Tinnitus and Labyrinthitis Quiz

Inner Ear (Tinnitus & Vertigo)

• Tinnitus is any sound perceived by a listener that is not from an external source for more than five minutes, absent external stimulation, and not immediately following loud noise exposure.
• Disturbing tinnitus affects 3-5% of individuals experiencing tinnitus.
• Two tinnitus types:
• Subjective: only heard by the patient (95%)
• Objective: detectable by an examiner with a stethoscope, often pulsatile (synced with heartbeat).
• Subjective tinnitus is more common than objective.
• Tinnitus causes can be:
• Unilateral: Non-pulsatile causes include idiopathic, noise-induced, and intracranial tumors. With hearing loss causes include idiopathic, presbycusis & noise-induced, drugs, and Meniere's disease. Pulsatile causes include aneurysm, vascular malformation, and glomus tumor.
• Bilateral: Non-pulsatile causes include idiopathic and drugs. With normal hearing causes include idiopathic and drugs. Pulsatile/objective causes include idiopathic, anaemia, and hypertension.
• 80% of patients with sensorineural hearing loss (SNHL) experience tinnitus.
• Hearing loss causes changes in auditory system neural activity, interpreted as sound by the brain; this resembles phantom limb syndrome.
• Areas of damaged cochlea hair cells cannot amplify sounds, creating a perceived phantom sound.

History

• Important features include sound quality (tonal, hissing, buzzing, clicking, ringing), localization (unilateral vs. bilateral, position), temporal features (episodic, fluctuating, constant, pulsatile), interaction with external sounds/ masking/inhibition/exacerbation, pitch (high—inner ear; cracking—middle ear; pulsating—vascular), and loudness.

Physical Examination

• Palpation/light compression of the jugular vein can lessen venous-origin tinnitus. Valsalva manoeuvre can achieve a similar effect.
• Auscultation of the neck/cranium can detect carotid bruit/blood turbulence from arteriovenous malformation.
• Otoscopy/Otomicroscopy can reveal glomus tumors or tympanic hemangiomas.
• Oropharyngeal exam can show soft palate contraction in palatal myoclonus.

Investigations

• Tympanometry may show myoclonic activity and patulous Eustachian tube.
• Pure-tone audiometry can detect conductive hearing loss secondary to vascular lesions affecting the middle ear.
• Gadolinium-enhanced CT or MRI imaging is frequently necessary.
• Patulous Eustachian tube (PET) is where the Eustachian tube remains intermittently open, causing autophony (hearing self-generated sounds).

Management

• Tinnitus is a symptom, not a disease. Seek treatment for the cause.
• Reassurance/psychotherapy may be needed. Relaxation techniques/biofeedback may be useful.
• Sedation/tranquilizers may be needed initially for symptom adjustment.
• Masking, using noise to cover up the tinnitus, is often effective. Traditional/newer hearing aids with tinnitus masking.
• Sound machines/environmental noise can mask at night.

Vertigo

• Vertigo is the illusion of motion of oneself or the surroundings.
• Chief complaint is often dizziness, not vertigo in vestibular system injury.
• Vertigo is typically not permanent or continuous; the central nervous system adapts to the vestibular lesion.
• Constant dizziness lasting months is not usually vestibular in origin, often due to episodic dizziness.
• Vertigo duration-based causes:
• Seconds: Benign Paroxysmal Positional Vertigo (BPPV)
• Minutes: Migraine-associated vertigo, Vertebrobasilar insufficiency
• Hours: Meniere's disease (endolymphatic hydrops), Otic syphilis
• Weeks: CNS disorders, Multiple sclerosis, Acoustic neuromas, autoimmune diseases
• Variable duration: Inner ear fistula, Lyme disease, Labyrinthine concussion, blast trauma, barotrauma, superior semicircular canal dehiscence syndrome.
• Days: Vestibular neuritis, Labyrinthitis

Vertigo Types

• Peripheral: more severe, short-lived, associated with peripheral symptoms (tinnitus, hearing loss, ear discharge, otalgia), associated with peripheral nystagmus
• Central: milder, long-lived and chronic, associated with central symptoms (diplopia, slurred speech, dysarthria, dysphoria), associated with central nystagmus

Diagnosis

• Diagnosis relies primarily on history (onset, character, duration, relation to head movements, associated symptoms like tinnitus/hearing loss) and physical examination, with limited need for investigative procedures.
• Neurological symptoms (loss of consciousness, weakness, numbness, dysarthria, diplopia) are relevant to the diagnosis.

BPPV

• Sudden vertigo lasting seconds associated with specific head positions.
• No associated hearing loss.
• Characteristic nystagmus (latent, geotropic, fatigable) evident in the Dix-Hallpike test.
• Posterior semicircular canal (PSC) most commonly affected (93% unilateral, 8% bilateral).
• Presentation typically in the 5th decade, with approximately 20% of vertigo clinic patients diagnosed with BPPV.
• Recurrence rate of about 10-15% per year likely due to canalithiasis.

Predisposing Factors for BPPV

• Circumstances placing the head in inverted orientations (e.g., dental procedures, hairdressing).
• Age, inactivity, and family history
• Trauma, vestibular neuritis, other ear diseases, Meniere's syndrome
• Triggering positions (e.g., rolling over, getting out of bed, looking up/back, bending over).
• Dix Hallpike Test: latent period (1-5 seconds) is followed by acute vertigo/nystagmus towards affected side (typically 10-40 seconds), repeated testing.

Treatment of PSC BPPV

• Treatment Repositioning, using gravity to move canalith debris out of the affected semi-circular canal and into the vestibule using maneuvers (e.g., Epley maneuver).
• Epley maneuver repeated until no nystagmus occurs (effective in >90% of cases for BPPV elimination).
• Epley maneuver steps (illustrated on page 23).

Meniere's Disease

• Endolymphatic hydrops (excessive endolymph build-up). Etiology unknown.
• Secondary hydrops from head trauma or surgery, or due to inner ear disorders, allergies, or systemic conditions (e.g., diabetes, autoimmune).
• Episodic vertigo (hours), fluctuating hearing loss, tinnitus, pulsatile aural pressure are diagnostic features (unilateral onset but in 25% of cases is bilateral).

Vestibular Neuritis

• Vertigo lasting days after upper respiratory infection.
• No hearing loss.
• No other neurological signs/symptoms.
• Viral infections, vascular occlusion, and immunologic mechanisms are potential causes.
• Postural instability toward injured ear but patient can typically walk normally.

Labyrinthitis

• Viral induced Endolabyrinthitis; not fatal unless it causes suppurative labyrinthitis which can lead to meningitis and fatal.
• Suppurative Labyrinthitis: vertigo + permanent SNHL.
• Routes of spreading into labyrinth:
• Acute otitis media (AOM)
• Weakened oval window membrane (post stapes surgery)
• Dehiscent oval window (congenital labyrinthine deformities)
• Cholesteatomatous lateral semi-circular canal fistula.

Diffuse Suppurative Labyrinthitis

• Caused by S. pneumoniae; H. influenzae; Neisseria meningitides
• Management includes admission and i.v antibiotics to prevent further bacterial invasion.
• Other related ear disorders include Ramsay Hunt syndrome (herpes zoster oticus) that can cause vertigo, hearing loss, facial paralysis, ear pain, and vesicles in auditory canal/auricle. Acoustic neuroma is caused by a tumor of the nerve tissue. Typical symptoms are ringing, vertigo, and hearing loss in one ear.

General Management

• Stabilize body's fluid/electrolyte balance including a hydrops diet (minimize solutes, adequate fluid, limit caffeine/alcohol).
• Physicians can prescribe diuretics along with environment modifications
• Manage persistent symptoms including aminoglycoside therapy like intratympanic gentamicin (10% risk of worsening hearing loss, but is used for secondary issues).
• Other surgical measures include endolymphatic sac decompression, vestibular neurectomy, and labyrinthectomy.