OTOGENIC BRAIN ABSCESS by dr.ravindra

c.t.findings of otogenic brain abscess,journal on uses of c.t.in otogenic brain abscess

1. Role of c.t.scan in diagnosis & management of otogenic intra cranial abscess MODERATOR:Dr.C.P.DAS PRESENTER:RAVINDRA.D

2. Complications of c.s.o.m . DEFINiTION Spreading of infection beyond muco-periosteal lining of middle ear cleft to involve bone & neighboring structures like facial nerve, inner ear, dural venous sinuses, meninges , brain tissue & extra-temporal soft tissue .

3. FEATURES Severe otalgia , painful swelling around ear, Vertigo, nausea, vomiting, Headache + blurred vision + projectile vomiting, Fever + neck rigidity + irritability / drowsiness, Facial asymmetry , Otorrhoea + Retro-orbital pain + diplopia , Ataxia.

4. ROUTES OF ENTRY Congenital bony defects: facial canal, tegmen plate. Anatomical pathway: oval window, round window, internal auditory canal, suture line, cochlear & vestibular aqueduct Bony erosion ( cholesteatoma destruction, osteitis ). Retrograde Thrombophlebitis. Acquired bony defects: fracture, neoplasm, stapedectomy Peri -arteriolar space of Virchow-Robin : spread into brain.

5. CLASSIFICATION Intra-cranial complications Extra-cranial complications Intra-temporal Extra-temporal Systemic: septicemia, otogenic tetanus

6. INTRA CRANIAL COMPLICATIONS Extra- dural abscess Subdural abscess Meningitis Brain abscess Lateral Sinus thrombophlebitis Otitic hydrocephalus

7. EXTRA CRANIAL COMPLICATIONS INTRA TEMPORAL Acute mastoiditis Coalescent mastoiditis Masked mastoiditis Facial nerve palsy Labyrinthitis Labyrinthine fistula Petrositis . EXTRA TEMPORAL Post-auricular abscess Bezold abscess Behind the mastoid( Citelli’s )abscess Meatal (Luc’s)abscess Zygomatic abscess

8. FACTORS AFFECTING PATHOGEN FACTORS PATIENT FACTORS  High virulence bacteria  Young age  Antimicrobial resistance  Poor immune status  Chronic disease (DM, TB) PHYSICIAN FACTORS  Poor socio- economi C status  Non-availability  Lack of health awareness  Injudicious antibiotic use  Error in recognizing dangerous symptoms & signs

9. OTOGENIC BRAIN ABsCESS 50-75 % adult brain abscess & 25% in child is otogenic. Temporal abscess is twice as common as cerebellar abscess ROUTES OF INFECTION : Direct spread :  via Tegmen plate: Temporal abscess  via Trautmann’s triangle: Cerebellar abscess 2. Retrograde spread: via thrombophlebitis

10. sometimes the infection could extend via the Virchow -Robin spaces in to the cerebral white matter. Virchow–Robin spaces (VRS)  are perivascular, fluid-filled canals that surround perforating arteries and veins in the parenchyma of the brain. Cerebellar abscess is usually preceded by thrombosis of lateral sinus. Abscess in the cerebellum may involve the lateral lobe of the cerebellum, and it may be adherent to the lateral sinus or to a patch of dura underneath the Trautmann's triangle.

11. trautmann’s triangle Superiorly: superior petrosal sinus Posteriorly : sigmoid sinus Anteriorly : solid angle (semi-circular canals) It is Pathway to posterior cranial fossa from mastoid cavity

12. Stages of brain abscess INVASION OR ENCEPHALITIS (1-10 days) LOCALIZATION OR LATENT ABSCESS (10-14 days) EXPANSION OR MANIFEST ABSCESS (> 14 days): leads to raised intracranial tension & focal signs TERMINATION OR ABSCESS RUPTURE: leads to fatal meningitis

13. bacteriology Anaerobic streptococci Streptococcus pneumoniae Staphylococci Proteus E. coli Pseudomonas Bacteroidis fragilis

14. Focal clinical features TEMPORAL LOBE CEREBELLUM  Nominal aphasia  I/L n ystagmus  Quadrantic homonymous  I/L weakness hemianopia (C/L)  I/L hypotonia  Epileptic seizures  I/L ataxia  Pupillary dilatation  Intention tremor  Hallucination (smell & taste)  Past-pointing  C/L hemiplegia  Dysdiadochokinesia

15. Clinical features of raised i.c.t . Seen more in cerebellar abscess Severe persistent headache, worse in morning, Projectile vomiting, Blurring of vision & Papilloedema , Lethargy  drowsiness  confusion  coma Bradycardia , Subnormal temperature.

16. investigations CT SCAN OF BRAIN & TEMPORAL BONE WITH CONTRAST It shows Ring enhancement with central necrosis, and surrounding edema. It is used for: Site, size & staging of abscess Observe progression of brain abscess Associated intra-cranial complications MRI BRAIN To differentiate pus, abscess ,capsule, edema & normal brain Spread to ventricles & subarachnoid space AVOID LUMBAR PUNCTURE TO PREVENT CONING

17. TEMPORAL ABSCESS CERBELLAR ABSCESS C.T.FEATURES

18. TREATMENT MEDICAL High dose broad spectrum I.V. antibiotics: Ceftriaxone + Metronidazole + Gentamicin I.V. Dexamethasone 4mg Q6H: for decreasing edema I.V. 20% Mannitol (0.5 gm/kg):for decreasing I.C.T. Anti-epileptics like Phenytoin sodium Antibiotic ear drops and aural toilet.

19. SURGICAL Repeated burr hole aspirations, Excision of brain abscess with capsule (best T/T) Open incision & evacuation of pus, Radical mastoidectomy after pt becomes stable.

20. journal ROLE OF C.T.SCAN IN DIAGNOSIS AND MANAGEMENT OF OTOGENIC INTRACRANIAL ABSCESS

21. INTRODUCTION In the 5 yr. period preceding the introduction of antibiotics, approximately 1 in 40 deaths in a large hospital is due to intra cranial complications of C.S.O.M. The complications develop when middle ear infection spreads from its confined space to adjacent space and structures. The symtomatology of these complications is slow in development and diagnosis is difficult. C.T. scan has formed the main stay of diagnosis in recent years. It offers a highly accurate and rapid means of establishing the diagnosis and following the course of disease.

22. Materials &methods All cases with h/o C.S.O.M. and having additional symptoms of fever, ear ache, vertigo, head ache, vomitings, altered sensorium were investigated. Patients with otogenic brain abscess diagnosed with C.T.scan were included in study. All pts were infused with triple antibiotics( gr.+,gr-ve,anaerobic ), Mannitol , dexamethasone , anti convulsants are used when needed. Usually trans mastoid route was used to drain the abscess, Then, cortical mastoidectomy was done.

23. Status of the dural /sinus plate was observed. Usually it found eroded…if it is intact,then it was drilled. Burr hole,craniotomy approaches were used when the abscess Is not approachable through trans mastoid route. Repeat C.T.scans done after 10 to 14 days of antibiotics to confirm resolution of abscess. If the size found greater than 1.5c.m.then re aspiration was done. The canal wall down mastoidectomy was done once the C.T. showed resolution of abscess. Suitable tympanoplasty , meatoplasty done depending upon middle ear disease.

24. Results and observations Symptoms and signs of cerebellar abscess were present in 4 out of 18 cases…but 8 out of 18 were diagnosed on C.T.scan . Symptoms and signs of temporal lobe abscess were present in 5 out of 18 cases…but 7 out of 18 were diagnosed on C.T.scan . 12 pts.had other intra cranial complications which could be detected by C.T.scan . This emphasizes the need of C.T.scan in diagnosis of multiple complications.

25. Repeat C.T.scan after clinical improvement and cessation of pus was done in 15 pts. Resolution was observed in 10 pts.but 5 showed residual abscess and required re drianage procedure. After final confirmation of resolution, all had underwent canal wall down mastoidectomy as all have extensive attico antral CSOM. The pts were followed for an average period of 14 months. No pt reported with recurrence of intra cranial complications.

26. c.t.scan findings in p ts. LEFT TEMPORAL LOBE ABSCESS PRE OP.

27. 14 DAYS AFTER TRANS MASTOID DRIANAGE

28. 26 DAYS AFTER 1 ST DRAINAGE

29. LARGE CEREBELLAR ABSCESS PRE OP.

30. RESIDUAL ABSCESS ON 18 TH DAY OF DRAINAGE

31. FULLY RESOLVED CEREBELLAR ABSCESS

32. DISCUSSION The procedure of C.T.is non invasive, easily available, relatively cheap and can be repeated with out any hazards to the pts. The uses of C.T. in a case of otogenic brain abscess are: In coma pts,where history,signs,symptoms are unavailable, it helps in accurate diagnosis. In case of bilateral disease, it helps in deciding which ear to operate first. In case of brain abscess associated with other complications, it helps in deciding which complication to be given priority.

33. By knowing exact size and multiplicity of abscess, it avoids unnecessary surgery. By knowing the stage of abscess, surrounding edema, it helps in deciding timing of surgery. By knowing the size and position we can know the best approach for the drainage of abscess. Follow up C.T. scans help in confirming the resolution of abscess. We can detect residual abscess and treat them adequately thus reducing over all mortality and morbidity.

34. conclusion All the complications of CSOM are decreasing with increased use of antibiotics. The treatment plan should be tailored according to pt’s condition. It is recommended to confirm the brain abscess by follow up C.T. scan in all pts. This will eliminate residual abscess and helps in reducing the mortality and morbidity.

35. bibliography SCOTT&BROWN 7 TH EDITION LUDDMAN INDIAN JOURNAL OF OTOLARYNGOLOGY AND HEAD&NECK SURGERY( july - sept 2011)