent | Present - vertical skew deviation |
A normal head impulse test in a patient with acute continuous vertigo is not reassuring - it points to a central lesion. Any central feature, or any new neurologic sign (dysarthria, dysphagia, diplopia, ataxia out of proportion, limb weakness or numbness), mandates emergent stroke evaluation. Cerebellar and lateral medullary (Wallenberg) strokes commonly present as isolated vertigo in older adults with vascular risk factors.
Persistent postural-perceptual dizziness is chronic non-vertiginous unsteadiness worsened by upright posture and complex visual environments, often following an acute vestibular event; it responds to vestibular rehabilitation and SSRIs rather than to suppressants.
Tinnitus. Bilateral, non-pulsatile tinnitus with presbycusis is usually benign; treat the hearing loss and offer sound therapy and cognitive behavioral therapy. Unilateral tinnitus requires audiometry and MRI for vestibular schwannoma, and pulsatile tinnitus requires vascular imaging to evaluate for a dural arteriovenous fistula, carotid stenosis, glomus tumor or idiopathic intracranial hypertension.
A 58-year-old man awoke 2 days ago unable to hear from his left ear, with left aural fullness and a new roaring tinnitus. There is no pain, discharge, vertigo or preceding illness. The left ear canal and tympanic membrane are normal on otoscopy. A 512 Hz Weber test lateralizes to the right ear, and the Rinne test shows air conduction greater than bone conduction bilaterally. What is the most appropriate action?
A 66-year-old woman reports 5 days of brief spinning episodes lasting about 30 seconds that occur when she rolls over in bed or tips her head back. She has no hearing loss, tinnitus, headache or neurologic symptoms. Dix-Hallpike to the right produces upbeating torsional nystagmus after a 5-second latency that lasts 25 seconds and lessens on repeat testing. What is the most appropriate treatment?
A 74-year-old man with poorly controlled type 2 diabetes (A1c 9.8 percent) has 3 weeks of severe deep left ear pain that keeps him awake, worse than the examination findings would suggest. The canal contains granulation tissue at the bony-cartilaginous junction and scant discharge; the tympanic membrane is intact. He is afebrile. Which management plan is correct?