Cerebral ischemic infarction

Schaefer PW, Hunter GJ, He J, Hamberg LM, Sorensen AG, Schwamm LH, Koroshetz WJ, Gonzalez RG. Predicting cerebral ischemic infarct volume with diffusion and perfusion MR imaging. Am J Neuroradiol 2002 23 1785-1794. 

Nagai, N., et al.. Role of plasminogen system components in focal cerebral ischemic infarction a gene targeting and gene transfer study in mice. Circulation, 1999. 99(18) p. 2440-4. 

Although the majority of cerebral infarctions are located in the territories of the internal carotid arteries, 20% of cerebral ischemic infarctions involve tissue supplied by the vertebrobasilar circulation. Basilar artery occlusion is a life-threatening condition whose unfavourable spontaneous prognosis can only be improved by early detection and subsequent aggressive recanafization therapy (Pfefferkorn et al. 2006). 

There are two main classifications of cerebral ischemic events transient ischemic attacks and cerebral infarction. 

Saunders D. E., Howe F. A., van den Boogaart A., McLean M. A., Griffiths J. R., and Brown M. M. (1995). Continuing ischemic damage after acute middle cerebral artery infarction in humans demonstrated by short-echo proton spectroscopy. Stroke 26 1007-1013. 

Studer A, Georgiadis D, Baumgartner RW (2003) Ischemic infarct involving all arterial territories of the thalamus. Acta Neurol Scand 107 423-425 Timsit SG, Sacco RL, Mohr JP et al (1992) Early clinical differentiation of cerebral infarction from severe atherosclerotic stenosis and cardioembolism. Stroke 23 486-491 Tong DC, Adami A, Moseley ME et al (2000) Relationship between apparent diffusion coefficient and subsequent hemorrhagic transformation following acute ischemic stroke. Stroke 31 2378-2384... 

The early ischemic changes on CT are subtle and the CT may appear normal if performed in the first few hours. The sensitivity of CT within five hours of ischemic stroke was reported as 58% in one early study (Horowitz et al. 1991) although a higher rate of 68% has been reported within two hours (von Kummer et al. 1994) and even higher of 75% within three hours with middle cerebral artery infarction (Barber et al. 2000). The interobserver reliability and reproducibility of CT in the estimation of the degree of ischemic... 

Upregulation of adhesion molecules has been documented in human stroke patients [7]. It was demonstrated that leukocytes from patients suffering an ischemic stroke or transient ischemic attack showed increased CDl la expression within 72 hours of the onset of symptoms [123]. Increased ICAM-1 expression on the surface of vessels fi om cerebral cortical infarcts was detected in four patients [124]. In some studies, soluble isoforms of adhesion molecules shed fi om the surfaces of activated cells were quantified in serum. Serum endothelial-leukocyte adhesion molecule-1 (ELAM-1, E-selectin) levels increased up to 24 hours after stroke. Similar increases were observed in serum vascular cell adhesion molecule-1 (VCAM-1) levels and these increases were sustained up to 5 days [125]. In contrast, serum ICAM-1 levels in acute ischemic stroke patients have been found to be lower than or the same as those of asymptomatic control subjects matched for age, sex, and vascular risk factors [125,126]. The reason not to detect an increase in serum levels of adhesion molecules might be due to the late enrolling of patients. Once adhesion molecules bind to leukocytes and endothelial cells, they can no longer be detected in serum [7]. 

The incidence of major adverse reactions to dipyridamole was determined in a multicenter retrospective study, involving 73 806 patients who underwent intravenous dipjridamole stress imaging in 59 hospitals and 19 countries (4). The main conclusion was that the risk of serious dipjridamole-induced adverse effects is very low, a conclusion that is in line with other reports (5), and comparable to that reported for exercise testing in a similar patient population. Combined major adverse events among the entire patient population included 7 cardiac deaths (0.95 per 10000), 13 non-fatal myocardial infarctions (1.76 per 10000), 6 non-fatal sustained ventricular dysrhythmias (0.81 per 10000) (ventricular tachycardia in 2 and ventricular fibrillation in 4), 9 transient cerebral ischemic attacks (1.22 per 10000), 1 stroke, and 9 severe cases of bronch-ospasm (1.22 per 10000). Minor non-cardiac adverse effects were less frequent among the elderly and more frequent in women and patients taking maintenance aspirin. 

Although dizziness is a fairly frequent complaint at the beginning of diuretic treatment (1), postural hjrpotension is rarely reported. Ischemic complaints (mesenteric infarction and transient cerebral ischemic attacks) have been observed in elderly patients, but it is not clear whether these resulted from diminished organ perfusion or from an effect of the drug itself. The former is more likely, since similar problems have arisen with any form of antihypertensive treatment in old people who have to some degree become dependent on their hypertension to ensure a blood supply through sclerotic vessels. 

Cerebral ischemic injury is a common cause of dementia in older adults. Combination cases of vascular dementia and Alzheimer disease are also quite frequent. Vascular causes of dementia include subcortical vascular dementia, multi-infarct dementia, ischemic dementia, cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), and leuko-araiosis (see the Cerebrovascular Diseases section earlier in this chapter). ... 

Rhizoma Chuanxiong (3 g/day for 14 days) was claimed to ameliorate symptoms of acute cerebral infarction [364]. In a separate study by the same group of investigators in China, Rhizoma Chuanxiong (1 g/day for 1-2 years) was reported to improve symptoms of transient cerebral ischemic attack [365]. Nevertheless, which symptoms were examined and the details of the scoring system adopted were not documented in either study. 

Pressman BD, Touije EJ, Thompson JR (1987) An early CT sign of ischemic infarction increased density in a cerebral artery. Am J Neuroradiol 8 645-648. 

Fig. 5.10 CT images in a patient with left hemiparesis. Admission CTP images show cerebral blood flow (CBF, upper left), cerebral blood volume (CBV, upper middle), and mean transit time (MTT, upper right). The presence of a matched CBF/CBV perfusion deficit suggests irreversibly ischemic infarct core , likely to correlate with DWI findings, and not a target for reperfusion therapies The admission non-contrast CT...

Serious adverse effects of epinephrine potentially occur when it is given in an excessive dose, or too rapidly, for example, as an intravenous bolus or a rapid intravenous infusion. These include ventricular dysrhythmias, angina, myocardial infarction, pulmonary edema, sudden sharp increase in blood pressure, and cerebral hemorrhage. The risk of epinephrine adverse effects is also potentially increased in patients with hypertension or ischemic heart disease, and in those using (3-blockers (due to unopposed epinephrine action on vascular Ui-adrenergic receptors), monoamine oxidase inhibitors, tricyclic antidepressants, or cocaine. Even in these patients, there is no absolute contraindication for the use of epinephrine in the treatment of anaphylaxis [1,5,6]. 

Ischemic stroke has numerous causes. Cerebral infarction may result from large artery atherosclerosis, cardiac embolism, small artery lipohyalinosis, cryptogenic embolism, or, more rarely, from other diverse conditions such as arterial dissection, infective endocarditis, and sickle cell disease. Arterial occlusion is the cause of at least 80% of acute cerebral infarctions. " ... 

Hunter GJ, Silvennoinen HM, Hamberg LM, Koroshetz WJ, Buonanno FS, Schwamm LH, Rordorf GA, Gonzalez RG. Whole-brain CT perfusion measurement of perfused cerebral blood volume in acute ischemic stroke probability curve for regional infarction. 

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