Audiology Lesson 5 - Middle Ear Disorders Flashcards
Describe Otitis Media and list its various manifestations
Otitis media is a middle ear inflammation.
- Otitis media with effusion,
- Acute suppurative otitis media,
- Barotrauma of the middle ear,
- Chronic suppurative otitis media,
- Chronic otitis
media with cholesteatoma.
All of these disorders are related to a dysfunction of the Eustachian tube
Describe how middle ear disorders are related to Eustachian Tube Dysfunction
Eustachian tube dysfunction leads to a middle ear disventilation, so a negative pressure that leads to edema and flogosis of the middle ear.
Note: These infections are more common in pediatric patients because the eustachian tube in infants and children is different from that of adults - it is shorter
in pediatric age and it runs more horizontally; in this way infections derived from the nasopharynx are more frequent
Describe the main causes of Eustachian tube obstruction
Extrinsic pressure
i. adenoids (usually a bilateral problem)
ii. tumors of the rhinopharynx or cysts in adults
iii. nasal packing
iv. nasogastric feeding tube.
Edema: i. Rhinosinusitis ii. Allergies iii. Wegener granulomatosis a very important vasculitis that involves the upper airways and sometimes also the ear iv. radiotherapy
c. Malfunction of tubal muscles: (The levator and tensor palatini)
i. Down syndrome
ii. cleft palate.
When should you suspect a tumour in a case of otitis media?
If there is an inflammation of the upper airways, usually the problem is BILATERAL ;
if there is adenoids (which are typical in
children) also the problem is BILATERAL.
A MONOLATERAL problem in adults without history of inflammation should lead you to suspect a tumor, which is a unilateral condition. In these
patients you must perform a fibroscopy to evaluate the nasopharynx and to exclude a tumor.
Describe Otitis Media with Effusions and elaborate on the types of effusions
This is otitis media which is characterized by the presence of effusive fluids, which means non suppurative fluids in the middle ear.
Very frequent in pre-school age; it generally affects both ears and it is typical of the winter season.
Symptoms:
▪ Hearing loss & fullness
▪ Mild ear pain.
TYPES OF EFFUSIONS
Serous effusion can be observed, through the tympanic membrane with air bubbles in the middle ear
Mucous effusion has a bulging of the tympanic membrane due to the presence of mucous in the middle ear.
Glue Ear where the mucous in the middle ear resembles glue. It is characterized by a metaplasia of the epithelium of the middle ear, in particular there is a change from cuboidal to columnar mucous producing epithelium and the result is a chronic conductive hearing loss.
Describe the management of Glue Ear
In this situation we need to resolve the conductive
hearing loss, which may be at about 60 dB, significant!
In this situation we must perform an incision in the tympanic membrane and remove the glue by means of aspiration
However, we need
to be sure that our clinical diagnosis is chronic otitis
media because it can sometimes be misdiagnosed with the other types of blue tympanum.
Explain what blue tympanum is and describe all it’s causes
Blue tympanum is an otomacroscopic finding characterized by a typical blue color of the tympanum.
CAUSES
- Blood collection after a barotraumatic event
- An abnormal jugular bulb
- Acute Otitis media with effusion
- A glomus tumour (in this case making an incision in the tympanic membrane would be a big mistake!)
Describe the Tympanometry curves we may observe in otitis media
Type C - mild involvement of the conductive system
Type B - Complete conductive system involvement - severe conductive hearing loss
Fully describe suppurative otitis media, its diagnosis and clinical picture, natural history and compliactions
It is a suppurative infection with BACTERIAL etiology
The most common bacterial agents are:
▪ S. Pneumoniae (25-30%),
▪ H. Influenza (40-45%),
▪ M. Catarrhalis (10-15%).
It is a disorder typical of winter season
Typical symptoms are:
- Severe ear pain,
- Hearing loss,
- Fever
- Purulent aural discharge only if there is a perforation.
Diagnosis is otoscopic, there are distinguishable 3 phases in the natural history:
- Hyperemic and exudative phase -
characterized by hyperemic tympanic membrane - Rupture phase -
Perforation of the tympanic membrane. There is aural discharge, and usually a resolution of ear pain (as earpain is usually caused by the bulging of the tympanic membrane)
c. Healing phase
When complications are suspected, imaging tests are required
COMPLICATIONS OF SUPPERATIVE OTITIS MEDIA
- Sensorineural hearing loss: CT scan should be performed
- Vertigo/dizziness: because vertigo is the expression of the involvement of the vestibular system of the inner ear.
- Headache (may signify edema)
The treatment is systemic antibiotics
Describe Chronic suppurative otitis media and its symptoms
Chronic suppurative otitis media is characterized by a persistent perforation of the tympanic membrane and by suppurative involvement of the tympanic cavity.
The suppurative involvement comes from watery income of microorganism or an upper airways infection.
Eustachian tube dysfunction and nature, pathogenicity, resistance of infecting organisms (S. Aureus,Proteus,
Pseudomonas) are involved in chronic suppurative otitis media
SYMPTOMS
- Aural discharge with fetid smell (due to presence of anaerobes)
- Hearing loss (conductive or mixed, as infection may reach the inner ear via the round window)
- Ear pain (rarely)
Chronic suppurative otitis media is a typical tympanoplasty candidate
Chronic suppurative otitis media may be wet or dry
- dry (only chronic perforation)
- wet (there is also a suppurative event)
Explain how to differentiate between the left ear and the right ear on otomicroscope
By looking at the manubrium of the malleus.
Fully describe what a cholesteatoma is and it’s histopathology and classification
“wrong skin in the wrong place” when put simply
From an histo-pathological point of view it is made up of three layers:
- A central mass characterized by an accumulation of keratin.
- A matrix which is a stratified squamous epithelium. It is very important to remove matrix during surgical removal of the cholesteatoma. If we do not completely remove the matrix there will be recurrence of the disease. Moreover the matrix determines the progressive uncontrolled growth of the cholesteatoma.
- The last layer is the peri-matrix, it is an inflammatory reactive tissue.
CLASSIFICATION From a topographic point of view we classify it into: 1. choleastoma of the external ear 2. choleastoma of the middle ear 3.petrous bone cholesteatoma
Discuss the pathophysiology of cholesteatoma (congenital and aquired) - ALL THEORIES
There are 5 theories for the pathophysiology of cholesteatoma.
- Congenital theory - embryonic inclusions or rests of epithelial cells - probably epidermal rests in the amniotic fluid collecting in the tympanic cavity through the Eustachian tube and consequently cholesteatoma develops in the antero-superior quadrant of the tympanic cavity . This is related to the congenital form.
- Metaplasia theory - acquired cholesteatoma which is the result of recurrent otitis.
- Migration or invasion theory: the cholesteatoma is result of migration of squamous epithelial cell along the tympanic membrane perforation. Usually it happens when the perforation involves the annulus because annulus represents a protection between the middle ear and the external one.
- Basal cell hyperplasia or papillary ingrowth theory - cholesteatoma arisinf from an intact pars flaccida
- MOST IMPORTANT - the Invagination theory. A Dynfunctional eustachian tube results in –> impaired ventilation in the middle ear –>This results in a structural weakening of the TM –> retraction pockets can form (which aren’t self cleaning) –> lead to the accumulation of keratin debris which is the first step in the formation of a cholesteatoma. If it develops there will be a perforation of the tympanic membrane and a migration of the accumulation of the keratin in the tympanic cavity.
It can occur at any age. The congenital type is quite uncommon. In the acquired form, there is an history of recurrent
or chronic otitis and history of previous surgery.
Fully describe the clinical manifestation of cholasteatoma
These patients usually present with a history of recurrent otitis and with effusion, sometimes glue ear. In the effusion there is usually no infection but there is only a problem of ventilation and so tympanic cavity is filled
with inflammatory fluids
Symptoms can include
- Aural fetid discharge -
frequently related to a super- infection of anaerobes or Pseudomonas
- Hearing loss (conductive or mixed)
- Pain is not typical (chronic perforation
Describe the diagnosis and treatment of cholesteatoma
Diagnosis
- Otomicroscopy
- CT scan (when cholestatoma is not directly visible, also allows to see the size)
Treatment
- Surgery with a retro-auricular access
