Synonyms:
Primary angiitis of the central nervous system PACNS a.k.a. Granulomatous angiitis of the CNS GANS a.k.a. isolated CNS vasculitis
Diagnosis:
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
CSF:
- 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)
MRI
Angiogram
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
Treatment:
- Corticosteroids
- Cyclophosphamide