- The inflammation of blood vessels can lead to changes in blood vessel structure and function as well as stasis and thrombosis.
- There are many different types of patterns of pathologies that affect blood vessels and some of these only happen with intracranial vessels.
- Possibly due to an immune reaction to an antigenic stimulus
- There is deposition of immune complexes in the vessel walls
- Genetic, environmental and other mechanisms
A size based classification approach is often used.
|Large Vessel||Giant cell arteritis, Cranial arteritis, Takayasu arteritis|
|Medium sized||Classical Polyarteritis nodosa, Kawasaki disease|
Summaries of individual characteristics
|Giant cell arteritis||Older patient at least > 50 with ESR > 50 and elevated CRP. Affects large vessels. Headache, temporal artery tenderness, jaw claudication, diplopia, transient or more lasting visual loss. The target antigen of the immune response is probably within the internal elastic layer of the vessel wall. This is supported by the observation that the anterior circulation is relatively spared due to lack of an internal elastic layer|
|Kawasaki syndrome||A mucocutaneous lymph node syndrome. Cerebral involvement rare. Classically seen in children with prolonged fever.|
|Classic polyarteritis nodosa||Medium sized vessels. Part of a systemic PAN. Skin, renal and other changes|
|Churg-Strauss syndrome||Asthma and eosinophil granulomas (Antibodies to Myeloperoxidase ANCA/MPO)|
|Microscopic polyangiitis||Mean age of onset is 57 years and commoner in males. May have an active glomerulonephritis. Asthma and eosinophil granulomas (Antibodies to Myeloperoxidase ANCA/MPO)|
|Wegener granulomatosis||May have an active glomerulonephritis. CXR changes may be seen. Granulomas of the upper airways and renal involvement. Antibodies to cANCA /Proteinase 3. Responds to steroids and cyclophosphamide.|
|Immune complex deposition||SLE, RA|
|Takayasu's arteritis||Inflammatory arteritis with stenotic lesions of the aortic arch and its branches.|
|Cryoglobulinaemic angiitis||Cryoglobulins and complement in vessel lumens and walls. Possess cold-precipitable immunoglobulins. Skin, joints, gut, and glomeruli often are involved. Look for purpura. Association with SLE/RA or lymphoproliferative disorders and Hepatitis C infection. Cerebral involvement uncommon.|
|Primary Angiitis of the CNS||Inflammatory often segmental vasculitis found only in the cerebral circulation. Occurs at any age. Poorly responsive to steroid.|
- Elicit a history of connective tissue disease e.g. joint pain and swelling, myalgia
- Both haemorrhagic or ischaemic stroke may ensure
- Inflammatory changes lead to seizures, headache and encephalopathy.
- Coma may develop due to widespread oedema and raised ICP.
- Look for vasculitis rashes, eyes for inflammatory changes, retina and even perineum for ulceration.
- Renal urine analysis to exclude a glomerulonephritis.
- FBC: WCC, DWCC, CRP, ESR and abnormal LFTs, U&E, Urinalysis. Coagulation. Complement levels fall in vasculitis associated with immune complexes
- Anticardiolipin-antibodies, lupus anticoagulant, electrophoresis, CK, LDH, haptoglobin, ferritin, ACE
- Cryoglobulins, TSH, thyroid antibodies, RF, ANA, Anti ds-DNA, anti-histone, complement, anti-Ro [SS-A] and anti-La [SS-B-], c- and pANCA/MPO [myeloperoxidase], anti-endothelial antibodies
- Drug screening, blood cultures, Syphilis serology, borreliosis, hepatitis B, and C, HIV
- CSF analysis may be useful. The CSF may (it is not always) inflammatory with raised protein and white cells but no evidence of organisms or malignant cells or TB which is important especially before considering immunosuppression. However, in primary angiitis of the central nervous system the CSF may be normal.
- MRI: Standard imaging will show the characteristic changes of infarction on DWI and ADC maps and gradient echo sequences will show changes. Some MRI sequences will allow evidence of inflammatory changes. 18-fluorodeoxyglucose positron emission tomography scanning can also be useful in showing increased uptake and inflammatory changes in the vessel walls.
- Angiography: Before considering immunosuppression, angiography is important and DSA will provide the most useful findings.
- Biopsies: Targeted biopsies leptomeninges can be useful to show evidence fo an active vasculitis process but in segmental disease may be negative
Differential for "Beading" appearance
- Management requires the use of toxic immunosuppressive therapy so all attempts must be made to establish a reliable diagnosis and assess if the treatment is more harmful than the vasculitis.
- Standard therapies include steroids and pulse cyclophosphamide as induction treatment.
- Alternative option is the use of the anti-CD20 antibody rituximab.
- Other agents include Methotrexate, azathioprine, and mycophenolate mofetil are recommended as alternatives to Cyclophosphamide once remission is achieved.