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neuro.brain-abscess.v1

Brain Abscess (Pyogenic)

neurologyacuteadultgeriatricacuteinpatient
Start encounter →Print handoutPRODUCTION

Lane-F id/neuro acute build (2026-05-26) — authored at INTEGRATED. ESCMID 2024 (Bodilsen Clin Microbiol Infect PMID 37648062) is the canonical brain-abscess guideline; the brief mentioned a candidate Tunkel IDSA 2017 brain abscess guideline, but PubMed verification found NO such guideline — Tunkel 2017 IDSA addresses healthcare-associated ventriculitis / meningitis only. ESCMID 2024 was used as the primary guideline anchor. Bodilsen/Eriksen CID 2026 PMID 40476360 emulated-trial evidence (adjusted RR 2.47 mortality, 2.25 rupture with nonoperative vs neurosurgery) drives the strong neurosurgical-drainage recommendation. Registry-id mapping: panel.hepatic→panel.lft, calc.charlson_comorbidity→calc.clinical_frailty_scale (per Lane-F memory). No calc.bms_peds (paediatric-only). No dedicated workup.brain_abscess in registry — used workup.acute_headache (red-flag pivot), workup.encephalopathy (AMS pivot), workup.bacterial_meningitis (overlap), workup.sepsis_bundle (septic physiology), workup.first_seizure (seizure pivot), workup.cryptococcal_meningitis (immunocompromise pivot). RxCUIs RxNav-verified 2026-05-26: ceftriaxone 2193, metronidazole 6922, vancomycin 11124, meropenem 29561, dexamethasone 3264, levetiracetam 114477, voriconazole 121243 (CORRECTED — brief candidate 313802 was INVALID; reverse-lookup via RxNav drugs.json gave canonical IN 121243), amphotericin B liposomal 236594, TMP-SMX 10831. All confirmed as resolving IN/PIN/MIN concepts with correct name match. Settings: ed + inpatient + icu (no home / outpatient — outpatient phase covered by OPAT continuation only; never discharge home before stable on regimen with reliable access). No transition setting playbook authored — OPAT transition handled as inpatient → home OPAT discharge criterion. Severity triggers (15): 8 acute red-flags (GCS ≤8, intraventricular rupture, midline shift >5mm, abscess ≥2.5cm accessible, multi-loculated/posterior-fossa, status, septic-shock overlap, severe immunocompromise) + 8 phenotype-by-source rows (otogenic, odontogenic, sinogenic, hematogenous/endocarditis, post-traumatic, post-neurosurgical, immunocompromised, cryptogenic) — encoded as severity_triggers (not sibling_differentiation) because source-specific sibling engines do not yet exist. Calculators (5): calc.nihss (focal deficit), calc.qsofa (sepsis screen), calc.sofa (multi-organ failure), calc.clinical_frailty_scale (geriatric outcome — substitutes calc.charlson_comorbidity per registry gotcha), calc.news2 (monitoring). Panels (7): panel.cbc + panel.inflammation + panel.coag + panel.lft + panel.renal + panel.cardiac (endocarditis pivot) + panel.csf (only when LP safe after imaging clears mass effect). Schema-blocked: no brain-abscess-specific score (e.g., brain-abscess prognostic score variants) in clinical-tools-registry; bedside metric defaulted to GCS + NIHSS + CFS combinations. No calc.gcs / calc.mrs in registry — surfaced as schema-blocked tickets in companion brief.

Entry points (7)

  • symptom
    New persistent headache + focal deficit (~40% — Bodilsen CID 2024 PMID 37946527; classic triad only ~22% complete)
    headache_plus_focal_deficit
  • symptom
    Fever + focal neurological deficit / new seizure / AMS — pivot to brain-abscess workup (ESCMID 2024 PMID 37648062)
    fever_plus_focal_neurological_deficit
  • symptom
    New seizure in patient with otitis / sinusitis / dental / endocarditis / immunocompromise / post-neurosurgical context
    new_seizure_with_predisposing_source
  • history
    Post-neurosurgical fever + new deficit — empiric carbapenem + vancomycin pending imaging (ESCMID 2024 PMID 37648062)
    post_neurosurgical_fever_or_deficit
  • history
    Known infective endocarditis with new focal CNS deficit — septic embolic abscess vs ischemic stroke (urgent MRI)
    endocarditis_with_focal_deficit
  • history
    Immunocompromised (HIV / transplant / chemo) with focal CNS lesion — abscess vs toxoplasmosis vs lymphoma vs Nocardia / fungal (Brouwer NEJM 2014 PMID 25075836)
    immunocompromised_with_focal_cns
  • imaging
    Incidental ring-enhancing lesion on CT/MRI — DWI restriction + clinical context drives abscess vs tumour
    ring_enhancing_lesion_on_imaging

Required inputs (21)

  • agerequired
    demographic • used at CONTEXT
    Adults median age 58 (Bodilsen CID 2024 PMID 37946527); incidence rising in elderly (Omland/Bodilsen 2024 PMID 38547383)
  • temperaturerequired
    vital • used at FRAME
    Fever present in only ~50% (Bodilsen CID 2024 PMID 37946527) — afebrile presentation common; cannot exclude on absence
  • gcsrequired
    vital • used at CONTEXT
    GCS quantifies AMS severity; GCS ≤8 = intubation; serial monitoring drives ICP / herniation triggers (ESCMID 2024 PMID 37648062)
  • sbprequired
    vital • used at CONTEXT
    Cushing reflex (HTN + bradycardia) marker of impending herniation; baseline + serial
  • headache_presentrequired
    symptom • used at ENTRY
    Headache in ~70% — most common single symptom (Bodilsen CID 2024 PMID 37946527)
  • focal_neurological_deficitrequired
    symptom • used at RED_FLAGS
    Focal deficit in ~40-86% by series (Bodilsen CID 2024 PMID 37946527: 86% any deficit); drives MRI urgency + neurosurgery consult
  • seizure_present
    symptom • used at CONTEXT
    Seizure in ~25%; post-abscess epilepsy ~30% long-term — drives AED selection + outpatient surveillance
  • predisposing_sourcerequired
    history • used at DIFFERENTIAL
    Otogenic / odontogenic / sinogenic / hematogenous / post-traumatic / post-neurosurgical / immunocompromised / cryptogenic — drives empiric coverage selection (ESCMID 2024 PMID 37648062)
  • immunocompromise_statusrequired
    history • used at CONTEXT
    HIV / transplant / chemo / hematologic malignancy — expands differential to Nocardia + fungal + Toxo + mycobacterial; broadens empiric coverage to TMP-SMX + voriconazole (ESCMID 2024 PMID 37648062)
  • recent_neurosurgery_or_head_traumarequired
    history • used at CONTEXT
    Post-neurosurgical / post-traumatic source → S. aureus + GNR incl Pseudomonas → empiric meropenem + vancomycin or linezolid (ESCMID 2024 PMID 37648062)
  • endocarditis_history_or_riskrequired
    history • used at CONTEXT
    Endocarditis / IVDU / valvular disease → hematogenous source → empiric vancomycin coverage + TTE/TEE workup
  • right_to_left_shunt_or_pavm
    history • used at BRANCHING_WORKUP
    PAVM (HHT) and right-to-left shunt — risk factor for cryptogenic abscess; bubble-echo + chest CT (Bodilsen 2024 PMID 38064178)
  • creatinine_baselinerequired
    lab • used at INITIAL_WORKUP
    Vancomycin / aminoglycoside / amphotericin nephrotoxicity; baseline Cr + CrCl drives dose
  • cbc_with_diffrequired
    lab • used at INITIAL_WORKUP
    Leukocytosis variable (only ~60-70%); baseline before therapy
  • crp_esrrequired
    lab • used at INITIAL_WORKUP
    CRP + ESR elevated in ~80%; supports inflammatory milieu; serial for treatment response (CRP weekly)
  • blood_cultures_x2required
    lab • used at INITIAL_WORKUP
    Positive in ~25-30% (higher with hematogenous / endocarditis source); MUST draw before empiric abx
  • aspirate_culture_when_obtained
    lab • used at BRANCHING_WORKUP
    Stereotactic aspirate is the diagnostic gold-standard — gram + culture + 16S PCR / molecular if available; ESCMID 2024 PMID 37648062 recommends molecular diagnostics when cultures negative
  • hiv_screen
    lab • used at CONTEXT
    HIV status drives differential (toxoplasmosis prior; HAART status) and empiric coverage breadth
  • mri_brain_with_gadolinium_and_dwirequired
    imaging • used at INITIAL_WORKUP
    MRI gold-standard — ring-enhancing lesion + central DWI restriction differentiates abscess from neoplasm; ESCMID 2024 PMID 37648062 strong/high recommendation
  • ct_head_with_contrast_if_mri_unavailable
    imaging • used at INITIAL_WORKUP
    CT acceptable if MRI delay; ring-enhancing lesion with surrounding edema; sensitivity lower than MRI
  • source_imaging
    imaging • used at BRANCHING_WORKUP
    Sinus / temporal-bone CT (sinogenic / otogenic); panoramic / dental CT (odontogenic); TTE → TEE (endocarditis); CT chest (PAVM / pulmonary source); CT body if cryptogenic adult

12-phase flow (12)

  1. 1FRAME
    Pyogenic CNS focal infection — neurosurgical + ID + neurology multi-D management; ESCMID 2024 (Bodilsen PMID 37648062) is canonical
    inputs: temperature
    advance: Brain abscess on differential
  2. 2ENTRY
    ED triage: new headache + focal deficit / seizure / AMS in predisposing context → STAT MRI brain + blood cultures + multi-D activation
    inputs: age, headache_present
    advance: Imaging ordered + cultures drawn
  3. 3CONTEXT
    Capture predisposing source, immunocompromise, recent neurosurgery / trauma, endocarditis risk, congenital R-L shunt / PAVM, baseline neuro status
    inputs: gcs, sbp, predisposing_source, immunocompromise_status, recent_neurosurgery_or_head_trauma, endocarditis_history_or_risk
    advance: Source / host context captured
  4. 4RED_FLAGS
    GCS ≤8 (intubate + ICU); midline shift >5 mm; intraventricular rupture (devastating, ~80% mortality); posterior fossa with brainstem compression / hydrocephalus; multi-loculated; Cushing reflex; status epilepticus (route to neuro.status-epilepticus.core.v1)
    inputs: gcs, focal_neurological_deficit
    actions: workup.encephalopathy, workup.acute_headache
    advance: Red-flag triage complete
  5. 5INITIAL_WORKUP
    STAT MRI brain with gadolinium + DWI (ring-enhancing + central restriction = abscess) → blood cultures × 2 → CBC + CRP + ESR + BMP + LFT + coag + HIV + lactate → STAT neurosurgery consult for stereotactic aspiration (≥2.5 cm or accessible — Bodilsen CID 2026 PMID 40476360); empiric IV abx IMMEDIATELY after cultures + ideally after aspiration if surgery within 24 h (ESCMID 2024 PMID 37648062 conditional/low allows brief delay)
    inputs: mri_brain_with_gadolinium_and_dwi, blood_cultures_x2, cbc_with_diff, crp_esr, creatinine_baseline
    actions: panel.cbc, panel.inflammation, panel.coag, panel.lft, panel.renal, panel.cardiac
    advance: MRI obtained + cultures drawn + neurosurgery dispositioned + empiric abx started
  6. 6BRANCHING_WORKUP
    Source-specific imaging: sinus / temporal-bone CT (otogenic / sinogenic); panoramic / dental CT (odontogenic); TTE → TEE (endocarditis pivot per Duke); CT chest with contrast (PAVM / right-to-left shunt for cryptogenic — Bodilsen 2024 PMID 38064178); CT body for occult primary in cryptogenic adult; molecular diagnostics on aspirate when cultures negative (ESCMID 2024 PMID 37648062)
    inputs: source_imaging, aspirate_culture_when_obtained, right_to_left_shunt_or_pavm
    actions: panel.csf
    advance: Source identified or cryptogenic phenotype assigned
  7. 7DIFFERENTIAL
    By source: otogenic (Strep + anaerobes; temporal lobe / cerebellum) / odontogenic (Strep + Fusobacterium + Actinomyces; frontal) / sinogenic (Strep; frontal) / hematogenous (S. aureus + viridans Strep) / post-traumatic (S. aureus + GNR) / post-neurosurgical (S. aureus + GNR incl Pseudomonas) / immunocompromised (Toxo + Nocardia + fungal + TB) / cryptogenic (~30%; oral-cavity polymicrobial dominant — Bodilsen CID 2024 PMID 37946527). Non-infectious mimics on imaging: glioma / metastasis / lymphoma (DWI helps); toxoplasmosis (HIV); tuberculoma; cysticercosis
    inputs: predisposing_source
    advance: Phenotype assigned + empiric regimen finalised
  8. 8RISK_STRATIFICATION
    Severity drivers: GCS, abscess size >2.5 cm, multi-loculated, deep / posterior fossa location, immunocompromise, rupture risk, intraventricular extension. NIHSS for focal deficit quantification; SOFA/qSOFA if septic; Clinical Frailty Scale (CFS) for geriatric outcome (calc.charlson_comorbidity not in registry — use calc.clinical_frailty_scale)
    inputs: gcs, focal_neurological_deficit
    actions: calc.nihss, calc.qsofa, calc.clinical_frailty_scale
    advance: Severity stratified + ICU vs floor decided
  9. 9TREATMENT
    STAT stereotactic aspiration ≥2.5 cm / accessible (Bodilsen CID 2026 PMID 40476360 — neurosurgery halves mortality + rupture risk). EMPIRIC IV abx: community-acquired immunocompetent = ceftriaxone 2 g IV q12h + metronidazole 500 mg IV q8h (ESCMID 2024 PMID 37648062 strong/moderate) ± vancomycin 15-20 mg/kg q8-12h trough 15-20 (MRSA risk: IVDU, hardware, post-neurosurgical); post-neurosurgical = meropenem 2 g IV q8h + vancomycin OR linezolid 600 mg IV q12h (ESCMID 2024 conditional/low); severe immunocompromise = add TMP-SMX 5 mg/kg trimethoprim component IV q6-8h (Nocardia) + voriconazole 6 mg/kg IV q12h × 2 then 4 mg/kg q12h (fungal). Duration 6-8 wk IV (ESCMID 2024 conditional/low — no routine early PO switch). Dexamethasone 0.15 mg/kg IV q6h ONLY for severe mass effect / impending herniation (ESCMID 2024 strong/low; not routine). Levetiracetam 1 g IV load + 500-1000 mg q12h ONLY for clinical / electrographic seizure (no routine prophylaxis — ESCMID 2024 conditional/very low). Source control: ENT for otogenic / sinogenic; dental for odontogenic; cardiac surgery for endocarditis; embolisation / lobectomy for PAVM
    inputs: creatinine_baseline, predisposing_source
    actions: workup.bacterial_meningitis, workup.sepsis_bundle
    advance: Empiric abx started + neurosurgery dispositioned + source control planned
  10. 10DISPOSITION
    Admit ICU if GCS ≤8 / intubated / status / impending herniation / haemodynamic instability; admit neurology / ID / neurosurgery floor for routine course; transfer to neurosurgery-capable centre if local; NEVER discharge from ED
    inputs: gcs
    advance: Disposition documented
  11. 11MONITORING
    Daily neuro exam + GCS; CBC + CRP + ESR weekly (CRP-trajectory drives duration); BMP + LFT weekly; vancomycin trough q-dose initially; voriconazole trough day 5; repeat MRI at 2 wk → 4-6 wk → end-of-therapy (UK survey PMID 42081068 shows variable cadence; ESCMID 2024 PMID 37648062 conditional/very low for routine reimaging); cEEG if persistent AMS or refractory seizure
    inputs: gcs, crp_esr, creatinine_baseline
    advance: Monitoring plan documented
  12. 12FOLLOWUP
    OPAT for IV completion if clinically stable + reliable access + ID-OPAT capacity; neurology clinic at 6-8 wk + 6 mo + 12 mo (AED management, neurocognitive battery, return-precautions for late epilepsy ~30%); ID clinic at end-of-therapy; source-control follow-up (dental, ENT, cardiology, pulmonology for PAVM — bubble-echo + chest CT per Bodilsen 2024 PMID 38064178); driving evaluation per jurisdictional regulation
    advance: Long-term plan documented + OPAT / rehab arranged