Cerebral blood flow and metabolism in severely head-injured children

1989 ◽  
Vol 71 (1) ◽  
pp. 63-71 ◽  
Author(s):  
J. Paul Muizelaar ◽  
Anthony Marmarou ◽  
Antonio A. F. DeSalles ◽  
John D. Ward ◽  
Richard S. Zimmerman ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Head Injury ◽  
Severe Head Injury ◽  
Cerebral Blood Volume ◽  
Closed Head Injury ◽  
Volume Index ◽  
Content Type ◽  
Gcs Score ◽  
Fine Print

✓ The literature suggests that in children with severe head injury, cerebral hyperemia is common and related to high intracranial pressure (ICP). However, there are very few data on cerebral blood flow (CBF) after severe head injury in children. This paper presents 72 measurements of cerebral blood flow (“CBF15”), using the 133Xe inhalation method, with multiple detectors over both hemispheres in 32 children aged 3 to 18 years (mean 13.6 years) with severe closed head injury (average Glasgow Coma Scale (GCS) score 5.4). In 25 of the children, these were combined with measurements of arteriojugular venous oxygen difference (AVDO2) and of cerebral metabolic rate of oxygen (CMRO2). In 30 patients, the first measurement was taken approximately 12 hours postinjury. In 18 patients, an indication of brain stiffness was obtained by withdrawal and injection of ventricular cerebrospinal fluid and calculation of the pressure-volume index (PVI) of Marmarou. The CBF and CMRO2 data were correlated with the GCS score, outcome, ICP, and PVI. Early after injury, CBF tended to be lower with lower GCS scores, but this was not statistically significant. This trend was reversed 24 hours postinjury, as significantly more hyperemic values were recorded the lower the GCS score, with the exception of the most severely injured patients (GCS score 3). In contrast, mean CMRO2 correlated positively with the GCS score and outcome throughout the course, but large standard deviations preclude making predictions based on CMRO2 measurements in individual patients. Early after injury, there was mild uncoupling between CBF and CMRO2 (CBF above metabolic demands, low AVDO2) and, after 24 hours, flow and metabolism were completely uncoupled with an extremely low AVDO2. Consistently reduced flow was found in only four patients; 28 patients (88%) showed hyperemia at some point in their course. This very high percentage of patients with hyperemia, combined with the lowest values of AVDO2 found in the literature, indicates that hyperemia or luxury perfusion is more prevalent in this group of patients. The three patients with consistently the highest CBF had consistently the lowest PVI: thus, the patients with the most severe hyperemia also had the stiffest brains. Nevertheless, and in contrast to previous reports, no correlation could be established between the course of ICP or PVI and the occurrence of hyperemia, nor was there a correlation between the levels of CBF and ICP at the time of the measurements. The authors argue that this lack of correlation is due to: 1) a definition of hyperemia that is too generous, and 2) the lack of a systematic relationship between CBF and cerebral blood volume. The implications of these findings for therapeutic modes of controlling ICP in children, such as hyperventilation and the use of mannitol, are discussed.

The outcome of severe closed head injury

1991 ◽  
Vol 75 (Supplement) ◽  
pp. S28-S36 ◽  
Author(s):  
Lawrence F. Marshall ◽  
Theresa Gautille ◽  
Melville R. Klauber ◽  
Howard M. Eisenberg ◽  
John A. Jane ◽  
...  
Keyword(s):  
Head Injury ◽  
Mortality Rate ◽  
Severe Head Injury ◽  
Closed Head Injury ◽  
Data Bank ◽  
Content Type ◽  
Severity Of Injury ◽  
Gcs Score ◽  
Fine Print ◽  
Overall Mortality

✓ The outcome of severe head injury was prospectively studied in patients enrolled in the Traumatic Coma Data Bank (TCDB) during the 45-month period from January 1, 1984, through September 30, 1987. Data were collected on 1030 consecutive patients admitted with severe head injury (defined as a Glasgow Coma Scale (GCS) score of 8 or less following nonsurgical resuscitation). Of these, 284 either were brain-dead on admission or had a gunshot wound to the brain. Patients in these two groups were excluded, leaving 746 patients available for this analysis. The overall mortality rate for the 746 patients was 36%, determined at 6 months postinjury. As expected, the mortality rate progressively decreased from 76% in patients with a postresuscitation GCS score of 3 to approximately 18% for patients with a GCS score of 6, 7, or 8. Among the patients with nonsurgical lesions (overall mortality rate, 31%), the mortality rate was higher in those having an increased likelihood of elevated intracranial pressure as assessed by a new classification of head injury based on the computerized tomography findings. In the 276 patients undergoing craniotomy, the mortality rate was 39%. Half of the patients with acute subdural hematomas died — a substantial improvement over results in previous reports. Outcome differences between the four TCDB centers were small and were, in part, explicable by differences in patient age and the type and severity of injury. This study describes head injury outcome in four selected head-injury centers. It indicates that a mortality rate of approximately 35% is to be expected in such patients admitted to experienced neurosurgical units.

Changes in cerebral blood flow during PaCO2 variations in patients with severe closed head injury: comparison between the Fick and transcranial Doppler methods

1998 ◽  
Vol 88 (6) ◽  
pp. 996-1001 ◽  
Author(s):  
Aram Ter Minassian ◽  
Eliane Melon ◽  
Caroline Leguerinel ◽  
Carlo Alberto Lodi ◽  
Françis Bonnet ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Head Injury ◽  
Transcranial Doppler ◽  
Closed Head Injury ◽  
High Group ◽  
Content Type ◽  
Closed Head ◽  
Fine Print ◽  
Group 1

Object. The aim of this study was to reassess whether middle cerebral artery blood flow velocity (MCAv) variations measured by transcranial Doppler ultrasonography during acute PaCO2 manipulation adequately reflect cerebral blood flow (CBF) changes in patients with severe closed head injury. Methods. The study was performed by comparing MCAv variations to changes in CBF as assessed by measurements of the difference in the arteriovenous content in oxygen (AVDO2). The authors initiated 35 CO2 challenges in 12 patients with severe closed head injury during the acute stage. By simultaneous recording of systemic and cerebral hemodynamic parameters, 105 AVDO2 measurements were obtained. Patients were stratified into two groups, “high” and “low,” with respect to whether their resting values of MCAv were greater than 100 cm/second during moderate hyperventilation. Four patients displayed an elevated MCAv, which was related to vasospasm in three cases and to hyperemia in one case. The PaCO2 and intracranial pressure levels were not different between the two groups. The slope of the regression line between 1 divided by the change in (Δ)AVDO2 and ΔMCAv was not different from identity in the low group (1/ΔAVDO2 = 1.08 × ΔMCAv − 0.07, r = 0.93, p < 0.001) and significantly differed (p < 0.05) from the slope of the high group (1/ΔAVDO2 = 1.46 × ΔMCAv − 0.4, r = 0.83, p < 0.001). Conclusions. In patients with severe closed head injury, MCAv variations adequately reflect CBF changes as assessed by AVDO2 measurements in the absence of a baseline increase in MCAv. These observations indicate that both moderate variations in PaCO2 and variations in cerebral perfusion pressure do not act noticeably on the diameter of the MCA. The divergence from the expected relationship in the high group seems to be due to the heterogeneity of CO2-induced changes in cerebrovascular resistance between differing arterial territories.

Cerebral circulation after head injury

1983 ◽  
Vol 59 (3) ◽  
pp. 439-446 ◽  
Author(s):  
Jørn Overgaard ◽  
William A. Tweed
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Head Injury ◽  
Neurological Outcome ◽  
Cerebral Perfusion ◽  
Boundary Zone ◽  
Content Type ◽  
Poor Neurological Outcome ◽  
Gcs Score ◽  
Fine Print

✓ A considerable body of evidence suggests that posttraumatic disturbances of the cerebral circulation contribute to poor neurological outcome after blunt head injury, especially when regional cerebral blood flow (rCBF) falls to the ischemic range (below 17 ml/100 gm/min). Cerebral infarction concentrated in the arterial boundary regions has been described in patients who died. Since arterial boundary zones are the cortical areas most susceptible to cerebral ischemia, the authors have investigated the relationship between neurological outcome and the anatomic pattern of rCBF values in the acute phase. The bolus-injection xenon-133 washout technique was used to measure rCBF in 35 regions of the hemisphere during the 1st week after head injury. Eighty-eight hemispheres were studied in 80 patients whose Glasgow Coma Scale (GCS) score was less than 8 on admission to the neurosurgical department. A characteristic pattern of rCBF was found in patients who later died of neurological complications, or who survived in a persistent vegetative state, with low flows in regions conforming to the arterial boundary zones. These patients also had lower average global cerebral blood flow (CBF), GCS scores, and cerebral perfusion pressure compared with those who recovered, with or without neurological deficits; the latter group had an rCBF pattern similar to that of normal individuals. There was little change in the GCS score between the time of hospital admission and CBF measurement, suggesting that the major neurological injury had occurred prior to admission. It was not possible to determine whether boundary-zone ischemia preceded neurological deterioration, but the rCBF pattern of boundary-zone flow deprivation was clearly related to poor neurological outcome. These observations suggest that elevated intracranial pressure and arterial hypotension were important etiological factors. Measures to protect regional cerebral perfusion should be instituted as early as possible after injury, preferably before the patient reaches the hospital.

Relationship of early cerebral blood flow and metabolism to outcome in acute head injury

1990 ◽  
Vol 72 (2) ◽  
pp. 176-182 ◽  
Author(s):  
Jurg L. Jaggi ◽  
Walter D. Obrist ◽  
Thomas A. Gennarelli ◽  
Thomas W. Langfitt
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Head Injury ◽  
Vegetative State ◽  
Closed Head Injury ◽  
Total Sample ◽  
Prognostic Indicators ◽  
Content Type ◽  
Blood Flows ◽  
Fine Print

✓ Cerebral blood flow (CBF) measurements were obtained acutely in 96 comatose patients with closed head injury, using the intravenous 133Xe technique. Arteriojugular venous oxygen differences and cerebral metabolic rate for oxygen (CMRO2) were determined in a subgroup of 66 patients. The relationship between each of these variables and outcome at 6 months was analyzed, using the Glasgow Outcome Scale. The CMRO2 was significantly depressed in patients who subsequently died or remained in a vegetative state, whereas higher values were obtained in patients who later regained consciousness. Although CBF was not predictive of outcome in the total sample, omission of patients with acute hyperemia resulted in a significant relationship that paralleled the metabolic findings. Follow-up studies in the survivors revealed a correlation between CBF and degree of functional recovery, the lowest blood flows being obtained among patients with severe disability. Age, initial Glasgow Coma Scale score, and occurrence of intracranial hypertension were each found to be predictive of outcome, thus confirming previous reports. When these variables were combined with CMRO2 in a logistic regression analysis, the probability of recovery was correctly predicted in 82% of the cases. The CMRO2 was relatively independent of the other prognostic indicators and, next to age, contributed most to the prediction.

Early changes measured by magnetic resonance imaging in cerebral blood flow, blood volume, and blood-brain barrier permeability following dexamethasone treatment in patients with brain tumors

1999 ◽  
Vol 90 (2) ◽  
pp. 300-305 ◽  
Author(s):  
Leif Østergaard ◽  
Fred H. Hochberg ◽  
James D. Rabinov ◽  
A. Gregory Sorensen ◽  
Michael Lev ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Magnetic Resonance ◽  
Brain Tumors ◽  
Mr Imaging ◽  
Blood Volume ◽  
Cerebral Blood Volume ◽  
Clinical Effects ◽  
Content Type ◽  
Fine Print

Object. In this study the authors assessed the early changes in brain tumor physiology associated with glucocorticoid administration. Glucocorticoids have a dramatic effect on symptoms in patients with brain tumors over a time scale ranging from minutes to a few hours. Previous studies have indicated that glucocorticoids may act either by decreasing cerebral blood volume (CBV) or blood-tumor barrier (BTB) permeability and thereby the degree of vasogenic edema.Methods. Using magnetic resonance (MR) imaging, the authors examined the acute changes in CBV, cerebral blood flow (CBF), and BTB permeability to gadolinium-diethylenetriamine pentaacetic acid after administration of dexamethasone in six patients with brain tumors. In patients with acute decreases in BTB permeability after dexamethasone administration, changes in the degree of edema were assessed using the apparent diffusion coefficient of water.Conclusions. Dexamethasone was found to cause a dramatic decrease in BTB permeability and regional CBV but no significant changes in CBF or the degree of edema. The authors found that MR imaging provides a powerful tool for investigating the pathophysiological changes associated with the clinical effects of glucocorticoids.

A multicenter trial on the efficacy of using tirilazad mesylate in cases of head injury

1998 ◽  
Vol 89 (4) ◽  
pp. 519-525 ◽  
Author(s):  
Lawrence F. Marshall ◽  
Andrew I. R. Maas ◽  
Sharon Bowers Marshall ◽  
Albino Bricolo ◽  
Michael Fearnside ◽  
...  
Keyword(s):  
Placebo Group ◽  
Head Injury ◽  
Severe Head Injury ◽  
Treated Group ◽  
Good Recovery ◽  
Content Type ◽  
Significant Difference ◽  
Tirilazad Mesylate ◽  
Gcs Score ◽  
Fine Print

Object. The authors prospectively studied the efficacy of tirilazad mesylate, a novel aminosteroid, in humans with head injuries. Methods. A cohort of 1120 head-injured patients received at least one dose of study medication (tirilazad or placebo). Eighty-five percent (957) of the patients had suffered a severe head injury (Glasgow Coma Scale [GCS] score 4–8) and 15% (163) had sustained a moderate head injury (GCS score 9–12). Six-month outcomes for the tirilazad- and placebo-treated groups for the Glasgow Outcome Scale categories of both good recovery and death showed no significant difference (good recovery in the tirilazad-treated group was 39% compared with the placebo group in which it was 42% [p = 0.461]; death in the tirilazad-treated group occurred in 26% of patients compared with the placebo group, in which it occurred in 25% [p = 0.750]). Subgroup analysis suggested that tirilazad mesylate may be effective in reducing mortality rates in males suffering from severe head injury with accompanying traumatic subarachnoid hemorrhage (death in the tirilazad-treated group occurred in 34% of patients; in the placebo group it occurred in 43% [p = 0.026]). No significant differences in frequency or types of serious adverse events were shown between the treatment and placebo groups. Conclusions. Striking problems with imbalance concerning basic prognostic variables were observed in spite of the large population studied. These imbalances concerned pretreatment hypotension, pretreatment hypoxia, and the incidence of epidural hematomas. In future trials of pharmacological therapy for severe head injury, serious consideration must be given to alternative randomization strategies. Given the heterogeneous nature of head injury and the identification of populations that do relatively well with standard therapy, target populations with a higher risk for mortality and morbidity may be more suitable for clinical trials of such agents.

Dynamic autoregulatory response after severe head injury

2002 ◽  
Vol 97 (5) ◽  
pp. 1054-1061 ◽  
Author(s):  
Roman Hlatky ◽  
Yu Furuya ◽  
Alex B. Valadka ◽  
Jorge Gonzalez ◽  
Ari Chacko ◽  
...  
Keyword(s):  
Blood Flow ◽  
Head Injury ◽  
Severe Head Injury ◽  
Content Type ◽  
Factors Affecting ◽  
Physiological Variables ◽  
End Tidal ◽  
A Prospective Study ◽  
Pressure Autoregulation ◽  
Fine Print

Object. The purpose of this study was to evaluate the extent and timing of impairment of cerebral pressure autoregulation after severe head injury. Methods. In a prospective study of 122 patients with severe head trauma (median Glasgow Coma Scale Score 6), dynamic tests of pressure autoregulation were performed every 12 hours during the first 5 days postinjury and daily during the next 5 days. The autoregulatory index ([ARI] normal value 5 ± 1.1) was calculated for each test. The changes in the ARI over time were examined and compared with other physiological variables. The ARI averaged 2.8 ± 1.9 during the first 12 hours postinjury, and continued to decrease to a nadir of 1.7 ± 1.1 at 36 to 48 hours postinjury. At this nadir, in 87% of the patients the value was less than 2.8. This continued deterioration in the ARI during the first 36 to 48 hours postinjury occurred despite an increase in cerebral blood flow ([CBF], p < 0.05) and in middle cerebral artery blood flow velocity ([BFV], p < 0.001), and could not be explained by changes in cerebral perfusion pressure, end-tidal CO2, or cerebral metabolic rate of O2. A marked decrease in cerebrovascular resistance ([CVR], p < 0.001) accompanied this deterioration in the ARI. Patients with a relatively higher BFV on Day 1 had a lower CVR (p < 0.05) and more impaired pressure autoregulation than those with a lower BFV. Conclusions. The inability of cerebral vessels to regulate CBF normally may play a role in the vulnerability of the injured brain to secondary ischemic insults. These studies indicate that this vulnerability continues and even increases beyond the first 24 hours postinjury. Local factors affecting cerebrovascular tone may be responsible for these findings.

Dissociation of cerebral blood flow, glucose metabolism, and electrical activity in pediatric brain death

1993 ◽  
Vol 79 (5) ◽  
pp. 752-755 ◽  
Author(s):  
Michael D. Medlock ◽  
William C. Hanigan ◽  
Robert P. Cruse
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Glucose Metabolism ◽  
Brain Death ◽  
Electrical Activity ◽  
Closed Head Injury ◽  
Content Type ◽  
Positron Emission ◽  
Mononuclear Cell Infiltrates ◽  
Fine Print

✓ A 2-month-old infant demonstrated clinical brain death 48 hours after suffering a closed head injury accompanied by cardiac arrest. Two nuclear cerebral blood flow (CBF) studies demonstrated normal perfusion. On the 11th day following injury, cerebral electrical activity ceased and a normal glucose metabolic gradient between gray and white matter was documented on positron emission tomography. Autopsy revealed widespread necrosis with mononuclear cell infiltrates throughout all cerebral cortical layers. Nine children have previously been described with clinical brain death, electrocerebral silence, and evidence of CBF by radionuclide scan. The dissociation between cerebral electrical activity and blood flow may be explained by an increase in cranial volume allowed by the expansile neonatal skull, preventing both intracranial hypertension and a reduction in perfusion pressure. The persistence of glucose metabolism may be associated with the presence of inflammatory microglial cells in the ischemic cortex. The authors conclude that persistence of CBF and glucose metabolism in brain-dead children may not indicate neuronal survival. If repeated neurological examinations with or without electroencephalography support the diagnosis of brain death, the presence of CBF and glucose metabolism should not alter this conclusion.

Acute regional cerebral blood flow changes caused by severe head injuries

1991 ◽  
Vol 74 (3) ◽  
pp. 407-414 ◽  
Author(s):  
Donald W. Marion ◽  
Joseph Darby ◽  
Howard Yonas
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Head Injury ◽  
Brain Stem ◽  
Head Injuries ◽  
Clinical Signs ◽  
Content Type ◽  
Tomography Method ◽  
Gcs Score ◽  
Mass Lesions

✓ To evaluate the changes in cerebral blood flow (CBF) that occur immediately after head injury and the effects of different posttraumatic lesions on CBF, 61 CBF studies were obtained using the xenon-computerized tomography method in 32 severely head-injured adults (Glasgow Coma Scale score (GCS) ≤ 7). The measurements were made within 7 days after injury, 43% in the first 24 hours. During the 1st day, patients with an initial GCS score of 3 or 4 and no surgical mass had significantly lower flows than did those with a higher GCS score or mass lesions (p < 0.05): in the first 1 to 4 hours, those without surgical mass lesions had a mean CBF of 27 cc/100 gm/min, which rose to 44 cc/100 gm/min by 24 hours. Patients without surgical mass lesions who died tended to have a lower global CBF than did those with better outcomes. Mass lesions were associated with a high global CBF and bihemispheric contusions with the lowest flows. By 24 hours after injury, global blood flow increased in groups that originally had low flows and decreased in those with very high initial flows, such that by 36 to 48 hours, most patients had CBF values between 32 and 55 cc/100 gm/min. Lobar, basal ganglion, and brain-stem blood flow values frequently differed by 25% or more from global averages. Brain-stem CBF varied the most but did not correlate with clinical signs of brain-stem dysfunction. Double studies were performed at two different pCO2 values in 10 patients with various posttraumatic lesions, and the CO2 vasoresponsivity was calculated. Abnormal CO2 vasoresponsivity was found with acute subdural hematomas and defuse cerebral swelling but not with epidural hematomas. In patients without surgical mass lesions, the findings suggest that CBF in the first few hours after injury is often low, followed by a hyperemic phase that peaks at 24 hours. Global CBF values vary widely depending on the type of traumatic brain injury, and brain-stem flow is often not accurately reflected by global CBF values. These findings underscore the need to define regional CBF abnormalities in victims of severe head injury if treatment is intended to prevent regional ischemia.

Improved confidence of outcome prediction in severe head injury

1981 ◽  
Vol 54 (6) ◽  
pp. 751-762 ◽  
Author(s):  
Raj K. Narayan ◽  
Richard P. Greenberg ◽  
J. Douglas Miller ◽  
Gregory G. Enas ◽  
Sung C. Choi ◽  
...  
Keyword(s):  
Head Injury ◽  
Computerized Tomography ◽  
Clinical Data ◽  
Clinical Examination ◽  
Confidence Level ◽  
Severe Head Injury ◽  
Clinical Signs ◽  
Content Type ◽  
Gcs Score ◽  
Fine Print

✓ An analysis of clinical signs, singly or in combination, multimodality evoked potentials (MEP's), computerized tomography scans, and intracranial pressure (ICP) data was undertaken prospectively in 133 severely head-injured patients to ascertain the accuracy, reliability, and relative value of these indicants individually, or in various combinations, in predicting one of two categories of outcome. Erroneous predictions, either falsely optimistic (FO) or falsely pessimistic (FP), were analyzed to gain pathophysiological insights into the disease process. Falsely optimistic predictions occurred because of unpredictable complications, whereas FP predictions were due to intrinsic weakness of the indicants as prognosticators. A combination of clinical data, including age, Glasgow Coma Scale (GCS) score, pupillary response, presence of surgical mass lesions, extraocular motility, and motor posturing predicted outcome with 82% accuracy, 43% with over 90% confidence. Nine percent of predictions were FO and 9% FP. The GCS score alone was accurate in 80% of predictions, but at a lower level of confidence (25% at the over-90% level), with 7% FO and 13% FP. Computerized tomography and ICP data in isolation proved to be poor prognostic indicants. When combined individually with clinical data, however, they increased the number of predictions made with over 90% confidence to 52% and 55%, respectively. Data from MEP's represented the most accurate single prognostic indicant, with 91% correct predictions, 25% at the over-90% confidence level. There were no FP errors associated with this indicant. Supplementation of the clinical examination with MEP data yielded optimal prognostic power, an 89% accuracy rate, with 64% over the 90% confidence level and only 4% FP errors. The clinical examination remains the strongest basis for prognosticating outcome in severe head injury, but additional studies enhance the reliability of such predictions.

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