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Brain abscess-backup

4 min read

SURGERY 2

Brain Abscess

Dr. Safdar Malik

Definition

Form within 2 weeks (short time)

become symptomatic

  • Brain abscess is a focal suppurative infection within the brain parenchyma, typically surrounded by a vascularized capsule.

  • Cerebritis: is often employed to describe a nonnencapsulated brain abscess.

Brain Abscess

Bone in the size and start compressing Should be removed

Pathophysiology

Risk Factors

Signs & symptoms

Evaluation

Treatment

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Epidemiology

  • Relatively uncommon
  • Incidence~.3-1.3:100000 person per year

Etiology

Brain abscess may develop by

  1. Direct spread from a contiguous cranial site of infection
  2. Head trauma, neurosurgical procedures
  3. Hematogenous spread → Just like mets spread

(any problem in face, it go directly into brain)

25% cases : There is no primary source of infection

Predisposing conditions

  • Otitis media

  • Mastoiditis

  • Paranasal sinusitis

  • Pyogenic infection of chest or any other part of body

  • Penetrating head injury

  • Neurosurgical procedure

  • Dental infection → eg. from dental procedures

  • There is an artery that is communicating with intracranial arteries. So infection can spread

Cont.

In Immunocompetent persons:

  • Streptococcus spp. (aerobic, Anaerobic and viridans) 40%
  • Enterobacteriaceae (Proteus, E.coli, Klebsella) 25%
  • Anaerobes (Bacteroides, Fusobacterium) 30%
  • Staphylococci 10%
  • Taenia solium(NCC)
  • Mycobacterial infection (tuberculoma)

Cont.

In immuno-compromised host

  • Nocardia
  • T gondii
  • Aspergillus
  • Candida
  • C. neoformans

→ in patients already suffering from brain tumors, HIV …

Stages (14 days)

  1. Early Cerebritis: 1-3 days → head ache, flu like symptoms

A perivascular infiltration of inflammatory cells around a central core of coagulation necrosis

  1. Late Cerebritis: 4-9 days

Pus formation in necrotic center which is surrounded by inflammatory cells and fibroblast

  1. Early Capsule Formation: 10-13 days

A capsule that is better develop on cortical then on ventricle side of lesion

  1. Late Capsule Formation: beyond 14 days

A well defined necrotic center surrounded by a dense collageous capsule

Clinical Presentation

  • Typically presents as an expanding intracranial mass rather than as a infectious process
  • Symptoms are gradual in onset
  • Patients present in weeks to month
  • Usually presents 11-12 days following onset of symptoms.

Symptoms

  • Classical triad: seen in <50% patients

  • Headache 75%

  • Fever 50% most common symptoms

  • Focal neurologic deficit 15-35%

Cont.

  • Focal neurologic deficit

  • Aphasia

  • Hemiparesis

  • Visual field defect

  • Ataxia

  • Nystagmus

  • Seizures → have some localization → Temporal, Frontal, Parietal lobes are all different

  • Raised ICP-Papilledema

  • Meningismus Uncommon unless abscess rupture in ventricle

vomiting, LOC, seizures, empyema Can form if abscess form between sub dural or extradural

  • history taking is very imp. (ask about flu like symptoms)

Investigations

  • TLC, DLC

  • ESR, CRP

  • Blood cultures

  • Neuroimaging studies:

  • MRI: better esp can detect early stages of cerebritis

  • CT Scan: a focal area of hypodensity surrounded by ring enhancement with surrounding edema (hypodensity)

CT Scan

  • • elementary
  • • address is
  • • similar to
  • • mets
  • • (both also
  • • take short
  • • history)

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1/25/24

14

MRI

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Microbiological Evaluation

CT-guided stereotactic needle aspiration

  • Gram’s Stain
  • Culture : Aerobic, Anaerobic, Mycobacterial and fungal cultures

Blood Culture

LP: do not perform

D/D

  • Bacterial Meningitis
  • Meningoencephalitis
  • Acute disseminated encephalomyelitis
  • Empyema
  • Saggital Sinus Thrombosis
  • Primary or Secondary brain tumor
  • CVA

Treatment

  • Combination of high dose parental antibiotics and neurosurgical drainage
  • Third/fourth grneration cephalosporin+Metronidazole
  • Patients with neurodurgery/Head trauma
    • Vancomycin+Ceftazidine
    • Meropenem+Vancomycin
  • Modify antibiotics as per culture results
  • Duration: Min 6-8 weeks

Cont.

  • Prophylactic anticonvulsant

    • Should continue atleast 3 months after resolution of abscess

  • Role of steroids → becameful if patient is diabetic

    • dose with antibiotic not alone

    • Not given routinely

    • Usually reserved forof significant periabscess edema with mass effect and raise ICP

    • Dexamethasone 10 mg 6 hrly

Cont.

  • Aspiration and Drainage of the abscess under stereotactic guidance
  • Craniotomy and Complete excision of a bacterial abscess: reserved for multiloculated abscess or in those where aspiration is unsuccessful.

Prognosis

  • Mortality rate <15%
  • Neurological sequelae ≥20% of survivors

ENT

ENT

Brain Abscess

  • Definition: Localized suppuration in the brain substance.
  • It is the most lethal complication of suppurative otitis media.
  • Incidence: 50% is otogenic brain abscess.

Pathology

  • Site: Temporal lobe or, less frequently, in the cerebellum (more dangerous).

Diagnosis

  • CT scans
  • MRI

Treatment

  • Medical:
    • Systemic antibiotics
    • Measures to decrease intracranial pressure
  • Surgical:
    • Neurosurgical drainage of the abscess
    • Mastoidectomy

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