Brain abscess: Difference between revisions

 
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==Background==
==Background==
[[File:Brainlobes.png|thumb|Lobes of the brain.]]
*Caused by one of three methods:
*Caused by one of three methods:
**Hematogenous spread (33%)
**Hematogenous spread (33%)
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**Direct implantation by surgery or penetrating trauma (10%)
**Direct implantation by surgery or penetrating trauma (10%)
*Microbiology
*Microbiology
**Anaerobes and Gram-negative rods are typical pathogens
**[[Streptococci]] in 50% of cases<ref>Somand D, Meurer W. Central Nervous System Infections. EMCNA 2009; 27: 89-100.</ref>
**Staph is involved with direct implantation cases
**[[Anaerobes]] and [[Gram-negative]] rods are typical pathogens
**[[Staph]] is involved with direct implantation cases


==Clinical Features==
==Clinical Features==
*Pts rarely appear acutely ill
*Patients rarely appear acutely ill
*Classic traid of HA, fever, AND focal neuro deficit is present in <33%
*Classic triad of headache, fever, '''AND''' focal neuro deficit is present in <33%
**Headache is most common symptom (present in almost all cases)
**[[Headache]] is most common symptom (present in almost all cases)
**Fever (~50% of pts)
**[[Fever]] (~50% of patients)
*Focal neuro symptoms or seizure (~33% of pts)
*[[Focal neuro]] symptoms or seizure (~33% of patients)
*Neck stiffness (<50% of pts)
*Neck stiffness (<50% of patients)
*Signs of increased ICP: vomiting, confusion, obtundation (50% of pts)
*Signs of [[increased ICP]]: [[papilledema]], [[vomiting]], [[confusion]], [[coma|obtundation]] (50% of patients)


==Differential Diagnosis==
==Differential Diagnosis==
*[[CVA]]
*[[CVA]]
*[[Meningitis]]
*[[Meningitis]], [[encephalitis]]
*Malignancy
*Malignancy


{{Intracranial mass DDX}}
{{Intracranial mass DDX}}
{{AMS and fever DDX}}


==Diagnosis==
==Evaluation==
===Workup===
[[File:PMC4857327 10.1177 2050313X15591314-fig3.png|thumb|Brain abscess on CT (arrows) with left hemiplegia.]]
[[File:PMC3970313 ic-46-45-g001.png|thumb|Nocardia brain abscess on MRI. (A) T1-WI shows rim-enhancing lesion with associated edema in the right occipital lobe. (B) The dark signal on T2-WI and consistent thickness of the wall suggest a brain abscess.]]
*[[Head CT]] with contrast
*[[Head CT]] with contrast
*[[Blood cultures]]
===Evaluation===
*CT with contrast
**Ring enhancing lesion surrounding low-density center surrounded by white matter edema
**Ring enhancing lesion surrounding low-density center surrounded by white matter edema
**Early in course ring may be less defined; CT may only show area of focal hypodensity
**Early in course ring may be less defined; CT may only show area of focal hypodensity
*[[Blood cultures]]
*Consider additional workup to evaluate for alternate etiologies/complications of underlying disease process


==Treatment==
==Management==
===[[Antibiotics]]===
===[[Antibiotics]]===
{{Brain abscess antibiotics}}
{{Brain abscess antibiotics}}
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==References==
==References==
 
<references/>
[[Category:Neuro]]
[[Category:Neurology]]
[[Category:ID]]
[[Category:ID]]

Latest revision as of 22:29, 25 January 2023

Background

Lobes of the brain.
  • Caused by one of three methods:
    • Hematogenous spread (33%)
    • Contiguous infection from middle ear, sinus, teeth (33%)
    • Direct implantation by surgery or penetrating trauma (10%)
  • Microbiology

Clinical Features

Differential Diagnosis

Intracranial Mass

Altered mental status and fever

Evaluation

Brain abscess on CT (arrows) with left hemiplegia.
Nocardia brain abscess on MRI. (A) T1-WI shows rim-enhancing lesion with associated edema in the right occipital lobe. (B) The dark signal on T2-WI and consistent thickness of the wall suggest a brain abscess.
  • Head CT with contrast
    • Ring enhancing lesion surrounding low-density center surrounded by white matter edema
    • Early in course ring may be less defined; CT may only show area of focal hypodensity
  • Blood cultures
  • Consider additional workup to evaluate for alternate etiologies/complications of underlying disease process

Management

Antibiotics

Otogenic source

Sinogenic or odontogenic source

Penetrating trauma or neurosurgical procedures

Hematogenous source

No obvious source

Disposition

  • Neurosurgery consultation

References

  1. Somand D, Meurer W. Central Nervous System Infections. EMCNA 2009; 27: 89-100.