This site is targeted at medical and radiology professionals, contains user contributed content, and material that may be confusing to a lay audience. Use of this site implies acceptance of our Terms of Use.

Leptomeningitis

Leptomeningitis (more commonly referred to as meningitis) refers to inflammation of the subarachnoid space (i.e. arachnoid mater and pia mater). It is usually infective.

Causes

Infective
  • pyogenic meningitis
    • elderly
      • Listeria monocytogenes
      • Streptococcus pneumoniae
      • Neisseria meningitidis
      • Gram negative bacilli 
    • adults
      • Streptococcus pneumoniae
      • Neisseria meningitidis
      • Group B Strep
    • children
      • Neisseria meningitidis
    • infants
      • Streptococcus pneumoniae
      • Neisseria meningitidis
    • neonates
      • Group B Strep
      • E. coli
  • viral meningitis
    • Enterovirus
  • chronic meningitis
  • fungal meningitis
Aseptic meningitis

Radiographic features

CT
  • may be normal
  • hyperdensity around basal cisterns (especially in tuberculosis
  • leptomeningeal enhancement
  • complications or sources of the meningitis
MRI
  • T1 - may be normal; sulci may appear less hypointense than normal
  • T1 C+ (Gd) - leptomeningeal enhancement
  • FLAIR - demonstrates hyperintense signal in CSF space, especially in the sulci
  • MR angiography - arterial narrowing or occlusion
  • complications or sources of the meningitis

Complications

The complications of meningitis can be remembered using the mnemonic HACTIVE.

See also

Updating… Please wait.
Loadinganimation

Alert_accept

Error Unable to process the form. Check for errors and try again.

Alert_accept Thank you for updating your details.