iothalamate-meglumine and Ischemic-Attack--Transient

To elucidate the relationship between abnormal enhancement of the cisterns on computed tomography and cerebral vasospasm, we performed a systematic and prospective study in 60 patients with ruptured cerebral aneurysms. There is a significant relationship between the findings of contrast-enhanced computed tomography (CECT) within Day 3 of rupture and cerebral vasospasm. Among 37 patients undergoing CECT between Day 0 and Day 3, 17 (46%) showed prominent increases in density in the region around the circle of Willis and its branches. In 13 of 17 cases (76%), severe vasospasm with motor paralysis occurred. In the remaining 4 cases (24%) with only slight or no cerebral vasospasm, the hematoma in the subarachnoid space was removed surgically by Day 3. In 19 of 20 cases without remarkable CECT, no severe cerebral vasospasm with motor paralysis occurred. There is no significant relationship between the CECT findings after Day 3 and cerebral vasospasm. The results indicate that the prominent increase in density in the region of the circle of Willis and its branches often observed on CECT within Day 3 of subarachnoid hemorrhage is useful for prediction of the occurrence of cerebral vasospasm and also provide information on the pathogenesis of cerebral vasospasm.

Topics: Aged; Circle of Willis; Female; Humans; Intracranial Aneurysm; Iothalamate Meglumine; Ischemic Attack, Transient; Male; Middle Aged; Prospective Studies; Radiographic Image Enhancement; Subarachnoid Hemorrhage; Tomography, X-Ray Computed

Topics: Aged; Female; Humans; Intracranial Aneurysm; Iothalamate Meglumine; Ischemic Attack, Transient; Male; Middle Aged; Prospective Studies; Radiographic Image Enhancement; Subarachnoid Hemorrhage; Tomography, X-Ray Computed

An important computerized tomographic (CT) pattern is described, in which selective enhancement of cerebral gray matter occurs after intravenous administration of contrast medium. Analysis of 76 cases displaying the enhancement pattern revealed that the phenomenon occurs in diseases characterized by hypoxia, and may be attributed to regional vascular dysautoregulation. Eighty percent of these patients had primary cerebrovascular disease (infarctions or transient ischemic attacks); 20% with other disorders also had evidence of cerebral ischemia or infarction. When hypoxia progressed to infarction, the enhancement was accompanied by one or more parenchymal areas of decreased density. However, in transient ischemic attacks, it occurred without other parenchymal abnormality and represents the first recognized CT sign of cerebral hypoxia. Enhancement was observed within 3 weeks of onset in 80% of cases, but in 20% it persisted for up to 4 months, indicating a protracted state of dysautoregulation.

Topics: Adolescent; Aged; Brain; Cerebral Infarction; Cerebrovascular Disorders; Female; Humans; Hypoxia, Brain; Intracranial Aneurysm; Intracranial Arteriovenous Malformations; Iothalamate Meglumine; Ischemic Attack, Transient; Male; Middle Aged; Tomography, X-Ray Computed

The passage of contrast medium was observed using serial computed tomography (CT) in 24 stroke patients. Density--time profiles of various brain regions were plotted. In normal brain tissue, X-ray attenuation showed a maximum increase during the arterial phase (16.4 +/- 11.0%) and was 2.8 +/- 2.2% above control during stable distribution. In hypoperfusion, increase in attenuation was always below 10% in the arterial phase, while hyperperfusion was characterized by an attenuation increase of 25 to 70%. Enhancement was defined by a density increase of 16.8 +/- 14.8% and a tissue/blood ratio between 7 and 60%. An attempt was made to establish a relationship between the serial CT pattern and the prognosis. Enhancement tended to indicate severe morphological changes followed by permanent neurological deficit, whereas hyperperfusion was generally an indicator of probably recovery.

Topics: Adult; Aged; Blood-Brain Barrier; Brain; Cerebrovascular Disorders; Humans; Iothalamate Meglumine; Ischemic Attack, Transient; Middle Aged; Perfusion; Radiographic Image Enhancement; Tomography, X-Ray Computed