Idiopathic
Infective
o Neurosyphilis
o CNS tuberculosis: tuberculous pachymeningitis
o CNS cryptococcosis
o Bacterial meningitis
Inflammatory
o granulomatosis with polyangiitis
o Erdheim-Chester Disease (Histiocytosis)
o IgG4-related hypertrophic pachymeningitis
o giant cell arteritis
o neurosarcoidosis
o Microscopic polyangiitis
o polyarteritis nodosa
o rheumatoid arthritis
o relapsing polychondritis
o Behηet disease
o Rosai-Dorfman disease
Other
o Haemodialysis
o mucopolysaccharidoses
Neoplasm
o meningeal metastases
o meningeal involvement with CNS lymphoma
o multiple meningiomas including lymphoplasmacyte-rich meningioma
Spontaneous intracranial hypotension
Idiopathic 30%
GPA 17%
Erdheim-Chester 17%
IgG4 5%
TB 5%
Rosai-Dofman 3%
Microscopic polyangiitis 3%
Sarcoidosis 3%
Cryptococcal
Lyme disease
ENT infection
Post-LP
CSF hypotension
Lymphoma