Understanding Dangerous Tinnitus

By Dr. Chien-Chih Chen (ENT & Neurology Specialist, Yuan Jing ENT & Neurology Clinic)

According to Contemporary Basic Neurology (edited by Dr. Chien-Chih Chen), dangerous tinnitus can be classified into the following two categories:

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1. Tinnitus Requiring Urgent Medical Attention:

(1) Sudden sensorineural hearing loss: cochlear neuritis (e.g., Ramsay Hunt syndrome), auditory neuritis, etc.

(2) Epileptic seizures: Although tinnitus is rarely the initial manifestation of epilepsy, it may indicate a psychiatric disorder or one of several relatively benign conditions. Patients with lesions involving the superior temporal gyrus may report buzzing or rumbling sounds in the ears. If the lesion is located in the posterior temporal lobe on one side, patients may hear voices (sometimes repetitive, unintelligible sentences) or music. Some patients with auditory aura epilepsy and a strong family history have normal neuroimaging findings but are found to carry LGI1 gene mutations.

(3) Cerebral ischemia or infarction: vertebrobasilar insufficiency, migraine with brainstem aura, brainstem stroke (e.g., Millard-Gubler syndrome), Susac syndrome (retinocochleocerebral vasculopathy), MELAS syndrome (mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes), NARP syndrome (neuropathy, ataxia, retinitis pigmentosa), Fabry disease, homocystinuria, antiphospholipid syndrome, etc.

(4) Intracranial hemorrhage: cerebellar hemorrhage compressing the auditory nerve, etc.

(5) Inflammatory diseases affecting the brainstem: multiple sclerosis, brainstem encephalitis (viral infection), etc.

(6) Risk of self-harm or suicide: depression, schizophrenia, somatic symptom or conversion disorders, personality disorders, etc.

(7) Others, etc.
 

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2. Non-Urgent but Potentially Serious Tinnitus:

(1) Head and neck tumors associated with tinnitus: nasopharyngeal carcinoma, middle ear effusion following radiotherapy for head and neck cancer, etc.

(2) Intracranial tumors: metastatic brain tumors, cerebellopontine angle tumors (e.g., vestibular schwannoma or meningioma), etc.

(3) Intracranial vascular abnormalities: carotid-cavernous fistula (CC fistula), persistent trigeminal artery, etc.

(4) Intracranial infectious or inflammatory diseases: neuroborreliosis (Lyme disease), neurosarcoidosis, neurosyphilis, relapsing polychondritis, brainstem encephalitis (paraneoplastic syndrome, anti-NMDA receptor encephalitis), etc.

(5) Chronic intracranial hemorrhagic disorders: superficial siderosis of the central nervous system, etc.

(6) Nucleus accumbens syndrome: commonly referred to as "tinnitus addiction syndrome," etc.

(7) Others, etc.

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With the exception of sudden sensorineural hearing loss and middle ear effusion, most of these forms of "tinnitus" are actually of central nervous system origin ("brain tinnitus"). Therefore, when evaluating tinnitus, it is essential to distinguish between true ear-related tinnitus and brain-related tinnitus. ```