Vascular malformations of the central nervous system.
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Arteriovenous Malformations↗
Biomedical subjects
D M Moody
Publications and source records attributed to D M Moody.
Periventricular venous collagenosis: association with leukoaraiosis.
PURPOSE: To investigate the association between an age-related degenerative disease of subependymal veins and leukoaraiosis. MATERIALS AND METHODS: Brains obtained at autopsy from 22 patients (average age, 73.2 years; range, 25-95 years) were examined with magnetic resonance (MR) imaging and neuropathologic methods with alkaline phosphatase microvascular staining. The degrees of leukoaraiosis shown on MR images and of deep venous occlusion were scored independently and results compared with logistic regression analysis. RESULTS: Noninflammatory collagenous thickening of venous walls resulting in severe periventricular venous stenosis was found in 13 (65%) of 20 patients over 60 years old. Advanced leukoaraiosis was found in 10 (77%) of these 13 patients. Greater venous disease was associated with more severe leukoaraiosis. CONCLUSION: Periventricular venous collagenosis, a commonly observed and previously ignored degenerative disease of elderly humans, is strongly associated with leukoaraiosis. Stenosis or occlusion of deep cerebral veins may promote development of leukoaraiosis.
Adult↗
Brain slice holder for MR.
We made an MR-compatible brain slice holder that ensures that the images have the same location and orientation as the subsequent histologic sections. This device encloses the unfixed tissues, thus reducing the danger of exposure to pathogens. MR imaging time is saved by scanning selected slices rather than the whole brain; this technique is especially useful when brain sections at varying angles, rather than parallel slices, are taken.
Brain↗
Flow phenomena in a cystic basal ganglia structure do not rule out a lacunar infarct.
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Arteries↗
Arteriolar tortuosity of the white matter in aging and hypertension. A microradiographic study.
Previous studies have shown tortuous arteries and arterioles in the brains of older people, but the effects of age and other factors have not been studied. To examine the effects of hypertension, age, race and sex on white matter (WM) arteriolar tortuosity (AT), we performed high-resolution microradiography and morphometry of human brains taken at autopsy from 44 subjects of various ages (range 30-96 years; 31 hypertensives/13 normotensives). About 70% of tortuosities in the WM were found at the gray-white interfaces of the insular region and adjacent subcortical-WM of the inferior frontal and superior temporal gyri. Six morphologic types of tortuous profiles were identified. The number of tortuous profiles increased with age, but not significantly. Hypertension, sex and race had no effect on tortuosity. Our findings also suggest that 1) WM AT is found mostly at the interfaces between gray matter and WM and, therefore, 2) the physical properties of the WM somehow predispose to the development of AT; 3) AT is not associated with tortuosity in the veins; and 4) the location of complex arteriolar coils supports a recent claim that they can be mistaken for the Charcôt-Bouchard microaneurysms if injection of contrast media and low-magnification radiography of the brain slices are employed for that purpose.
Adult↗
Air embolus risk with glass versus plastic syringes: in vitro study and implications for neuroangiography.
PURPOSE: To assess syringe use among neuroangiographers and evaluate air emboli produced with glass and plastic syringes. MATERIALS AND METHODS: Questionnaires on syringes use were sent to 100 members of the American Society of Neuroradiology (ASNR). An in vitro system counted emboli during injections of contrast material and saline solution with either glass or plastic syringes. At Doppler sonography, an embolic signal was defined as the power of the reflected amplitude with auditory and visual confirmation. RESULTS: Of 62 respondents, 11.3% used glass syringes exclusively and 80.6% used plastic exclusively. Glass breakage was experienced by 72.5%, and 40% of them recalled an injury associated with such a breakage. No statistically significant difference was found between glass and plastic syringes for introduction of air emboli, though two outlying values represented larger numbers of emboli in the group with plastic syringes and contrast material. CONCLUSION: No reason for the continued use of glass syringes was found. No statistically greater risk of air emboli was shown with plastic syringes, and risk of breakage and injury is prevented. Caution is advised when injecting contrast material with plastic syringes because more air emboli may be introduced.
Cerebral Angiography↗
Surrogate tissues for detecting brain microemboli after cardiopulmonary bypass.
During cardiopulmonary bypass (CPB) microemboli lodge in the brain and other organs. Microemboli were counted in tissue samples of skin, muscle and brain from autopsy cases that had recently undergone CPB, and in skin and muscle biopsies obtained from patients before and after CPB. Unlike the brain, skin and muscle showed few microemboli.
Biopsy↗
Alkaline phosphatase histochemical staining in the study of germinal matrix hemorrhage and brain vascular morphology in a very-low-birth-weight neonate.
We evaluated the utility of alkaline phosphatase (AP) histochemical staining for studying intraparenchymal vascular morphology in the brain of a 31-wk-gestation (1480 g) neonate who died of respiratory insufficiency after 23 h. In this baby, afferent cerebral vessels (arteries, arterioles, and capillaries) stained with AP, whereas efferent vessels (venules, veins) did not. The large periventricular channels in the germinal matrix were determined to be veins, according to AP staining criteria. Arterioles connected with these large periventricular veins after passing through 4- to 6-microns capillaries. Branchings and connections of the cerebral circulation were conventional; i.e. no arterial rete or arteriovenous shunts were found. With this method of differential vascular staining, bleeding in the germinal matrix was found to be perivenous only. No dilated capillaries or arterioles were seen. Smooth muscle was identified in extrastriatal medullary arteries. This preliminary investigation suggests that AP histochemical staining is an excellent method for studying brain vascular morphology and pathology of the very-low-birthweight neonate.
Adult↗
Microvascular density of the human paraventricular nucleus decreases with aging but not hypertension.
Microvascular density was determined in the supraoptic nuclei (SON) and paraventricular nuclei (PVN) of fixed brain tissue from 19 human subjects ranging in age from 30 to 85 years. Eight of these patients had hypertension. No sex- or hypertension-related differences in microvascular density were found in either the SON or PVN. However, capillary density decreased in the PVN with aging. These results indicate a differential pattern of microvascular loss in the human hypothalamus with aging.
Adult↗
Brain embolic phenomena associated with cardiopulmonary bypass.
Various biologic and non-biologic materials may be embolized to the brain after the use of cardiopulmonary bypass (CPB) pumps during open heart surgery but their relative frequency and importance are uncertain. Among the nonbiologic materials, Antifoam A, which contains organosilicates and silicon, continues to be employed as an additive to prevent frothing. Recent improvements in filtration and oxygenation techniques have clearly reduced the incidence of large emboli and complications like stroke but other neurologic sequelae following open heart surgery are common and in many cases poorly explained. A recently developed histochemical technique for the demonstration of the endothelial alkaline phosphatase (AP) was employed in a post-mortem study of brains from 8 patients and 6 dogs dying within a few days after open heart surgery employing cardiopulmonary bypass perfusion. Brains from 38 patients and 6 dogs who were not subjected to heart surgery were studied as controls with the same technique. The AP-stained slides are suitable for both light microscopic examination of the thick celloidin sections as well as a subsequent processing for high-resolution microradiography. Small capillary and arteriolar dilatations (SCADs) were seen in the test subjects/animals but not controls. SCADs were seen in all parts of the brain. Approximately 50% of the SCADs showed birefringence when examined with polarized light. SCADs are putative embolic phenomena and the exact nature and source of the embolic material is under investigation. A glycolipid component is indicated by preliminary studies. SCADs are difficult to find in routine paraffin sections and most if not all of the offending material seems to be dissolved during processing.(ABSTRACT TRUNCATED AT 250 WORDS)
Alkaline Phosphatase↗
The Charcôt-Bouchard aneurysm controversy: impact of a new histologic technique.
For over a century a controversy has existed about the prevalence and significance of Charcôt-Bouchard (C-B) aneurysms, especially regarding their relationship to intracerebral hemorrhage (ICH) in man. We reassessed C-B aneurysms by staining thick brain sections from 35 hypertensives and 20 normotensives with the alkaline phosphatase (AP) endothelial stain followed by light microscopy and high-resolution microradiography. Charcôt-Bouchard aneurysms were conspicuously absent in both groups which included four cases of hypertensive ICH. The three-dimensional perspective and enhanced ability to trace vessels with these techniques helped to identify arteriolar coils and twists that can be mistaken for aneurysms when demonstrated by injection methods. Routine brain pathologic sections from 2,800 autopsies over a decade showed rare examples of parenchymal aneurysms. We conclude that elimination in our study of a) injection artifacts and b) misinterpretations shows that C-B aneurysms are uncommon and have little relationship to ICH. Despite this, and in view of the original contribution of Charcôt and Bouchard, the occasional examples of brain parenchymal aneurysms should continue to bear their names.
Aged↗
Does tortuosity in cerebral arterioles impair down-autoregulation in hypertensives and elderly normotensives? A hypothesis and computer model.
A mathematical model of pressure/flow relationships in straight and tortuous intracerebral arterioles is presented. Using this model, it is predicted that patients with severe tortuosity would never be able to tolerate an appreciable decrease in MAP. This morphological alteration may explain the inability of a few hypertensive and normotensive elderly patients to tolerate periods of mild reductions in blood pressure. The alkaline phosphatase histochemical staining technique is potentially an excellent method of establishing the identity of deep white matter signal alterations seen on MRI because of its ability to trace the vascular supply from the brain surface to the lesion.
Aging↗
Brain microemboli during cardiac surgery or aortography.
We have observed many focal dilatations or very small aneurysms in terminal arterioles and capillaries of 4 of 5 patients and 6 dogs who had recently undergone cardiopulmonary bypass. A smaller number of sausagelike dilatations distended medium-sized arterioles. Two other patients had a small number of the same microvascular changes following proximal aortography. Thirty-four patients and 6 dogs not undergoing cardiopulmonary bypass had none. (A 35th patient who had not undergone cardiopulmonary bypass or aortography showed a small number of dilatations; mediastinal air was a suggested source.) Some of the dilatations exhibited various forms of birefringence. Because most of the dilatations appear empty, we speculate that they are the sites of gas bubbles or fat emboli that have been removed by the solvents used in processing. These microvascular events, occurring only in conjunction with major arterial interventions, may be the anatomical correlate of the neurological deficits or moderate to severe intellectual dysfunction seen in at least 24% of patients after cardiac surgical procedures assisted by cardiopulmonary bypass.
Adult↗
Sexual dimorphism of the human corpus callosum studied by magnetic resonance imaging: fact, fallacy and statistical confidence.
Magnetic resonance (MR) imaging was performed in 120 normal right-handed individuals (60 males, 60 females) to clarify existing contradictory data concerning possible sexual dimorphism of the human corpus callosum (CC). Five linear and three area measurements of the CC and brain were obtained directly at the MR scanner console from midline sagittal T1-weighted images. The anteroposterior length of the CC was significantly larger in males than in females (p = 0.0005). No other differences in absolute callosal measurements between the sexes could be demonstrated. However, several size ratios did achieve statistical significance (p less than 0.05), being consistently larger in females: splenial width/length CC, splenial width/brain length, and area of CC/area of brain. Where no statistically significant differences were obtained, precision, tolerance, and confidence interval calculations are presented. The data in this large series support a limited but definite sexual dimorphism of the CC in right-handed individuals.
Adult↗
Early cerebral infarction: gadopentetate dimeglumine enhancement.
Gadopentetate dimeglumine was administered prospectively to 50 patients who presented for magnetic resonance (MR) imaging within 2 weeks after a cortical cerebral infarction. Twenty-two patients (44%) were imaged within 3 days after clinical ictus. Abnormalities detected with gadopentetate dimeglumine enhancement were observed in 46 (92%) of 50 patients. Classic parenchymal enhancement was a late finding, observed in all patients (17 of 17) imaged at 7-14 days after infarction. Before this time, three additional phases of contrast material-related abnormalities were observed. Enhancement of vessels supplying the infarct ("intravascular enhancement sign") was the earliest finding, seen in 17 (77%) of 22 infarcts aged 1-3 days. From day 2 to day 6, abnormal enhancement of meninges adjacent to the infarct was frequently noted ("meningeal enhancement sign"). Finally, a transition phase that combined intravascular or meningeal enhancement with early parenchymal enhancement was seen from day 3 to day 6. Gadopentetate dimeglumine-enhanced MR imaging in early stroke reveals evidence of vascular engorgement and sluggish flow, which precede the development of classic parenchymal enhancement.
Brain↗
Features of the cerebral vascular pattern that predict vulnerability to perfusion or oxygenation deficiency: an anatomic study.
In an ongoing study of brain microvasculature in humans at autopsy, we had the opportunity to analyze the overall scheme of this vascular supply. The native endothelial membrane enzyme, alkaline phosphatase, is used to precipitate black lead sulfide salt in the vessel wall, rendering the brain microvasculature visible by both light microscopy and microradiography. There are six distinct patterns of intraparenchymal afferent blood supply to the supratentorial brain: short arterioles from a single source (e.g., those in the cortex); short- to intermediate-length arterioles, single source (anterior two-thirds of the corpus callosum); short- to intermediate length arterioles and arteries, dual source (subcortical U fibers); intermediate-length arterioles and arteries, triple source (extreme/external capsule and claustrum); long arteries and arterioles, single source (centrum semiovale); and large, long muscular arteries, single source (thalamus and basal ganglia). The nature of this arrangement offers some protection to certain regions of the cerebrum from circulatory challenges such as hypotension, while leaving other areas vulnerable. The distal arterioles supplying two of these protected regions, the U-fiber area and the extreme/external capsule and claustrum area, also exhibit the feature of interdigitation, which can offer additional collateral potential from one arteriolar territory to the next. Aging, hypertension, diabetes mellitus, and atherosclerosis can have a significant impact on brain microcirculation. The way in which vascular patterns dictate the distribution of these effects is discussed. The ability to stain the cerebral microvessels and demonstrate the finer points of their patterns in sections and microradiographs has enabled us to resolve some long-standing questions about vascular connections and directions.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
Is Gd-DTPA required for routine cranial MR imaging?
Gadopentetate dimeglumine (gadolinium diethylenetriaminepentaacetic acid [DTPA]) was administered prospectively to 500 consecutive children and adults referred for routine cranial magnetic resonance (MR) imaging over a 4-month period. Pre- and postcontrast images were blindly and independently interpreted by two experienced neuroradiologists. Specific criteria were provided to the readers to define objectively when contrast material enhancement (or lack thereof) would be considered "radiologically helpful." Contrast-enhancing lesions were observed in 99 cases (20%). In only 15 cases (3%) did Gd-DTPA permit detection of lesions not also apparent on the precontrast studies. Contrast enhancement was considered radiologically helpful in 74 of the 99 cases. Lack of enhancement was considered helpful in 112 of the 500 cases (22%). Factors that may indicate increased usefulness of Gd-DTPA include increased patient age, definite lesion seen at computed tomography or precontrast MR imaging, prior craniotomy for tumor, and clinically documented systemic or central nervous system disease. Gd-DTPA should probably be used routinely for cranial MR imaging in most patients, except, perhaps, children and young adults with normal precontrast images.
Adolescent↗
The value of magnetic resonance imaging in the detection of type II hemorrhagic lacunes.
Lacunar infarcts (lacunes) are small necrotic/cystic lesions of the brain associated with hypertension. Many are clinically silent, but some are associated with localizing symptoms and signs. Lacunes recently were classified into three types, namely, those resulting from small infarcts (type I), those arising as small hemorrhages (type II), and those due to dilatation of perivascular spaces (type III). The type II lacunes are thought to be much less common than those of type I. Type II lacunes have not previously been reported during life. We report a case of subacute type II lacune in the pontine tegmentum that was detected by magnetic resonance imaging and later verified by histopathologic examination. The patient was hypertensive and had numerous other type I lacunes. This case shows that the magnetic resonance imaging features of hemorrhagic lacunes are identical to those of small hemorrhages or small hemorrhagic infarcts and that magnetic resonance imaging is a useful tool in the detection of lacunes and their correlation with clinical neurologic symptoms and signs.
Aged↗