II. Pathophysiology

  1. Frontal, temporal, and Parietal Lobes are most commonly affected

III. Causes: Source

  1. Unknown primary source of abscess in 20-40% of cases
  2. Direct Spread
    1. Subdural Abscess (Subdural Empyema) is spread of Sinusitis or Mastoiditis in 60-90% of cases
      1. Mastoiditis (due to Chronic Otitis Media)
      2. Frontal Sinusitis or Ethmoid Sinusitis
      3. Dental Infection
    2. Retained Foreign Body such as bullet fragments (abscess development may be years later)
    3. Neurosurgery (abscess development may be >1 year later)
  3. Hematogenous spread
    1. Lung Abscess or empyema in host with chronic lung disease (e.g. Cystic Fibrosis, Bronchiectasis)
    2. Esophageal procedures (e.g. esophageal dilation, Varices management)
    3. Cyanotic Congenital Heart Disease
    4. Bacterial Endocarditis
    5. Pulmonary AV Malformation with right to left shunt
    6. Skin Infections
    7. Intraabdominal and pelvic infections

IV. Causes: Organisms

  1. Strepotococcus esp. viridans (60-70%)
  2. Staphylococcus, esp. Staphylococcus aureus (10-14%)
  3. Other source site-specific organisms (in addition to Staphylococcus and Streptococcus species)
    1. Actinomyces (lung)
    2. Bacteroides (sinus, dental, ear) in up to 20-40% of cases
    3. Clostridium (penetrating Head Trauma)
    4. Enterobacteriaciae, Gram Negative Rods (ear) in up to 25-33% of cases
    5. Enterobacter (urine, penetrating Head Trauma, neurosurgery)
    6. Fusobacterium (sinus, dental, lung)
    7. Haemophilus (sinus, dental)
    8. Pseudomonas (ear, urine, neurosurgery)
  4. Immunocompromised patients
    1. See Brain Lesion in HIV
    2. Aspergillus
    3. Coccidioides
    4. Cryptococcus
    5. Listeria
    6. Nocardia
    7. Toxoplasma gondii
    8. Other fungus (e.g. Candida)
  5. Immigrants
    1. Cysticercosis (most common)
    2. Entamoeba histolytica
    3. Schistosoma

V. Symptoms

  1. Often initially subacute (results in delayed diagnosis typically >1 week)
  2. Headache (69%), typically unilateral in the region of abscess
  3. Neck Stiffness (15%), associated with posterior abscess (e.g. occiput)
  4. Vomiting (suggests Increased Intracranial Pressure)

VI. Signs

  1. Fever (45%)
  2. Focal neurologic deficit (50%, delayed finding >1 week after Headache onset)
    1. Oculomotor findings (CN 3 or CN 6) suggests Increased Intracranial Pressure
  3. Seizure (25%)
  4. Altered Level of Consciousness (associated with significant brain edema and with worse prognosis)

VII. Imaging

  1. CT Head with contrast OR
  2. MRI Brain with gadolinium (preferred)

VIII. Differential Diagnosis

IX. Diagnostics

  1. Lumbar Puncture
    1. Contraindicated in focal symptoms/signs, CNS mass, Increased Intracranial Pressure (risk of Herniation)
    2. Obtain CNS imaging prior to Lumbar Puncture

X. Labs

  1. Serology
    1. Blood anti-Toxoplasma IgG
    2. CSF anti-cysticercal Antibody
  2. CT-guided or neurosurgery obtained fluid
    1. Gram Stain
    2. Acid-fast stain and modified acid fast (Mycobacteria, Nocardia)
    3. Fungal stains
    4. Aeorbic and Anaerobic Bacterial cultures
    5. Mycobacterial culture
    6. Fungal Culture

XI. Management

  1. See Toxoplasmosis
  2. Bacterial cause (initial empiric therapy, including for Subdural Empyema)
    1. Overall antibiotic course of 4-6 weeks is typical
    2. Cefotaxime 2 g IV q4 hours OR Ceftriaxone 2 g IV every 12 hours (or Pen G 3-4 MU q4h) AND
    3. Metronidazole 7.5 mg/kg every 6 hours
    4. Add Vancomycin for suspected Staphylococcus aureus
  3. Nocardia initial empiric therapy
    1. Trimethoprim-Sulfamethoxazole (or Linezolid 500 mg IV or oral every 12 hours) AND
    2. Imipenem 500 mg IV every 6 hours (or Meropenem 2 g IV every 8 hours)
    3. Add Amikacin 7.5 mg/kg every 12 hours, if multiorgan involvement
  4. Post-Trauma or Post-Surgical
    1. Vancomycin 15-20 mg/kg every 8-12 hours (or Linzeolid 600 mg q12h) AND
    2. Cefepime 2 g IV every 8 hours (or Meropenem 2 g IV every 8 hours)

XII. References

  1. (2016) Sanford Guide, accessed 4/9/2016
  2. Southwick in Calderwood (2016) UpToDate, accessed 4/9/2016
  3. Brouwer (2014) N Engl J Med 371:447 [PubMed]

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Related Studies

Ontology: Brain Abscess (C0006105)

Definition (MSH) A circumscribed collection of purulent exudate in the brain, due to bacterial and other infections. The majority are caused by spread of infected material from a focus of suppuration elsewhere in the body, notably the PARANASAL SINUSES, middle ear (see EAR, MIDDLE); HEART (see also ENDOCARDITIS, BACTERIAL), and LUNG. Penetrating CRANIOCEREBRAL TRAUMA and NEUROSURGICAL PROCEDURES may also be associated with this condition. Clinical manifestations include HEADACHE; SEIZURES; focal neurologic deficits; and alterations of consciousness. (Adams et al., Principles of Neurology, 6th ed, pp712-6)
Concepts Disease or Syndrome (T047)
MSH D001922
SnomedCT 441806004, 60404007, 192738001
English Brain Abscesses, Abscess, Brain, BRAIN ABSCESS, brain abscess, brain abscess (diagnosis), Brain abscess NOS, Abscess of brain (disorder), Abscess of brain, Brain Abscess [Disease/Finding], brain abscesses, cerebral abscess, abscess brain, abscess cerebral, Brain Abscess, Brain abscess, Brain--Abscess, brain; abscess, abscess; brain
Italian Ascesso cerebrale, Ascesso cerebrale NAS, Ascesso del cervello
Dutch hersenabces NAO, abces; hersenen, hersenen; abces, hersenabces, Abces, hersen-, Hersenabces
French Abcès cérébral SAI, Abcès du cerveau, Abcès cérébral, Abcès cérébraux
German Gehirnabszess NNB, Gehirnabszess, Hirnabszeß
Portuguese Abcesso cerebral NE, Abscesso Encefálico, Abscesso Cerebral, Abcesso do cérebro
Spanish Absceso cerebral NEOM, Absceso Encefálico, absceso de cerebro (trastorno), absceso de cerebro, Absceso Cerebral, Absceso cerebral
Japanese 脳膿瘍NOS, ノウノウヨウNOS, ノウノウヨウ, 脳膿瘍, 膿瘍-脳
Swedish Hjärnabscess
Czech mozek - absces, Absces mozku, Absces mozku NOS
Finnish Aivopaise
Polish Ropień mózgu
Hungarian agytályog k.m.n., agytályog
Norwegian Hjerneabscess

Ontology: Intracranial abscess (C0021874)

Concepts Disease or Syndrome (T047)
ICD9 324.0
SnomedCT 192746000, 192738001, 27614006
English Intracranial abscess NOS, intracranial abscess (diagnosis), intracranial abscess, Intracranial abscess NOS (disorder), Intracranial abscess, Intracranial abscess (disorder), abscess; intracranial, intracranial; abscess, Intracranial abscess, NOS, Intracranial Abscess
Dutch intracraniaal abces, abces; intracraniaal, intracraniaal; abces
French Abcès intracrânien
German intrakranieller Abszess
Italian Ascesso intracranico
Portuguese Abcesso intracraniano
Spanish Absceso intracraneal, absceso intracraneal, SAI (trastorno), absceso intracraneal, SAI, absceso intracraneal (trastorno), absceso intracraneal
Japanese 頭蓋内膿瘍, トウガイナイノウヨウ
Czech Intrakraniální absces
Hungarian Intracranialis abscessus

Ontology: Empyema, Subdural (C0038539)

Definition (MSH) An intracranial or rarely intraspinal suppurative process invading the space between the inner surface of the DURA MATER and the outer surface of the ARACHNOID. Bacteria and other pathogenic organisms may gain entrance to the subdural space from the FRONTAL SINUS; ETHMOID SINUS; middle ear (EAR, MIDDLE); MASTOID; or as the result of CRANIOCEREBRAL TRAUMA or NEUROSURGICAL PROCEDURES. This condition may be associated with intracranial sinus thrombosis (SINUS THROMBOSIS, INTRACRANIAL). Circumscribed collections of purulent material in the subdural space are referred to as subdural abscesses. (From Adams et al., Principles of Neurology, 6th ed, p709)
Concepts Disease or Syndrome (T047)
MSH D013354
SnomedCT 37660004
English Empyema, Subdural, Subdural Empyema, Subdural Empyemas, subdural empyema (diagnosis), subdural empyema, Empyema, Subdural [Disease/Finding], subdural abscess, Empyema (collection of pus), subdural space, Subdural abscess, Subdural empyema, Subdural abscess (disorder), empyema; subdural, abscess; subdural, subdural; abscess, subdural; empyema
French Empyème sub-dural, Empyème subdural, Empyème sous-dural, Empyèmes sous-duraux, Empyèmes subduraux
Swedish Subduralempyem
Czech subdurální empyém, Subdurální empyém
Finnish Subduraaliempyeema
Japanese 膿瘍-硬膜下, 硬膜下蓄膿症, 蓄膿症-硬膜下, 硬膜下膿瘍, 硬膜下蓄膿, コウマクカチクノウショウ
Polish Ropniak podtwardówkowy
Norwegian Subduralt empyem, Subduralempyem
Spanish empiema subdural, Empiema subdural, absceso subdural (trastorno), absceso subdural, Empiema Subdural
Dutch subduraal empyeem, abces; subduraal, empyeem; subduraal, subduraal; abces, subduraal; empyeem, Empyeem, subduraal, Subduraal empyeem
German subdurales Empyem, Empyem, subdurales, Subdurales Empyem, Abszeß, subduraler
Hungarian Subduralis empyema
Italian Empiema subdurale, Empiema sottodurale
Portuguese Empiema subdural, Empiema Subdural