[Pathogenesis of focal, transitory cerebral ischemic accidents]

Transient ischaemic focal cerebral attacks (TIA's) are due to: 1) atherosclerosis when embolism may take place or perhaps transient occlusion of the internal carotid artery or mural or transiently occlusive thrombus of an intracranial artery stenosis or transient systemic hypotension. In recent years embolism may have been overdiagnosed; 2) cardiac embolism due to dysrythmias, myocardial infarction, endocarditis, valvular prosthesis, etc.; 3) miscellaneous causes, often difficult to demonstrate such as tortuosity of the extracranial cerebral arteries, dissecting aneurysms, changes in cerebrovascular resistance; 4) not unfrequently no cause is found, especially in young patients.