HILTON HEAD, SC—Vasculitis is a general term for a group of uncommon diseases involving inflammation of blood vessels, which can lead to the occlusion or destruction of the vessels and to ischemia of the tissues supplied by those vessels. Central nervous system (CNS) vasculitis can be a primary disease or occur secondary to infections or as part of a systemic vasculitis or systemic inflammatory (eg, rheumatologic) disease. Without prompt diagnosis and treatment, patients are at high risk of permanent neurologic disability or death, according to a presentation at the 41st Annual Contemporary Clinical Neurology Symposium.
If diagnosed and treated early, CNS vasculitis has a good prognosis, but delayed intervention can result in severe morbidity or mortality, said Siddharama Pawate, MD, Associate Professor of Neurology at the Vanderbilt University Medical Center in Nashville. “You have to do extensive workups sometimes before you can make a diagnosis,” he said, citing the need for neurology, rheumatology, and infectious disease input. “Investigations include serologic testing, CSF analysis, MRI, and brain biopsy.”
Rare But With a High Risk of Morbidity
The 2012 International Chapel Hill Consensus Conference on the Nomenclature of Vasculitis adopted an extensive list of names for the numerous manifestations of vasculitis. These include:
• Large-vessel vasculitis (eg, giant cell arteritis)
• Medium-vessel vasculitis (eg, polyarteritis nodosa)
• Small-vessel vasculitis (eg, microscopic polyangiitis and granulomatosis with polyangiitis [Wegener’s granulomatosis])
• Variable-vessel vasculitis (eg, Behçet’s disease)
• Single-organ vasculitis (eg, primary CNS vasculitis)
• Vasculitis associated with systemic disease (eg, rheumatoid vasculitis)
• Vasculitis associated with probable etiology (eg, hepatitis B virus-associated or cancer-associated vasculitis)
CNS vasculitis may be grouped into two larger categories—infectious CNS vasculitis and immune-mediated CNS vasculitis. Dr. Pawate provided a brief overview of infectious causes of vasculitis including bacterial, mycobacterial, varicella-zoster, fungal, and neurocysticercosis, but devoted the main part of his presentation to the latter of the two categories, including a focus on primary CNS vasculitis (PCNSV), which is also known as primary angiitis of the CNS (PACNS). Dr. Pawate offered an analysis of what is entailed in the recognition, diagnosis, and treatment of CNS vasculitis in general and its immune-mediated variants more specifically.
CNS vasculitis may occur as part of a broader systemic vasculitis. Giant cell arteritis (GCA) is a medical emergency that can cause permanent visual loss if not diagnosed and treated early. Vision loss occurs most often due to anterior ischemic optic neuropathy but also central retinal artey occlusion and posterior ischemic optic neuropathy. The American College of Rheumatology criteria for GCA diagnosis include three out of the five following core features: age 50 or older at onset, new-onset headaches, temporal artery abnormality, elevated erythrocyte sedimentation rate (ESR) of at least 50 mm/h and abnormal temporal artery biopsy (TAB). High-dose steroids should be started if there is suspicion, without waiting for biopsy results. Recently, the anti-IL6 monoclonal antibody tocilizumab has been approved by the FDA as a treatment for GCA. Granulomatosis with polyangiitis (GPA, Wegener’s granulomatsis) most often causes peripheral neuropathy, but can cause a small/medium vessel CNS vasculitis. Eosinophilic granulomatosis with polyangiitis (Churg-Strauss syndrome) is characterized by the triad of asthma, hypereosinophilia, and necrotizing vasculitis usually in that order. CNS involvement is common as part of the vasculitis. CNS vasculitis may also be seen in Behcet’s disease manifesting as dural sinus thrombosis and arterial occlusion or aneurysm.
In SLE, vasculitis has a prevalence ranging between 11% and 36% but CNS involvement is much less common. There are rare case reports of CNS vasculitis occurring in patients with rheumatoid arthritis.