diseases of the TM and middle ear

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L.3+4 Diseases of the tympanic membrane & Middle ear

Diseases of the tympanic membrane

From anatomical point of view the tympanic membrane(TM) is part of the
external ear, but from physiological point of view its part of the middle ear.
The diseases affecting the tympanic membrane TM is usually traumatic in
nature (the commonest) & is usually caused by:
1. direct:
a. Foreign body: self induced or accidentally e.g.(pin, hair clips).
b. Iatrogenic: as in unskilled ear syringing or unskilled foreign body removal.
c. Fractures of the base of the skull.
2. indirect:
Occurs due to a sudden raise of pressure in the EAC leading to rupture
of the TM & this is caused by (blow on the ear, explosions, flying &diving).
Symptoms:
1. Ear ache (pain in the ear) which is either mild to moderate & usually
transient occurring at the time of TM rupture.
2. If the laceration is large blood comes out through the EAC (otorrhea) which
is usually transient.
3. Sometimes the patient said that when he blows the nose, he feels air comes
out of the ear to the outside & this occurs due to the passage of air from the
pharynx through the E.tube to the middle ear & through the perforated tympanic
membrane to the outside.
4. Usually there is conductive deafness of the affected ear.
Signes:
Blood is sometimes seen in the EAC & by examination with the auroscope we
can see fresh laceration & perforation of the TM with irregular edges,
surrounded by area of hyperemia & blood clots.
Hearing assessment usually revealing conductive deafness.
Treatment:
Conservative: by the use of prophylactic AB & keeping the ear dry specially
during bathing (we tell the patient to put a cotton irrigated with oily material
during bathing & not to blow the nose forcefully). Small perforation usually
heals within 6-8 weeks. Analgesia is also used.
Surgery: this is used in large perforations the perforation is grafted by
temporalis fascia autograft by an operation called: myringoplasty, the operation
is done 3-6 months after the onset of trauma.


Diseases of the middle ear

Congenital diseases:

a. .Aplasia: its complete absence of the middle ear & the child presented by
conductive deafness. The patient is treated by hearing aids.
b. .Ossicle abnormalities: it’s either complete absence, or isolated ossicles
deficiency, or incomplete ossicles, or fusion of ossicles (loss of the synovial
joints in between the ossicles). These abnormalities treated by ossiculoplasty.
c. . Wall dehiscence: there is incomplete walls of the middle ear & there may be
soft tissues in the middle ear according to the defect; as jugular vein in case
of inferior wall dehiscence.

Traumatic diseases:

a. .Ossicle disruption: it may occur due to trauma, head injury, or iatrogenic
(during surgical procedures) the patient complains from tinnitus, conductive
deafness, and intact or ruptured tympanic membrane. Treatment is by
ossiculoplasty.
b. .Otitic barotrauma :
Defined as middle ear trauma due to rapid decrease of the middle
ear pressure below the atmospheric pressure. This is mostly seen during flying &
diving.
Physiology: at rest the Eustachian tube is closed & opens only
during swallowing, yawing, & during Valsalva maneuver in which there is flow of
air to the middle ear through the Eustachian tube which causes equalization of
the middle ear pressure with the atmospheric pressure.
During ascend by airoplain to high altitude there is normally a
decrease in the atmospheric pressure & there is a relative increase of the
middle ear pressure & in order to equalize the middle ear pressure with the
atmospheric pressure, there is a flow of air from the middle ear to the pharynx
through the Eustachian tube (to correct the pressure difference).
During diving or during airplane descend, there is a increase of the
atmospheric pressure & a relative decrease in the middle ear pressure. In order
to correct the pressure difference there must be an active opening of the
Eustachian tube (by swallowing or chewing) in order to allow the passage of air
from the pharynx to the middle ear.


Etiology:
This condition occur when the person fails to open the Eustachian
tube during diving or descent as a result of either edema of the Eustachian tube
opening (usually occur after URTI as common cold) or the patient stop swallowing
(due to sleeping for example).
Pathogenesis:
In failure of Eustachian tube opening no air will flow from the
pharynx to the middle ear causing marked decrease of the middle ear pressure &
middle ear effusion & collapse of the tympanic membrane (retracted tympanic
membrane) & may end with rupture.

Signs & Symptoms:

1. Sever earache due to stretching of the tympanic membrane.
2. Conductive hearing loss due to effusion of the middle ear or rupture of the
tympanic membrane.
3. Bleeding from the ear due to rupture of the tympanic membrane.
4. Tinnitus may occur.
5. Congested & retracted tympanic membrane.
6. Middle ear effusion or ruptured tympanic membrane with audiological
evidence of conductive hearing loss.


Prophylaxis:
· ·Avoiding diving or flying with problems in the URT.
· ·Avoiding of sleeping during flying or mainly during descend.
· ·Instructions to pilots or travelers how to open the E.tube (swallowing,
chewing, or by repeated autoinflation of the middle ear by forced expiration
against closed epiglottis which is called valsalva maneuver).
Treatment:
1. .Conservative treatment by vasoconstructive ear drops to decrease the edema
around the E.tube.
2. .Myringotomy if the conservative treatment fails, this is done by inducing a
sharp pointing knife to make a hole in the light reflex area of the tympanic
membrane & decreasing the pressure to prevent rupture of the tympanic membrane.

c. .Fractures of the temporal bone:

These fractures usually occurs after head injury & are either longitudinal
(vertical) , or transverse according to there direction in the temporal bone.
The longitudinal fractures (80%)usually passes through the middle ear &
EAC while the horizontal (transverse) fractures (20%) passes through the inner
ear & facial nerve canal.
Clinical features:
1. Rupture of the TM usually occur in longitudinal fractures & seen during
examination as a tear surrounded by blood clots & sometimes fresh blood coming
out of the ear which usually occur when the blood is mixed with CSF.
2. Conductive hearing loss of the affected ear, also occur in longitudinal
fractures causing TM rupture &/or ossicles disruption.
3. Facial nerve palsy due to involvement of the facial nerve canal by in the
temporal bone by transverse fractures.
4. Sensorineural hearing loss due to involvement of the inner ear by transverse
fractures.
Investigation: the gold standard investigation is CT scan.
Treatment:
Conservative treatment is the rule at first, if complete healing does not occur
then surgery is indicated (repair of the TM & ossicles disruption, facial nerve
graft, CSF leakage repair).


Inflammatory diseases:

A. Acute suppurative otitis media:

Its an acute suppurative (pyogenic) inflammation of the mucosal lining of the
middle ear cleft (not middle ear cavity, because the middle ear cleft consist
of; middle ear, Eustachian tube & the mastoid air cells).
Organisms responsible for this infection are H.influenzae, strept. pneumonae &
moraxella catarrhalis.
Routes of spread:
1. Eustachian tube: as occurs in rhinitis, pharyngitis, sinusitis & adenoiditis.
In this case the whole of the middle ear cleft is involved & it’s the most
common route of infection.
2. Perforated TM in which the bacteria from the atmosphere affect the middle ear
cleft causing secondary infection.
3. Iatrogenic as in case of inexperienced ear syringing.

Pathology & clinical features:

The acute suppurative otitis media is divided (pathologically & clinically)
into 3-stages:
1. Stage of hyperemia:
Pathologically: there is congestion (hyperemia) of the middle ear mucosa &
tympanic membrane with serous exudate & finally Eustachian tube obstruction.
Clinically:
· ·Dull earache.
· ·Conductive hearing loss.
· ·Tinnitus.
· ·Hyperemia of the TM usually started along the handle of the malleus & then
the periphery of the TM & the whole membrane is involved without rupture.
2. Stage of suppuration:
Pathologically: the exudation increase in amount & change from serous to mucous
or purulent or mucopurulent exudate, this occurs due to bacterial spread with
increase in WBCs.
Clinically:
· ·Sever earache(throbbing pain)
· ·Sever conductive deafness.
· ·Tinnitus (increase in severity).
· ·Fever.
· ·TM pulging & appear angry red in color (not bright & there is no light
reflex from the TM).
3. .Stage of tympanic membrane perforation:
Pathologically: there is pus accumulated in the EAC due to increase in the
pressure of the pus in the middle ear & consequent pressure necrosis of the TM &
perforation mostly in the central part of the TM.
Clinically:
· ·Mild earache (decrease in severity).
· ·Conductive deafness (remain for few weeks).
· ·Tinnitus (remain for few weeks).
· ·Fever.
· ·Otorrhea (mucopurulent or even bloody).
· ·Pus is seen in the EAC &after suction cleaning of the EAC the TM is
ruptured usually in the central part.


Treatment:
a. . Systemic treatment:
1. Broad-spectrum antibiotics: as penicillin, ampicilline, and cephalosporins.
These antibiotics should be used in proper dose & duration, which depend on the
severity, age & type of the antibiotic used.
2. Analgesics: in case of sever pain e.g. aspirin, paracetamole or even
voltarin may be used.
b. .Local treatment:
This is directed according to the stage of the disease:
Stage 1: vasoconstrictive nasal drops to decrease edema of the E. tube &
equalize the pressures in the middle & external ears.
Stage 2: Myringotomy (incision of the TM).
Stage 3: aural toilet by removing the discharge & ear suction clearance or dry
mopping.

Prognosis:

Depend on the virulence of the microorganism:
1. Complete cure in which the hearing & middle ear mucosa returns to normal.
2. Development of chronic otitis media (whether suppurative or non-suppurative)
in which the hearing & middle ear mucosa never return to normal.
4. .Development of complications (intracranial or extracranial).


B. Otitis media in children

Otitis media is very common in children because the infection is much easier

than in adults for the following causes:
· ·The Eustachian tube is shorter, wider & more horizontal in children than in
adults.
· ·More frequent episodes of upper respiratory tract infections (URTI) in
children than in adults.
· ·The transmission of microorganisms from older person to a child during
lifting & kissing the baby.
· ·Artificial milk or bottle feeding that causes infection by :
1. The supine position of the baby during bottle feeding facilitate the
transmission of fluid to the ear than in breast feeding in which the child is
hold in an upright position.
2. The bottle is more liable for contamination than breast-feeding.
· ·The vomitus (infected vomitus) as in case of gastroenteritis which transmit
the microorganisms to the middle ear through the Eustachian tube.
· ·The general resistant of children is low & that may be due to teething,
frequent gastroenteritis & bottle-feeding.
Symptoms:
1. Systemic symptoms: as fever, earache, convulsions, sometimes diarrhea &
vomiting which must be differentiated from gastroenteritis, continuos crying
(irritability) & sleep disturbances.
2. Local symptoms: the child pulls or rubs his ear & moves his head from side to
side.
Signes:
The tympanic membrane is intact (because it’s thicker than that of adults
so it resists pulging or perforation).
Treatment:
Similar to that in adults, but the myringotomy is more indicated here
especially in infants where bony dehiscence is more common & the possibility of
facial nerve affection is high.


C. Chronic non-suppurative otitis media

It’s a chronic non-suppurative (non purulent) inflammation of the mucosal

lining of the middle ear cleft, the discharge or the fluid in the middle ear is
serous at first then becomes glue like thick secretion (due to absorption of
water from the fluid).
There are 2-types of chronic non suppurative otitis media:

A. Secretory otitis media (otitis media with effusion, glue ear):

It’s a chronic disease of the middle ear cavity, characterized by
accumulation of seromucinous secretion in the middle ear cavity, it usually
affect children below 5 or 6 years old.
Etiology:
1. .Allergic type may be present with allergic rhinitis.
2. .Incomplete treatment of acute suppurative otitis media, either due to
improper antibiotic, incomplete course of treatment..etc.
3. .Eustachian tube obstruction by a mass in the nasopharynx e.g. adenoid,
tumor, or congenital anomaly.
4. .Eustachian tube dysfunction due to congenital abnormality e.g. cleft palate.
Symptoms:
1. .Hearing loss, which is usually conductive type in the preschool age,
discovered by the parents & in the school by the teachers.
2. .Tinnitus.
3. .Sensation of bubbles in the ear.
Signs:
1. .Retracted TM.
2. .Dull looking TM (not bright) with loss of the light reflex.
3. .Restriction of TM mobility.
4. .Conductive hearing loss.
5. .Air fluid level &/or bubbles behind the TM.
6. .The TM never perforates.
Investigation:
1. .Tuning fork tests:
These tests are used for rapid clinical assessment before any subjective
or objective hearing tests are done. The usual tests are Weber test (lateralized
to the ear with conductive deafness) & Rinne test (revealing bone conduction BC
is better than air conduction i.e. –ve Rinne test).
2. .Pure tone audiometry(PTA):
Usually reveals an air-bone gap
which means that bone conduction
is better than air conduction.
3. .Impedance audiometry (tympanometry):
This investigation depend on the
objective mobility of the TM by
applying pressure in the EAC &
recording the mobility of the TM
objectively resulting normally in a
high peak curve, but in secretory
otitis media it becomes a flat curve.
4. .Lateral soft tissue x-ray of the post nasal space:
This x-ray shows a soft tissue mass in the postnasal space, which is
either an adenoid, or tumor, or congenital remnant tissue.
Treatment:
1. .Conservative medical treatment:
a. .Treat the predisposing factor.
b. .Antibiotics.
c. .Decongestants, anti-inflammatory drugs &/or steroids.
d. .Autoinflation of the Eustachian tube by: valsalva maneuver, chewing, yawing,
& swallowing.
2. .Surgical treatment:
a. .Myringotomy alone (if there is serous fluid).
b. .Myringotomy with insertion of ventilation tube (grommet).


B. Adhesive otitis media:
It’s a long-term sequel of secretory otitis media characterized by fibrous
adhesion between the TM & the medial wall of the middle ear cavity.

D. Chronic suppurative otitis media (CSOM)

It’s a chronic suppurative inflammation of the mucosal lining of the middle
ear cleft (middle ear cavity, E.tube, mastoid air cells). Usually the patient
has a perforation in the TM, the causative organisms are usually mixed bacteria
(G-ve, G+ve) but its mostly G-ve (proteus, pseudomonas). CSOM is divided into
two types:

A. .Mucosal CSOM (tubo-tympanic, safe type):

This type is characterized by a central perforation (in the pars tensa)
surrounded by a rim of a normal TM, it involve the mucosa only (does not
involve the periosteum or the bone)which is associated with low risk of
complications ( safe type). On examination we see a central perforation a fluid
accumulates below the lower rim of the TM (usually not seen) because the middle
ear cavity is larger than the area of the TM.

Etiology of CSOM:

1. .Usually follows acute suppurative otitis media due to:
a. .Inadequate antibiotic course &/or improper antibiotic combinations.
b. .Inadequate drainage of pus due to small & high perforation in the TM.
2. .Organic factors: a. Recurrent infective adenoiditis.
b. High virulence infection.
3. .Low resistance: as in DM & malnutrition.
Symptoms:
1. .Ear discharge (Otorrhea) almost always & usually intermittent.
2. .Hearing loss mild to moderate.
3. .Tinnitus.
4. .Vertigo & dizziness (if there is inner ear involvement).
Signs:
1. .Mucopurulent odorless scanty or profuse discharge from the middle ear fills
the EAC.
2. . Central perforation in the TM.
3. .The mucosa of the middle ear may show sessile like granulation due to edema
& inflammation.
4. .Aural polyp, which may develop from the edematous mucosa of the middle ear
filling the EAC.
5. .Conductive hearing loss.
Investigation:
a. .Swab from the ear discharge for C/S.
b. .Pure tone audiometry for the type & degree of hearing loss.
c. .Mastoid X-ray (lateral oblique view).
Treatment:
1. .Medical conservative treatment to control the infection by:
a. .Repeated aural toilet, to remove the discharge by dry mopping or suction.
b. .Keep the ear dry by putting cotton with oil in the ear during bathing.
c. .AB+ steroid ear drops 3-times daily.
d. .Systemic AB.
2. .Surgical treatment: tympanoplasty after controlling the infection & this
term means eradication of the diseased mucosa & bone & reconstruction of the
hearing mechanism of the ear.


B. Cholesteatomatous CSOM (attico-antral, tympano-mastoid, unsafe type):
It’s a CSOM characterized by involvement of the middle ear & mastoid
antrum, the TM is perforated at the attic area (pars flaccida) in addition there
is involvement of the upper & posterior walls of the middle ear. This type is
more prone to complications & need urgent surgery, which is the only possible
treatment.
Definition of cholesteatoma:
It’s a sac lined by a keratinized epithelia (Stratified sequamous epithelia)
similar to that of the skin & filled by sheets of keratin & cholesterol
crystals, when these contents becomes infected then otorrhea develops.
Mechanism of formation of cholesteatoma:
There is retraction of the pars flaccida & then perforation of the TM & entrance
of this part in the middle ear forming a sac like structure, which gradually
becomes bigger due to proliferation of the skin of the pars flaccida.
Etiology of cholesteatoma:
1. .Acquired:
a. .Primary acquired: it occurs without a history of otitis media due to
prolonged Eustachian tube dysfunction & -ve middle ear pressure leading to
retraction of the TM & formation of retraction pocket in the middle ear , which
is lined by sequamous epithelia.
b. .Secondary acquired: this type follows otitis media in which there is a
perforation in the TM & migration of the skin cells of the TM into the middle
ear through the perforation.
2. .Congenital:
It develops behind an intact TM from the embryonic cell rests.
Symptoms:
· ·Deafness (conductive type).
· ·Otorrhea malodorous & scanty.
· ·Tinnitus.
Signs:
· ·Purulent malodorous, scanty Otorrhea.
· ·TM perforation in the attic area (pars flaccida).
· ·Cholesteatoma may be seen through the perforation.
· ·Sessile like granulation in the middle ear mucosa.
· ·Aural polyp may be seen in the EAC.
· ·Hearing assessment show conductive deafness.
Investigation:
1. .C/S of the pus.
2. .Mastoid x-ray (lateral oblique view).
3. .CT scans of the temporal bone.
4. .Pure tone audiometry.
Treatment:
Surgery is the gold standard of treatment by removal of the cholesteatoma &
diseased bone & mucosa by mastoidectomy operations (cortical, modified radical &
radical mastoidectomy).
Complications of CSOM:
These are thought of if the patient develop: (earache, headache, vertigo &
facial nerve paralysis) in addition to symptoms related to the brain affection
(loss of consciousness, behavioral changes & epilepsy).
Mode of spread of infection:
a. .Direct spread through osteitis or erosion by cholesteatoma.
b. . Venous spread through retrograde thrombophlebitis.
c. .Labyrinthine spread through the inner ear.
d. .Others: fracture lines, ununited cranial sutures & congenital dehiscence.
Types of complications:
A. .Intracranial complications:
These are all described under neurological diseases:
1. .Patchy meningitis.
2. .Leptomeningitis.
3. .Thrombophlebitis of the sigmoid sinus.
4. .Otitic hydrocephalus.
5. .Brain tissue lesions (encephalitis, brain abscess).
B. .extracranial complications:
1. .Osteomylitis of the temporal bone (rare).
2. .Blood stream complications (uncommon).
3. .Labyrinthitis.
4. .Facial nerve paralysis.
5. .Sub-periosteal abscesses:
a. .Post-auricular abscess: it’s the commonest type in the mastoid area
especially in children.
b. .Zygomatic abscess: anterior & above the ear.
c. .Von-Bezolds abscess: on the anterior surface of the sternomastoid muscle.
d. .Citellis abscess: above the digastric muscle.
e. .Pharyngeal abscesses: Parapharyngeal & retropharyngeal abscesses.
6. .Mastoiditis:
Inflammation of the bony wall of the mastoid process (osteitis not
osteomylitis). It usually begins as osteitis & then necrosis of the bony wall
with pus formation in the mastoid process called acute mastoiditis. Erosion of
the bone in different directions in the mastoid area may form the above
abscesses.
Symptoms of mastoiditis:
1. .Earache 2. Deafness 3. High fever especially in children.
Signs of mastoiditis:
1. .Tenderness on the mastoid process.
2. .Abscesses may form as mentioned above.
3. .Otorrhea.
4. .Sagging of the posterosuperior wall of the EAC.
5. .TM may be intact.
It’s important to differentiate between mastoiditis & furunculosis as
follows:


Mastoiditis furunculosis

1. History of otitis media present absent

2. Symptoms: pain over the mastoid on moving the auricle
Deafness marked absent
3. Signs: fever high absent
tenderness post auricular on tragus pressure
4. Post auricular sulcus obliterated present
5. Sagging of the EAC posterosuperior
wall absent
6. Otorrhea high amount scanty
7. TM perforated normal

8. x-ray

clouding of the
mastoid process normal

Investigation of mastoiditis:

1. .Mastoid x-ray.
2. .C/S of pus.
3. .Pure tone audiometry.


Treatment of mastoiditis:
Usually respond to medical treatment for prolonged period with
broad-spectrum antibiotics, local & systemic decongestant & antibiotic with
steroid ear drops.
Surgery is indicated if there is failure of medical treatment or if the
patient develops complications.
Tumors of the middle ear

These are either benign or malignant:

1. .Malignant tumors: are very rare & mostly squamous cell carcinomas & treated
as in any part of the body by resection & radiotherapy.
2. .Benign tumors : are more common & the commonest is glomus tumors which arise
from the paraganglionic cells present at the promontory in the middle ear
(glomus tympanicus) or at the jugular bulb (glomus jugulare).
Clinical features:
a. .Pulsating tinnitus.
b. .Cranial nerves pulsy.
c. .Deafness.
d. .Otorrhea.
e. .Ruptured TM.
f. .Pulsating mass in the EAC bleeds on touch.
Investigation:
a. .CT scans.
b. .MRI.
c. .Angiography.
d. .Biopsy.
Treatment: Surgical removal of the tumor, sometimes radiotherapy may be
effective.


Otosclerosis

Definition: a new spongy bone formation in a localized area, usually around the

footplate of the stapes & in area around the oval window. It affects or
restricts the movement of the stapes footplate causing conductive deafness.
Etiology:
Usually unknown & familiar & non-gen related, affecting mostly females
between 20-30 yr. old & its usually bilateral.
Clinical features:
1. .Conductive deafness.
2. .Tinnitus.
3. .Patient hears better in a noisy environment (paracusis willisi).
4. .Normal TM.
Treatment:
1. .Hearing aids.
2. .Fluoride therapy.
3. .Surgical treatment: by operation called (stapedectomy) which is removal of
the stapes footplate & replaced by prosthesis situated in the foramen formed
after removal of the bone