From the Research
Diagnosis of Central Nervous System (CNS) Vasculitis
- Brain biopsy is considered the diagnostic gold standard for primary CNS vasculitis (PCNSV) 1
- However, biopsy may be falsely negative when unaffected tissue is sampled, and it carries a small but significant risk of serious complications 1
- Non-invasive imaging techniques, such as magnetic resonance imaging (MRI) and angiography, are often used in the diagnostic workup, but they are not specific or sensitive for PCNSV 2, 3
Comparison of Biopsy and Non-Invasive Imaging
- A study found that cerebral angiography findings were not associated with biopsy findings in patients with suspected PCNSV 2
- Another study found that brain biopsy was diagnostic of PCNSV in 71% of cases, while angiography defined PCNSV had distinct clinical features, including acute onset, focal weakness, and visual impairment 4
- A review of imaging findings in PCNSV noted that MRI is extremely sensitive but non-specific, and that conventional or magnetic resonance angiography (MRA) typically shows segmental narrowing and dilation in multiple cerebral arteries 1
Diagnostic Challenges
- The diagnosis of PCNSV is often difficult due to the lack of specific clinical features, classical clinical course, and confirmatory blood or imaging investigations 5
- Differential diagnosis includes secondary CNS vasculitides and non-inflammatory cerebral vasculopathies, such as reversible cerebral vasoconstriction syndrome 3
- A binary set of diagnostic criteria has been proposed, dividing cases into "definite" primary CNS vasculitis, where tissue proof is available, and "possible," where it is not 5