1. OTOSCLEROSIS (Syn. Otospongiosis)
Otosclerosis is an abnormal growth of bone in the ears, which causes hearing loss. 
Ahmed Salam Lectures
Medical Student “TSU”

2. G.S.M MEDICAL LECTURES/ Otosclerosis
AHMED SALAM
MD STUDENT
Anatomy:
Otic labyrinth(membranous labyrinth): It consists of utricle,saccule, cochlea,semicircula duct s ,endolymphatic duct and sac and It is filled with endolymph.
Periotic labyrinth or perilymphatic labyrinth(space):It surrounds the otic labyrinth and is filled with perilymph.includes vestibule,scala tympani,scala vestibuli,perilymphatic space of semicircular canals and the periotic duct.
Otic capsule: It is the bony labyrinth.It has three layers……
Endosteal.
Enchondral.
Periosteal.

3. G.S.M MEDICAL LECTURES/ Otosclerosis
AHMED SALAM
MD STUDENT
Aetiology:
The exact cause of otosclerosis is not known how ever the following facts have been documented:-
Anatomical basis.
Heredity: About 50% of otosclerotics have positive family history.
Race.
Sex.
Age of onset: Deafness usually starts between 20 and 30 years of age and is rare before 10 and after 40 years .
Effect of other factors.

4. G.S.M MEDICAL LECTURES/ Otosclerosis
AHMED SALAM
MD STUDENT
Pathology:
Grossly: otosclerotic Lesion appears chalky white greyish or yellow Sometimes it is red in colour due to increased vascularity in which case the otosclerotic focus is active and rapidly progressive.
Microscopically: immature active lesions there are numerous marrow and vascular paces with plenty of osteoblasts and osteoclasts and a lot of cement substance which stains blue (blue mantles) with haematoxylin-eosin stain.

5. Types of Otosclerosis:
G.S.M MEDICAL LECTURES/ Otosclerosis
AHMED SALAM
MD STUDENT
Types of Otosclerosis:
Stapedial otosclerosis: Stapedial otosclerosis causing stapes fixation and conductive deafness is the most common variety:-
anterior focus.
Posterior focus.
Circumferential.
Biscuit type.
Obliterative type(completely).

6. G.S.M MEDICAL LECTURES/ Otosclerosis
AHMED SALAM
MD STUDENT
Types of stapedial otosclerosis. (A) Anterior focus. (B) Posterior focus. (C) Circumferential. (D) Biscuit type(thick plate). (E) Obliterative.

7. G.S.M MEDICAL LECTURES/ Otosclerosis
AHMED SALAM
MD STUDENT
Cochlear otosclerosis: Cochlear otosclerosis involves region of round windo or other areas in the otic capsule and cause sensorineural hearing loss.
Histologic otosclerosis: This type of otoscleros is remains a symptomatic and causes neither conductive nor sensorineural hearing loss.

8. Symptoms: Hearing loss.
G.S.M MEDICAL LECTURES/ Otosclerosis
AHMED SALAM
MD STUDENT
Symptoms:
Hearing loss.
Paracusis willisii: An otosclerotic patient hears better in noisy than quiet surroundings.
Tinnitus: It is more commonly seen in cochlear tosclerosis and in active lesions.
Vertigo.
Speech: well moduted soft speech.

9. G.S.M MEDICAL LECTURES/ Otosclerosis
AHMED SALAM
MD STUDENT
DX and Signs
Tympanic membrane is quite normal and mobile(Schwartze sign).
Eustachian tube function is normal.
Tuning fork tests show negative Rinne.
Pure tone audiometry shows loss of air conduction.
Bone conduction is normal In some cases there is a dip in bone conduction curve.
Speech audiometry reveals normal.
Tympanometry may be normal in early cases but later shows as curve due to ossicular stiffness.

10. Otosclerosis left ear note dip at 2000 Hz(Carhart's notch).
G.S.M MEDICAL LECTURES/ Otosclerosis
AHMED SALAM
MD STUDENT
Otosclerosis left ear note dip at 2000 Hz(Carhart's notch).
Bone conduction

11. G.S.M MEDICAL LECTURES/ Otosclerosis
AHMED SALAM
MD STUDENT
Treatment:
Medical: There is no medical treatment that cures otosclerosis Sodium fluoride has been tried to hasten the maturity of active focus and arrest further cochlear loss.
Surgical: Stapedectomy with prosthesis replacement is the treatment of choice. Here the fixed otosclerotic stapes is removed and a prosthesis inserted between the incus and oval window. Prosthesis employed may be a teflon piston, stainless steel piston, platinum teflon or titanium teflon piston. In 90% of patients, there is good improvement in hearing after stapedectomy.

12. G.S.M MEDICAL LECTURES/ Otosclerosis
AHMED SALAM
MD STUDENT
(A) Before removal of stapes. (B) Stapes
removed and replaced by a teflon piston.
Stapes prostheses:(A) Teflon piston. (B)
Platinum teflon piston.(C)Titanium teflon piston.

13. Steps of stapedectomy:
G.S.M MEDICAL LECTURES/ Otosclerosis
AHMED SALAM
MD STUDENT
Steps of stapedectomy:
Meatal incision and elevation of the tympano meatal flap.
Exposure of stapes area. This may require removal of posterosuperior bony over hang of the canal.
Removal of stapes superstructure.
Creation of a hole in the stapes footplate(stapedotomy)or removal of a part of footplate (stapedectomy).
Placement of prosthesis.
Repositioning the tympanomeatal flap .

14. G.S.M MEDICAL LECTURES/ Otosclerosis
AHMED SALAM
MD STUDENT