Primary Angiitis of the Central Nervous System


Primary angiitis of the central nervous system PACNS a.k.a. Granulomatous angiitis of the CNS GANS a.k.a. isolated CNS vasculitis


Brain +Meningeal biopsy:

  • 1 cm wedge biopsy with meninges, grey & white matter
  • Small or medium sized vessels. Parenchymal or meningeal
  • Transmural destruction. Granulomatous (multinucleated cells) or lymphocytic infiltrate. Sometime macrophages. Intimal proliferation may occur
  • Infarcts may be present as well as reactive astrocytosis

Findings on Investigations:

MRI features:

  • May be normal
  • Infarcts: cortical & subcortical
  • T2,FLAIR: nonspecific High intensity lesions. Involves white matter, cortex & basal ganglia
  • Hemorrhage may occur: SAH, IPH, Subdural

MR perfusion: perfusion defects
MRA: false negatives occur
Catheter Angiogram:

  • May be normal (false negative, resolution is 0.5mm (500microm) in diameter), low specificity
  • Symmetric (circumferential & long segments) narrowing of the distal or proximal arteries & dilatation.
  • Beading


  • Abnormal in 80-90% of cases
  • Leukocytosis
  • Raised protein

Transcranial Doppler TCD:

  • Low sensitivity
  • increased velocities in intracranial vessels

Investigations to Consider:

ESR: typically normal
CSF: pleocytosis, mainly lymphocytes & elevated protein. Oligoclonal bands occasionally. Culture & testing for (Lyme, Syphilis, Hemophilus influenzae, TB, VZV, Cryptococcus, Coccidiodes)
Toxicology screen: methamfetamine, cocaine
Rule out other types of vasculitis:

  • Autoimmune:
    • Vasculitis screen: ESR, CRP, ANA screen, ENA panel (anti- dsDNA, anti-Sm, anti-RNP, SSA, SSB, anti-Jo-1, antitopoisomerase ‘formerly anti Scl-70’, antinucleolar, anticentromere), ANCA (c-ANCA, p-ANCA), Complement C3, C4 and CH50: SLE, Sjogren’s syndrome and others.
    • Complement C3, C4 & CH50: screens for consumptive process
    • ANCA: Wegener granulomatosus
    • Hepatitis panel: HBSAg in polyarteritis nodosa
    • Anticardiolipin antibody, lupus anticoagulant: Sneddon syndrome
    • ACE level, CXR: CNS sarcoid angiitis
    • Pathergy test: Behcet syndrome
  • Infectious:
    • Lyme serology, Hemophilus influenzae (blood culture & serology)
    • RPR, VDRL, TB PCR (other TB testing)
    • VZV IgG, VZV PCR, HIV testing
    • Cryptococcus antigen, Coccidiodes serology,
    • Thick & thin smears for Malaria
  • Consider, CT chest, abdomen and pelvis:
    • Paraneoplastic vasculitis (very rare)

Brain biopsy:

  • Confirms diagnosis
  • Rules out intravascular lymphoma & lymphomatoid granulomatosis


  • Corticosteroids
  • Cyclophosphamide

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