most tinnitus originating in the auditory system is due to a sensorineural hearing loss with resulting dysfunction within the auditory system
mostly this is high pitched
Ménière's disease is generally low pitched tinnitus
a whooshing sound is generally regarded as being pulsatile tinnitus and is often due to vascular noises and these are generally of more acute concern than normal tinnitus for an acutely serious cause
some vascular causes are not pulsatile such as venous hum and tinnitus due to atherosclerotic plaque narrowing of arterial vessels
venous hum is soft, low-pitched hum (usually bilateral but may be unilateral) which can change with:
pressure over the jugular vein may reduce it or stop it
change in head position
activity
patients with vascular causes generally do not have other otologic symptoms due to the vascular cause such as deafness, vertigo or fullness in the ear however, these may occur in patients with paragangliomas or for other reasons
Aetiology
audible bruits
turbulent blood flow in arteries near the temporal bone can cause audible bruits
almost half have defined vascular aetiologies such as:
dural arteriovenous fistula
rare, tend to develop more often in those aged over 50yrs and usually form after a venous thrombosis (eg. post head injury, post-op neurosurgery, CNS infections, etc)
may cause headache, visual disturbance and stroke-like symptoms1)
carotid-cavernous sinus fistula
rare, tend to develop more often in those aged over 50yrs and usually form after a venous thrombosis (eg. post head injury, post-op neurosurgery, CNS infections, etc)
may cause exophthalmos and increased ocular tearing and reddening of eye(s) along with blurred vision and eye pain
may also cause stroke-like symptoms, N/V or seizures2)
congenital A-V malformations
tend to present in those aged under 50yrs
other vascular-related causes include:
paraganglioma - these are highly vascular
venous hums:
benign raised intracranial hypertension
systemic hypertension
dehiscent or dominant jugular bulb (abnormally high placement of the jugular bulb)
neuro-muscular causes:
these generally cause a clicking sound
spasm of one or both of the muscles within the middle ear (the tensor tympani and the stapedius muscle)
may also complain of hearing loss or aural fullness
tympanometry and otoscopy can be particularly useful in diagnosis
myoclonus of the palatal muscles that attach to the Eustachian tube orifice
may be caused by multiple sclerosis (MS) or other neurologic conditions such as brainstem microvascular issues, metabolic or toxic neuropathies
respiratory “pulsations” similar to the roar of waves at a beach “ocean roar”
patulous Eustachian tube that remains abnormally patent, allowing too much and then too little aeration of the middle ear space with respiration, tends to disappear when lying down
also causes unusual awareness of their own voice (autophony) and ear discomfort
due to significant weight loss or after external beam radiation to or near the nasopharynx
machine-like grinding
chondrosarcoma
aberrant carotid artery
endolymphatic sac tumors
Clinical Mx in the ED
clinical assessment for evidence of diagnostic clues
pulsatile vs clicking vs hum vs ocean roar vs machine-like grinding
effects of posture
presence of otologic symptoms or signs: deafness, vertigo, etc
presence of bruits or hypertension
presence of cranial nerve pathology or other neurology
frequent or constant pulsatile tinnitus can herald a potentially life-threatening illness
consider CT brain with either CT or MRI angiography (or both)
MRA is generally the preferred option if a vascular cause is suspected
High-resolution CT scanning is required if a paraganglioma is suspected
all of these patients require evaluation by an otolaryngologist or neurologist