What causes tinnitus
Tinnitus is the perception of sound without an external source, most commonly described as ringing, buzzing, hissing or roaring in one or both ears. It is a symptom, not a disease, with numerous potential causes. The most common cause is sensorineural hearing loss from age-related degeneration (presbycusis) or noise exposure, which reduces auditory input and leads the brain to generate compensatory neural activity perceived as sound. Subjective tinnitus (heard only by the patient) accounts for the vast majority of cases; objective tinnitus (heard by the examiner too, often vascular or palatal) is rare.
Neurological causes requiring evaluation include vestibular schwannoma (acoustic neuroma) — a benign tumour on the vestibulocochlear nerve that typically presents with unilateral tinnitus and gradual hearing loss, sometimes with dizziness; vascular abnormalities (arteriovenous malformation, dural arteriovenous fistula, carotid stenosis) producing pulsatile tinnitus synchronous with heartbeat; medication-induced tinnitus (aspirin in high doses, aminoglycoside antibiotics, loop diuretics, quinine, certain chemotherapy agents); and central neurological conditions affecting auditory processing. Eustachian tube dysfunction, temporomandibular joint (TMJ) disorders and middle ear pathology are common non-neurological causes that should also be excluded.
- Sensorineural hearing loss — most common cause, age-related or noise-induced
- Vestibular schwannoma — unilateral tinnitus with hearing loss, dizziness
- Vascular — pulsatile tinnitus, arteriovenous malformation, carotid stenosis
- Medication-induced — aspirin, aminoglycosides, loop diuretics, quinine
- TMJ and Eustachian tube dysfunction — non-neurological causes
Related: Neurologist Kathmandu → · Dr. Jitendra Knowledge Hub → · ICHD-3 Topic →
When neurological evaluation is needed
Tinnitus warrants neurological evaluation when it is unilateral, pulsatile (synchronous with heartbeat), progressive, or accompanied by hearing loss, dizziness or other neurological symptoms. Unilateral tinnitus with ipsilateral hearing loss is the classic presentation of vestibular schwannoma and requires MRI with gadolinium contrast. Pulsatile tinnitus may indicate a vascular abnormality requiring imaging (CT angiography or MR angiography) and potentially interventional treatment.
Evaluation includes detailed history of tinnitus characteristics (continuous vs pulsatile, unilateral vs bilateral, pitch, loudness), associated symptoms (hearing change, dizziness, fullness, pain), medication history, noise exposure, and impact on sleep and quality of life. Audiometry quantifies hearing loss and may demonstrate speech discrimination asymmetry suggestive of vestibular schwannoma. Neurological examination screens for cranial nerve abnormalities, particularly hearing and vestibular function. Brain imaging with MRI (including internal auditory canal sequences) is considered when vestibular schwannoma, central vascular abnormalities or other structural causes are suspected. Dr. Jitendra Prasad Yadav (NMC 8029) evaluates tinnitus with neurological context at Kathmandu Neurology Clinic & Cognitive Center, Durbar Marg, Opposite of Yak & Yeti Hotel, distinguishing neurological from non-neurological causes and referring to audiology and ENT as appropriate.
- Unilateral tinnitus — MRI to exclude vestibular schwannoma
- Pulsatile tinnitus — CT or MR angiography for vascular causes
- Tinnitus with hearing loss, dizziness or cranial nerve signs — neurological review
- Medication review — aspirin, aminoglycosides, loop diuretics
- Audiometry and speech discrimination — quantify hearing loss