Monday, July 31, 2017

Important Clinical Findings In The Tympanic Membrane and Middle Ear

“Chalk” patches. White areas of tympanosclerosis are common findings on examination of the ear drum. They are of little significance in themselves, and the hearing is often normal.

A past history of otorrhea in childhood or grommet insertion is usual. Chalk patches do occur with no
apparent past otitis media. Extensive tympanosclerosis with a rigid drum is a sequela of past otitis media, and the ossicles, too, may be fixed or noncontinuous.

Scarring of the drum. A gossamer-thin membrane can be seen to close this previously well-defined central perforation (arrow).

At first sight with the auriscope, a central perforation would appear to be the diagnosis; more careful
examination with a pneumatic otoscope will show that this thin membrane moves and seals the defect, giving reassurance that the drum is intact.

Scarring of the drum with retraction onto the round window, promontory, and incus is also evidence of past otitis media.

It is sometimes difficult to be sure whether this type of drum is intact; a thin layer of epithelium indrawn onto the middle-ear structures may seal the middle ear, and examination with the operating
microscope may be necessary to be certain of an intact drum.

Scarred tympanic membrane. A scarred tympanic membrane in which the drum has become atelectatic and indrawn onto the long process of the incus and promontory.

A retracted tympanic membrane which is thin and indrawn onto the long process of the incus (a), head of the stapes (b), promontary (c), and round window (d).

The stapedius tendon is also seen in this panoramic view obtained with a fiberoptic endoscope.

Traumatic perforation. A blow on the ear with the hand is a common cause of traumatic perforation
which has an irregular margin.

Pain and transient vertigo at the time of injury are followed by a tinnitus and hearing loss.

Healing perforation. Almost all traumatic perforations heal spontaneously within two months, a thin
membrane growing across the defect.
Traumatic perforations are usually central, but if the perforation extends to the annulus, healing may not occur. The extremely large traumatic perforations may also fail to close spontaneously.

Taking care to avoid water entering the middle ear and avoiding inflating the middle ear with the Valsalva maneuver are the only precautions the patient
need take.
A middle-ear infection with discharge is the commonest complication, usually settling with a course of topical and systemic antibiotics.
Blast injuries, barotrauma, foreign bodies or their careless removal, and even over-enthusiastic kissing of the ear may also cause traumatic perforations.

Central perforation. Acute otitis media with pus under pressure in the middle ear may rupture the drum, and although healing usually occurs, a permanent perforation can result. These perforations are usually central.

A small perforation may be symptom-free, but episodes of otorrhea with head colds and after swimming are common, along with a conductive hearing loss.
The otorrhea tends to be profuse and mucopurulent, and may be intermittent or persistent.
This type of central perforation, when dry, is successfully closed with a fascial graft (myringopalsty).
Other complications with central perforations are rare, so they are described as “safe” perforations. A
central perforation may persist after an episode of acute otitis media and otorrhea in childhood. Myringoplasty is usually delayed in children since closure by puberty is common. If, however, the
upper respiratory tract is free of infection, and the perforation is the site of recurrent infections with impaired hearing, these are indications to proceed with myringoplasty in childhood.

A posterior marginal perforation of the eardrum, taken with the fiberoptic camera, showing the round window and head of the stapes. A thin fibrous connection can be seen (arrow) which connects to the necrotic long process of the incus.

This type of ossicular discontinuity is a common cause of conductive hearing loss following otitis
media (with or without a perforation). Ossicular reconstruction surgery will restore the hearing.

Squamous epithelium on the incus. The marginal perforation may enable squamous epithelium to
migrate into the middle ear. In this ear, white squamous epithelium has formed on the incus.

Marginal perforations, therefore, are described as “unsafe” since there is a risk of cholesteatoma.

Attic perforation. Debris adherent to the pars flaccida of the drum (arrow) suggests an underlying
attic perforation.

Perforations of the pars flaccida (attic perforations) are invariably associated with cholesteatoma formation.

Cholesteatoma. The debris, when removed, exposes a white mass of epithelium characteristic of a
cholesteatoma (arrow).

Cholesteatoma is not a neoplasm; it is simply squamous epithelium in the middle ear. If ignored, it increases in size, becomes infected, and is associated with a scanty, fetid otorrhea. It may erode bone, leading to serious complications.
Extension to involve the dura with intracranial infection may occur, and the facial nerve and labyrinth too may be eroded. The extent of the cholesteatoma determines the danger:
A small attic pocket of epithelium is relatively harmless, and can be removed with suction, but an extensive mass of epithelium is dangerous and needs exploration and removal via a mastoidectomy
A chronic discharging ear is not painful, and persistent pain and headache, or severe vertigo, strongly
suggest an intracranial complication or labyrinth.

Mastoid abscess. A red, acutely tender swelling filling the
postauricular sulcus , and pushing the pinna conspicuously forwards and outwards, is characteristic of a mastoid abscess.

In the past, mastoidectomy was needed for an acute mastoid abscess complicating acute otitis media. This was extremely common in the preantibiotic era, and required exenteration of the mastoid air cells (cortical mastoidectomy).
The operation is now rarely performed in countries where antibiotics are available

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