Gradually progressive dementia without discrete cerebrovascular events in a patient with Sneddon's syndrome

A 37-year-old man sought medical advice because of an 8-year history of a s lowly progressive dementing illness with no clinically apparent discrete st rokelike episodes, Cognitive functioning was markedly, globally impaired wi thout lateralizing or localizing features, Widespread livedo reticularis le d to a diagnosis of Sneddon's syndrome. Antiphospholipid antibodies and lup us anticoagulant were negative. Magnetic resonance imaging showed widesprea d cerebral atrophy, cortical and subcortical cerebral infarcts, and extensi ve periventricular white matter abnormalities. Cerebral angiography reveale d diffuse medium- and small-vessel occlusive disease, with numerous collate rals in the mid and distal circulation but no evidence of atherosclerosis o r vasculitis, No other cause of a dementing illness was found. We postulate that our patient's dementia was due to the cumulative effects of multiple cerebral infarcts.