Angiography in Cerebral Infarction

Abstract

The diagnosis of cerebral infarction by angiography is based on a variety of findings, involving both anatomical and pathophysiological considerations. These findings at the time of angiography are dependent upon the type of infarction that we are dealing with (hemorrhagic versus nonhemorrhagic), its location, and the time interval between the onset of symptoms and the performance of the angiographic procedure. Rapid serial angiography is indispensable in the study of cerebral infarction. Most patients are never referred to the Department of Radiology for cerebral angiography, but the number seen has increased of late because of the importance given to possible correctible lesions in the extracranial vessels. Other cases are referred because a hemorrhagic infarction requiring surgical intervention is suspected or because the diagnosis of cerebral infarction cannot be made with certainty on clinical grounds. Because of our desire to arrive at an accurate diagnosis and because the morbidity of the procedure is decreasing, the frequency of referrals for angiography is constantly increasing. The statistical incidence of roentgen findings in infarcts is likely to be inaccurate because so many of the cases are not referred for angiography. Pathologic proof is obtained only when, in the presence of a mass effect, surgery is carried out or when the patient comes to autopsy. In the other cases, one must rely on clinical diagnosis and on follow-up neurological examinations which show a course compatible with that of cerebral infarction. Material The material available for evaluation consists of 40 cases. All patients with transient ischemic attacks lasting for minutes or hours with complete recovery of function were excluded in the evaluation of angiographic findings of cerebral infarction. There were some positive findings in 37 of the 40 patients (92 per cent), with 19 obstructed intracerebral vessels. Thirteen patients, 12 of whom were female, were between ten and forty years of age, and 27, including 9 females, were between forty-one and seventy years. The higher incidence in females between the ages of ten and forty raises the question of possible hormonal influence connected with the use of contraceptives, but no such relationship could be established in this series of cases (6 were taking oral contraceptives and 6 were not). The problem of old cerebral infarction is briefly reviewed for the sake of completeness. Angiographic Findings The angiographic findings in cerebral infarction may be divided as follows: I. Initial Vasodilatation: The initial effect is that of vasodilatation as a response to high CO2 tension or to lowering of the pH. Vasodilatation probably occurs within a few seconds of insult and could manifest itself by an increase in the speed of circulation through the local area.