What is the etiology of unilateral tinnitus that worsens with yawning?

Etiology of Unilateral Tinnitus that Worsens with Yawning

Unilateral tinnitus that worsens with yawning is most commonly caused by temporomandibular joint dysfunction, eustachian tube dysfunction, or vascular abnormalities that are exacerbated by jaw movement during yawning. 1, 2

Primary Etiologies

Temporomandibular Joint (TMJ) Related Causes

• TMJ derangement or dysfunction can cause unilateral tinnitus that worsens with jaw movements like yawning due to the close anatomical relationship between the TMJ and the ear structures 3
• Mechanical stress during yawning can alter middle ear pressure or stimulate the auditory structures, exacerbating tinnitus symptoms 4

Vascular Causes

• Vascular abnormalities near the ear can produce sounds that become more audible during yawning due to changes in blood flow patterns 2
• Potential vascular etiologies include:
  • Sigmoid sinus diverticulum or dehiscence 2
  • High jugular bulb or jugular bulb dehiscence 2
  • Persistent petrosquamosal sinus 2
  • Arteriovenous malformations or fistulas 2
  • Carotid artery abnormalities (including aberrant internal carotid artery) 1, 2

Middle Ear/Eustachian Tube Related Causes

• Eustachian tube dysfunction can cause tinnitus that worsens with yawning due to pressure changes 5
• Patulous eustachian tube (abnormally patent) can cause autophony and tinnitus that changes with respiratory movements and jaw actions 6
• Middle ear muscle spasm (tensor tympani or stapedius) can be triggered by jaw movements 7

Other Potential Causes

• Paragangliomas (glomus tumors) in the middle ear can cause pulsatile tinnitus that may be affected by position changes during yawning 2
• Superior semicircular canal dehiscence can cause sound-induced or pressure-induced tinnitus 2
• Acoustic neuroma with vascular compression of the cochlear nerve can present with unilateral tinnitus 8

Diagnostic Approach

Initial Assessment

• Determine if the tinnitus is pulsatile or non-pulsatile, as this helps differentiate vascular from non-vascular causes 1, 2
• Perform a targeted history and physical examination to identify conditions that if promptly managed may relieve tinnitus 1
• Comprehensive otologic examination to check for retrotympanic masses or vascular abnormalities 1

Recommended Workup

• Obtain a prompt, comprehensive audiologic examination for unilateral tinnitus 1
• For unilateral tinnitus, imaging studies are indicated 1
  • CT temporal bone is recommended for suspected bony abnormalities or middle ear pathology 1, 2
  • MRI with contrast is recommended if acoustic neuroma or other retrocochlear pathology is suspected 1
  • CT angiography or MR angiography may be needed for suspected vascular causes 2

Management Considerations

• Treatment should target the underlying cause rather than just symptom management 6
• For TMJ-related tinnitus, addressing the TMJ dysfunction through dental/jaw therapies may help 3
• For vascular causes, surgical repair or embolization may be indicated in severe cases 2
• For eustachian tube dysfunction, nasal steroids, decongestants, or pressure equalization techniques may help 5

Important Caveats

• Unilateral tinnitus requires more thorough investigation than bilateral tinnitus due to higher risk of underlying pathology 1, 4
• Tinnitus that changes with body position or maneuvers (like yawning) often suggests a mechanical or vascular etiology rather than sensorineural causes 7, 5
• Do not routinely recommend medications like antidepressants or anxiolytics without addressing the underlying cause 1
• Dietary supplements like Ginkgo biloba, melatonin, or zinc are not recommended as primary treatment 1