creation date: 2026-04-26 20:19
tags: Workups
Tinnitus
Background
Tinnitus is classically described as a high-pitched ringing or buzzing that is only audible to the patient.
Tinnitus is most commonly subjective (examiner cannot hear it) but objective tinnitus can occur from an aneurysm.
Pathophysiology
Tinnitus can occur from a number of conditions. The pathophysiology of primary tinnitus is not fully understood. It is generally thought to be a combination of peripheral cochlear injury and central auditory system adaptation.
Peripheral cochlear injury may include:
- Outer hair cells
- Inner hair cells
- Stereocilia
- Cochlear nerve
When sound input drops due to cochlear injury, the auditory system attempts to increase “gain” to compensate which results in the phantom perception of sound.
Differential Diagnosis
Primary tinnitus
Idiopathic, often associated with sensorineural hearing loss (eg. presbycusis, noise-related).
Secondary tinnitus
Vascular:
- Arterial bruit
- Arteriovenous malformation
- Carotid atherosclerosis, dissection, tortuosity
- Paget disease
- Vascular tumours
- Venous hum
Infectious:
- Bacterial (Lyme, syphilis), fungal, viral
Neurologic:
- Idiopathic intracranial hypertension
- Idiopathic stepedial or tensor tympani muscle spasm
- Multiple sclerosis
- Palatal myoclonus
- Spontaneous intracranial hypotension
- Type 1 Chiari malformation
- Vestibular migraine
Iatrogenic:
- Drug induced (incl. NSAIDs, antibiotics, vaccines; some at high doses)
- Cerumen removal
Otologic:
- Cerumen impaction
- Cholesteatoma
- Foreign body
- Meniere disease
- Middle ear effusion
- Otitis
- Otosclerosis
- Patulous eustachian tube
- Tympanic membrane perforation
- Vestibular schwannoma
Somatic:
- Head or neck injury
- TMJ dysfunction
Initial Evaluation
History
Red flags are should include:
- Pulsatile tinnitus
- Asymmetric tinnitus or hearing loss associated
- Focal neurologic abnormalities
Once red flags are ruled out, a tinnitus history includes:
- Onset/duration (6 month cutoff for acute)
- Provocation by positional changes or activity
- Quality
- Ringing/buzzing/hissing (primary tinnitus)
- Roaring/loss of low-frequency hearing (Meniere)
- Rhythmic clicking (myoclonus/spasms)
- Pulsatile (vascular lesion)
- Severity (mild, moderate, severe)
- Location (uni- vs. bilateral)
Associated symptoms include:
- Ear drainage and pain
- Vertigo, imbalance
- Hearing loss (asymmetric/unilateral vs. symmetric)
- Headache
Physical Exam
The physical exam consist of:
- Neurological exam (incl. cerebellar testing, cranial nerves, ocular)
- Ear inspection
- MSK (TMJ)
- Vascular (examine for bruits over ear canal/periauricular, carotids)
Investigations
Imaging studies are indicated for tinnitus that is:
- Unilateral
- Pulsatile
- Associated with asymmetric hearing loss
- Associated with neurologic abnormalities
MRI with and without contrast is the preferred imaging modality for asymmetric or unilateral, nonpulsatile tinnitus.
Temporal-bone CT without contrast or head CT angiography is preferred for pulsatile tinnitus.
Laboratory testing is generally not routine unless there is clinical suspicion for a specific contributing condition.
In cases without red flags but are associated with hearing loss or is bothersome without hearing loss, a prompt (within 4 weeks) audiologic evaluation is indicated.