Causes of stroke

The abstract of the paper “Etiology of Motor or Sensory Stroke”[l] follows the text in declaring that “the causes of ischemic stroke in the other 81 patients were penetrating artery disease (32 patients), large artery occlusive disease (17), cardioembolism (12), other causes (8), and undetermined (12).” No clinicdpathological correlation is offered for any of the cases in this series. The authors presume that any cardiac abnormality establishes the cardiac came of a small cerebral infarction. With no better evidence, small deep lesions not associated with the cardiac disease process are held to be cazrsed by penetrating artery disease, unless they are larger than 2 cm when they become “stroke of undetermined cause.” The dictionary definition of cause is “something that brings about an effect or result.” I believe that this should be a sacred word in scientific writing, not an ought-to-be or mightbe relationship. Terms such as “phenomenon,” “correlated finding,” “risk factor,” and “possible cause” are not equivalent. There is ample evidence [2-51 that small holes in the brain may derive from more than one mechanism. The authors’ last page confession that “recognition of a vascular lesion does not constitute proof that the lesion caused the patient’s stroke” seems to deny their own conclusion. If we are ever to learn anything about the pathogenesis of cerebrovascular disease, I believe that both authors and editors will have to insist upon phenomenological and logical criteria equivalent to Koch‘s postulates for infectious disease [61.