Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content ++ Direct extension from a local infection: ear infection, dental abscess, infection of paranasal sinuses or mastoid air cells, epidural abscessDirect inoculation: head trauma or surgical proceduresRemote or hematogenous spread: bacteremia, endocarditis, and congenital heart disease ++ Bacterial: often polymicrobial; gram-negative and gram-positive: Staphylococcus, Streptococci, Bacteroides, Prevotella, Fusobacterium, Enterobacteriaceae, Pseudomonas species, and anaerobes. Less common: Haemophillus influenzae, Streptococcus pneumoniae, and Neisseria meningitides; Nocardia in immunosuppressed hostsMycobacterial (M tuberculosis, Mycobacterium avium intracellulare)Protozoan (Toxoplasma gondii, Entamoeba histolytica, Trypanosoma cruzi, Schistosoma, Paragonimus)Helminths (Taenia solium)Fungal: mainly immunocompromised patients (Aspergillus, Candida, Cryptococcus, Mucorales, Coccidioides, Histoplasma capsulatum, Blastomyces dermatitidis)Secondary to underlying tumors/malignancy ++ Alterations in mental status: anywhere along a continuum from confusion/inattention to comaFever/chillsStiff neckSymptoms of increased intracranial pressure: headache, vomiting, visual disturbancesSeizuresDecreased motor skills or sensation perceptionLanguage difficulty ++ Blood culturesCT and MRI of brain: Diffusion-weighted imaging (DWI) is helpful to distinguish abscess versus necrotic tumor (sensitivity and specificity over 90%)Antibody testing (Toxoplasma gondii and Taenia solium if epidemiology consistent with diagnosis)CXR: look for images suggesting septic emboliEEGNeedle sampling (CT-guided, stereotactic) of collection for causative agent if feasible ++ Identification of causative organisms(s) is paramount to successful therapy. Initial therapy should be commenced with broad-spectrum antibiotics that cross blood–brain and blood–CSF barriers; choice of surgical procedure needs to be tailored to and specific for each patientEmpiric antibiotics:Dental origin: amoxicillin + ornidazole (or metronidazole)Ear, mastoid, unclear origin: cefotaxime + ornidazole (or metronidazole)Immunocompromised: imipenem + trimethoprim/sulfamethoxazoleSurgical options:Twist drill craniotomyTherapeutic burr-hole drainageCT-guided stereotactic procedure: for most superficial and large abscesses; allows drainage and identification of causative pathogenCraniotomy (rare)Combination approach:Surgical aspiration or removal of all abscesses larger than 2.5 cm in diameter6 weeks or longer course of intravenous antibioticsWeekly CT or MRICure rate of more than 90% serial imaging until radiographic resolutionAny enlargement or failure to resolve should lead to further surgical aspiration or excisionMedical approach favored in clinical situations of:Multiple abscessesSmall abscess (less than 2 cm)Toxoplasma: very amenable to medical therapy aloneTuberculous abscesses often can be managed medicallyAbscess anatomically very deep: difficult to access and may be harmful to attempt surgical approachTarget treatment to culture data; removal of the primary focus paramount; treat for at least 6 weeksAntiepileptics—in high-risk patients—initiated immediately and continued for at least 1 yearOutcomeMortality is 50% to 90% and morbidity is even higher if severe neurologic impairment is evident at the time of presentation (or with extremely rapid onset of illness), even with immediate medical treatmentPneumococcal abscess has the highest mortality among bacterial etiologies (20–30% in adults, 10% in children) and morbidity (15%)Viral meningitis (without encephalitis) mortality rate is less than 1%Prognosis worse for patients at extremes of age, with significant comorbidities and immunosuppression ... Your Access profile is currently affiliated with [InstitutionA] and is in the process of switching affiliations to [InstitutionB]. Please select how you would like to proceed. Keep the current affiliation with [InstitutionA] and continue with the Access profile sign in process Switch affiliation to [InstitutionB] and continue with the Access profile sign in process Get Free Access Through Your Institution Learn how to see if your library subscribes to McGraw Hill Medical products. Subscribe: Institutional or Individual Sign In Error: Incorrect UserName or Password Username Error: Please enter User Name Password Error: Please enter Password Sign in Forgot Password? Forgot Username? Download the Access App: iOS | Android Sign in via OpenAthens Sign in via Shibboleth You already have access! Please proceed to your institution's subscription. Create a free profile for additional features.