Pathophysiology of periventricular tissue changes with raised CSF pressure in cats

1983 ◽  
Vol 59 (4) ◽  
pp. 606-611 ◽  
Author(s):  
Gary A. Rosenberg ◽  
Linda Saland ◽  
Walter T. Kyner
Keyword(s):  
Blood Flow ◽  
Steady State ◽  
White Matter ◽  
Caudate Nucleus ◽  
Clinical Symptoms ◽  
Periventricular White Matter ◽  
Content Type ◽  
Acute Hydrocephalus ◽  
Tissue Changes ◽  
Adult Cats

✓ Intraventricular pressure (IVP) is increased in the early stages of acute hydrocephalus. Pressure falls, however, when compensatory routes for cerebrospinal fluid (CSF) absorption develop. In order to better understand the pathophysiology of acute hydrocephalus, the authors performed ventriculocisternal perfusions on adult cats with outflow pressures maintained at either −5, 20, or 40 cm H2O. Cerebral blood flow (CBF) was determined by the iodoantipyrine method. Penetration of an extracellular marker, horseradish peroxidase (HRP), was visualized histologically. Capillary transfer of radiolabeled molecules from CSF to blood was measured by steady-state tissue clearance. Increased IVP had several effects: 1) significant reduction in mean CBF in the periventricular white matter; 2) penetration of the HRP into deep white matter; and 3) prolongation of steady-state tissue clearance half-time for (14C)-ethylene glycol in the caudate nucleus. Reduced blood flow to periventricular white matter and impaired molecular clearance in the caudate nucleus may contribute to the clinical symptoms in acute hydrocephalus.

Brain blood volume and blood flow in patients with plateau waves

1985 ◽  
Vol 63 (4) ◽  
pp. 556-561 ◽  
Author(s):  
Minoru Hayashi ◽  
Hidenori Kobayashi ◽  
Yuji Handa ◽  
Hirokazu Kawano ◽  
Masanori Kabuto
Keyword(s):  
Blood Flow ◽  
Caudate Nucleus ◽  
Frontal Lobe ◽  
Blood Volume ◽  
Temporal Lobe ◽  
Clinical Symptoms ◽  
Systemic Blood Pressure ◽  
Content Type ◽  
Rapid Sequence ◽  
Plateau Waves

✓ Plateau waves, characterized by acute transient rises of the intracranial pressure (ICP), are accompanied by a marked decrease of the cerebral perfusion pressure. Patients with plateau waves, however, often show no clinical symptoms of ischemia of the brain stem, such as vasopressor response or impairment of consciousness during the waves. The authors studied brain blood volume and blood flow with dynamic computerized tomography using rapid-sequence scanning in patients with plateau waves identified during continuous ICP recording. Following an intravenous bolus injection of contrast medium, density-versus-time curves were obtained for the regions of interest; that is, the frontal lobe, the temporal lobe, the caudate nucleus, the putamen, and the pons. The dynamic studies were undertaken when the ICP was high during a plateau-wave phase and when it was low during an interval phase between two plateau waves. The results indicate that, in the cerebral hemisphere (frontal lobe, temporal lobe, caudate nucleus, and putamen), plateau waves were accompanied by an increase in blood volume and, at the same time, a decrease in blood flow. In the pons, however, both the blood volume and blood flow showed little change during plateau waves as compared with the intervals between two plateau waves. These observations may explain why there is no rise in the systemic blood pressure and why patients are often alert during plateau waves.

Beagle pup model of brain injury: regional cerebral blood flow and cerebral prostaglandins

1987 ◽  
Vol 67 (2) ◽  
pp. 278-283 ◽  
Author(s):  
Laura R. Ment ◽  
William B. Stewart ◽  
Charles C. Duncan ◽  
Bruce R. Pitt ◽  
Judith Cole
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Brain Injury ◽  
White Matter ◽  
Regional Cerebral Blood Flow ◽  
Ventilatory Support ◽  
Periventricular White Matter ◽  
Regional Cerebral Blood ◽  
Content Type ◽  
Carbon 14

✓ Asphyxia is the most common cause of severe brain injury in very young children, and frequently results in lesions of the periventricular white matter in addition to other neuropathological changes. This study examines the effects of asphyxia on regional cerebral blood flow (rCBF) and the role of prostaglandins (PG's) in its control in the newborn beagle pup. Pups were anesthetized, tracheotomized, paralyzed, artificially ventilated, and randomly assigned to two groups: asphyxial insult produced by discontinuing ventilatory support, and no insult. Experiments for carbon-14-iodoantipyrine autoradiographic determination of rCBF and regional cerebral PG determination were performed on separate groups of pups. These studies demonstrated a significant increase in cortical gray PGE2 levels at a time when rCBF was significantly impaired in response to severe asphyxial insult. No such increase was noted in the periventricular white matter zones.

Evaluation of periventricular hypodensity in experimental hydrocephalus by metrizamide CT ventriculography

1982 ◽  
Vol 56 (2) ◽  
pp. 235-240 ◽  
Author(s):  
Hideo Hiratsuka ◽  
Hitoshi Tabata ◽  
Shin Tsuruoka ◽  
Masaru Aoyagi ◽  
Kodai Okada ◽  
...  
Keyword(s):  
White Matter ◽  
Specific Gravity ◽  
Iodine Concentration ◽  
Periventricular White Matter ◽  
Hounsfield Units ◽  
Content Type ◽  
Experimental Hydrocephalus ◽  
Enhanced Ct ◽  
Kaolin Injection ◽  
The Brain

✓ Hydrocephalus was induced in 13 dogs by injecting kaolin into the cisterna magna and was evaluated by computerized tomography (CT) scans. Modification of periventricular hypodensity was observed by metrizamide-enhanced CT ventriculography. Periventricular hypodensity was seen as early as 12 hours after kaolin injection. On CT ventriculography, metrizamide stayed longer in the ventricles of hydrocephalic dogs than in those of normal dogs, and migrated into the areas of periventricular hypodensity; the changes became significant within 12 to 24 hours. Four of the dogs were killed immediately after CT ventriculography, and the iodine concentration was measured. Iodine concentration was highest in the periventricular white matter, followed by the basal ganglia, and it was low in the cerebral and cerebellar cortex. When the change in Hounsfield units found by CT ventriculography at the regions of interest was compared to the actual iodine concentrations, the figures were quite compatible. Similarly, the specific gravity was measured in tissue from various parts of the brain of two hydrocephalic dogs, and compared against the value of that from five normal dogs. The specific gravity values were particularly low in the periventricular white matter of the hydrocephalic brains, suggesting a higher water content in that region. Since the increased migration of metrizamide occurred at the same region, it is suggested that development of periventricular hypodensity is due to increased transit of cerebrospinal fluid from the ventricles to the white matter.

scholarly journals Cerebral Blood Flow Heterogeneity in Preterm Sheep: Lack of Physiologic Support for Vascular Boundary Zones in Fetal Cerebral White Matter

2007 ◽  
Vol 28 (5) ◽  
pp. 995-1008 ◽  
Author(s):  
Melissa M McClure ◽  
Art Riddle ◽  
Mario Manese ◽  
Ning Ling Luo ◽  
Dawn A Rorvik ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
White Matter ◽  
Ischemia Reperfusion ◽  
Three Dimensional ◽  
Cerebral White Matter ◽  
Periventricular White Matter ◽  
Fetal Sheep ◽  
Border Zones ◽  
Neurologic Disability

Periventricular white matter (PVWM) injury is the leading cause of neurologic disability in survivors of prematurity. To address the role of ischemia in PVWM and cerebral cortical injury, we hypothesized that immaturity of spatially distal vascular ‘end zones’ or ‘border zones’ predisposes PVWM to greater decreases in cerebral blood flow (CBF) than more proximal structures. We quantified regional CBF with fluorescently labeled microspheres in 0.65 gestation fetal sheep in histopathologically defined three-dimensional regions by post hoc digital dissection and coregistration algorithms. Basal flow in PVWM was significantly lower than in gyral white matter and cortex, but was equivalent in superficial, middle, and deep PVWM. Absolute and relative CBF (expressed as percentage of basal) did not differ significantly during ischemia or reperfusion between PVWM, gyral white matter, or cortex. Moreover, CBF during ischemia-reperfusion was equivalent in three adjacent PVWM levels and was not consistent with the magnitude of severity of PVWM injury, defined by TUNEL (terminal deoxynucleotidyltransferase-mediated dUPT nick end labeling) staining. However, the magnitude of ischemia was predicted by the severity of discrete cortical lesions. Hence, unlike cerebral cortex, unique CBF disturbances did not account for the distribution of PVWM injury. Previously defined cellular maturational factors, thus, appear to have a greater influence on PVWM vulnerability to ischemic injury than the presence of immature vascular boundary zones.

Infantile hydrocephalus: clinical, histological, and ultrastructural study of brain damage

1972 ◽  
Vol 36 (3) ◽  
pp. 255-265 ◽  
Author(s):  
R. O. Weller ◽  
Kenneth Shulman
Keyword(s):  
White Matter ◽  
Axonal Degeneration ◽  
Acute Stage ◽  
Periventricular White Matter ◽  
Infantile Hydrocephalus ◽  
Shunt Insertion ◽  
Content Type ◽  
Experimental Hydrocephalus ◽  
Histological Appearance ◽  
Human Material

✓ Cerebral biopsies were taken from five hydrocephalic infants at the time of primary ventricular shunt insertion. The histological appearance of the biopsies have been correlated with the children's subsequent intellectual and neurological development. In addition, the known sequence of histological events in puppies with experimental hydrocephalus has been correlated with an interpretation of the human material. One child showed periventricular white matter edema and sporadic axonal degeneration characteristic of the acute stage of experimental hydrocephalus in young dogs; this patient developed normally. Biopsies from the other children were not edematous but showed the extensive astrocytosis of white matter seen in long-standing hydrocephalus in young dogs. These children all showed mental retardation. The implications of these clinicopathological results for the treatment of hydrocephalic children are discussed.

Effect of aminophylline and isoproterenol on spinal cord blood flow after impact injury

1980 ◽  
Vol 53 (3) ◽  
pp. 385-390 ◽  
Author(s):  
Diana Dow-Edwards ◽  
Vincent DeCrescito ◽  
John J. Tomasula ◽  
Eugene S. Flamm
Keyword(s):  
Spinal Cord ◽  
Blood Flow ◽  
White Matter ◽  
Cord Blood ◽  
Gray Matter ◽  
Adenosine Monophosphate ◽  
Spinal Cord Blood Flow ◽  
Content Type ◽  
Cord Injury ◽  
Matter Flow

✓ A study of the effects of spinal cord injury upon spinal cord blood flow was carried out in cats. A 400 gm-cm impact produced an overall reduction in spinal cord blood flow of 24% in the white matter and 30% in the gray matter, as determined by 14C-antipyrine autoradiography. At the level of the injury, white-matter flow was 8.1 ml/100 gm/min, a reduction of 49%, and in the gray matter, 12.5 ml/100 gm/min, a reduction of 76%. Treatment with aminophylline and isoproterenol improved the overall blood flow in the spinal cord. At the level of the injury, white-matter flow after this treatment was no longer significantly different from control values. The gray-matter flow remained decreased to 26.2 ml/100 gm/min, a reduction of only 47%. It is proposed that aminophylline and isoproterenol may increase cyclic adenosine monophosphate (AMP) and prevent platelet aggregation along the endothelial surfaces of the microcirculation, and may thereby help to maintain improved perfusion of the injured spinal cord.

Effects of methylprednisolone on peritumoral brain edema

1983 ◽  
Vol 59 (4) ◽  
pp. 612-619 ◽  
Author(s):  
Kazuo Yamada ◽  
Yukitaka Ushio ◽  
Toru Hayakawa ◽  
Norio Arita ◽  
Noriko Yamada ◽  
...  
Keyword(s):  
Blood Flow ◽  
Brain Edema ◽  
Capillary Permeability ◽  
Clinical Symptoms ◽  
Treated Group ◽  
Untreated Group ◽  
Content Type ◽  
Intracerebral Transplantation ◽  
Edema Fluid ◽  
Peritumoral Brain Edema

✓ Peritumoral brain edema was produced by intracerebral transplantation of Walker 256 tumor in rats. Local cerebral blood flow (LCBF), local cerebral glucose utilization (LCGU), and capillary permeability were studied in untreated and methylprednisolone-treated rats by quantitative autoradiography. In the untreated group, LCBF and LCGU were widely depressed in the cortex and deep structures of the hemisphere ipsilateral to the tumor. In the methylprednisolone-treated animals, LCBF and LCGU were significantly better than in the untreated animals. Capillary permeability was highly increased in the viable part of the tumor in the untreated animals. In the methylprednisolone-treated group, capillary permeability of the tumor was significantly lower than that in the untreated group. These results may suggest that increase in capillary permeability of the tumor is the major source for edema fluid production, and that methylprednisolone improves brain edema by decreasing capillary permeability of the tumor. Decrease in edema fluid formation may result in restoration of blood flow and glucose metabolism in the adjacent brain tissue, and may improve clinical symptoms and signs.

Beagle puppy model of perinatal cerebral infarction

1985 ◽  
Vol 63 (3) ◽  
pp. 441-447 ◽  
Author(s):  
Laura R. Ment ◽  
William B. Stewart ◽  
Charles C. Duncan ◽  
Bruce R. Pitt ◽  
Aldo Rescigno ◽  
...  
Keyword(s):  
White Matter ◽  
Cerebral Infarction ◽  
Perinatal Asphyxia ◽  
Prostaglandin E ◽  
Periventricular White Matter ◽  
Central Gray Matter ◽  
Content Type ◽  
Carbon 14 ◽  
Arterial Blood ◽  
Central Gray

✓ Asphyxia, with its attendant hypotension, is by far the most common cause of neonatal cerebral infarction and frequently results in lesions of the parieto-occipital white matter. This study examines the effects of hypotension on regional cerebral blood flow (CBF), local cerebral glucose utilization (LCGU), and serum prostaglandin levels in newborn beagle pups. The animals (24 to 96 hours old) were anesthetized, tracheotomized, and paralyzed. Pups were randomly divided into two groups: one was subjected to hemorrhagic hypotension and the other received no insult. Hypotension was induced by slow venous hemorrhage to maintain a mean arterial blood pressure of 20 to 30 mm Hg. Autoradiographic determinations of LCGU using carbon-14 (14C)-2-deoxyglucose were performed 45 minutes after randomization to groups. Autoradiographic determinations of CBF were performed using 14C-iodoantipyrine on a second group of pups 15 minutes after randomization. Prostaglandins were measured immediately before and 15 minutes after insult or control manipulation. There were no significant differences in the values for thromboxane B2 or 6-keto-prostaglandin F1α, the stable breakdown products of thromboxane A2, and prostacyclin. Prostaglandin E2 levels significantly increased in response to hemorrhagic hypotensive insult. In addition, although regional CBF was maintained in cortical and central gray matter structures during hypotension, CBF to the periventricular temporal and parietal white matter zones significantly decreased, and LCGU was increased in these same regions during hypotensive insult. The uncoupling of CBF and metabolism in these periventricular white matter regions may be responsible for the neuropathological sequelae of perinatal asphyxia.

Protective effect of nimodipine on behavior and white matter of rats with hydrocephalus

2001 ◽  
Vol 94 (5) ◽  
pp. 788-794 ◽  
Author(s):  
Marc R. Del Bigio ◽  
Eric M. Massicotte
Keyword(s):  
White Matter ◽  
Protective Effect ◽  
Treatment Period ◽  
Calcium Influx ◽  
Periventricular White Matter ◽  
Cognitive Behavior ◽  
Continuous Administration ◽  
Content Type ◽  
Experimental Hydrocephalus ◽  
Fine Print

Object. Hydrocephalus, a pathological dilation of the ventricles of the brain, causes damage to periventricular white matter, at least in part, through chronic ischemia. The authors tested the hypothesis that treatment with nimodipine, an L-type calcium channel-blocking agent with demonstrated efficacy in a range of cerebral ischemic disorders, would ameliorate the adverse effects of experimental hydrocephalus. Methods. Hydrocephalus was induced in 3-week-old rats by injection of kaolin into the cisterna magna. The rats were treated by continuous administration of nimodipine or control vehicle for 2 weeks, beginning 2 weeks after induction of hydrocephalus. During the treatment period, the animals underwent repeated tests of motor and cognitive behavior. At the end of the treatment period, the rat brains were analyzed by histopathological and biochemical means. Nimodipine treatment prevented the declines in motor and cognitive behavior that were observed in untreated control rats. During the treatment period, ventricular enlargement, determined by magnetic resonance imaging, was equal in the two groups, although the corpus callosum was thicker in the treated rats. Myelin content in white matter and synaptophysin content in gray matter, an indicator of synapses, did not differ. Conclusions. The protective effect of nimodipine is most likely based on improved blood flow, although prevention of calcium influx—mediated proteolytic processes in axons cannot be excluded. Adjunctive pharmacological therapy may be beneficial to patients with hydrocephalus.

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