Central nervous system vasculitis
- Isolated (or primary) central nervous system vasculitis is restricted to the central nervous system
- Onset of primary cerebral vasculitis is usually acute or subacute and, similar to moyamoya, may present with headaches, behavioral changes, neurologic deficits, or ischemic or hemorrhagic stroke
- Secondary central nervous system vasculitis occurs in association with a wide variety of systemic or infectious diseases (eg, collagen vascular disease, varicella-zoster virus, HCV, HIV)
- Common additional symptoms that occur in secondary central nervous system vasculitis but are not routinely found in moyamoya: fatigue, weight loss, fever, myalgia, arthralgia, and progressive neuropathy
- Hemorrhage caused by vasculitis or vasculopathy
- Most commonly identified on head CT as hyperdensity within cerebral sulci
- Also may be identified on MRI:
- On fluid inversion attenuation recovery sequences as sulcal hyperintensity
- On gradient echo or susceptibility-weighted imaging sequences as hypointense signal abnormality
- Laboratory studies that usually are performed to work-up central nervous system vasculitis do not offer a definitive diagnosis in most cases; they usually are done during investigation to exclude other conditions
- Patients with central nervous system vasculitis may have a modestly elevated erythrocyte sedimentation rate, but this is not universally observed
- Patients with vasculitis often have a positive antinuclear antibody test result, but this is not specific
- CT and MRI are usually abnormal, but findings are not specific
- Result of cerebrospinal fluid analysis is usually abnormal, but not specific:
- Mild lymphocytic pleocytosis
- Low glucose level
- Mild to moderate elevation in protein level
- Increase in oligoclonal bands and elevated IgG index
- Polymerase chain reaction or antibody testing for specific viruses may be diagnostic (eg, varicella-zoster IgM or polymerase chain reaction)
- Diagnosis of central nervous system vasculitis usually requires catheter cerebral angiography or brain biopsy
- Most typical findings of vasculitis on cerebral angiography are widespread segmental changes in the contour and caliber of vessels
- Brain biopsy is a test of last resort to confirm central nervous system vasculitis. It shows a lymphocytic inflammatory reaction with variable numbers of plasma cells, histiocytes, neutrophils, and eosinophils
