BRAIN ABCESS, SUBDURAL EMPYEMA AND EXTRADURAL ABCESS

By:M.M.Fathima Asrin

OBJECTIVES

• Describe the following aspects of brain abcessEtio-pathogenesisMorphology of brainClinical features• Describe the subdural empyema and

extradural abcess

What is brain abscess?

Focal collection of pus within brain parenchyma

pathogenesis?

• Infection:mostly by bacteria Direct

20-60% of the cases Focal abscess

Hematogenous Multiple abscesses No identifiable sources in 20-40% of the cases

Primary sources in direct spread and distribution of abscess

• Otitis media – inferior temporal lobe and cerebellum

• Frontal or ethmoid sinuses – frontal lobe

• Dental caries – frontal lobe• Foreign bodies

Primary sources of hematogenous spread

• Chronic pulmonary infections – lung abscess and empyema

• Skin infection• Intrabdominal and pelvic infection• Bacterial endocarditis• Cyanotic congenital heart disease – most

common in children

Morphology?

• Discrete lesions with central liquefactive necrosis

• Surrounded by fibrous capsule & zone of reactive gliosis

• Neovascularization around necrosis with marked tissue oedema

Symptoms?

• Headache – most common• Neck stiffness– Associated with occipital abscess– Abscess leaks into lateral ventricle

• Altered mental status – cerebral edema• Vomiting – increased intracranial pressure

Physical finding?• febrile – not very reliable

• Focal neurological deficit – days or weeks after onset of headache

Parietal lobe-hemiparesis Temporal lobe-dysphasia Cerebellum-ataxia & nystagmus

• Seizure– May be first manifestation of brain abscess

• Third or sixth cranial palsy – increased intracranial pressure• Papilledema – cerebral edema

Tests?

1. WBC : normal or mild increase 2. ESR : increase in 90%3. CSF : not specific ,LP is contraindicated due to

risk of herniation4. Brain CT-contrast

• ring enhancement lesion• Multi loculation • Multiplicity• Finding of gas

Treatment options?

• Antibiotics • Surgical drainage

SUBDURAL EMPYEMA AND EXTRADURAL ABCESS

Focal collection of pus around dura matter following infection usually from direct spread

Assoc.with infection of skull, air sinuses , ear infection surgical procedure

large subdural abcess has tendency to behave like a mass lesion & may cause thrombophlebitis in bridging veins that cross subdural space

Abcess in spinal epidural space may cause spinal cord compression

• PresentationFever,headache,neck stiffness,focal

neurological signs,coma• Treatment with antibiotics plus

surgical drainage results in complete recovery usually

Thank You