WS: Current concepts of cerebrovascular disease-stroke. A new look at emergency carotid artery operations for the treatment of cerebrovascular insufficiency. Stroke

IN ADDITION to motor and sensory deficits, strokes may produce impairment of language, of visual-spatial perception, and of other aspects of cognitive behavior known collectively as "higher cortical func-tions. " These disorders are of interest to the physician because they are helpful in localizing the site of a cerebral lesion. Knowledge of these disorders is necessary for evaluation of a patient's level of func-tioning, for selection of appropriate rehabilitation, and for determining prognosis. Furthermore, the cognitive disorders produced by strokes may be con-sidered "experiments of nature " which offer fascinat-ing insight into the organization of the central nervous system and so-called "brain and behavior relation-ships. " The cerebral lesions induced by tumors, infec-tions, and trauma are often less clearly localized than some vascular lesions. Strokes, therefore, represent the best pathological model from which one can infer the organization of behavior. The various aspects of higher cortical functions affected by strokes include 1) attention and con-sciousness, 2) language and related functions, 3) visual-spatial perception and constructional abilities, 4) memory, 5) intelligence, and 6) emotional behavior and personality. These are also the steps usually followed by a mental status examination.1 This article will deal with aphasia, apraxia, and related disorders. Aphasia Broca's observation 120 years ago that strokes affecting the left hemisphere may produce aphasia marked the birth of a new branch of science, known today as neuropsychology. The hemisphere dominant for speech is the left hemisphere, not only in almost every right-handed person, but also in the majority of left-handed persons. The language areas of that hemisphere are supplied by the middle cerebral artery. It is estimated that up to 40 % of all stroke victim