Stroke by cause: some common, some exotic, some controversial.

See related article, pages 2533–2537 I n this exciting era of stroke prevention and treatment, the stroke neurologist is privileged and obliged to determine with reasonable certainty the cause of every cerebral or ocular vascular event. Investigation must seek evidence for either cardiac, large-artery, penetrating artery (lacunar) or, in their absence, for a growing miscellany of " other " causes. Thanks to the increasing accuracy of cardiac, aortic, arterial, and brain imaging, precise evidence about the cause but also the site, size, and type (hemorrhagic or bland) of the lesion will be available. In conjunction with a careful history of the mode of onset of present symptoms and of past events, the modern imaging data will allow for specific and particular short and long-term treatment programs for most patients. Decisions about the use of anticoagulants, platelet inhibitors, or recommendations for surgical procedures directed to the heart or the great vessels depend on the accurate accumulation of data about stroke-by-cause. When rheumatic heart disease virtually disappeared and as the population aged, nonvalvular atrial fibrillation (NVAF) became increasingly prevalent. Scepticism greeted the hypothesis that there was a causal relationship between AF without valve disease and stroke. These doubts were reduced when observational studies reported an increasing incidence of stroke with NVAF. 1 Dispute ceased when clinical trials proved without equivocation that the occurrence of stroke in these individuals was significantly and substantially reduced with the use of anticoagulants. Apart from rhythm monitoring and echocardiography, extensive cardiac investigation is not required. NVAF is a disease to which the elderly are predisposed, and it is predicted that by 2050 50% of individuals Ն80 years of age will be afflicted. 2 Long-term warfarin has become the proven therapy for patients with persisting NVAF who are without contraindications to anticoagulation. Aspirin alone has muted benefit and should be used when anticoagulants are contraindicated. Akin to the disagreements in the early days of the observations about NVAF, controversy has characterized the acceptance of claims about many of the newer examples of cardiac causes of stroke. Additional clinical and pathological studies are bringing some of these putative claims into proper perspective. For example, the causal association of stroke and patent foramen ovale (PFO) is now widely accepted. French investigators have been at the forefront in the studies of PFO as a cause of stroke, and Mas has done a recent review of this topic. 3 The condition is …