Clinical Significance of the Cerebral Perforating Arteries.

There is scarce data in the contemporary literature regarding the correlation of the microanatomy of the perforating arteries, their atherosclerosis, and the ischemia in their territory. In order to examine, at least partially, those parameters, the perforating arteries of 12 brains were microdissected or their vascular casts were obtained. In addition, 30 specimens of the perforators were used for a histological and immunohistochemical study. Finally, radiological images of 14 patients with deep cerebral infarcts were examined following a selection among 62 subjects. It was found out that certain groups of the perforators ranged in number between 0 to 11 (1.1-8.4 on average). In addition to the origin from the parent vessels, some of the perforators also arose from the leptomeningeal branches. Occlusion of such a branch may result in both a superficial and a deep ischemic lesion. Besides, the common stems of certain perforators supplied both right and left portions of the corresponding brain regions. Occlusion of such a common trunk leads to bilateral infarction. The atherosclerosis of the perforating vessels, which was found in one third of the specimens, is the basis for the ischemic lesions development on their territory. Among the 62 patients with ischemic lesions, 14 had a deep cerebral infarcts, most often within the thalamus, as well as on the territory of the middle cerebral and the anterior choroidal artery perforators of the hemispheres. Our study showed that a strong correlation exists between certain microanatomical features, atherosclerosis, and region of supply of the perforating arteries, on the one hand, and location of the ischemic lesions on the other hand.

Clinical significance of blood supply to the internal capsule and basal ganglia.

Although the general vascular supply of the basal ganglia and internal capsule is well known, precise data are lacking regarding the variations of the vascular territories in the two regions. Twelve hemispheres were studied following an injection of coloured ink into the main cerebral arteries, namely the anterior cerebral (ACA), middle cerebral (MCA), anterior choroidal (AChA) and posterior cerebral artery (PCA). Serial sections of the injected hemispheres were taken in the axial or coronal plane. In 75% of the hemispheres, ACA perforators were seen to supply the inferomedial part of the head of the caudate nucleus and the anterior limb of the internal capsule, as well as the anterior and inferior portions of the putamen and globus pallidus. The MCA vessels perfused the superolateral part of the head and body of the caudate nucleus, the superior part of the entire internal capsule, most of the putamen and part of the globus pallidus. The AChA perforators perfused the medial segment of the globus pallidus, the inferior part of the posterior limb, the retrolenticular and sublenticular portions of the internal capsule, and occasionally its genu. The same segment of the globus pallidus and the inferior part of the genu of the internal capsule were most likely supplied by the perforators of the internal carotid artery. A predominance of ACA territory was noticed in one specimen (8.33%) and a predominance of MCA territory in two specimens (16.67%). The obtained anatomical data may help radiologic determination of perforators involved in ischemic events, as well as a better understanding of the neurological deficits in the same events.

Posterior reversible encephalopathy syndrome--A case report.

INTRODUCTION: Posterior reversible encephalopathy syndrome (PRES) is characterized by the following symptoms: seizures, impaired consciousness and/or vision, vomiting, nausea, and focal neurological signs. Diagnostic imaging includes examination by magnetic resonance (MR) and computed tomography (CT), where brain edema is visualized bilaterally and symmetrically, predominantly posteriorly, parietally, and occipitally. CASE REPORT: We presented a 73-year-old patient with the years-long medical history of hypertension and renal insufficiency, who developed PRES with the symptomatology of the rear cranium. CT and MR verified changes in the white matter involving all lobes on both sides of the brain. After a two-week treatment (antihypertensive, hypolipemic and rehydration therapy) clinical improvement with no complications occurred, with complete resolution of changes in the white matter observed on CT and MR. CONCLUSION: PRES is a reversible syndrome in which the symptoms withdraw after several days to several weeks if early diagnosis is made and appropriate treatment started without delay.

Common features of the cerebral perforating arteries and their clinical significance.

BACKGROUND: The perforating vessels supply very important regions of the brain stem and diencephalon, as well as the basal ganglia and internal capsule. Some of their micro-anatomical characteristics are still not well known. The aim of this study was to examine and evaluate the features of all the perforating vessels. METHODS: The arteries of 24-32 cerebral hemispheres, diencephalons and halves of the brain stem were injected with India ink mixture or methylmethacrylate, and microdissection was performed or the vascular casts were produced and examined under the sterescopic microscope. RESULTS: It was noticed that the perforators ranged from 0 to 14 in number, with the smallest mean value (1.1) for the diencephalic perforators and the largest one (8.1) for the lenticulostriate arteries. The smallest mean diameter (175 µm) was found in the group of the perforators of the anterior communicating artery, whereas the largest one is related to the Heubner's artery (668 µm), the diencephalic thalamoperforating vessels (562 µm), the premamillary vessel (489 µm) and the lenticulostriate arteries (469 µm). The perforators most frequently originated from the pial branches of the basilar artery (91.7 %) and of the posterior cerebral artery (59.4 %). The common stems were most often formed by the perforators of the basilar (79.2 %), posterior cerebral (75.0 %) and middle cerebral arteries (40.6 %). Some perforators arose close to or from the terminal divisions, the branching sites or the junctions of the parent arteries, where the saccular aneurysms most often develop. The anastomoses among the perforators were present in a range from 6.3 % to 53.2 %. CONCLUSIONS: The micro-anatomical data obtained may be useful for neurosurgeons when operating at the base of the brain, as well as for a neurological and radiological evaluation of the perforators in the occlusive cerebrovascular disease, or in the cases of an aneurysm, arteriovenous malformation (AVM) or tumour presence.