2.  Age  Poor socio-economic group  Virulence of organisms  Immune-compromised host  Preformed pathways  Cholesteatoma

3.  Direct Bone Erosion  Venous Thrombophlebitis  Performed pathways

4. A) Intratemporal(confines within the temporal bone):  Mastoiditis  Petrositis  Facial paralysis  Labyrinthitis

5. B)Intracranial:  Extradural abscess.  Subdural abscess  Meninigitis  Brain abscess  Lateral sinus Thrombophlebitis  Otitic Hydrocephalus

7. When the infection spreads from mucosal lining to bony wall of mastoid air cells we called it as mastoiditis. Aetiology: It usually accompanies or follows ASOM.The determining factors being high virulence of organisms or lowered resistance of patient.

8. Pathology: 1)Production of pus under tension. 2)Hyperaemic decalcification and osteoclastic resorption of bony walls.

10. Clinical Features: Symptoms:  Pain behind the ear.  Fever.  Ear discharge

11. Signs:  Mastoid Tenderness.  Ear Discharge  Sagging of postero-superior meatal wall  Perforation of tympanic membrane  Swelling over the mastoid  Hearing loss.  General findings

13. Investigations: Blood counts ESR X-ray mastoid Ear swab

14. Treatment:  Hospitalisation of patient  Antibiotics  Myringotomy  Cortical Mastoidectomy. It is indicated when there is Sub-periosteal abscess. Sagging of postero-superior meatal wall. Positive resorvoir sign. No response within 48 hrs of adequate medical treatment. Mastoiditis leading to complications

15. Spread of infection from middle ear and mastoid to petrous part of temporal bone is called petrositis. Clinical features:  Gradenigo’s syndrome : It is the classical presentation, and consist of a triad of a)external rectus palsy b)deep seated ear or retro orbital pain c)persistent ear discharge.  Fever, headache, vomiting, neck rigidity,facial paralysis.

16. Treatment:  Cortical, modified or radical mastoidectomy is often required.  Iv antibiotics should precede and follow surgical intervention. Treatment:  Cortical, modified or radical mastoidectomy is often required.  Iv antibiotics should precede and follow surgical intervention.

17. There are three types of labyrinthitis: a)Circumscribed labyrinthitis b)Diffuse serous labyrinthitis c)Diffuse suppurative labyrinthitis

18. A)Circumscribed labyrinthitis(Fistula of labyrinth): There is thining or erosion of bony capsule of labyrinth. Aetiology:  CSOM with cholesteatoma  Neoplasms of middle ear  Surgical or accidental trauma to labyrinth

19. Clinical features: A part of membranous labyrinth is exposed and becomes sensitive to pressure changes. so complain of:  Triensient vertigo often induced by pressure on tragus, cleaning the ear or while performing valsalva manoeuvre.  Diagnose by fistula test. Treatment: a)Mastoid exploration. b)Systemic antibiotics.

20. It is diffuse intra-labyrinthine inflammation without pus formation and is a reversible condition if treated early. Aetiology:  Pre-existing circumscribed labyrinthitis associated with chronic middle ear suppuration or cholesteatoma.  In acute infections inflammation spreads through round window.

21. Clinical features: In mild cases-vertigo and nausea. In severe cases-vertigo is worse with marked nausea, vomiting and even spontaneous nystagmus. Chochlea is also affected with some degree of SNHL. Total loss of vestibular and cochlear function.

22. Treatment: Medical-  Bed rest  Antibacterial Therapy  Labyrinthine sedatives- prochlorperazine(stemetil)  Myringotomy if labyrinthitis has followed ASOM and drum is bulging.  Surgical: mastoidectomy

23. This is diffuse pyogenic infection of labyrinth with permanent loss of vestibular and cochlear functions. Aetiology: It usually follows serous labyrinthitis, pyogenic organisms entering through a fistula.

24. Clinical Features:  There is severe vertigo, nausea, and vomiting due to acute vestibular failure.  Spontaneous nystagmus.  Patient looks toxic with total loss of hearing. Treatment:

25. Otogenic brain abscess: 50% of brain abscess in adults and 25%in children are otogenic.Cerebral abscess is seen twice as frequently as cerebellar abscess. Routes of infection: They develops as a result of direct extension of middle ear infection through tegmen or by thrombophlebitis.

26. Pathology: a)Stage of invasion(initial encephalitis) b)Stage of localisation(latent abscess) c)Stage of enlargement(manifest abscess) d)Stage of termination(rupture of abscess)

27. Clinical Features: Brain abscess is often associated with other complications. It can be divided into: a)Those due to raised ICP b)Those due to area of brain affected

28. a)Symptoms and sign of raised ICP  Headache  Nausea and vomiting  Level of consciousness  Papiloedema  Slow pulse and subnormal temp.

29. b)Localising Features: Temporal lobe abscess:  Nominal Aphasia  Homonymous hemianopia  Contralateral motor paralysis  Epeliptic fits

30. Investigations: a)Skull x-rays including mastoids b)CT scan c) LP Treatment:  High dose of iv antibiotics.  For raised ICP-Dexamethasone 4mg iv 6 hrly  Discharge from ear is treated by suction clearance and topical ear drops.  Neurosurgical treatment.

31.  ETIOLOGY:  COMPLICATION OF ACUTE COALESCENT MASTOIDITIS,MASKED MASTOIDITIS OR CHRONIC SUPPURATION OF MIDDLE EAR AND CHOLESTEATOMA  CLINICAL FEATURE a) HETIC TYPE OF FEVER WITH RIGOR b) HEADACHE c) PROGRESSIVE ANAEMIA &EMACIATION d) PAPILLOEDEMA

32.  TRETMENT  SYSTEMIC ANTIBACTERIAL  MASTOIDECTOMY & EXPOSURE OF SINUS  LIGATION OF INTERNAL JUGULAR VEIN  ANTICOAGULANT THERAPY  SUPPORTIVE TRETMENT