Corona radiata

Stab-kranz, m. (Biol.) corona radiata. -kraut, n, = Eberraute. -magnet, m. bar magnet, -thermometer, n. m. thermometer graduated directly on the stem (instead of having a separate scale). 

The middle cerebral artery enters the Sylvian fissure and divides into two to four branches, which supply the lateral parts of the cerebral hemisphere. From its main trunk, a medial and lateral group of tiny lenticulostriate arteries and arterioles pass upwards to penetrate the base of the brain and supply the basal ganglia and internal capsule (Marinkovic et al. 1985). Some of these small penetrating vessels extend up into the white matter of the corona radiata in the centrum semiovale towards the small medullary perforating branches of the cortical arteries coming down from above. 

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... 

Pure motor stroke constitutes about 50% of lacunar cases. It consists of a unilateral motor deficit involving two or three areas, the face, upper arm and/or leg, including the whole of each area that is affected. There are often sensory symptoms but no sensory signs. The lesion occurs at locations where the motor pathways are closely packed together and separate from other pathways usually in the internal capsule or pons, sometimes the corona radiata or cerebral peduncle, and rarely in the medullary pyramid. There may be a flurry of immediately preceding TIAs, the so-called capsular warning syndrome (Donnan et al. 1996). 

Sensorimotor stroke constitutes about 35% of cases. It is the combination of a pure motor stroke with sensory signs in the affected body parts. The lesion is usually in the thalamus or internal capsule, but it can be in the corona radiata or pons. A similar clinical picture can be caused by cortical infarcts, leading to misclassification (Blecic et al. 1993). 

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. 

FIGURE 9.12 Autoradiogram of the distribution of In-labeled transferrin in cat brain following a 75- iL infusion at 1.15 [xL/min into the corona radiata. 

Pure motor hemiparesis involving face, arm, and leg Contralateral posterior limb internal capsule or overlying corona radiata... 

Fig. 3.10 Example of one of the multiple differential diagnoses of NCCT hypodensity. Patient awoke with left hemiparesis. (a) NCCT shows hypodensity in the right corona-radiata (arrow). (b, c) Axial FLAIR and T2-weighted MR images demonstrate a...

Fig. 7.9 T2 shine through. Seventy-eight-year-old male with dizziness. DWI hypeiintense lesions in the right posterior frontal subcortical white matter and bilateral posterior corona radiata are hypeiintense on FLAIR images and ADC maps and hypoin-...

Fig. 7.12 Acute ischemic stroke with DWI reversibility. Sixty-nine-year-old male with sudden onset of speech difficulties and R-sided weakness. MRA demonstrated MCA occlusion. He was treated with lA rtPA with complete recanalization. DWI images and ADC maps demonstrate acute ischemia involving the left caudate body, corona radiata, and frontal subcortical white...

Higano, S., et al., Diffusion anisotropy of the internal capsule and the corona radiata in association with stroke and tumors as measured by diffusion-weighted MR imaging. AJNR Am J Neuroradiol, 2001. 22(3) p. 456-63. 

Fig. 8.9 Diffusion-perfusion mismatch. The patient is a 58-year-old woman with 5 h of slurred speech and right hemiparesis. The DWI image shows a small infarct in the left caudate nucleus and corona radiata. CBV is mildly elevated within the infarct, and within a much larger region of the left MCA territory (arrows on...

Fig. 9.7 A 61-year-old male presented with left facial droop and dysartria. (a, b) CTA demonstrated a proximal right MCA occlusion (white arrows), (c, d) Initial DWI performed 12.7 h after stroke onset showed multiple punctate fod of diffusion abnormality in the right centrum semiovale and corona radiata consistent with small acute infarcts, (e, f) Mean transit time (MTT) MR...

Simultaneously, the probabihty of egg fertilization is reduced. In humans, fertiUty of the egg cell is preserved for a period of 12-24h after ovulation and complete uncovering of the oocyte occurs after 30 h. Hyaluronan and other glycosaminoglycans of zona pellucida and corona radiata prevent the egg from adhering to the wall of fallopian tube, thus reducing the risk of ectopic pregnancy. It has been experimentally demonstrated that retardation of HA breakdown in the intercellular matrix leads to inhibition of folUcular cells apoptosis and preservation of egg fertility [46]. For the fertilization to take place, that is, introduction... 

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