What does otosclerosis look like on an audiogram?
On an audiogram, patients with otosclerosis commonly have conductive hearing loss with a drop in the bone-conduction threshold at 2,000 Hz, called a Carhart notch. This finding, in addition to an absent acoustic reflex, is generally thought to be diagnostic of otosclerosis.
What is obliterative otosclerosis?
Obliterative otosclerosis involves total obscuration of the oval window and its margins (Fig. 11–1). It is thought to be evidence of very advanced otoscle- rosis. Young patients are especially at risk, particularly when active, aggres- sive otosclerosis develops around puberty.
How is otosclerosis diagnosed?
Otosclerosis is diagnosed using tests including:
- hearing tests – a person with otosclerosis typically has a hearing loss that affects all frequencies (pitches). The hearing loss may be conductive or mixed in nature.
- CT scan – to check for damage to the cochlear nerve and labyrinth.
What is fenestral otosclerosis?
fenestral (stapes) otosclerosis is a common cause of progressive conductive hearing loss, usually bilateral. concomitant sensorineural hearing loss and vestibular symptoms (unsteadiness and/or vertigo) may develop in patients with advanced disease (retrofenestral [cochlear] otosclerosis)
What type of Tympanogram is otosclerosis?
Type AS (shallow) tympanograms show decreased compliance, suggesting a stiff middle ear system, which can be caused by myringosclerosis or otosclerosis. Type B tympanograms with little or no mobility of the tympanic membrane are suggestive of middle ear effusion.
What is Type A Tympanogram?
Type A tympanograms look like a teepee, and indicate a normal middle ear system, free of fluid or physiological anomalies which would prevent the admittance of sound from the middle ear into the cochlea.
What are the stages of otosclerosis?
There appear to be three stages of otosclerosis -resorptive osteoclastic stages with signs of inflammation, followed by an osteoblastic stage involving immature bone, followed by mature bone formation.
What does otosclerosis look like on a CT scan?
The CT evidence of otosclerosis included sclerosis or spongiosis at the cochlear promontory; sclerosis or spongiosis around the cochlea; thickened stapes footplate; or sclerotic, spongiotic, narrowed, or enlarged round or oval windows.
Can you see otosclerosis on CT scan?
High-resolution CT (HRCT) of the temporal bone is the modality of choice for the preoperative evaluation of otosclerosis.
What does Type B tympanogram mean?
Tympanogram tracings are classified as type A (normal), type B (flat, clearly abnormal), and type C (indicating a significantly negative pressure in the middle ear, possibly indicative of pathology).
What is the pathophysiology of obliterative otosclerosis?
On the other hand diffuse, obliterative otosclerosis was defined as the pathology involving the whole footplate and also in some cases extending beyond the confines of the annular ligament. In each group preoperative air- and bone-conduction levels at 125-6000 Hz and 500-4000 Hz were noted respectively.
What tests are used to diagnose otosclerosis?
The first step in a diagnosis is to rule out other diseases or health problems that can cause the same symptoms as otosclerosis. Next steps include hearing tests that measure hearing sensitivity (audiogram) and middle-ear sound conduction (tympanogram). Sometimes, imaging tests—such as a CT scan—are also used to diagnose otosclerosis.
What is Oto tosclerosis?
O tosclerosis or Otospongiosis is primary disease of bony labyrinth or the inner ear. The irregularly laid spongy bone replace the normal enchondral layer of bony otic capsule. Otosclerosis can cause Conductive deafness mostly, or sensorineural deafness or none depending on the region of disease.
What is the difference between annular and diffuse obliterative otosclerosis?
Patients with diffuse obliterative otosclerosis have more extensive footplate pathology than annular cases. As a result of this more skill is required for diffuse otosclerosis cases, and postoperative hearing results are usually worse than annular cases.