From the Guidelines
Tinnitus is caused by a variety of factors, including damage to the tiny sensory hair cells in the inner ear, age-related hearing loss, prolonged exposure to loud noises, or sudden acoustic trauma, as well as other causes such as earwax blockage, ear bone changes, Meniere's disease, blood vessel disorders, and certain medications known as ototoxic drugs 1. The causes of tinnitus can be classified into different categories, including primary and secondary tinnitus, subjective and objective tinnitus, and pulsatile and nonpulsatile tinnitus. Primary tinnitus is idiopathic, whereas secondary tinnitus is associated with an underlying cause. Subjective tinnitus is perceived by the patient only and comprises 70% to 80% of cases, while objective tinnitus can be detected on examination by the clinician 1. Some of the key factors that contribute to tinnitus include:
- Damage to the tiny sensory hair cells in the inner ear
- Age-related hearing loss
- Prolonged exposure to loud noises
- Sudden acoustic trauma
- Earwax blockage
- Ear bone changes (otosclerosis)
- Meniere's disease
- Blood vessel disorders
- Certain medications known as ototoxic drugs, particularly some antibiotics, cancer medications, diuretics, and high doses of aspirin
- Head or neck injuries
- Temporomandibular joint (TMJ) disorders
- Acoustic neuromas
- Certain medical conditions like high blood pressure, diabetes, and thyroid problems
- Stress and depression, which may not directly cause tinnitus but can worsen its perception 1. It is essential to note that the American Academy of Otolaryngology and Head and Neck Surgery Foundation (AAO-HNS) guidelines recommend targeted history and clinical examination as the initial evaluation and determination as to whether the tinnitus is bothersome or not, before any imaging 1. The type of tinnitus and associated symptoms often determine the choice of imaging studies and their appropriateness, and clinicians should decide whether to apply these recommendations to patients with these conditions on an individualized basis 1.
From the Research
Causes of Tinnitus
- Tinnitus is often associated with sensorineural hearing loss 2
- Vascular tumors and vestibular schwannoma are less common but potentially dangerous causes of tinnitus 2
- Cerumen impaction can also cause tinnitus, as well as other symptoms such as hearing loss, itching, and pain 3
- Other factors that may contribute to tinnitus include noise exposure, which can help prevent the development or progression of tinnitus if avoided 2
Diagnosis and Management
- A comprehensive audiologic evaluation should be performed for patients who experience unilateral tinnitus, tinnitus that has been present for six months or longer, or that is accompanied by hearing problems 2
- Neuroimaging is not part of the standard workup unless the tinnitus is asymmetric or unilateral, pulsatile, associated with focal neurologic abnormalities, or associated with asymmetric hearing loss 2
- Treatment options for tinnitus include cognitive behavior therapy, sound therapy, and tinnitus retraining therapy, although evidence for their effectiveness varies 2, 4, 5
Pathophysiology
- Tinnitus is thought to be related to changes in the tonotopic organisation of central auditory pathways, as well as changes in non-auditory brain areas 5
- Increased neuronal firing rate and enhanced neuronal synchrony have also been recorded in central auditory pathways in reaction to deprived auditory input, and are thought to represent the neuronal correlate of tinnitus 5