These circulating antibodies may be associated with a syndrome of transient bilateral chorea or hemichorea; some patients have an additional slight hemiparesis or other subtle focal signs. Almost all of the affected patients we have seen have been women with thrombocytopenia, most of whom probably have systemic lupus, at least on the grounds of laboratory studies. A direct connection of the choreic syndrome to the antibodies comparable to what is proposed in Sydenham chorea may be valid, but is unproven. Some cases display microinfarctions in the basal ganglia, perhaps on the basis of valvular vegetations. The choreic syndrome may be precipitated in these patients by the introduction of estrogen-containing birth control pills and is improved, usually promptly, by corticosteroids or antiplatelet agents. This movement disorder in the syndrome is reviewed by Asherson and colleagues.
The Sneddon syndrome (described by him in a 1965 article) is an arteriopathy producing deep blue-red skin lesions of livedo reticularis and livedo racemosa in association with multiple ischemic strokes. Many, but not all, patients have high titers of antiphospholipid antibodies. Although the skin lesions show a noninflammatory vasculopathy with intimal thickening, the pathology of the occlusive disease has not been adequately studied. In a report of 17 such patients by Stockhammer and coworkers, 8 had strokes and MRI showed lesions in 16 patients. The age of patients with strokes was 30 to 35 years; hence this condition is considered in young adults with cerebrovascular disease. Many of the lesions on MRI were small, deep, and multiple. Although there is a tendency for strokes to recur, many of the patients have remained well for years after a single stroke. Skin biopsy aids in diagnosis.
There are instances in which the radiologic changes caused by recurrent small infarctions of antiphospholipid syndrome are difficult to distinguish from multiple sclerosis, as discussed in several parts of Chap. 35, on demyelinative diseases. Associations of the antiphospholipid syndrome with transverse myelitis (see Chap. 42), hearing loss, and a number of other processes have been suspected but not proven.
Treatment During the period in which the diagnosis is being established by repeating the antibody tests, or after just a single arterial ischemic stroke, consensus groups have stated that it is reasonable to treat these patients with antiplatelet or anticoagulant agents (see Lim and colleagues). (Venous thrombosis is treated initially with heparin). Warfarin, perhaps the more the definitive therapy, alters the testing for antibodies and several guidelines recommend confirming the presence of antibodies after an interval of 2 weeks before starting treatment. However, warfarin has been used with greatest benefit and we have sometimes started this medication on suspicion of the syndrome. Khamashta and colleagues have found that the INR must be maintained close to 3 for effective prevention of stroke. According to the study conducted by Crowther and colleagues, an INR of 2 to 3 conferred the same degree of protection from thrombosis as did higher levels, but the number of thrombotic events was low in both groups and there was only 1 stroke in 114 patients over a period of about 3 years. Patients with severe thrombocytopenia and with other intrinsic coagulopathies should be treated with warfarin very cautiously. Although the INR is used as a gauge of the level of anticoagulation, it is also altered by the antibodies; no ideal method for monitoring the treatment has been devised. Aspirin, on uncertain grounds, is thought not to confer protection for stroke, but in only a few small series has its effect been analyzed. In “catastrophic” cases with repetitive strokes, intravenous immunoglobulin and plasma exchange have been used with some effect.