Diseases of the Middle Ear Dr. Haitham Alnori

Acute Otitis Media Chronic Otitis Media Non-suppurative otitis media: OME Chronic Suppurative otitis media CSOM

Chronic Suppurative Otitis Media CSOM Persistent disease, insidious in onset manifested clinically as long standing painless aural discharge with deafness. Two clinical types: tubotympanic (safe) and atticoantaral (dangerous) disease.

Tubotympanic Disease It tends to follow a benign clinical course and rarely gives rise to any serious complications. It is considered as tubotympanic because in many cases the persisting or recurring infection spreads via the ET to the tympanic cavity.

Aetiology It is virtually always a complication of AOM where there is persisting perforation of the TM. It therefore usually starts in childhood. Reinfection either from the nasopharynx (adenoid and sinusitis) or through the perforation allows active infection to persist or to recur.

Bacteriology There is a high incidence of gram negative infection as E.coli, proteus and pseudomonas aeruginosa. Anaerobic microrganisms can be found as well.

Pathology Central perforation of the TM resulting from AOM. Repeated infection may cause polyp formation which consist of oedematous mucosa prolapsing through a perforation.

Clinical Picture Mucoid or mucopurulent discharge which may be intermittent or persistent. CHL: Its degree varies with the size and position of the perforation.

Examination 1. Otoscopy: Central TM perforation in pars tensa. 2. Tuning fork tests: CHL.

Investigations PTA:CHL. X-ray of mastoid shows sclerosis with clouding of the mastoid air cells. Swab of the aural discharge for C/S.

Treatment 1) Elimination of causes of Eustachian tube dysfunction: Treatment of sinusitis, adenoidectomy, treatment of allergic rhinitis… 2) Medical a. Aural toilet: Suction clearance and/or mopping with cotton-wool wicks. The patient should be warned not to get water into the ear when washing or swimming.

b. Local antibiotic/steroid drops e. g b. Local antibiotic/steroid drops e.g. ciprofloxacin/hydrocortisone, neomycin or gentamycin/dexamethasone drops. These drops are instilled after mopping the ear and the head should be on the side so that the affected ear is uppermost. c. Systemic antibiotics has little role in Rx.

3) Surgical treatment is indicated if the ear fails to dry. a 3) Surgical treatment is indicated if the ear fails to dry. a. Removal of aural polyp and granulation tissue: this improves aeration of mastoid and results in dry ear. b. Myringoplasty: Repair of the TM perforation by temporalis fascia is indicated when there is recurring discharge or there is disabling deafness.

Atticoantral Disease In this type of infection the bone of the attic, mastoid antrum and air cells are involved as well as the mucosa of the middle ear cleft. It is therefore referred to as atticoantral disease. As erosion of bone may extend to adjacent vital structures there is always a danger of serious complications , both intra- and extra-cranail. This type of infection is usually associated with cholesteatoma.

Cholesteatoma

Cholesteatoma Cholesteatoma is a sac of keratinizing squamous epithelium containing keratinous debris and surrounded by granulation tissue. In other word, it is skin in a wrong place.

The surface layers of epithelium keep producing keratin and this result in the appearance of a thin-walled sac containing cheesy material. The granulation tissue on the outside of the sac produces lysozymes and this gradually erodes the ossicles, ear drum and mastoid bone.

Cholesteatoma is not a tumor, though if untreated it will continue to expand and destroy surrounding structures.

Theories of origin of cholesteatoma Invagination theory: Cholesteatoma starts as a retraction pocket of the TM due to chronic Eustachian tube dysfunction. TM tends to be retracted in the attic region where the pars flaccida is thin. If the retraction pocket is more marked, a cholesteatoma sac may be formed inside the middle ear.

Emigration theory: Cholesteatoma arise from extension of squamous epithelium into the middle ear through attic TM perforation. Metaplasia theory: Squamous metaplasia of the middle ear mucosa in response to chronic infection

Bacteriology Similar to that of tubotympanic disease with higher incidence of pseudomonas.

Clinical Picture The onset of symptoms is insidious so that the patient may be unaware of the starting point. Persistent or recurrent purulent aural discharge. The discharge however, is purulent rather than mucopurulent and is frequently scanty and foul smelling.

CHL; Usually marked hearing loss because of involvement of the ossicular chain. Bleeding from the ear if granulation tissue is present. Headache, vertigo and facial paralysis all indicate complications.

Examination Otoscopy: Attic (unsafe ) perforation situated in the pars flaccida. Cholesteatoma may be seen as a white- greyish substance projecting from an attic perforations. Granulation tissue may be seen as well occupying such perforation.

Tuning fork tests: CHL. Fistula sign: Cholesteatoma can cause erosion of the lateral semicircular canal leading to labyrinthine fistula. If such fistula is present, any change of pressure in the middle ear as by Seigle aural speculum will probably produce vertigo and nystagmus. If the test is positive, it is an indication of urgent surgery because of the risk of labyrinthitis.

Investigations PTA:CHL. CT scan of temporal bone: Cholesteatoma appear as an area of translucency with a clearly outlined bony margin. Swab of the aural discharge for C/S.

Treatment Cholesteatoma is a surgical disease and there is NO "medical treatment", except for small choleasteatoma in very elderly patient where suction under the microscope with close observation is accepted.

Goals of surgery -Eradication of potentially dangerous disease by modified radical mastoidectomy to prevent complications. This suregry carries some risk of facial palsy and dead ear. -Reconstruction of hearing mechanism (tympanoplasty) which usually involves reconstruction of ossicular chain (ossiculoplasty). -Creation of dry self-cleaning cavity.

Complications of Otitis Media Occurs when the infective process spreads beyond the confines of the middle ear. Routes of infection 1. Direct spread through bone a. Superiorly to the middle cranial fossa through the tegmen tympani. b. Posteriorly to the posterior cranial fossa. c. Inferiorly through the floor producing a septic thrombosis of the IJV.

2. Venous spread to the cerebral venous sinuses. 3. Spread via labyrinth intracranially through the oval and round windows. 4. Other routes: Fracture lines and congenital dehiscence.

Extracranial complications of otitis media Mastoiditis. Labyrinthitis. Petrositis. Facial nerve paralysis.

Intracranail complications of otitis media Extradural Abcess. Subdural abscess Lateral (sigmoid) sinus thrombosis Meningitis Brain abscess Otitic hydrocephalus.

Acute Mastoiditis Acute infection of the mastoid antrum and air cells by virtue of the mucosal continuity between the middle ear cleft and the mastoid process. The pus may break through the superficial cortex forming sub-periosteal abscess.

Aetiology It commonly complicate AOM if it has been either untreated or given inadequate antibiotic therapy. Acute mastoidis can be superimposed on a chronic atticoantral disease in which the cholesteatoma has invaded the mastoid bone.

Clinical Picture It is more common in children than adults. 1. The patient generally looks ill with fever. 2. Earache followed by aural discharge with relief of pain. This is followed by cessation of discharge and recurrence of pain with pyrexia. 3. If the disease continues uncontrolled the pus may break through the superficial cortex and forms sub-periosteal abscess.

Examination Retroauricular swelling and tenderness over the mastoid area with fluctuation if sub-periosteal abscess forms. Soft tissue oedema with displacement of the auricle downwards and outwards. The postauricular sulcus tends to be retained. Narrowing of the EAM due to sagging of the postero-superior meatal wall.

Differential Diagnosis Acute mastoiditis Furuncle of EAM Preceding history of AOM No such history Deafnerss No deafness until the canal is occluded Otoscopy: signs of AOM Signs of otitis externa Tendernesss on pressure over mastoid Tenderness on pressing the tragus Postauricular sulcus tends to remain Postauricular sulcus is obliterated Radiographic changes of mastoiditis Normal radiology

Investigations X-ray and Ct scan shows opacity of the mastoid air cells.

Treatment I. Acute Otitis Media: Admission to hospital. Antibiotics according to C/S if there is discharge, if not IV claforan for 2-3 days followed by oral Amoxicillin-clavulanic acid for further week. Drainage followed by cortical mastidectomy if fluctuation and sub-periosteal abscess is formed.

II. Chronic Otitis Media: Modified radical mastoidectomy with reconstruction of the hearing mechanism.

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