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.

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.

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.

Infantile chronic subdural hematoma of the posterior fossa diagnosed by computerized tomography

1977 ◽  
Vol 47 (6) ◽  
pp. 949-952 ◽  
Author(s):  
Barry N. French ◽  
Arthur B. Dublin
Keyword(s):  
White Matter ◽  
Brain Stem ◽  
Computerized Tomography ◽  
Posterior Fossa ◽  
Subdural Hematoma ◽  
Chronic Subdural Hematoma ◽  
Cerebral White Matter ◽  
Hounsfield Units ◽  
Content Type ◽  
The Brain

✓ A 9-week-old infant manifested continuous vomiting for 1 week accompanied by a tense fontanel, “sun setting” of the eyes, frequent opisthotonos, and hypertonicity. The head circumference was at the 50th percentile. Computerized tomography (CT) revealed acute hydrocephalus and a posterior fossa subdural hematoma. The brain stem and cerebellum were of greater density (54 Hounsfield units) than normal cerebral white matter (42 Hounsfield units) whereas the subdural hematoma was the same density as normal cerebral white matter (“isodense”). The cerebellum and brain stem became enhanced by contrast (68 Hounsfield units), but no enhancement occurred in the cerebral white matter or subdural hematoma. A shunt followed by occipital craniectomy resolved both the hydrocephalus and subdural hematoma. Repeat CT scan 15 days postoperatively disclosed continuing higher density of the cerebellum and brain stem (60 Hounsfield units) relative to cerebral white matter. Increased density of the infantile cerebellum has been noted previously but not to the same extent as in this patient.

Reconstitution of shunted mantle in experimental hydrocephalus

1992 ◽  
Vol 76 (5) ◽  
pp. 856-862 ◽  
Author(s):  
Haruyuki Yamada ◽  
Akira Yokota ◽  
Akiko Furuta ◽  
Akio Horie
Keyword(s):  
White Matter ◽  
Histopathological Examination ◽  
Nerve Fibers ◽  
Ct Scans ◽  
Periventricular White Matter ◽  
Content Type ◽  
Experimental Hydrocephalus ◽  
Successful Recovery ◽  
Ventricular Shunting ◽  
Fine Print

✓ The morphological mechanism of the reconstitution of shunted mantle was studied histopathologically in 22 kaolin-treated hydrocephalic puppies. A remarkable attenuation of cerebral mantle to less than 1 cm in thickness was seen on computerized tomography (CT) scans of four animals sacrificed 1 to 2 months after kaolin treatment (preshunt group). Ventricular shunting resulted in successful recovery of the mantle on repeated CT scans obtained 1 to 2 months after shunting in seven animals (postshunt group). In the remaining 11 animals the cerebral mantle, which had been reduced to 4 mm in thickness prior to shunting, failed to recover even 2 months after the procedure (shunt-refractory group). On gross inspection, the preshunt specimens showed marked thinning of the white matter, with the cortical ribbon well preserved, while the postshunt specimens consisted predominantly of thickened white matter. Histopathological examination of the attenuated white matter of the preshunt specimens showed decreased nerve-fiber density, myelin destruction with myelin regeneration and/or repair of myelin sheaths, and reactive astrocytosis, which were prominent especially in the periventricular white matter. The main findings in the reconstituted white matter of the postshunt specimens were extensive myelin regeneration of residual axons and remarkable astroglial proliferation with mesenchymal reaction, particularly at capillaries. No clear evidence of increased numbers of nerve fibers or axonal regeneration was observed. The shunt-refractory specimens showed remarkable attenuation of cortex, in which reduced numbers of neurons and loss of cortical lamination were noted, with vestigial white matter. The results indicate that astroglial proliferation with mesenchymal reaction and myelin regeneration contribute to the reconstitution of the cerebral mantle volume following ventricular shunting in this model. It is suggested that the critical factor for mantle reconstitution in chronic hydrocephalus is whether cortex is preserved.

The effect of mannitol on cerebral white matter water content

1986 ◽  
Vol 65 (1) ◽  
pp. 41-43 ◽  
Author(s):  
Fred Nath ◽  
Sam Galbraith
Keyword(s):  
White Matter ◽  
Head Injury ◽  
Specific Gravity ◽  
Water Content ◽  
Subcortical White Matter ◽  
Cerebral White Matter ◽  
Brain Water Content ◽  
Content Type ◽  
The Brain ◽  
Brain Water

✓ The authors have studied the effect of a low-dose (0.28 gm/kg) bolus infusion of mannitol on brain water in man. In eight patients with severe head injury, small pieces of subcortical white matter were taken at craniotomy both before and after infusion of mannitol. The tissue specific gravity was measured using a graduated specific-gravity column, and from it the brain water content was calculated. White matter specific gravity rose from a mean (± standard error of the mean) of 1.0325 ± 0.0012 before mannitol infusion to 1.0352 ± 0.0011 after mannitol administration, and the brain water content fell from a mean of 80.94% ± 2.5% to 75.28% ± 2.3%. The differences were significant (p < 0.01). This study shows that, after head injury in man, mannitol increases the white matter specific gravity and probably does so by reducing brain water.

Cervical spinal cord in experimental hydrocephalus

1972 ◽  
Vol 37 (5) ◽  
pp. 538-542 ◽  
Author(s):  
George J. Dohrmann
Keyword(s):  
Spinal Cord ◽  
Brain Stem ◽  
Cervical Spinal Cord ◽  
Central Canal ◽  
Content Type ◽  
Experimental Hydrocephalus ◽  
Physiological Pressure ◽  
The Brain ◽  
Shunting Procedure ◽  
Fine Print

✓ Adult dogs were rendered hydrocephalic by the injection of kaolin into the cisterna magna. One group of dogs was sacrificed 1 month after kaolin administration, and ventriculojugular shunts were performed on the other group. Hydrocephalic dogs with shunts were sacrificed 1 day or 1 week after the shunting procedure. All dogs were perfused with formalin at physiological pressure, and the brain stem and cervical spinal cord were examined by light microscopy. Subarachnoid granulomata encompassed the superior cervical spinal cord and dependent surface of the brain stem. Rarefaction of the posterior white columns and clefts or cavities involving the gray matter posterior to the central canal and/or posterior white columns were present in the spinal cords of both hydrocephalic and shunted hydrocephalic dogs. Predominantly in the dogs with shunts, hemorrhages were noted in the spinal cord in association with the clefts or cavities. A mechanism of ischemia followed by reflow of blood is postulated to explain the hemorrhages in the spinal cords of hydrocephalic dogs with shunts.

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.

Xenon-enhanced CT CBF measurements in cerebral AVM's before and after excision

1983 ◽  
Vol 59 (1) ◽  
pp. 21-31 ◽  
Author(s):  
Takashi Okabe ◽  
John S. Meyer ◽  
Hiroyuki Okayasu ◽  
Richard Harper ◽  
James Rose ◽  
...  
Keyword(s):  
White Matter ◽  
Neurological Deficits ◽  
Total Excision ◽  
Content Type ◽  
Ventriculoperitoneal Shunting ◽  
Normal Individuals ◽  
Enhanced Ct ◽  
Before And After ◽  
Method Of Measurement ◽  
Cerebral Steal

✓ Unlike neurological deficits resulting from intracranial hemorrhage in patients with cerebral arteriovenous malformation (AVM), which have well defined etiology, the pathogenesis and treatment of progressive and/or fluctuating non-hemorrhagic neurological and psychological deficits require clarification. Values for local cerebral blood flow (LCBF) and local partition coefficients (Lγ) were measured by the method using stable xenon (Xe)-computerized tomography (CT-CBF) scanning, and were compared to 133Xe inhalation values using external probes in 16 patients with cerebral AVM's. Values were measured by both methods before and after total excision of AVM's in five cases. Neurological and mental status assessments were compared with LCBF results. Clinical improvement was most evident after total excision of AVM's. Other procedures, such as clipping of vessels, partial excision, and ventriculoperitoneal shunting for hydrocephalus, were associated with frequent complications. Embolization carried risks of cerebral infarction and was not efficacious unless combined with excision. Medical treatment resulted in poor or unsuccessful seizure control, with neurological deterioration despite anticonvulsant therapy. Compared with age-matched normal individuals, LCBF values in patients with AVM's were significantly reduced, particularly adjacent to the AVM's. Mean Lγ values for gray and white matter were normal. After excision, LCBF values in gray and white matter increased significantly up to normal. Due to overestimation of CBF by shunt flow with the 133Xe method of measurement, no correlation was found with results of the CT-CBF method before AVM excision, but significant correlation of the two methods resulted after excision. If accurate LCBF values are obtained by high resolution, direct measurement of tracer clearance from brain tissue, progressive and/or fluctuating neuropsychological deficits correlate with the degree of cerebral steal.

Composition of isolated edema fluid in cold-induced brain edema

1979 ◽  
Vol 51 (1) ◽  
pp. 70-77 ◽  
Author(s):  
Jurjen Gazendam ◽  
K. Gwan Go ◽  
Annie K. van Zanten
Keyword(s):  
Cerebrospinal Fluid ◽  
White Matter ◽  
Brain Edema ◽  
Vasogenic Edema ◽  
Colloid Osmotic Pressure ◽  
Freezing Damage ◽  
Content Type ◽  
Edema Fluid ◽  
The Brain ◽  
Fine Print

✓ Edema fluid isolated from cats with cold-induced brain edema was subjected to analysis of electrolyte content, enzyme activities, colloid osmotic pressure and the radioactivity of intravenously injected 99mTc-labeled albumin. The findings corroborate the essential features of vasogenic edema, such as its origin from the blood plasma, its rapid propagation into the white matter of the brain as contrasted with the delayed spread into gray matter, and its contribution to composition of cerebrospinal fluid. Moreover, the elevated activities of cellular enzymes and K+ content of edema fluid point to the admixture with cellular contents due to the freezing damage.

Altered diffusion and perfusion in hydrocephalic rat brain: a magnetic resonance imaging analysis

2000 ◽  
Vol 92 (3) ◽  
pp. 442-447 ◽  
Author(s):  
Eric M. Massicotte ◽  
Richard Buist ◽  
Marc R. Del Bigio
Keyword(s):  
Magnetic Resonance Imaging ◽  
White Matter ◽  
Magnetic Resonance ◽  
Rat Brain ◽  
Relaxation Times ◽  
Resonance Imaging ◽  
Waste Products ◽  
Content Type ◽  
Experimental Hydrocephalus ◽  
Fine Print

Object. It can be inferred from data published in the literature that brain compression occurs in the early stages of acute hydrocephalus and that drainage of extracellular waste products is impaired. The authors hypothesized that compression of the cortex would alter water distribution and retard the diffusion of fluid in the hydrocephalic brain.Methods. Proton diffusion, blood perfusion, and T1 and T2 relaxation times were determined in adult rat brain by using magnetic resonance imaging prior to, and 1 and 8 days after induction of hydrocephalus by kaolin injection. Five anatomical regions of interest were studied. The striatum, dorsal cortex, and lateral cortex exhibited decreased T2 and apparent diffusion coefficient (ADC) values but no change in perfusion. Examination of white matter revealed an initial decrease in ADC followed by a significant increase. The T2 relaxation times increased and perfusion decreased progressively between 1 and 8 days after induction of hydrocephalus.Conclusions. Acute experimental hydrocephalus causes compression of gray matter, perhaps associated with reduction in total water, which impairs diffusion of water in the tissue. White matter compression and hypoperfusion precede the development of edema. These findings have importance for understanding the neurochemical changes that occur in hydrocephalic brains.

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