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Regional cerebral blood flow in peritumoral brain edema during dexamethasone treatment: a xenon-enhanced computed tomographic study.

OBJECTIVE: Regional cerebral flood flow (rCBF) in peritumoral brain edema is assumed to be decreased because of increased interstitial pressure. Impaired blood flow might lead to local hypoxia, altered metabolism, and disturbed ion homeostasis, thus causing neurological sequelae. Steroid treatment is thought to positively influence the sequelae of brain edema. We aimed to determine the rCBF in peritumoral edema in humans receiving dexamethasone treatment and the relationship of rCBF to global CBF. METHODS: We measured rCBF in 11 patients with untreated anaplastic gliomas or glioblastomas that were World Health Organization Grade III or IV restricted to one hemisphere with significant peritumoral edema who were receiving a standard dose of dexamethasone. rCBF was determined using stable xenon-enhanced computed tomography in a stereotactic frame. Edema was defined both by means of actual histology (stereotactic biopsies) and by imaging criteria. RESULTS: rCBF in peritumoral edema was decreased by 32% as compared with contralateral normal white matter. In each patient, this reduction was linearly related to blood flow in nonaffected white matter and cortex. The flow ratio in the different compartments was 1 (edema):1.5 (contralateral white matter):2.7 (contralateral cortex). Absolute perfusion values in contralateral cortex (means +/- standard deviations) (29.9+/-7.1 ml/100 g/min) and contralateral white matter (16.1+/-3.7 ml/100 g/min) were significantly decreased as well. CONCLUSION: Our study demonstrated that rCBF in peritumoral brain edema during steroid treatment is still decreased and is in a range in which it may cause neurological sequelae. Also, global CBF was decreased in all patients.

Adult↗

Corneal edema with hydrogel lenses and eye closure: effect of oxygen transmissibility.

Several investigators have reported that significant corneal edema develops when daily wear hydrogel lenses are worn with the eyes closed. The amount of edema that develops when extended wear hydrogel lenses are worn with eye closure is not well documented. This study compared the amount of corneal edema that developed when subjects wore one daily wear lens with the edema that developed when they wore three lens types designed for extended wear. The daily wear lens was the U3 series Bausch & Lomb Soflens contact lens. The extended wear lenses were the Cooper Permalens, the Soft Lens Hydrocurve II 55 lens, and the Sauflon PW lens. The five subjects developed only small amounts of corneal edema when they wore the four lens types under opened-eye conditions but they developed significant amounts of corneal edema when they wore the four lens types for 3-hr periods with eye closure. The amount of corneal edema correlated well with the oxygen transmissibility (DK/L) of the study lenses. The results can be used to predict the amount of corneal edema that the average patient will develop initially when wearing a hydrogel lens of known water content or oxygen permeability (DK) and thickness (L) under opened and closed-eye conditions.

Adult↗

Impact of intraoperative edema during transperineal permanent prostate brachytherapy on computer-optimized and preimplant planning techniques.

The purpose of this study was to prospectively evaluate intraoperative prostatic edema during prostate brachytherapy with real-time ultrasound imaging and assess its impact upon the postimplant dosimetry of computer-optimized intraoperatively planned patients. Fifty consecutive patients with early-stage favorable risk adenocarcinoma of the prostate underwent transperineal ultrasound-guided I125 brachytherapy. Ultrasound volume studies of the prostate were performed immediately before and after placement of brachytherapy needles in the operating room. Twenty-five patients underwent intraoperative computer-optimized treatment planning using a genetic algorithm. Twenty-five patients underwent preimplant ultrasound studies for preimplant treatment planning. Postimplant dosimetry was performed on computed tomography scans obtained after the implant. Statistical analysis was performed taking into account patient age, preneedle volume, increase in intraoperative edema, use of hormonal therapy, type of isotope, number of needles or seeds used, and seed activity. For the intraoperatively planned patients, a median increase of 30% in intraoperative volume was found for the entire group. No correlation between the extent of intraoperative edema and %D90 (percentage of prescribed dose that covers 90% of the target volume) was found. None of the other analyzed variables correlated with %D90. Patients whose treatment was planned preoperatively experienced a median increase of 18.4% in target volume. A negative correlation between the amount of edema and the %D90 was found to be statistically significant (-0.55, P = 0.0047). All patients who underwent prostate brachytherapy experienced intraoperative prostatic edema. When planned intraoperatively, the amount of edema had no impact on the %D90. This may be because of the ability of intraoperative computer-optimized treatment planning to account for edema related to the procedure. Preplanned patients who encountered a greater degree of intraoperative edema had less %D90 target coverage.

Aged↗

Tachyphylaxis in 12-0-tetradecanoylphorbol acetate- and arachidonic acid-induced ear edema.

12-0-Tetradecanoylphorbol acetate (TPA) applied to mouse ears rapidly induces an edema which is maximal by 6 hr but has substantially waned by 24 hr. (This is in contrast to many inflammatory agents that cause a prolonged edema lasting many days.) Reapplication of TPA at 16-24 hr will not provoke a second edematous response although increased erythema is evident. Arachidonic acid (AA) applied to mouse ears (4 mg) provokes an even more rapid edema which is maximal at 1 hr and has substantially waned by 6 hr. Reapplication of AA at 3-24 hr also will not provoke a second edematous response although, again, increased erythema does result. Pretreatment of ears with AA results in inhibition of the edema response to subsequent application of TPA, and TPA pretreatment moderately inhibits a subsequent response to AA. TPA-induced edema can be delayed by agents such as naproxen, an inhibitor of AA cyclooxygenase. In contrast, AA-induced edema is inhibited only by agents, such as phenidone, that inhibit both cyclooxygenase and lipoxygenase. The data suggest that the edemas result from interaction of the products of the cyclooxygenase and lipoxygenase pathways of AA metabolism. The lack of secondary edema response appears to be related to the inability of TPA or AA to reinduce vascular permeability. The effect is specific to AA and TPA; responses to xylene or anthralin are unaffected by TPA or AA pretreatment. It is postulated that the tachyphylactic effects observed involve lipoxygenase metabolites of AA.

Animals↗

Topographical corneal edema. An update.

Measurement of the topographical corneal edema response has been previously restricted by the use of optical pachometry and small sample sizes. This study uses ultrasound pachometry to measure changes in the corneal thickness of 23 subjects at 9 locations during 2 hours' wear of a thick soft contact lens. The data are analysed using both averaged and individual location data. The averaged location analysis supports the current paradigm that less edema occurs in the peripheral cornea than in the central cornea during contact lens wear. However, the individual location analysis reveals a more complex corneal edema response in which the greatest amount of edema following 2 hours' contact lens wear occurred in the central and mid-peripheral temporal cornea, in comparison with the peripheral nasal and peripheral inferior cornea which showed the least edema. The edema measured in the peripheral temporal and peripheral superior cornea following 2 hours' contact lens wear was not significantly different from that measured in the central cornea. The edema measured in the central cornea following 2 hours' contact lens wear was not significantly different from that found at any mid-peripheral location. This study demonstrates that the corneal edema response associated with 2 hours' wear of a thick soft contact lens is a complex dynamic topographical process and cannot be simply modelled using averaged data from small samples.

Adult↗

The effect of age on the edema response of the central and mid-peripheral cornea.

Corneal edema was induced by a 2-h closed-eye wear of a thick hydrogel contact lens. Corneal edema production and edema recovery responses were measured in the central and mid-peripheral (3 mm inferior) cornea of 10 younger (20.4 +/- 2.0 years) and 10 older (69.0 +/- 3.4 years) subjects using optical pachometry. The amount of edema produced was not significantly different between the two corneal locations nor between the two age groups. The edema recovery rates of the central and mid-peripheral cornea were not significantly different in either the younger or older group. The edema recovery rates at both corneal positions were significantly faster in the younger group than in the older group. The results of this study suggest that the mechanisms that control edema production and recovery in the inferior mid-peripheral cornea are similar to those previously described in central and temporal mid-peripheral locations. Ageing appears to influence the edema production and recovery mechanisms of both the central and mid-peripheral cornea in similar ways.

Adult↗

Potential impact of prostate edema on the dosimetry of permanent seed implants using the new 131Cs (model CS-1) seeds.

Our aim in this work was to study the potential dosimetric effect of prostate edema on the accuracy of conventional pre- and post-implant dosimetry for prostate seed implants using the newly introduced 131Cs seed, whose radioactive decay half-life (approximately 9.7 days) is directly comparable to the average edema resolution half-life (approximately 10 days) observed previously by Waterman et al. for 125I implants [Int. J. Radiat. Oncol. Biol. Phys. 41, 1069-1077 (1998)]. A systematic calculation of the relative dosimetry effect of prostate edema on the 131Cs implant was performed by using an analytic solution obtained previously [Int. J. Radiat. Oncol. Biol. Phys. 47, 1405-1419 (2000)]. It was found that conventional preimplant dosimetry always overestimates the true delivered dose as it ignores the temporary increase of the interseed distance caused by edema. The overestimation for 131Cs implants ranged from 1.2% (for a small edema with a magnitude of 10% and a half-life of 2 days) to approximately 45% (for larger degree edema with a magnitude of 100% and a half-life of 25 days). The magnitude of pre- and post-implant dosimetry error for 131Cs implants was found to be similar to that of 103Pd implants for typical edema characteristics (magnitude < 100%, and half-life <25 days); both of which are worse compared to 125I implants. The preimplant dosimetry error for 131Cs implants cannot be compensated effectively without knowing the edema characteristics before the seed implantation. On the other hand, the error resulted from a conventional post-implant dosimetry can be minimized (to within +/-6%) for 131Cs implants if the post-implant dosimetry is performed at 10+/-2 days post seed implantation. This "optimum" post-implant dosimetry time is shorter than those determined previously for the 103Pd and 125I implants at 16+/-4 days and 6+/-1 weeks, respectively.

Brachytherapy↗

Pharmacological and molecular characterization of the mechanisms involved in prostaglandin E2-induced mouse paw edema.

The present study evaluated some of the mechanisms underlying prostaglandin E2 (PGE2)-induced paw edema formation in mice. Intraplantar (i.pl.) injection of PGE2 (0.10-10.0 nmol/paw) into the hindpaw elicited a dose-related edema formation, with a mean ED50 value of 0.42 nmol/paw. The coinjection of selective E-prostanoid (EP)3 [(2E)-N-[(5-bromo-2-methoxyphenyl)-sulfonyl]-3-[5-chloro-2-(2-naphthylmethyl)phenyl]acrylamide; L826266), but not EP2 or EP4 (all 10 nmol/paw), receptor antagonists significantly inhibited PGE2-induced paw edema. Like L826266, the PGE2-induced paw edema was markedly reduced by treatment with pertussis toxin and phospholipase C (PLC) inhibitor 1-[6-[[17beta-methoxyestra-1,3,5(10)-trien-17-yl]amino]hexyl]-1H-pyrrole-2,5-dione (U-73122). Likewise, the selective neurokinin (NK)1 receptor antagonist N-[(4R)-4-hydroxy-1-(1-methyl-1H-indol-3-yl)carbonyl-l-prolyl]-N-methyl-N-phenyl-methyl-3-(2-aphthyl)-l-alaninamide (FK888) and the antagonist of vanilloid receptor (TRPV1) receptors 4'-chloro-3-methoxycinnamanilide (SB366791) (both 1 nmol/paw) also significantly inhibited PGE2-mediated paw edema. Conversely, the selective NK2, NK3, and calcitonin gene-related peptide (CGRP) CGRP(8-37) receptor antagonists all failed to interfere with PGE2-induced paw edema. The neonatal treatment of mice with capsaicin was also able to reduce PGE2-induced paw edema. The inhibitors of protein kinase C (PKC) 3-[1-[3-(dimethylaminopropyl]-1H-indol-3-yl]-4-(1H-indol-3-yl)-1H-pyrrole-2,5-dione monohydrochloride (GF109203X) and mitogen protein-activated kinases (MAPKs; 30 nmol/paw) c-Jun NH2-terminal kinase (JNK) (anthra[1,9-cd]pyrazol-6(2H)-one; SP600125), extracellular signal-regulated kinase (PD98059), and p38 [4-(4-fluorophenyl)-2-(4-methylsulfinylphenyl)-5-(4-pyridyl)1H-imidazole; SB203580], but not protein kinase A, markedly decreased the PGE2-mediated edema formation. The i.pl. injection of PGE2 (3 nmol/paw) induced a significant activation of MAPKs, namely, JNK and p38, an effect that was largely prevented by the selective EP3 receptor antagonist L826266 (10 nmol/paw). Collectively, these findings indicate that edematogenic responses elicited by PGE2 are mediated by EP3 receptor activation, also involving the stimulation of PLC, PKC, and MAPKs pathways and the participation of TRPV1 and NK1 receptors. These results make a considerable contribution to our comprehension of the mechanisms involved in PGE2-mediated inflammatory responses in mice.

Actins↗

Preadult stage parasites and multiple timed exposure to infective larvae are involved in development of limb edema in Brugia malayi-infected Indian leaf monkeys (Presbytis entellus).

The pathogenesis of filarial limb edema is not known. The role of parasitological variables and parasite-mediated phenomena in the development of limb edema was investigated in the Presbytis entellus-Brugia malayi model. Infection was initiated with subcutaneous inoculation of infective third-stage larvae (L(3)), and the animals were reexposed to different doses of L(3) at the prepatent, patent, and diminishing microfilaremia (0 to 5% of peak microfilaremia count) stages of infection. A large L(3) inoculum size and repeated inoculation in the ankle region during the prepatent, patent, and diminishing microfilaremia stages of infection were found to be necessary for reproducible induction of limb edema. The preadult stage of the parasite was found to be the most potent inducer of limb edema, followed by L(5) and L(4). The presence of the proinflammatory cytokines tumor necrosis factor alpha, interleukin-1beta, and interleukin-6 in edema fluid in the leg receiving the parasite challenge indicated that the limb edema development was due to parasite-mediated cytokine responses. The absence of bacterial infection or anti-streptolysin O titer in the edema fluid and blood indicated that bacterial infection is not necessary for the development of limb edema.

Animals↗

Vaccination with genetically modified Shiga-like toxin IIe prevents edema disease in swine.

Escherichia coli strains producing Shiga-like toxin II variant (SLT-IIe, formerly called SLT-IIv) cause edema disease in weaned pigs. Vaccination of pigs with a genetically modified form of Shiga-like toxin IIe, SLT-IIe(E167Q), has been previously shown to be nontoxic and to induce antibodies to SLT-IIe (V.M. Gordon. S.C. Whipp, H.W. Moon, A.D. O'Brien, and J.E. Samuel, Infect, Immun. 60:485-502, 1992). Fifty micrograms of SLT-IIe(E167Q) toxin was used to vaccinate suckling pigs at 1 and 2 weeks of age. Both vaccinated and nonvaccinated pigs were orally inoculated with an SLT-IIe-producing strain of E. coli after weaning (3 to 4 weeks of age). Pigs fed a low-protein diet that were not vaccinated with SLT-IIe(E167Q) developed subclinical edema disease, histologically evident as vascular necrosis. Pigs fed a high-protein diet that were not vaccinated with SLT-IIe(E167Q) developed clinical edema disease manifested as vascular necrosis, reduced weight gain, ataxia, palpebral edema, lateral recumbency, and death. Pigs vaccinated with SLT-IIe(E167Q) had a reduction in the incidence of subclinical edema disease and never developed clinical edema disease. These data demonstrate that vaccination with a genetically modified form of SLT-IIe prevents edema disease and are consistent with the notion that diet influences susceptibility to edema disease.

Animals↗

Responses of pulmonary C-fibre and rapidly adapting receptor afferents to pulmonary congestion and edema in dogs.

The effects of cardiogenic and noncardiogenic pulmonary edema on the activities of rapidly adapting receptors (RARs) and pulmonary C-fibre receptors were investigated in dogs anaesthetized with chloralose. Cardiogenic pulmonary edema was produced by elevating the mean left atrial pressure by 25 mmHg (1 mmHg = 133.32 Pa) above the control value for a period of 45 min, by partial obstruction of the mitral valve. Noncardiogenic pulmonary edema was produced by injecting alloxan (100 mg/kg) intravenously. The effect of the latter was examined on RARs alone. Cardiogenic edema activated RARs (n = 8) and the activity was greatest during the first few minutes after elevation of mean left atrial pressure. The pulmonary C-fibre receptors (n = 6) were also activated by cardiogenic edema, but these responses were variable. Noncardiogenic pulmonary edema also activated RAR (n = 6), and this response was maintained during the entire recording period (20 min). The extravascular lung water (%), measured 15 min (n = 5) and 45 min (n = 5) after the elevation of the mean left atrial pressure, was significantly elevated above control values. However, these two values were not significantly different from each other. The extravascular lung water increased significantly after the injection of alloxan also (n = 5). These results show that during pulmonary edema, there is significant stimulation of the RARs and the pulmonary C-fibre receptors. It is suggested that the reflex respiratory responses observed in pulmonary edema may be due to the activation of both the RARs and the pulmonary C-fibre receptors.

Afferent Pathways↗

Expression of B1 kinin receptors mediating paw edema and formalin-induced nociception. Modulation by glucocorticoids.

Bradykinin (BK) and Tyr8-BK induced graded rat paw edema with EC50 values of 1.9 and 1.1 nmol/paw, while des-Arg9-BK (DABK, up to 300 nmol/paw) was marginally effective. Tyr8-BK, but not DABK, also caused a dose-related increase in mouse paw edema, with an EC50 of 1.3 nmol/paw. The response to Tyr8-BK (10 nmol/paw) in rat paw edema was antagonized by B2 receptor antagonists (HOE-140 or NPC 17731, 30 nmol/paw) but not by the B1 antagonist des-Arg9[Leu8]BK (DALBK, 100 nmol/paw). Daily intraplantar injections of Tyr8-BK (10 nmol/paw) for 7 days caused progressive desensitization (D) of edema in sham-operated and adrenalectomized Wistar rats. DABK (100 nmol/paw) caused marked paw edema in D paws from both groups, which was inhibited by DALBK (100 nmol/paw) and by dexamethasone (0.5mg/kg, s.c.). Systemic injection of lipopolysaccharide (10 micrograms/mouse, 24 h prior) potentiated the first and second phases of Formalin-induced pain but had no effect on paw edema. Coinjection of DABK (2-22 nmol/paw) with low doses of Formalin in lipopolysaccharide-treated mice, which had no effect on naive animals, dose dependently potentiated both phases of Formalin-induced pain but did not modify paw edema. These effects were antagonized by DALBK with ID50 values of 21.9 (first phase) and 64.1 (second phase) nmol/paw. Thus, both progressive desensitization of B2 receptors and systemic treatment with lipopolysaccharide induce a glucocorticoid-sensitive upregulation of B1 receptors mediating paw edema in the rat and Formalin-induced nociception in mice. These results suggest that induction of upregulation of B1 receptors may play important roles in controlling inflammatory processes and hyperalgesia.

Animals↗

Regional extravascular density of the lung in patients with acute pulmonary edema.

The regional distribution of extravascular lung density (lung tissue and interstitial or alveolar fluid per unit thoracic volume) and fractional pulmonary blood volume (volume of blood per unit thoracic volume) was measured in five patients with acute interstitial pulmonary edema and two patients with acute alveolar edema. We found a uniform increase in extravascular lung density in the patients with acute interstitial edema but a preferentially dependent distribution in the patients with alveolar edema. Fractional blood volume had an abnormally uniform distribution in patients with interstitial edema. In alveolar edema, there was marked redistribution of blood volume away from severely edematous regions. The results are in agreement with previous experimental work with animal models. The distribution of extravascular lung density and fractional blood volume in subjects with acute interstitial edema is, however, different from that found in subjects with chronic interstitial edema, suggesting that the pathophysiological characteristics of the two conditions may be different.

Acute Disease↗

Bronchial vascular reabsorption of low-protein interstitial edema liquid in perfused sheep lungs.

Previously, we quantified reabsorption of interstitial pulmonary edema liquid into the pulmonary circulation during recovery from hydrostatic edema. To determine whether the bronchial circulation also reabsorbs edema liquid, we induced very-low-protein interstitial edema in seven sheep lungs by perfusion of the pulmonary circulation with diluted blood and 1% albumin in Krebs-Henseleit buffer containing 125I-labeled albumin for 70 +/- 40 min. In eight control sheep we perfused the lungs with diluted blood and 5% albumin in Krebs-Henseleit buffer containing 125I-albumin without causing significant edema formation. Subsequently, we washed the intravascular tracer from the pulmonary circulation with buffered saline and then perfused the bronchial vessels via the bronchoesophageal artery with whole or diluted blood (normal protein osmotic pressure). We measured flow, hematocrit, and 125I-albumin concentration in the venous outflow into the left atrium and into the azygos vein for 2 h. We calculated the volume of liquid reabsorbed on the basis of the change in hematocrit and 12I-albumin concentration in the outflow. On the basis of hematocrit dilution, the net clearance of interstitial liquid (edema minus control) averaged 21 ml (15% of the induced edema). One the basis of 125I-albumin reabsorption, the net clearance of interstitial liquid was 12 ml. We conclude that the bronchial circulation may be a clearance route for interstitial liquid and protein during recovery from low-protein hydrostatic edema.

Absorption↗

Pulmonary edema related to changes in colloid osmotic and pulmonary artery wedge pressure in patients after acute myocardial infarction.

Pulmonary artery wedge and plasma colloid osmotic pressures and their relationship to pulmonary edema were investigated in 26 patients with acute myocardial infarction of whom 14 developed pulmonary edema. In the absence of pulmonary edema, both the pulmonary artery wedge pressure and plasma colloid osmotic pressure were in normal range; after onset pulmonary edema, a moderate increase in pulmonary wedge pressure and reduction in plasma colloid osmotic pressure were observed. When the gradient between the plasma colloid osmotic pressure and the pulmonary artery wedge pressure was calculated, highly significant differences were demonstrated (P less than 0.002). In the absence of pulmonary edema, this gradient averaged 9.7 (plus or minus 1.7 SEM) torr; following appearance of pulmonary edema, it was reduced to 1.2 (plus or minus 1.3) torr. During therapy with digoxin and furosemide, reversal of pulmonary edema was closely related to a concomitant change in the colloid osmotic-hydrostatic pressure gradient. These observations indicate that both increases in pulmonary capillary pressure and decreases in colloid osmotic pressure may follow the onset of pulmonary edema. Such decline in colloid osmotic pressure and especially the reduction in colloid osmotic-hydrostatic capillary pressure gradient may favor transudation of fluid into the lungs.

Adult↗

Increases in plasma oncotic pressure during acute cardiogenic pulmonary edema.

Colloid osmotic pressure (COP) was measured in 95 patients with clinical and radiological evidence of acute cardiogenic pulmonary edema. Fifty patients who were admitted for coronary observation but in whom acute myocardial infarctin was excluded, and 21 patients who had sustained acute myocardial infarction without evidence of left ventricular failure served as controls. Significantly higher values of COP, total plasma protein, and hematocrit were observed in patients with pulmonary edema. Increases in COP during pulmonary edema were best explained by transudation of hypooncotic fluid into extravascular spaces. Following treatment of pulmonary edema in 76 patients with furosemide, morphine, and oxygen, pulmonary edema was reversed in 65 patients. Reabsorption of hypooncotic fluid from extravascular sites with a significant decline in COP, total protein and hematocrit followed reversal of pulmonary edema. No significant changes in these parameters were observed in patients who failed to respond to therapy. These observations implicate filtration of hypooncotic fluid from the intravascular compartment during onset of cardiogenic pulmonary edema and reabsorption of hypooncotic fluid into the intravascular compartment during reversal of pulmonary edema.

Acute Disease↗

Relative edema volume is a predictor of outcome in patients with hyperacute spontaneous intracerebral hemorrhage.

BACKGROUND AND PURPOSE: Little is known about the relationship between perihematomal edema in spontaneous intracerebral hemorrhage (ICH) and outcome. The purpose of this study was to determine whether absolute or relative edema volume (edema volume divided by hematoma volume) predicts mortality or functional outcome in patients with hyperacute spontaneous ICH. We hypothesized that increasing baseline relative edema volume is associated with greater probability of poor functional outcome. METHODS: This was a secondary analysis of a prospective, population-based study of hematoma growth in 142 patients with spontaneous ICH. Patients were imaged within 3 hours of onset, then 1 and 20 hours later. Our primary analysis excluded patients with anticoagulant use (n=7), underlying aneurysm/vascular malformation (n=9), trauma (n=1), incomplete data (n=20), infratentorial ICH (n=17), intraventricular extension (n=38), and no consent (n=2). We analyzed whether associations existed between baseline edema volumes or other clinical/radiological variables and either 12-week modified Rankin Scale score >2 or 30-day mortality. Secondary analyses used 20-hour CT scan data, all patients with supratentorial ICH, and 12-week Barthel Index score <85. RESULTS: By multivariable logistic regression analysis, baseline relative edema was the strongest independent predictor of functional outcome and was associated with lesser odds of poor 3-month functional outcome (odds ratio, 0.09 per 1.0-unit [100%] increase; 95% CI, 0.01 to 0.64; P=0.016) and 12-week Barthel Index score <85 (odds ratio, 0.12; 95% CI, 0.02 to 0.91; P=0.039) but did not predict mortality. Secondary analyses confirmed this result. Absolute edema volume predicted neither mortality nor functional outcome. CONCLUSIONS: Relative edema is strongly predictive of functional outcome in patients with hyperacute supratentorial spontaneous ICH without intraventricular extension.

Acute Disease↗

Noninvasive quantification of brain edema and the space-occupying effect in rat stroke models using magnetic resonance imaging.

BACKGROUND AND PURPOSE: Brain edema is a life-threatening consequence of stroke and leads to an extension of the affected tissue. The space-occupying effect due to brain edema can be quantified in rat stroke models with the use of MRI. The present study was performed to test 2 hypotheses: (1) Can quantification of the space-occupying effect due to brain edema serve as a noninvasive measure for brain water content? (2) Does morphometric assessment of brain swelling allow determination of true infarct size on MRI after correction for the space-occupying effect of edema? METHODS: Thirty rats were subjected to permanent suture middle cerebral artery occlusion. MRI was performed after 6 or 24 hours, and hemispheric swelling was assessed morphometrically. Interobserver and intraobserver agreements were determined for MRI measurements. In study I, the space-occupying effect due to brain edema was correlated with the absolute brain water content by the wet/dry method. In study II, lesion volumes corrected and uncorrected for edema were calculated on MRI and on TTC staining and compared. RESULTS: Interobserver and intraobserver agreements for MRI measurements were excellent (r>or=0.97). Brain water content and hemispheric swelling correlated well after 6 and 24 hours (r>or=0.95). Corrected lesion volumes correlated with r=0.78 between TTC staining and MRI. Without edema correction, lesion volumes were overestimated by 20.3% after 6 hours and by 29.6% after 24 hours of ischemia. CONCLUSIONS: Morphometric assessment of hemispheric swelling on MRI can determine the increase in absolute brain water content noninvasively and can also provide ischemic lesion volumes corrected for brain edema.

Animals↗