On the movement of fluid through the brain of hydrocephalie cats

Marlin, Arthur E.; Wald, Abraham; Hochwald, G. M.; Malhan, C.

doi:10.1212/wnl.26.12.1159

Cited by 4 publications

(2 citation statements)

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“…[33] The mechanism of action may involve the maintenance of oncotic pressure and scavenging of toxic substances present in blood, which reduces the risk of intracellular edema and neurological injury. [34] In addition, lower albumin levels may occur in cases of malnutrition, which has been linked to decreased DTI indices in liver cirrhosis. [35] Our findings suggest that microstructural changes that result from cerebral edema might arise from decreases in albumin levels, and may reverse during clinical recovery.…”

Section: Discussionmentioning

confidence: 99%

Longitudinal Brain White Matter Alterations in Minimal Hepatic Encephalopathy before and after Liver Transplantation

Lin

Chou²,

Chen

et al. 2014

PLoS ONE

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Cerebral edema is the common pathogenic mechanism for cognitive impairment in minimal hepatic encephalopathy. Whether complete reversibility of brain edema, cognitive deficits, and their associated imaging can be achieved after liver transplantation remains an open question. To characterize white matter integrity before and after liver transplantation in patients with minimal hepatic encephalopathy, multiple diffusivity indices acquired via diffusion tensor imaging was applied. Twenty-eight patients and thirty age- and sex-matched healthy volunteers were included. Multiple diffusivity indices were obtained from diffusion tensor images, including mean diffusivity, fractional anisotropy, axial diffusivity and radial diffusivity. The assessment was repeated 6–12 month after transplantation. Differences in white matter integrity between groups, as well as longitudinal changes, were evaluated using tract-based spatial statistical analysis. Correlation analyses were performed to identify first scan before transplantation and interval changes among the neuropsychiatric tests, clinical laboratory tests, and diffusion tensor imaging indices. After transplantation, decreased water diffusivity without fractional anisotropy change indicating reversible cerebral edema was found in the left anterior cingulate, claustrum, postcentral gyrus, and right corpus callosum. However, a progressive decrease in fractional anisotropy and an increase in radial diffusivity suggesting demyelination were noted in temporal lobe. Improved pre-transplantation albumin levels and interval changes were associated with better recoveries of diffusion tensor imaging indices. Improvements in interval diffusion tensor imaging indices in the right postcentral gyrus were correlated with visuospatial function score correction. In conclusion, longitudinal voxel-wise analysis of multiple diffusion tensor imaging indices demonstrated different white matter changes in minimal hepatic encephalopathy patients. Transplantation improved extracellular cerebral edema and the results of associated cognition tests. However, white matter demyelination may advance in temporal lobe.

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Section: Discussionmentioning

confidence: 99%

Longitudinal Brain White Matter Alterations in Minimal Hepatic Encephalopathy before and after Liver Transplantation

Lin

Chou²,

Chen

et al. 2014

PLoS ONE

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“…Aquaporin 4 null mice, which develop hydrocephalus, have intact BBB as judged by intravenous injection of Evans blue dye (which forms a complex with plasma albumin, MW 69 kDa) [17]. Perfusion of 125 I-albumin (MW 69 kDa) or type II horseradish peroxidase (HRP; MW ~44 kDa) into the ventricles of cats with kaolin-induced hydrocephalus revealed no reverse flow across the BBB [18,19]. Similarly, in rats with kaolin-induced hydrocephalus, neither HRP nor microperoxidase (MW 1905 Da) injected into the ventricle crossed the endothelium.…”

Section: Introductionmentioning

confidence: 99%

Magnetic resonance imaging indicators of blood-brain barrier and brain water changes in young rats with kaolin-induced hydrocephalus

Bigio

Slobodian

Schellenberg

et al. 2011

Fluids Barriers CNS

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BackgroundHydrocephalus is associated with enlargement of cerebral ventricles. We hypothesized that magnetic resonance (MR) imaging parameters known to be influenced by tissue water content would change in parallel with ventricle size in young rats and that changes in blood-brain barrier (BBB) permeability would be detected.MethodsHydrocephalus was induced by injection of kaolin into the cisterna magna of 4-week-old rats, which were studied 1 or 3 weeks later. MR was used to measure longitudinal and transverse relaxation times (T1 and T2) and apparent diffusion coefficients in several regions. Brain tissue water content was measured by the wet-dry weight method, and tissue density was measured in Percoll gradient columns. BBB permeability was measured by quantitative imaging of changes on T1-weighted images following injection of gadolinium diethylenetriamine penta-acetate (Gd-DTPA) tracer and microscopically by detection of fluorescent dextran conjugates.ResultsIn nonhydrocephalic rats, water content decreased progressively from age 3 to 7 weeks. T1 and T2 and apparent diffusion coefficients did not exhibit parallel changes and there was no evidence of BBB permeability to tracers. The cerebral ventricles enlarged progressively in the weeks following kaolin injection. In hydrocephalic rats, the dorsal cortex was more dense and the white matter less so, indicating that the increased water content was largely confined to white matter. Hydrocephalus was associated with transient elevation of T1 in gray and white matter and persistent elevation of T2 in white matter. Changes in the apparent diffusion coefficients were significant only in white matter. Ventricle size correlated significantly with dorsal water content, T1, T2, and apparent diffusion coefficients. MR imaging showed evidence of Gd-DTPA leakage in periventricular tissue foci but not diffusely. These correlated with microscopic leak of larger dextran tracers.ConclusionsMR characteristics cannot be used as direct surrogates for water content in the immature rat model of hydrocephalus, probably because they are also influenced by other changes in tissue composition that occur during brain maturation. There is no evidence for widespread persistent opening of BBB as a consequence of hydrocephalus in young rats. However, increase in focal BBB permeability suggests that periventricular blood vessels may be disrupted.

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