summary on intracranial abscess with emphasis on aetiology, pathogenesis, pathology, forms of presentations , investigations and treatment options of brain abscess.

1. PRESENTATION AND MANAGEMENT
OF
INTRACRANIAL ABSCESS
EZEAKU , CHIZOWA OKWUCHUKWU
1

2. CASE PRESENTATION 1
• A .E, 4 year old female presented 4 days ago on account of seizure
and left extremity weakness noticed 1 day ago.
• There was an antecedent history of fever 1 week ago, managed with
OTC drugs.
• Examination revealed left hemiparesis LL>UL with hemiparetic gait.
• CT scan showed a ring enhancing hypodense region measuring
1.67cm with marked perilesional edema in the right frontal lobe
2

3. CASE PRESENTATION 1
• A diagnosis of Brain abscess ? Hematogenous route was made
• She is currently on IV antibiotics, steroid and anticonvulsant
• Neurology has improved since commencement of treatment
3

4. CASE PRESENTATION 2
• L.G , 55 year old male presented 3 weeks on account of headache
with discharging right scalp wound .Had a machete cut a week earlier
which was managed at home.
• Examination findings showed a 4X 6 cm wound on the right frontal
aspect of the scalp with seropurulent discharge.
• CT scan showed depressed communited frontal bone fracture.
• Had craniotomy with debridement and elevation of depressed
fracture.
4

5. CASE PRESENTATION 2
• 9 days later, developed altered sensorium with progressive purulent
discharge from traumatic wound.
• Repeat CT scan showed a right frontal lobe ring enhancing hypodense
lesion measure about 4cm with perilesional oedema with effacement
of the ipsilateral lateral ventricle.
• Assessment : Brain abscess 2 to direct contiguous spread .
• Had craniotomy, wound debridement with aspiration of abscess.
• Currently on IV antibiotics.
5

6. • INTRODUCTION
• EPIDEMIOLOGY
• CLASSIFICATION
• AETIOPATHOGENESIS
• PATHOLOGY
• CLINICAL FEATURES
• INVESTIGATIONS
• DIFFERENTIAL DIAGNOSIS
• TREATMENT OPTIONS
• COMPLICATIONS
• PROGNOSIS
• LOCAL EXPERIENCE
• FUTURE TRENDS
• CONCLUSION
6

7. INTRODUCTION
• Intracranial abscess consist of a collection of immune cells, pus, and
necrotic materials within the intracranial cavity.
• Usually from a bacterial, fungal, or protozoan infection
7

8. BRIEF HISTORY
•Intracranial abscesses has been a recognized disease entity since
antiquity.
• Hippocrates made the first association between otorrhea and
delirium.
• The first documented successful operation for intracranial abscess –
S.F. Morand in 1752.
8

9. EPIDEMIOLOGY
• Approx 1,500 -2500 cases reported annually in the United States
• M: F= 2.8 : 1.0 (SW, Nigeria)
• Mean age : 25.6yrs
• Commonest location: Frontal lobe(41%-UBTH, 32%(Memfy,UNTH)
• Mortality been showing a downward trend(0-24%)
9

10. CLASSIFICATION
• Based on location
Intraparenchymal 50%
Subdural 25%
Extradural 22%
Intraventricular 3%
10

11. CLASSIFICATION
• Based on number
• Solitary
• Multiple(5-50%)
11

12. CLASSIFICATION
• Based on causative agent
• Pyogenic abscess
• Tuberculous abscess
• Fungal abscess( Aspergillius, Candida, Histoplasma)
12

13. Hemispheric Distribution
• Right hemisphere 45%
• Left hemisphere 32%
• Bilateral 12.5%
• Multiple 9%
13

14. AETIOPATHOGENESIS(Risk factors)
Patient factor
• Age
• Poor physical condition- malnutrition, immunosuppression, infection at
secondary site (UTI, Chest infections), congenital heart diseases
• Local factors- dehydration, hypoxia, devitalised tissue
Surgical factor
• Re-operation
• Long operation times
• Inadequate aseptic technique
• Large surgical fields
14

15. AETIOPATHOGENESIS
• Abscess initiation:
• Disruption of the major brain barriers(BBB, BCSFB)
• Development and initiation depends :
• Organism(Virulence, dose, route of entry)
• Patient factors
• Anatomical defenses(Skull, meninges)
• Physiological: Immune defense mechanisms
15

16. AETIOPATHOGENESIS
• Direct spread (40-50%)
(Contiguous foci)
• Hematogenous (25-35%)
(Remote foci)
• Penetrating trauma/surgery (10%)
• Cryptogenic (15-20%)
16

17. Predisposing Condition Usual Microbial Isolates
Otitis media or mastoiditis Streptococci (anaerobic or aerobic),
(Temporal lobe/ cerebellum) Bacteroides and Prevotella spp.,
Enterobacteriaceae
Sinusitis (frontoethmoid or sphenoid) Streptococci, Bacteroides spp.,
(Frontal lobe /sella turcica)
Enterobacteriaceae, Staph. aureus,
Haemophilus spp.
Dental sepsis Fusobacterium, Prevotella and
(Frontal lobe> Temporal) Bacteroides spp., streptococci
Penetrating trauma or postneurosurgical S. aureus, streptococci,
Enterobacteriaceae, Clostridium spp.
17

18. • Lung abscess, empyema, bronchiectasis : Fusobacterium, Actinomyces, Bacteroides
Prevotella spp, streptococci, Nocardia
• Bacterial endocarditis :S. aureus, streptococci
• Congenital heart disease Streptococci, Haemophilus spp.
• Neutropenia Aerobic gram-negative bacilli, Aspergillus , Mucorales,
• Transplantation Aspergillus spp., Candida spp., Mucorales,
Enterobacteriaceae, Nocardia spp., Toxoplasma gondii
• HIV infection Toxoplasma gondii, Nocardia spp., Mycobacterium spp.,
Listeria monocytogenes, Cryptococcus neoformans
• PPID, 2000
18

19. PATHOGENESIS
19

20. Microscopy( 5 zones)
1. Necrotic core
2. Zone of inflammatory cells and
fibroblast
3. Dense collagen capsule
4. Zone of neovascularization
5. Reactive astrocytes, gliosis, and
cerebral edema
20

21. CLINICAL FEATURES
• Depends on
• Origin of infection /septic focus
• Site
• Size and number of lesions
• Specific brain structures involved
• The neighborhood anatomy disturbances involving cisterns, ventricles, and
the dural venous sinuses
• Predisposing risk factors
• Any secondary cerebral injury
21

22. CLINICAL FEATURES
• Present with features related to
 Focal mass expansion
 Raised intracranial pressure
 Diffuse destruction, and
Irritation of neural tissues
22

23. CLINICAL FEATURES
23

24. Possible Initial Findings in Patients with Brain Abscess Based on
Intracranial Location
INTRACRANIAL LOCATION FINDINGS
Parietal lobe
Headache
Visual field deficits (ranging from
inferior quadrantanopia to
homonymous hemianopia)
Frontal lobe
Headache
Drowsiness
Inattention
Personality change
Mental status deterioration
Hemiparesis
Motor speech disorder
Temporal lobe
Ipsilateral headache
Aphasia or dysphasia (if in the
dominant hemisphere)
Visual field deficit (ranging from
upper quadrant homonymous
quadrantanopia to complete
homonymous hemianopia)
24

25. Possible Initial Findings in Patients with Brain Abscess Based on Intracranial
Location
Cerebellum
Headache
Nystagmus
Ataxia
Vomiting
Dysmetria
Meningismus
Papilledema
Brainstem
Cranial nerve involvement
Deficits of ascending and
descending pathways
25

26. INVESTIGATIONS
Radiologic
• Magnetic resonance imaging (MRI) : Gold standard
• Contrast enhanced Cranial computed tomography scan
• Proton MR spectroscopy, Radiolabelled leucocyte scan
• Skull x-rays
Others
• Aspirate for microbiological assessment +/- cytology
• Full blood count/peripheral blood film
• Blood culture
• Erythrocyte sedimentation rate/ C-reactive protein
• Others: Echocardiography ,Hb genotype, Chest X-ray, Quanteferon,RVS
26

27. 27

28. 28

29. 29

30. DIFFERENTIAL DIAGNOSIS
• Based on clinical features
– Bacterial meningitis
– Focal encephalitis
– Brain tumour
– Intracranial hematoma
30

31. DIFFERENTIAL DIAGNOSIS
• Based on CT scan findings(Ring enhancing lesion)
– Metastasis
– Glioblastoma
– Subacute infarct
– Radiation necrosis
– Neurocysticercosis
31

32. TREATMENT
• Aim is to
• Identify offending microorganism with appropriate antibiotic coverage
• Remove the septic foci
• Other supportive /useful adjuncts
• Multidisciplinary approach
32

33. TREATMENT
• Combined medical and surgical
• Medical(selected cases)
33

34. Indications for surgery
• Obtain culture specimen
• Significant mass effect
• Raised intracranial pressure
• Evidence of foreign body or gas containing abscess
• Proximity to ventricles
• Poor neurological condition
• Inability to obtain weekly CT scan
• Fungal abscess
• Failure of non operative management
• Multiloculated abscess
34

35. Surgical options
• Aspiration
• Via Needle
• Free hand aspiration
• Stereotactic guided
• Neuroendoscopic aspiration
• Intraoperative ultrasound guided
• Surgical excision via a craniotomy
35

36. Aspiration
• Stereotactic aspiration recommended for small, multiple abscess or
when located in inaccessible or eloquent area
• Neuroendoscopic treatment, when compared to stereotactic
aspiration, has additional advantage of more complete drainage and
lavage especially in multiseptated or intraventricular abscess
• Associated repeated procedure
36

37. Indications for craniotomy and abscess excision
• Presence of foreign body
• Post traumatic/ gas containing abscess
• Superficial located abscess with thick membranes
• Peripheral abscess resistant to aspiration or antibiotics
• Cerebellar abscess
• Abscess that results from fistulous communication
37

38. Contraindications for craniotomy with abscess excision
• Abscesses in cerebritis stage
• Deep seated abscesses in eloquent areas
• Multiple abscesses
38

39. Specific Considerations
• Multiple abscess(5% -50% )- surgical(aspiration) or medical
only/combination
• Cerebellar abscess(6-35%) -Posterior fossa craniotomy advised+/-
ventriculostomy, however burr hole aspiration has emerged as a
satisfactory method
• Brainstem abscess-Posterior fossa craniotomy
• Tubercular abscess- AntiTb with drainage
• Subdural and epidural abscess- surgery(evacuation and membrane
excision) plus antimicrobial therapy
39

40. Medical Therapy
• Indicated for extremely poor surgical candidates with
• Microabscess(<2cm-debatable)
• Multiple abscess
• Cerebritis stage
• Inaccessible localization
• Concomitant meningitis, ependymitis
• Improvement on antibiotics therapy
40

41. 41

42. Duration of antibiotic
• Numerous recommendations
• 6-8 weeks IV, followed by 2-3months oral
• 12 weeks IV, for medical therapy alone
• Post excision- 4 to 6 weeks antibiotics
• Triple high dose therapy- 2 weeks IV, followed by 4 weeks oral
• 3-12 months antimicrobial for the immunocompromsed
42

43. Radiographic monitoring
• Cranial scans weekly during the course of therapy
• One week after discontinuation of therapy
• Scan one month later
• Monthly or bimonthly until radiographic resolution
43

44. Role of Steroids
• Controversial
• Indications:
• Impending brain herniation
• Progressive neurological deterioration
• Associated massive edema and mass effect
• Prolonged use is discouraged
44

45. Role of anticonvulsants
• Legg et al advocated 5year course for all patient with brain abscess.
• Muzumdar etal recommended discontinuation after 2 years of seizure
free, with no epileptic activity on EEG
• Also anticonvulsant is recommended for children who develop
seizure, most authors recommend providing at least 3 months of
prophylaxis if no more seizures have occurred.
45

46. Role of Hyperbaric oxygen
• In addition to surgery, hyperbaric oxygen therapy has been reported
to be a useful adjunct
• More useful in fungal brain abscess
• Although no randomized, prospective studies have been performed
to assess its efficacy.
46

47. COMPLICATIONS
• Reoccurrence(10%)
• Focal neurological deficit(30-50%)
• Mental retardation
• Seizure(70%)
• Venous sinus thrombosis
• Hydrocephalus
• Septicemia
• Meningitis
• Ventriculitis
47

48. PROGNOSIS
• Poor outcome associated with:
• intraventricular rupture(80% mortality)
• rapid progress prior to hospitalization
• coma or stupor,
• Initial GCS <12
• Aspergillosis(90%)
• Comorbidities(Charlson scale >/2)
48

49. LOCAL EXPERIENCE
• 5 cases
• M: F=3:2
• Age:4-55yrs
• Mortality rate : 40%
49

50. CURRENT TRENDS
• 16S Ribosomal sequencing
• Emphasis on stereotactic aspiration
50

51. CONCLUSION
• Intracranial abscesses are uncommon, serious, life-threatening
infections with varied aetiological agents and route of spread.
• Its numerous presentation may pose a diagnostic dilemma to the
clinician
• High index of suspicion, prompt response with appropriate
management will help to improve outcome
51

52. REFERENCE
• Olorunmoteni OE, Onyia CU, Elusiyan JBE, Ugowe OJ, Babalola TE,
Samuel I. Intracranial abscesses in children at Ile-Ife, Nigeria: a case
series and review of literature. Childs Nerv Syst. 2020 Aug;36(8):1767-
1771. doi: 10.1007/s00381-020-04529-2. Epub 2020 Feb 8. PMID:
32034520.
• Udoh DO, Ibadin E, Udoh MO. Intracranial abscesses: Retrospective
analysis of 32 patients and review of literature. Asian J Neurosurg
2016;11:384-91
• Chika Ndubisi,Samuel Ohaegbulam,Wilfred Mezue, Mark Chikani
Management of Brain Abscess: Changing Trend and Experience in
Enugu, Nigeria. July 2017Nigerian Journal of Surgery 23(2):106
52

53. REFERENCE
• Vincent Thamburaj. Textbook of Contemporary Neurosurgey,Vol 1
• Friedman Em, etal.Intracranial complications of sinusitis in children.A
sequuela of periapical abscess.Ann Otol Rhinol Laryngol.1982.41-3
• Brook I.Microbiology and treatment of brain abscess. J Clin Neurosci. 2017.
38:8-12
• Management of Brain Abscess. A seminar presentation by Dr Moses Inojie
• Muzumdar D, Jhawar S, Goel A. Brain abscess: An overview. Int J
Surg. 2011;9:136–44.
• Legg NJ, Gupta PC, Scott DF. Epilepsy following cerebral abscess. A clinical
and EEG study of 70 patients. Brain. 1973;96:259–68.
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54. • THANK YOU FOR LISTENING
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