VASCULITIS, RHEUMATIC DISEASE AND THE NEUROLOGIST - THE PATHOPHYSIOLOGY AND DIAGNOSIS OF NEUROLOGIC PROBLEMS IN SYSTEMIC-DISEASE

We review cerebrovascular involvement in vasculitides and collagen vascular diseases. Pathogenesis, clinical syndromes, and diagnostic procedures are summarized. Mechanisms of tissue dysfunction in the vasculitides and co a gen vascular diseases include vasculitis, vasculopathy, coagulopathies, emboli, compression from granulomas and transient cellular dysfunction. Underlying immune-mediated processes may be immune-complex deposition, T-cell-mediated effects on endothelial cells, monocyte-mediated effects, direct effects of antibodies on cell membranes, and cytokine-associated changes. Clinically, focal neurological deficits are often accompanied by headaches, behavioral changes, memory disturbances and encephalopathy. Strokes associated with seizures and cranial-nerve involvement are especially frequent. In polyarteritis nodosa, isolated angiitis of the CNS, Churg-Strauss angiitis, and Wegener's granulomatosis strokes may result from vasculitis. Strokes in patients with systemic lupus erythematosus may be attributable to cardiogenic embolism, coagulopathy (antiphospholipid antibodies). and vasculopathy. Diffuse abnormalities in CNS lupus have been attributed to autoantibodies which interact directly with neurons. Both inflammation and thrombosis of the venous system are characteristic in Behcet's disease. In all vasculitides affecting predominantly large- and medium-sized vessels, angiography is the most important too for diagnosis. In MRI, both cortical and subcortical bilateral multiocular lesions are suggestive of vasculitis. Since all neuroradiological results are rather nonspecific, histology specimens should confirm the diagnosis before treatment is instituted. In questionable cases, a leptomeningeal biopsy is mandatory. If laboratory tests support the diagnosis of a systemic vasculitis, immunosuppressive therapy should be instituted in close cooperation with the rheumatologist and the clinical immunologist.