It is not entirely clear to us what proportion of the cerebrovascular features of lupus might be explained on the basis of the coagulation disorder or Libman-Sacks (non-bacterial thrombotic) endocarditis. Other neurologic manifestations are related to hypertension, which frequently accompanies the disease and may precipitate cerebral hemorrhage; to endocarditis, which may give rise to cerebral embolism; to thrombotic thrombocytopenic purpura, which commonly complicates the terminal phase of the disease (Devinsky et al); and to treatment with corticosteroids, which may precipitate or accentuate muscle weakness, seizures, and psychosis. In other cases, steroids appear to improve these neurologic manifestations. A similar set of neurologic problems arises in relation to the antiphospholipid antibody syndrome, which may be a feature of lupus or arise independently (see “Antiphospholipid Antibody (Hughes) Syndrome”) and a special syndrome of chorea occurs with few other systemic manifestations of lupus, presumably on an autoimmune basis.
This is yet another poorly understood form of vasculitis, consisting of a microangiopathy affecting mainly the brain and retina (Susac and colleagues, 1979). Psychiatric symptoms, headache, dementia, sensorineural deafness, vertigo, and impairments of vision are the clinical manifestations. These are generally young patients, more often women and present with an incomplete syndrome, without one or more of the core features of deafness or branch retinal artery occlusion or encephalopathy. Funduscopy shows multiple retinal artery branch occlusions and retinal angiography shows multiple additional infarctions and evidence of diffuse vascular leakage from endothelial injury. The MRI may show characteristic white matter lesions, particularly in the central portion of the corpus callosum (Fig. 33-38) (see Susac and colleagues, 2003). Antibodies to endothelial cells have been identified by Magro and colleagues in many of their cases. The patients seem to respond to steroid therapy and most cases are singular and do not relapse but there are exceptions.
This disorder is suitably considered here because it is a chronic, recurrent vasculitis, involving small vessels, with prominent neurologic manifestations. It is most common in Turkey, where it was first described, in other Mediterranean countries, and in Japan, but it occurs throughout Europe and North America, affecting men more often than women. The disease was originally distinguished by the triad of relapsing iridocyclitis and recurrent oral and genital ulcers, but it is now recognized to be a systemic disease with a much wider range of symptoms, including erythema nodosum, thrombophlebitis, polyarthritis, ulcerative colitis, and a number of neurologic manifestations, some of them encephalitic or meningitic in nature. The most reliable diagnostic criteria, according to the International Study Group that assembled data on 914 cases from 12 medical centers in 7 countries, were recurrent aphthous or herpetiform oral ulceration, recurrent genital ulceration, anterior or posterior uveitis, cells in the vitreous or retinal vasculitis, and erythema nodosum or papulopustular lesions.