Perforating artery

Slow application of 0.2-l.5mL of alcohol through the inflated balloon catheter induces necrosis of the myocardium, which is seen as an obvious contrast enhancement on echocardiography. If the gradient post instillation of alcohol remains above 30 mmHg, the balloon may be positioned more proximally in the vessel or a second septal perforating artery may be treated in the same way,... 

Gerraty et al. (2002) 19 Clinical diagnosis of acute lacunar syndrome In 13 cases DWI and PI altered the final diagnosis of infarct pathogenesis from small perforating artery occlusion to large artery embolism... 

Subcortical white matter infarcts may mimic a superficial MCA infarct causing a partial anterior circulation syndrome or present as a lacunar syndrome (pure motor, ataxic hemiparesis or sensori motor stroke). Superficial perforating artery infarcts (medullary branches) are often accompanied by cortical spotty lesions. Borderzone and white matter medullary branches infarctions are usually caused by hypoperfusion due lo large vessel occlusion or stenosis (Bogousslavsky 1993 Donnan and Yasaka 1998), but white matter medullary branches infarction can also be caused by cardioembolism (Lee et al. 2003). 

Lee PH, Bang OY, Oh SH et al (2003) Subcortical white matter infarcts. Comparison of superficial perforating artery and internal borderzone infarcts using diffusion-weighted magnetic resonance imaging. Stroke 34 2630-2635 Leys D, Mounier-Vehier F, Lavenu I et al (1994) Anterior choroidal artery territory infarcts. Study of presumed mechanisms. Stroke 25 837-842... 

The posterior cerebral artery encircles the midbrain close to the oculomotor nerve at the level of the tentorium and supplies the inferior part of the temporal lobe, and the occipital lobe (Marinkovic et al. 1987). Many small perforating arteries arise from the proximal portion of the posterior cerebral artery to supply the midbrain, thalamus, hypothalamus and geniculate bodies. Sometimes a single perforating artery supplies the medial part of each thalamus, or both sides of the midbrain. In approximately 15% of individuals, the posterior cerebral artery is a direct continuation of the posterior commrmicating artery, its main blood supply then coming from the internal carotid artery rather than the basilar artery. 

Parenchymal anastomoses. These occasionally develop in the precapillary bed of the perforating arteries at the base of the brain supplying the basal ganglia. 

Lacunar syndromes are defined clinically. They are highly predictive of small, deep lesions affecting the motor and/or sensory pathways in the corona radiata, internal capsule, thalamus, cerebral peduncle or pons. Although a few patients have a partial anterior circulation infarct (Bamford et al. 1987 Anzalone and Landi 1989 Arboix et al. 2007), the great majority have small iirfarcts, which are sometimes visible on CT, more often on MRI. These are caused by presumed occlusion of a small perforating artery affected by intracranial small vessel disease (see Fig. 10.2). There is no visual field defect, no new cortical... 

Small deep infarcts in the subcortical white matter of the corona radiata may result from small vessel disease affecting the long medullary perforating arteries extending down from cortical branches of the middle cerebral artery or from embolism. Such centrum semiovale infarcts present as either a lacunar syndrome or, occasionally, as a partial anterior cirulation syndrome with cortical features (Read et al. 1998 Lammie and Wardlaw 1999). They are not, however, easy to classify or to distinguish from border zone infarcts deeper in the white matter lying between the arterial territories of the deep perforators from the first part of the middle cerebral artery and the superficial medullary perforators. 

The few pathological data available indicate that cerebral microbleeds are small areas of old hemorrhage, often associated with lipohyalinosis in the deep perforating arteries feeding the affected area of the brain (Fazekas et al. 1999). It is unclear whether the presence of microbleeds increases the risk of intracerebral hemorrhage in patients treated with antiplatelet or anticoagulant therapy (Cordonnier et al. 2007) although they seem not to be associated with increased risk in thrombolysis (Ch. 11). 

Vascular pixel elimination. Peripheral blood vessels and perforating arteries should be excluded from CTP maps, as they may mimic areas of falsely high perfusion within brain tissue [144]. Kudo et al. [92] evaluated the efficacy of vascular pixel elimination in CTP imaging, in comparison with that in PET imaging. Any pixel with higher CBV value than a threshold of 8 mL/min was marked and eliminated from the CBF calculation. The correlation of CT-CBF and PET-CBF measurements was significantly improved when pixels with CBV values above that threshold were eliminated. 

Perforating arteries, an important collateral pathway to the kidney, arise from the intraparenchymal branches of the renal artery and exit from the kidney to anastomose with various retroperitoneal arteries [18]. In addition to the main renal artery and perforating arteries, the superior, middle, and inferior capsular arteries should be considered as well. The superior capsular artery may arise from the inferior adrenal artery, main renal artery, or aorta. The middle capsular artery, which may consist of one or more branches, arises from the main renal artery. The inferior capsular artery may originate from the gonadal artery, an accessory or aberrant lower pole, or even the main renal artery. These vessels form a rich capsular network that anastomoses freely with perforating arteries and other retroperitoneal (especially lumbar) arteries and also with internal iliac, intercostal, and mesenteric arteries [18]. 

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