OTOSCLEROSIS - causes, types, symptoms & treatment

Otosclerosis is the overgrowth of the spongy bones in the bones of the middle ear leading to the fixation of the bones causing conductive hearing loss in patient.

This lecture includes its pathophysiology, causes, risk factors, symptoms and treatment

1. OTOSCLEROSIS By : Miss Saili Gaude Principal Shivam College of Nursing, Amirgadh

2. Definition Otosclerosis – abnormal hardening of the ear bone. In this condition the spongy bone overgrow preventing movement of stapes bone over the oval window resulting in conductive deafness.

3. Etiology Unknown Family history More common in women than men History of measles infection Bone disorders Endocrine (pregnancy) Infections Trauma Autoimmune

4. TYPES

5. TYPES OF CLINICAL OTOSCLEROSIS 1) Stapedial otosclerosis 2) Cochlear otosclerosis 3) Mixed otosclerosis

6. 1. STAPEDIAL OTOSCLEROSIS The otosclerosis focus may produce ankylosis of the membraneous labyrinth. Here the stapes hardens There is fixation of stapes resulting in immobilization of the bone. Thus there is disruption of the vibrations from tympanic to cochlea. The hardening occurs most commonly at “Fistula ante fenestrum ” which is a small cleft present in front of the oval window. Types :

7. 2. COCHLEAR OTOSCLEROSIS Defined as otosclerosis located in the otic capsule involving the cochclear endosteum and causing sensorineural hearing loss or mixed type of hearing loss. It involves the region of round window and labyrinth in the absence of stapes. Sensorineural hearing loss occurs due to liberation of toxic materials from abnormal bone into inner ear. It is very rare Positive schwartze sign and positive family history

8. 3. MIXED OTOSCLEROSIS Otosclerosis causes both fixation of the stapes as well as in involvement of the labyrinth so that there are mixed hearing loss.

9. Clinical manifestations Hearing loss – usually starts in one ear and than progresses to the other. Occurs gradually Inability to hear low pitched sounds Cannot hear whispers Tinnitus- ringing sensation in the ears

10. Patholphysiology

11. PATHOGENESISN Divided in 2 phases: 1) EARLY SPONGIOTIC PHASEA- In this there is active reabsorption of bone. Dilation of vessels is seen. Schwartz’s sign is present. Bone turnover is increased and there is increased vascularity 2) LATE OR SCLEROTIC PHASE- formation of new bone in resorption areas. New bone is dense and sclerotic. Dense mineralization occurs.

12. DIAGNOSTIC EVALUATION TUNING FORK EVALUATION- rinne’s test is negative while in severe condition Webr’s test may be positive with lateralization of sound AUDIOMETRY -pure tone audiometry reveals conduction hearing loss. TYMPANOMETRY- normal in early conditions but with severity , a stiffness or flattening curve may be observed, indicating low compliance of the ossicular chain and tympanic membrane. CT Scan- otosclerosis is typically diagnosed using high resolution computed tomography of the temporal bones. The fenestral foci, which are located in the area anterior to the oval window, can be found in more than 80% cases SCHWARTZE SIGN: the schwartze sign which is also known as flamingo flush sign or rising sun sign, is a characteristically reddish discolouration of the promontory due to the characteristic otosclerotic lesion

13. AUDIOMETRY

14. TUNING FORK EVALUATION

15. TYMPANOMETRY

16. MEDICAL MANAGEMENT Fluoride Vitamin D Calcium Mechanism of action is controversial but usually helps by slowing the progression of otosclerosis Patient may require hearing aid to amplify sound

17. GENERAL MEASURES Avoidance of noisy environment Side lying position Continuous applications of medications High protein diet

18. Surgical management Stapedotomy or stapedectomy with prosthesis placement. 1. Stapedectomy : removal of portion of the sclerotic stapes footplate of stapes or complete removal of the stapes and the implant with prosthesis to maintain suitable conduction. 2. Stapedotomy : modern surgery called stapedotomy is performed by drilling a small hole in the stapes footplate with micro drill or laser and then insertion of a piston like prosthesis

19. STAPEDECTOMY

20. STAPEDOTOMY

21. Complications Sensorineural hearing loss Facial palsies Tinnitus