Leptomeningitis

Last revised by Dr Yahya Baba ◉ on 15 Feb 2022

Citation, DOI & article data

Citation:

Gaillard, F., Baba, Y. Leptomeningitis. Reference article, Radiopaedia.org. (accessed on 30 Jun 2022) https://doi.org/10.53347/rID-4988

DOI:

https://doi.org/10.53347/rID-4988

Permalink:

https://radiopaedia.org/articles/4988

rID:

4988

Article created:

14 Nov 2008 by Assoc Prof Frank Gaillard ◉ ◈

Revisions:

45 times by 14 users - see full revision history

System:

Central Nervous System

Sections:

Tags:

infection, infectious disease

Synonyms:

Meningitis

Leptomeningitis, which is more commonly referred to as meningitis, represents inflammation of the subarachnoid space (i.e. arachnoid mater and pia mater) caused by an infectious or noninfectious process.

pyogenic meningitis
- elderly
  - Streptococcus pneumoniae
  - Listeria monocytogenes
  - Neisseria meningitidis
  - Gram negative bacilli
- adults
  - Streptococcus pneumoniae
  - Neisseria meningitidis
  - Group B streptococcus
- children
  - Neisseria meningitidis
- infants
  - Streptococcus pneumoniae
  - Neisseria meningitidis
- neonates
  - Group B streptococcus
  - Escherichia coli
  - Listeria monocytogenes
viral meningitis
- Enterovirus
- JC virus meningitis
mycobacterial meningitis
- Mycobacterium tuberculosis
  - tuberculous meningitis
  - tuberculous pachymeningitis
fungal meningitis
- Cryptococcus neoformans (in patients with AIDS)
- Coccidioides immitis

For a further discussion related to other etiological agents and other infective processes in the CNS, please refer to CNS infectious diseases.

Aseptic meningitis

leptomeningeal carcinomatosis
rheumatoid arthritis ²
granulomatous
- sarcoidosis
iatrogenic
- postoperative ⁴
- hydrogel-coated aneurysm coils ³

Radiographic features

CT

may be normal
subtle hydrocephalus
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
FLAIR C+ (Gd): has shown to be more sensitive and specific than T1 C+ (Gd) sequence in spotting leptomeningeal enhancement ⁶
MR angiography: arterial narrowing or occlusion