Acute Ischemic Infarction Research Articles

Ethanol intoxication: a risk factor for ischemic brain infarction.

One hundred consecutive patients (67 men, 33 women) aged from 15-55 with acute ischemic brain infarction verified by computed tomography and/or angiography and/or brain scanning were studied. In 40 cases the onset of symptoms was preceded within 24 hours by ethanol intoxication. Ethanol intoxication preceding brain infarction was 4-7 times as common in men and 6-15 times as common in women as ethanol intoxication in the general Finnish population of the same age and sex. Nineteen of the patients were heavy drinkers. Heavy drinking was twice as common in men and 5 times as common in women as heavy drinking in the general Finnish population of the same age and sex. Both occasional ethanol intoxication and regular heavy drinking seem to carry an increased risk of ischemic brain infarction. The ethanol-induced risk was highest in middle-aged women and young men.

Proton nuclear magnetic resonance imaging of acute experimental cerebral ischemia.

To determine the efficacy of proton nuclear magnetic resonance (NMR) imaging in documenting acute ischemic infarction and to characterize the changes in these images during the first 24 hours following the ischemic insult, serial NMR imaging was performed in gerbils that had undergone unilateral carotid artery ligation. No significant changes in the signal intensity, T1 or T2 relaxation times were noted for either asymptomatic animals or the control hemisphere of symptomatic gerbils. There was a significant increase in T1 and especially T2 relaxation times and in both the relative signal intensity and Hf(v) for the ischemic hemisphere of symptomatic gerbils. These parameters appeared to increase linearly over 24 hours. The ischemic lesion first could be detected by NMR as early as 3 hours after carotid artery ligation, our earliest time point. The physiologic significance of these changes is discussed. These data suggest that NMR imaging may have significant diagnostic importance for acute cerebral ischemia and infarction in man.

Positron Tomography in Ischemic Cerebrovascular Disease

The authors briefly review the advances in the field of cerebrovascular disease because of PT and show that considerable insight into the pathophysiology of acute ischemic infarction is being obtained in humans.

Ethanol intoxication: a risk factor for ischemic brain infarction in adolescents and young adults.

Between January 1978 and December 1979 23 consecutive patients aged under 40 years with acute ischemic brain infarction were admitted to the department of neurology, Meilahti University Hospital in Helsinki. In 10 patients (43%) the onset of symptoms was preceded within 24 hours by ethanol intoxication, and all but one symptom occurred at weekends when most liquor is consumed in Finland. Ethanol intoxication preceding the stroke was 4 times as common in female and 5 times as common in male patients as ethanol intoxication in the general Finnish population of the same age and sex. The present results support those of our previous study and suggest that occasional ethanol intoxication increases the risk of ischemic brain infarction both in adolescents and young adults.

Myocsrdial uptake of technetium-99m stannous pyrophosphate following direct current transthoracic countershock.

The effect of direct current (DC) countershock upon myocardial technetium-99m stannous pyrophosphate (PYP) uptake was studied in 22 dogs. All eight dogs imaged had positive abnormal PYP scintigrams that were usually indistinguishable from experimental infarction. In three animals, additional areas of radionuclide uptake were seen in overlying noncardiac tissue. Left and right ventricular myocardial PYP uptake averaged (+/- SEM) 23 +/- 5 times control and 24 +/- 6 times control, respectively. These activity ratios occurred without reduction in regional myocardial blood flow (RMBF), and were associated with histologic evidence of necrosis. The necrosis was usually epicardial, corresponding to the transmural site of greatest PYP uptake. The magnitude of PYP accumulation and the weight of damaged tissue increased with increasing applied energy. Thus, PYP uptake following DC countershock could result in false-positive interpretation of acute ischemic myocardial infarction. Since RMBF is normal in regions of PYP uptake, the major determinant of radionuclide accumulation is the extent of cellular damage.

Pathophysiology of cerebral infarction.

Evidence available at present from animal studies indicates that the flow of blood can be restored to ischemic zones in the brain as long as 24 hours after the onset of ischemia, and that such reperfusion could result in the restoration of function of neurons that have not been functioning during the period of ischemia. However, reperfusion also can cause worsening of ischemic cerebral edema resulting in increased neurological disability or death. Adequate measures for control of cerebral edema will be necessary if surgical intervention is to become an effective therapy for acute ischemic cerebral infarcts.

Embolism of the central retinal artery secondary to metastatic carcinoma.

A 54‐year‐old man experienced sudden loss of vision of one eye and was admitted four hours later for treatment of typical occlusion of the central retinal artery. The patient died three weeks later and the autopsy revealed bronchial carcinoma of the epidermoid type with metastasis in most visceral organs. Microscopic examination of the eye disclosed the central retinal artery to be patent but with atheromatous changes at the level of the lamina cribrosa. The retina showed evidence of acute ischaemic infarction of the inner retinal layers. Tumour emboli were observed in the retinal arterioles. Trypsin‐digest preparations were also employed to demonstrate tumour cells in the retinal arterioles.