Name
BRAIN ABSCESS
DESCRIPTION
DETAIL
CAUSES: β’ Direct extension from otitis, mastoiditis, sinusitis or dental infection β’ Cranial osteomyelitis β’ Penetrating skull trauma β’ Prior craniotomy β’ Bacteremia from lung abscess, pneumonia β’ Bacterial endocarditis β’ Fungal infection of the nasopharynx β’ Toxoplasma gondii (in AIDS patients) β’ Cyanotic congenital heart disease β’ Intravenous drug use β’ No source found in 20% β’ Most common infective organisms - streptococci, staphylococci, enteric gram-negative bacilli and anaerobes (usually same as source of infection), Nocardia -------------------------------------------------------------------------- D.D. : - SUBDURAL EMPYEMA - BACTERIAL MENINGITIS - VIRAL MENINGOENCEPAHLITIS - SUPERIOR SAGITTAL SINUS THROMBOSIS - AC DISSEMINATED ENCEPHALOMYELITIS - BRAIN TUMORS - CEREBRAL INFARCTION - CEREBRAL OR SUBDURAL HEMATOMAOTHER TESTS : * MICROBIOLOGIC DIAGNOSIS - BY GRAM STAINING OF ASPIRATED MATERIAL FROM ABSCESS OBTAINED BY STEREOTACTIC NEEDLE ASPIRATION β’ WBC may be normal or mildly elevated β’ Culture of abscess contents, predominant organisms include Toxoplasma (AIDS), Staphylococcus (trauma), aerobic or anaerobic bacteria, fungi (rare) β’ Blood studies - mild polymorphonuclear leukocytosis, elevated sedimentation rate IMAGING β’ CT or MRI are diagnostic methods of choice - fi ndings are dependent on stages of the abscess β’ Radionuclide 117 IN-labeled leukocytes may distinguish abscess from neoplasm
TYPENOTES
GENERAL MEASURES: * Palliative and supportive * Medical therapy : . For surgical inaccessible, multiple abscesses . For abscesses in early cerebritis stage . Small (< 2.5 cm) abscess . Therapy directed toward most likely organism SURGICAL MEASURES: . Surgical therapy . Mandatory when neurologic deficits are severe or progressive . Used when the abscess is in the posterior fossa . Abscess drainage - (via needle) under stereotactic CT guidance through a burr hole under local anesthesia, is most rapid and effective method. May be repeated if needed. . Craniotomy - if abscess is large or multilocular . Abscess resulting from trauma DRUG(S) OF CHOICE : β’ Antibiotics according to organism if known β’ If organism unknown, begin with penicillin G and metronidazole, or chloramphenicol (Chloromycetin), if metronidazole cannot be used β’ Add oxacillin or nafcillin if trauma or IV drug user (use vancomycin in penicillin-sensitive patients) β’ If gram-negative organism suspected (otic, GI, GU organ) add third-generation cephalosporin β’ Abscess associated with HIV infection assumed to be due to Toxoplasma gondii - daily doses of sulfadiazine and pyrimethamine. Therapy will be life-long in AIDS patients. β’ Anticonvulsants - phenytoin until abscess resolved or perhaps longer. Obtain anticonvulsant levels. β’ Following surgical procedure - corticosteroids to reduce edema. Dexamethasone. Taper rapidly. Use usually limited to 1 week. Continue antibiotics for 6-8 weeks. PATIENT MONITORING: β’ Postsurgical monitoring as needed β’ Serial CT or MRI - to confi rm progressive resolution, early detection and management of complications PREVENTION/AVOIDANCE: β’ Adequate treatment of otitis media, mastoiditis, dental abscess, other predisposing factors β’ Prophylactic antibiotics after compound skull fracture or penetrating head wound POSSIBLE COMPLICATIONS : β’ Permanent neurological deficits β’ Surgical complications β’ Recurrent abscess β’ Seizures EXPECTED COURSE/PROGNOSIS: Survival > 80% with early diagnosis and treatment
RELATED DISEASE
Not Available Disease
DISEASE
INVESTIGATION
CT SCAN HEAD, COMPLETE BLOOD COUNT, PUS CULTURE TEST, MRI