Tinnitus (Ear Ringing)

Tinnitus is the conscious perception of an auditory sensation in the absence of a corresponding external stimulus. It can be subjective (heard only by the patient) or objective (audible to the examiner, often pulsatile). Most cases are subjective and associated with sensorineural hearing loss due to noise exposure, presbycusis, ototoxic medications, Meniere's disease or vestibular schwannoma.

Pathophysiology involves maladaptive neural plasticity in the central auditory pathway following peripheral cochlear damage. Reduced afferent input leads to increased spontaneous firing and synchrony in the dorsal cochlear nucleus, inferior colliculus and auditory cortex, generating phantom auditory perception. Limbic and autonomic networks contribute to emotional distress and chronicity.

Pulsatile tinnitus may indicate vascular pathology (carotid stenosis, dural arteriovenous fistula, sigmoid sinus dehiscence, intracranial hypertension) and warrants imaging. Comprehensive evaluation includes audiometry, otoscopy, neurological examination and selected imaging (MRI for asymmetric tinnitus or unilateral sensorineural hearing loss).