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

1. MODERATOR:Dr.C.P.DAS
PRESENTER:RAVINDRA.D

2. 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.  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.  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.  Intra-cranial complications
 Extra-cranial complications
 Intra-temporal
 Extra-temporal
 Systemic: septicemia, otogenic tetanus

6. 1. Extra-dural abscess
2. Subdural abscess
3. Meningitis
4. Brain abscess
5. Lateral Sinus thrombophlebitis
6. Otitic hydrocephalus

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

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

9. 50-75 % adult brain abscess & 25% in child is otogenic.
Temporal abscess is twice as common as cerebellar abscess
ROUTES OF INFECTION:
1. 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. Superiorly: superior
petrosal sinus
Posteriorly: sigmoid sinus
Anteriorly: solid angle
(semi-circular canals)
It is Pathway to posterior
cranial fossa from mastoid
cavity

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

14.  Anaerobic streptococci
 Streptococcus pneumoniae
 Staphylococci
 Proteus
 E. coli
 Pseudomonas
 Bacteroidis fragilis

15. TEMPORAL LOBE CEREBELLUM
Nominal aphasia I/L nystagmus
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

16. Seen more in cerebellar abscess
 Severe persistent headache, worse in morning,
 Projectile vomiting,
 Blurring of vision & Papilloedema,
 Lethargy drowsiness confusion coma
 Bradycardia,
 Subnormal temperature.

17. 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

18. TEMPORAL ABSCESS CERBELLAR ABSCESS

19. 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.

20. 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.

22.  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.

23.  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.

24.  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.

25.  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.

26.  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.

27. LEFT TEMPORAL LOBE ABSCESS PRE OP.

28. 14 DAYS AFTER TRANS MASTOID DRIANAGE

29. 26 DAYS AFTER 1ST DRAINAGE

30. LARGE CEREBELLAR ABSCESS PRE OP.

31. RESIDUAL ABSCESS ON 18TH DAY OF DRAINAGE

32. FULLY RESOLVED CEREBELLAR ABSCESS

33.  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:
1. In coma pts,where history,signs,symptoms
are unavailable, it helps in accurate
diagnosis.
2. In case of bilateral disease, it helps in
deciding which ear to operate first.
3. In case of brain abscess associated with
other complications, it helps in deciding
which complication to be given priority.

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

35.  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.

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