Central nervous system (CNS) vasculitis is not a single disease but a collection of conditions that cause inflammatory damage of blood vessels in the brain and spinal cord. About half of the cases have no known cause and are therefore classified as primary vasculitis of the CNS. The other half of the cases arise in the setting of some other disorder, often a rheumatic disease such as systemic lupus erythematosus, and are classified as secondary forms of CNS vasculitis. Primary vasculitis of the CNS has been referred to by many names. Bowing to tradition, this chapter will use the term “primary angiitis of the CNS” (PACNS).
CNS vasculitis presents a two-handed clinical challenge. On the one hand, clinicians need to recognize and treat those rare patients whose strokes and other neurologic deficits result from CNS vasculitis. On the other hand, clinicians need to avoid overdiagnosis of CNS vasculitis and must realize that the angiographic and magnetic resonance imaging (MRI) abnormalities observed in CNS vasculitis can be mimicked by infection, tumor, and other conditions.
- Common presentation includes headache, encephalopathy, and multiple strokes.
- Brain MRI sensitive but not specific.
- Most patients in whom PACNS is suspected have some other disorder.
- Angiographic abnormalities are suggestive but not specific.
- Definitive diagnosis requires brain biopsy.
PACNS is a disease of unknown cause characterized by vasculitis limited to the brain and spinal cord. PACNS is rare; at large medical centers, PACNS constitutes only about 1% of all cases of systemic vasculitis. The annual incidence is 2.4 cases per 1,000,000 person-years. Evidence suggests that PACNS is not one disease. Indeed, the clinical picture of PACNS that emerges from reviewing the literature depends a great deal on whether the analysis focuses on biopsy-proven cases (BP-PACNS) or cases defined by angiography (AD-PACNS) without biopsy proof. Some clinicians have speculated that AD-PACNS may be caused by spasm rather than by inflammation. The term “benign angiography of the CNS” or reversible cerebral vasoconstriction syndrome is sometimes applied to cases of AD-PACNS. Table 40–1 outlines the clinical pictures of both BP-PACNS and AD-PACNS.
Table 40–1. Clinical and Laboratory Features of Pacns Based on the Method of Diagnosis.a |Favorite Table|Download (.pdf)
Table 40–1. Clinical and Laboratory Features of Pacns Based on the Method of Diagnosis.a
|Sex, no. (%)|
|Males||78 (69.0)||17 (30.8)||<.001|
|Females||38 (31.0)||38 (69.1)||<.001|
|Age, mean ± SD||46 ± 17||33 ± 14|
|Headache, no. (%)|
|Yes||63 (55.8)||43 (78.2)|
|No||50 (44.3)||12 (21.8)|
|Stroke, no. (%)|
|Yes||83 (86.5)||15 (32.6)|
|No||13 (13.5)||31 (67.4)||<.008|
|Seizure, no. (%)|
|Yes||29 (30.2)||11 (23.9)|
|No||67 (69.8)||35 (76.1)|
|Cerebral hemorrhage, no. (%)|
|Yes||13 (11.5)||5 (9.1)|
|No||100 (88.5)||50 (90.9)|
|Diffuse neurologic dysfunction, no. (%)|
|Yes||77 (68.1)||26 (47.3)|
|No||36 (31.9)||29 (52.7)||<.009|
|Decreased cognition, no. (%)|