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Jorge RE, Starkstein SE. Pathophysiologic aspects of major depression following traumatic brain injury. J Head Trauma Rehabil 2006; 20:475-87. [PMID: 16304485 DOI: 10.1097/00001199-200511000-00001] [Citation(s) in RCA: 108] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Mood disorders, particularly major depression, are the most frequent complication of traumatic brain injury. Major depression is present in about 40% of patients hospitalization for a traumatic brain injury. Anxiety disorders, substance abuse, dysregulation of emotional expression, and aggressive outbursts are frequently associated with major depression, and their coexistence constitutes a marker of a more disabling clinical course. The complex interactions of genetic, developmental, and psychosocial factors determine patients' vulnerability to developing affective disturbances following a traumatic brain injury. Symptoms of depression cluster into the domains of low mood and distorted self-attitude, lack of motivation and anhedonia, subjective cognitive complaints, and hyperactive and disinhibited behavior. It is reasonable to assume that these symptomatic clusters have specific underlying mechanisms that need to be integrated in a comprehensive pathophysiologic model.
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Affiliation(s)
- Ricardo E Jorge
- Department of Psychiatry, University of Iowa, Iowa City, USA.
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102
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Belli A, Sen J, Petzold A, Russo S, Kitchen N, Smith M, Tavazzi B, Vagnozzi R, Signoretti S, Amorini AM, Bellia F, Lazzarino G. Extracellular N-acetylaspartate depletion in traumatic brain injury. J Neurochem 2006; 96:861-9. [PMID: 16371008 DOI: 10.1111/j.1471-4159.2005.03602.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
N-Acetylaspartate (NAA) is almost exclusively localized in neurons in the adult brain and is present in high concentration in the CNS. It can be measured by proton magnetic resonance spectroscopy and is seen as a marker of neuronal damage and death. NMR spectroscopy and animal models have shown NAA depletion to occur in various types of chronic and acute brain injury. We investigated 19 patients with traumatic brain injury (TBI). Microdialysis was utilized to recover NAA, lactate, pyruvate, glycerol and glutamate, at 12-h intervals. These markers were correlated with survival and a 6-month Glasgow Outcome Score. Eleven patients died and eight survived. A linear mixed model analysis showed a significant effect of outcome and of the interaction between time of injury and outcome on NAA levels (p = 0.009 and p = 0.004, respectively). Overall, extracellular NAA was 34% lower in non-survivors. A significant non-recoverable fall was observed in this group from day 4 onwards, with a concomitant rise in lactate-pyruvate ratio and glycerol. These results suggest that mitochondrial dysfunction is a significant contributor to poor outcome following TBI and propose extracellular NAA as a potential marker for monitoring interventions aimed at preserving mitochondrial function.
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Affiliation(s)
- Antonio Belli
- Victor Horsley Department of Neurosurgery, The National Hospital for Neurology and Neurosurgery, London, UK
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103
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Kantarci K, Petersen RC, Boeve BF, Knopman DS, Tang-Wai DF, O'Brien PC, Weigand SD, Edland SD, Smith GE, Ivnik RJ, Ferman TJ, Tangalos EG, Jack CR. 1H MR spectroscopy in common dementias. Neurology 2006; 63:1393-8. [PMID: 15505154 PMCID: PMC2766798 DOI: 10.1212/01.wnl.0000141849.21256.ac] [Citation(s) in RCA: 178] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE To determine the 1H MR spectroscopic (MRS) findings and intergroup differences among common dementias: Alzheimer disease (AD), vascular dementia (VaD), dementia with Lewy bodies (DLB), and frontotemporal lobar degeneration (FTLD). METHODS The authors consecutively recruited 206 normal elderly subjects and 121 patients with AD, 41 with FTLD, 20 with DLB, and 8 with VaD. The 1H MRS metabolite ratio changes in common dementias were evaluated with respect to normal and also differences among the common dementias. RESULTS N-acetylaspartate (NAA)/creatine (Cr) was lower than normal in patients with AD, FTLD, and VaD. Myo-inositol (mI)/Cr was higher than normal in patients with AD and FTLD. Choline (Cho)/Cr was higher than normal in patients with AD, FTLD, and DLB. There were no metabolite differences between patients with AD and FTLD or between patients with DLB and VaD. NAA/Cr was lower in patients with AD and FTLD than DLB. MI/Cr was higher in patients with AD and FTLD than VaD. MI/Cr was also higher in patients with FTLD than DLB. CONCLUSIONS NAA/Cr levels are decreased in dementias that are characterized by neuron loss, such as AD, FTLD, and VaD. MI/Cr levels are elevated in dementias that are pathologically characterized by gliosis, such as AD and FTLD. Cho/Cr levels are elevated in dementias that are characterized by a profound cholinergic deficit, such as AD and DLB.
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Affiliation(s)
- Kejal Kantarci
- Department of Diagnostic Radiology, Mayo Clinic, Rochester, Minnesota
| | - Ronald C. Petersen
- Department of Neurology, Mayo Clinic, Rochester, Minnesota
- Department of Health Sciences Research, Mayo Clinic, Rochester, Minnesota
| | | | | | | | - Peter C. O'Brien
- Department of Clinical Epidemiology, Mayo Clinic, Rochester, Minnesota
| | | | - Steven D. Edland
- Department of Clinical Epidemiology, Mayo Clinic, Rochester, Minnesota
| | - Glenn E. Smith
- Departments of Psychiatry and Psychology, Mayo Clinic, Rochester, Minnesota
| | - Robert J. Ivnik
- Departments of Psychiatry and Psychology, Mayo Clinic, Rochester, Minnesota
| | - Tanis J. Ferman
- Departments of Psychiatry and Psychology, Mayo Clinic, Jacksonville, Florida
| | - Eric G. Tangalos
- Department of Internal Medicine, Mayo Clinic, Rochester, Minnesota
| | - Clifford R. Jack
- Department of Diagnostic Radiology, Mayo Clinic, Rochester, Minnesota
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104
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Soher BJ, Doraiswamy PM, Charles HC. A Review of 1H MR Spectroscopy Findings in Alzheimer's Disease. Neuroimaging Clin N Am 2005; 15:847-52, xi. [PMID: 16443495 DOI: 10.1016/j.nic.2005.09.013] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Hydrogen-1 MR spectroscopy (MRS) studies demonstrate metabolic differences between patients who have Alzheimer's disease (AD) and cognitive normal age-matched controls. Clinical MRS also shows regional variations in metabolites between patients who have AD and those who have other dementias. Single-voxel and volumetric standard MRS techniques and automated data processing software are available for clinical MR scanners. Improvements in specificity and sensitivity of AD diagnosis, using MRS techniques as an adjunct to clinical imaging, are under evaluation. Multiparametric data analyses show, however, that metabolite changes correlate with in-vitro, postmortem, and metabolic changes and to changes in or predictions of cognitive scores.
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Affiliation(s)
- Brian J Soher
- Center for Advanced MR Development, Department of Radiology, Duke University Medical Center, Durham, NC 27710, USA.
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105
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Abstract
PURPOSE OF REVIEW Behavioral and psychiatric disturbances are the more frequent consequences of traumatic brain injury and major determinants of the quality of life of patients. This review was designed to familiarize the reader with the more recent work published in this field. RECENT FINDINGS We have now a more consistent view of the epidemiology of post-traumatic brain injury psychiatric disorders both in adult and pediatric populations. Mood disorders, anxiety disorders and substance use disorders are the more prevalent psychiatric diagnoses among traumatic brain injury patients. The phenomenological characteristics and clinical correlates of major depression, post-traumatic stress disorder, alcohol use disorders, and post-traumatic brain injury attention deficit hyperactivity disorder have been studied in more detail. Newer structural, metabolic and functional neuroimaging techniques help to clarify the pathogenesis of these disorders. In turn, this knowledge may lead to the implementation of more efficient therapeutic interventions. Unfortunately, controlled treatment studies have been the exception in the field, and treatment decisions usually lack adequate empirical support. SUMMARY Recent advances in the basic neuroscience of traumatic brain injury as well as in behavioral genetics, social science and neuroimaging techniques should contribute to a better understanding of the pathophysiology of the psychiatric disorders occurring after the injury. There is a great need for randomized, double-blind, placebo-controlled trials to establish the most effective treatments for these disorders.
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Affiliation(s)
- Ricardo E Jorge
- Department of Psychiatry, Roy J and Lucille A Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA.
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106
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Payen JF, Francony G, Fauvage B, Le Bas JF. [Contribution of magnetic resonance spectroscopy in predicting severity and outcome in traumatic brain injury]. ACTA ACUST UNITED AC 2005; 24:522-7. [PMID: 15904731 DOI: 10.1016/j.annfar.2005.03.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Nuclear magnetic spectroscopy (MRS) is a useful method for noninvasively studying intracerebral metabolism. Proton MRS can identify markers of the neuronal viability (N-acetyl-aspartate, NAA), of the metabolism of cellular membranes (choline), of the cellular energy metabolism (creatine, lactate). In Phosphorus MRS, the peaks most readily identified are involved in the high-energy cellular metabolism (ATP, phosphocreatine, inorganic phosphate), and intracellular pH (pHi) can be determined using this method. MRS has been used in experimental models of traumatic brain injury (TBI), primarily to study the cellular metabolism and the relation between biochemical and histological changes after trauma. In trauma patients, significant changes in NAA, choline and pHi were found in both grey and white matter comparing with controls, and these alterations correlated with injury severity. Correlations have been reported between these biochemical changes (reduction in NAA, increase in choline) measured at 1 to 6 months after TBI and the clinical outcome of the patients. However, there are methodological issues which still impede to recommend MRS as a tool for predicting neurological outcome in the clinical setting.
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Affiliation(s)
- J-F Payen
- Département d'anesthésie-réanimation 1, hôpital Michallon, BP 217, 38043 Grenoble cedex 9, France.
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107
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Shutter L, Tong KA, Holshouser BA. Proton MRS in Acute Traumatic Brain Injury: Role for Glutamate/Glutamine and Choline for Outcome Prediction. J Neurotrauma 2004; 21:1693-705. [PMID: 15684761 DOI: 10.1089/neu.2004.21.1693] [Citation(s) in RCA: 98] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Proton magnetic resonance spectroscopy (MRS) is being used to evaluate individuals with acute traumatic brain injury and several studies have shown that changes in certain brain metabolites (N-acetylaspartate, choline) are associated with poor neurologic outcomes. The majority of previous MRS studies have been obtained relatively late after injury and none have examined the role of glutamate/ glutamine (Glx). We conducted a prospective MRS study of 42 severely injured adults to measure quantitative metabolite changes early (7 days) after injury in normal appearing brain. We used these findings to predict long-term neurologic outcome and to determine if MRS data alone or in combination with clinical outcome variables provided better prediction of long-term outcomes. We found that glutamate/glutamine (Glx) and choline (Cho) were significantly elevated in occipital gray and parietal white matter early after injury in patients with poor long-term (6-12-month) outcomes. Glx and Cho ratios predicted long-term outcome with 94% accuracy and when combined with the motor Glasgow Coma Scale score provided the highest predictive accuracy (97%). Somatosensory evoked potentials were not as accurate as MRS data in predicting outcome. Elevated Glx and Cho are more sensitive indicators of injury and predictors of poor outcome when spectroscopy is done early after injury. This may be a reflection of early excitotoxic injury (i.e., elevated Glx) and of injury associated with membrane disruption (i.e., increased Cho) secondary to diffuse axonal injury.
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Affiliation(s)
- Lori Shutter
- Department of Neurosurgery, University of Cincinnati Medical Center, Cincinnati, Ohio, USA
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108
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Abstract
Magnetic resonance imaging (MRI) is the neuroimaging method of choice for the noninvasive monitoring of patients with brain tumors due to the enormous amount of information it yields regarding the morphologic features of the lesion and surrounding parenchyma. Over the past decade, proton magnetic resonance spectroscopy (1H-MRS), which uses the same technology as MRI and can be performed during a routine clinical imaging examination, has been used to glean information about the metabolic status of the brain. Accurate interpretation of 1H-MRS data from individual patients requires an understanding of the various techniques for acquiring the data, the physiologic basis of the metabolic signatures obtained from different types of tumors, and the specificity of the technique. This review covers the basic physics of 1H-MRS, the spectral and physiological characteristics of the metabolites that are typically measured in various types of brain tumors, and the clinical utility of 1H-MRS with respect to diagnosis, therapeutic planning, and the assessment of response to treatment.
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109
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Moreno-Torres A, Pujol J, Soriano-Mas C, Deus J, Iranzo A, Santamaria J. Age-related metabolic changes in the upper brainstem tegmentum by MR spectroscopy. Neurobiol Aging 2004; 26:1051-9. [PMID: 15748785 DOI: 10.1016/j.neurobiolaging.2004.09.009] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2004] [Revised: 08/02/2004] [Accepted: 09/22/2004] [Indexed: 11/21/2022]
Abstract
Several neurodegenerative disorders have a profound metabolic and structural impact on the brainstem. MR spectroscopy provides metabolic information non-invasively and has the potential to characterize the changes associated with normal aging and differentiate them from neurodegenerative alterations. The present work was aimed at studying the upper brainstem tegmentum at the midbrain and pontine levels in 57 adult normal volunteers, aged 23-79 years, with long-echo time proton MR spectroscopy to evaluate possible regional differences and the effect of age. Higher ratios of N-acetyl aspartate (NAA)/total creatine (Cr) and choline-containing compounds (Cho)/Cr were observed in the pons compared to the midbrain, resulting from higher net NAA and Cho content. In the midbrain, there was a linear decline of NAA and Cho with age in subjects over 50, most probably related to neuronal tissue loss. In the pons, such an aging effect was not observed, with subjects over 50 showing higher Cr and Cho than the under-50 subjects. Our findings provided evidence of regional differences and suggest different effects of age on the two studied brainstem segments, hitherto undescribed.
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Affiliation(s)
- Angel Moreno-Torres
- Research Department, Centre Diagnòstic Pedralbes, 08950, Esplugues de Llobregat, Spain.
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110
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Ashwal S, Holshouser B, Tong K, Serna T, Osterdock R, Gross M, Kido D. Proton spectroscopy detected myoinositol in children with traumatic brain injury. Pediatr Res 2004; 56:630-8. [PMID: 15295080 DOI: 10.1203/01.pdr.0000139928.60530.7d] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Previous studies have shown that proton magnetic resonance spectroscopy (MRS) is useful in predicting neurologic prognosis in children with traumatic brain injury (TBI). Reductions in N-acetyl derived metabolites and presence of lactate have been predictive of poor outcomes. We examined another spectroscopy metabolite, myoinositol (mI), to determine whether it is altered after TBI. Found primarily in astrocytes, mI functions as an osmolyte and is involved in hormone response pathways and protein-kinase C activation. Myoinositol is elevated in the newborn brain and is increased in a variety of diseases. We studied 38 children (mean age 11 y; range 1.6-17 y) with TBI using quantitative short echo time occipital gray and parietal white matter proton MRS at a mean of 7 d (range 1-17 d) after injury. We found that occipital gray matter mI levels were increased in children with TBI (4.30 +/- 0.73) compared with controls (3.53 +/- 0.48; p = 0.003). We also found that patients with poor outcomes 6-12 mo after injury had higher mI levels (4.78 +/- 0.68) than patients with good outcomes (4.15 +/- 0.69; p < 0.05). Myoinositol is elevated after pediatric TBI and is associated with a poor neurologic outcome. The reasons for its elevation remain unclear but may be due to astrogliosis or to a disturbance in osmotic function.
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Affiliation(s)
- Stephen Ashwal
- Division of Child Neurology, Department of Pediatrics, Loma Linda University School of Medicine, Loma Linda, CA 92350, USA.
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111
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Bigler ED. Neuropsychological results and neuropathological findings at autopsy in a case of mild traumatic brain injury. J Int Neuropsychol Soc 2004; 10:794-806. [PMID: 15327725 DOI: 10.1017/s1355617704105146] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2003] [Revised: 03/17/2004] [Indexed: 01/16/2023]
Abstract
Autopsy studies were undertaken in a 47-year-old college-educated male patient who, 7 months prior to an unexpected death, had sustained a mild traumatic brain injury (TBI) as manifested by brief loss of consciousness and an initial Glasgow Coma Scale score of 14. The patient died from cardiac arrest secondary to an undiagnosed and unknown arteriosclerotic cardiovascular disease as assessed by the coroners office at the time of autopsy. Gross inspection of the brain at autopsy was normal; however, microscopic analysis demonstrated what were considered trauma findings of hemosiderin-laden macrophages in the perivascular space and macrophages in the white matter, particularly the section taken from the frontal lobe. The patient had partially returned to work at the time of death, but had encountered problems with diminished cognitive performance in his work as an appraiser. Neuropsychological studies were generally within normal limits although several tests of either speed of processing or short-term memory showed lower than expected performance. This case demonstrates the presence of subtle neuropathological changes in the brain of a patient who sustained a mild TBI and was still symptomatic for the residual effects of the injury 7 months post injury when he unexpectedly died.
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Affiliation(s)
- Erin D Bigler
- Departments of Psychology and Neuroscience, Brigham Young University, Provo, Utah 84602, USA.
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112
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Abstract
The neurophysiological basis of cognition is relatively unexplained, with most studies reporting weak relationships between cognition and measures of brain function, such as event-related potentials, brain size and cerebral blood flow. Magnetic resonance spectroscopy (MRS) is an in vivo method used to detect neurochemicals within the brain that are relevant to certain brain processes. The most widely used methods are 1H-MRS and 31P-MRS, which detect compounds that contain hydrogen and phosphorus, respectively. Recent studies have shown that the absolute concentrations or ratios of these neurochemicals, in particular N-acetyl aspartate (NAA), which is associated with neuronal viability, correlate with performance on neuropsychological tests or other measures of cognitive function in normal subjects. Many studies in adults and children have shown a relationship between neurometabolite values and cognitive status or extent of cognitive dysfunction in various neurological and neuropsychiatric disorders. We review these studies and conclude that MRS has potential applications for the study of cognitive processes in health and disease and may be used clinically for differential diagnosis, the early detection of pathology and the examination of longitudinal change.
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Affiliation(s)
- Amy J Ross
- School of Psychiatry, University of New South Wales, Kensington, New South Wales 2033, Australia.
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113
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Coles JP, Fryer TD, Smielewski P, Chatfield DA, Steiner LA, Johnston AJ, Downey SPMJ, Williams GB, Aigbirhio F, Hutchinson PJ, Rice K, Carpenter TA, Clark JC, Pickard JD, Menon DK. Incidence and mechanisms of cerebral ischemia in early clinical head injury. J Cereb Blood Flow Metab 2004; 24:202-11. [PMID: 14747747 DOI: 10.1097/01.wcb.0000103022.98348.24] [Citation(s) in RCA: 166] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Antemortem demonstration of ischemia has proved elusive in head injury because regional CBF reductions may represent hypoperfusion appropriately coupled to hypometabolism. Fifteen patients underwent positron emission tomography within 24 hours of head injury to map cerebral blood flow (CBF), cerebral oxygen metabolism (CMRO2), and oxygen extraction fraction (OEF). We estimated the volume of ischemic brain (IBV) and used the standard deviation of the OEF distribution to estimate the efficiency of coupling between CBF and CMRO2. The IBV in patients was significantly higher than controls (67 +/- 69 vs. 2 +/- 3 mL; P < 0.01). The coexistence of relative ischemia and hyperemia in some patients implies mismatching of perfusion to oxygen use. Whereas the saturation of jugular bulb blood (SjO2) correlated with the IBV (r = 0.8, P < 0.01), SjO2 values of 50% were only achieved at an IBV of 170 +/- 63 mL (mean +/- 95% CI), which equates to 13 +/- 5% of the brain. Increases in IBV correlated with a poor Glasgow Outcome Score 6 months after injury (rho = -0.6, P < 0.05). These results suggest significant ischemia within the first day after head injury. The ischemic burden represented by this "traumatic penumbra" is poorly detected by bedside clinical monitors and has significant associations with outcome.
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Affiliation(s)
- Jonathan P Coles
- The Division of Anaesthesia, and The Wolfson Brain Imaging Centre, University of Cambridge, Addenbrooke's Hospital, Cambridge, UK
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114
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Ashwal S, Holshouser BA, del Rio MJ, Tong KA, Applegate RL, Bailey LL. Serial proton magnetic resonance spectroscopy of the brain in children undergoing cardiac surgery. Pediatr Neurol 2003; 29:99-110. [PMID: 14580652 DOI: 10.1016/s0887-8994(03)00045-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
We used proton magnetic resonance spectroscopy to study 11 children (age < 8 years) with congenital heart disease undergoing cardiopulmonary bypass to determine whether low (10 +/- 4; n = 6) vs high (20 +/- 4; n = 5) perfusate hematocrits during bypass resulted in changes in brain metabolites which correlate with neurologic injury. Long and short echo time single voxel magnetic resonance spectroscopy in occipital gray matter and neurologic assessment were performed preoperatively and 2 and 5 days postoperatively. We also determined whether prolonged periods at low flow rates during bypass affected spectroscopy variables. We found no significant differences in metabolite ratios between the low vs high hematocrit groups or the lower vs higher flow rate groups (repeated measures analysis of variance of observation ranks converted to normal scores). However, our study was limited by statistical power due to the small sample size, therefore no conclusions could be made. Additional studies involving a greater number of patients are necessary. In all 11 children, magnetic resonance spectroscopy detected a significant decrease in brain N-acetyl-aspartate, and increases in myoinositol and glutamate/glutamine after surgery (Quade test) demonstrating that magnetic resonance spectroscopy is sensitive in detecting subtle postoperative changes in brain metabolites.
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Affiliation(s)
- Stephen Ashwal
- Department of Pediatrics, Loma Linda University School of Medicine, Loma Linda, CA 92350, USA
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115
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Schuhmann MU, Stiller D, Skardelly M, Bernarding J, Klinge PM, Samii A, Samii M, Brinker T. Metabolic changes in the vicinity of brain contusions: a proton magnetic resonance spectroscopy and histology study. J Neurotrauma 2003; 20:725-43. [PMID: 12965052 DOI: 10.1089/089771503767869962] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Proton MR spectroscopy (1H-MRS) has been previously used to monitor metabolic changes in areas of diffuse brain injury. We studied metabolism in the close vicinity of experimental traumatic brain contusions and remote on the contralateral side from 1h to 28d post-injury. Changes of creatine and phosphocreatine (Cr&PCr), N-acetylaspartate (NAA), choline (Cho), inositol (Ino), taurine (Tau), glutamate (Glu), and lactate (Lac) were assessed and compared to neuronal, glial and inflammatory changes in histology. In the pericontusional zone Cr&PCr, NAA, and Glu decreased immediately after trauma by -35%, -60%, and -37%, respectively, related to primary cell disintegration and secondary perturbations as reflected in histology. These metabolites partially recovered at 7d (-15%, -37%, and -21% respectively), in parallel to indicators of repair in immunhistochemistry. Control levels were not regained at 28d, in correlation to a decrease of viable neurons. Cho and Ino, initially lowered by -26% and -31% respectively, increased at 7d by +74% and 31%, reflecting glial activation and proliferation. The signal including the lactate resonance increased by >1000% with a maximum at 7d, possibly related to energy failure, inflammation and glial activation. A partial contribution of lipids to this signal cannot be fully excluded. The contralateral side showed mild astroglial activation in histology, but no changes in 1H-MRS. The study demonstrates the feasibility of volume selective 1H-MRS using the LCModel (Linear Combination of Model in vitro spectra of metabolites solutions) to monitor metabolic changes close to focal traumatic lesions and suggests how metabolic alterations can be differentiated in cause.
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Affiliation(s)
- Martin Ulrich Schuhmann
- Department of Pediatric Neurosurgery, Wayne State University School of Medicine, Children's Hospital of Michigan, Detroit, Michigan, USA.
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116
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Kotwal GJ, Lahiri DK, Hicks R. Potential intervention by vaccinia virus complement control protein of the signals contributing to the progression of central nervous system injury to Alzheimer's disease. Ann N Y Acad Sci 2002; 973:317-22. [PMID: 12485887 DOI: 10.1111/j.1749-6632.2002.tb04659.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Traumatic brain injury (TBI) is one of the few known risk factors for Alzheimers disease (AD) and for depression. The mechanisms by which trauma causes delayed cognitive deficits are largely unknown. In recent studies, it was demonstrated that the complement system (an important component of the immune system and a mediator of inflammation) is activated both in human AD and following experimental TBI in rats. Amyloid proteins are also present in AD and following TBI, and are known to activate complement in vitro. Based on these and other previous studies, it was hypothesized that regulation of the complement system will attenuate the long-term consequences of TBI. Vaccinia virus complement control protein (VCP) is a protein encoded by vaccinia virus. It blocks both the classic and alternative pathways of complement activation in vitro, and by doings so prevents the generation of proinflammatory chemotactic factors. Based on in vitro studies VCP can block the complement activation by the amyloid beta peptide. Using a fluid percussion rat model that causes traumatic brain injury (TBI), it was found that VCP significantly enhances functional recovery as determined by the Morris Water Maze test. Taken togther these studies indicate that potentially VCP could block molecular signals such as the formation of amyloid beta or the activation of complement to inhibit formation of AD following TBI.
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Affiliation(s)
- Girish J Kotwal
- Department of Microbiology and Immunology, University of Louisville School of Medicine, Louisville, Kentucky 40202, USA.
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117
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Abstract
Diffuse axonal shear injury is a common traumatic brain injury, with significant neurologic and behavioral impact on patients. Radiologic recognition of this entity and understanding of its sequelae can be of utmost importance in the prediction of outcome and planning for rehabilitation. MRI has proven to be the optimal means of detection and characterization of DAI lesions, with GRE and FLAIR sequences being particularly helpful, and more advanced techniques such as MRS show preliminary evidence of some utility in determining outcome.
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Affiliation(s)
- Dima A Hammoud
- Division of Neuroradiology, Johns Hopkins University School of Medicine, 600 North Wolfe Street, Phipps B-100, Baltimore, MD 21287, USA
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118
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Signoretti S, Marmarou A, Tavazzi B, Lazzarino G, Beaumont A, Vagnozzi R. N-Acetylaspartate reduction as a measure of injury severity and mitochondrial dysfunction following diffuse traumatic brain injury. J Neurotrauma 2001; 18:977-91. [PMID: 11686498 DOI: 10.1089/08977150152693683] [Citation(s) in RCA: 171] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
N-Acetylaspartate (NAA) is considered a neuron-specific metabolite and its reduction a marker of neuronal loss. The objective of this study was to evaluate the time course of NAA changes in varying grades of traumatic brain injury (TBI), in concert with the disturbance of energy metabolites (ATP). Since NAA is synthesized by the mitochondria, it was hypothesized that changes in NAA would follow ATP. The impact acceleration model was used to produce three grades of TBI. Sprague-Dawley rats were divided into the following four groups: sham control (n = 12); moderate TBI (n = 36); severe TBI (n = 36); and severe TBI coupled with hypoxia-hypotension (n = 16). Animals were sacrificed at different time points ranging from 1 min to 120 h postinjury, and the brain was processed for high-performance liquid chromatography (HPLC) analysis of NAA and ATP. After moderate TBI, NAA reduced gradually by 35% at 6 h and 46% at 15 h, accompanied by a 57% and 45% reduction in ATP. A spontaneous recovery of NAA to 86% of baseline at 120 h was paralleled by a restoration in ATP. In severe TBI, NAA fell suddenly and did not recover, showing critical reduction (60%) at 48 h. ATP was reduced by 70% and also did not recover. Maximum NAA and ATP decrease occurred with secondary insult (80% and 90%, respectively, at 48 h). These data show that, at 48 h post diffuse TBI, reduction of NAA is graded according to the severity of insult. NAA recovers if the degree of injury is moderate and not accompanied by secondary insult. The highly similar time course and correlation between NAA and ATP supports the notion that NAA reduction is related to energetic impairment.
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Affiliation(s)
- S Signoretti
- Division of Neurosurgery, Medical College of Virginia, Virginia Commonwealth University, Richmond 23298-0508, USA
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119
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Kobayashi M, Takayama H, Suga S, Mihara B. Longitudinal changes of metabolites in frontal lobes after hemorrhagic stroke of basal ganglia: a proton magnetic resonance spectroscopy study. Stroke 2001; 32:2237-45. [PMID: 11588307 DOI: 10.1161/hs1001.096621] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE We investigated serial metabolic changes in frontal lobes of patients with deep intracerebral hemorrhage (ICH) to examine the correlation between N-acetylaspartate (NAA) and degree of motor impairment or clinical outcome. METHODS - Twenty patients with deep ICH were examined with proton magnetic resonance spectroscopy with the application of a multivoxel method (1 voxel=10x10x20 mm; 64 voxels). NAA/creatine ratios in the white matter of the primary motor and premotor areas on both sides were measured sequentially: within 48 hours, at 2 weeks, and 1 month after onset. The National Institutes of Health Stroke Scale and Barthel Index for disability were measured for each patient. RESULTS - In the primary motor area on the affected side, where the hematoma did not extend, the NAA/creatine ratio decreased sequentially. At 48 hours and 2 weeks after onset, a negative correlation was detected between NAA/creatine and hematoma volume, but there was no correlation 1 month later. At 2 weeks, NAA/creatine correlated negatively with motor impairment (r=-0.750), and there was a significant correlation with clinical outcome as early as 2 weeks after onset (r=0.954). These sequential changes of NAA/creatine varied according to patients' long-term clinical outcome. Patients with poor outcome demonstrated notable reduction of NAA/creatine over the bilateral frontal lobes. CONCLUSIONS - The delayed gradual reduction of NAA/creatine ratio in the frontal lobes correlates with motor deficit and clinical outcome after deep ICH, suggesting that the neural networks in the frontal lobe could be important for recovery.
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Affiliation(s)
- M Kobayashi
- Department of Neurosurgery, Institute of Brain and Blood Vessels, Mihara Memorial Hospital, Isesaki, Japan.
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120
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Abstract
Quantitative neuroimaging has now become a well-established method for analyzing magnetic resonance imaging in traumatic brain injury (TBI). A general review of studies that have examined quantitative changes following TBI is presented. The consensus of quantitative neuroimaging studies is that most brain structures demonstrate changes in volume or surface area after injury. The patterns of atrophy are consistent with the generalized nature of brain injury and diffuse axonal injury. Various clinical caveats are provided including how quantitative neuroimaging findings can be used clinically and in predicting rehabilitation outcome. The future of quantitative neuroimaging also is discussed.
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Affiliation(s)
- E D Bigler
- Department of Psychology, Brigham Young University, Provo, Utah, USA.
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121
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Brooks WM, Friedman SD, Gasparovic C. Magnetic resonance spectroscopy in traumatic brain injury. J Head Trauma Rehabil 2001; 16:149-64. [PMID: 11275576 DOI: 10.1097/00001199-200104000-00005] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Magnetic resonance spectroscopy (MRS) offers a unique non-invasive approach for assessing the metabolic status of the brain in vivo and is particularly suited to studying traumatic brain injury (TBI). In particular, MRS provides a noninvasive means for quantifying such neurochemicals as N-acetylaspartate (NAA), creatine, phosphocreatine, choline, lactate, myo-inositol, glutamine, glutamate, adenosine triphosphate (ATP), and inorganic phosphate in humans following TBI and in animal models. Many of these chemicals have been shown to be perturbed following TBI. NAA, a marker of neuronal integrity, has been shown to be reduced following TBI, reflecting diffuse axonal injury or metabolic depression, and concentrations of NAA predict cognitive outcome. Elevation of choline-containing compounds indicates membrane breakdown or inflammation or both. MRS can also detect alterations in high energy phosphates reflecting the energetic abnormalities seen after TBI. Accordingly, MRS may be useful to monitor cellular response to therapeutic interventions in TBI.
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Affiliation(s)
- W M Brooks
- Clinical and Magnetic Resonance Research Center; Department of Neurosciences, University of New Mexico Health Sciences Center, Albuquerque, 87131, USA.
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122
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Gasparovic C, Arfai N, Smid N, Feeney DM. Decrease and recovery of N-acetylaspartate/creatine in rat brain remote from focal injury. J Neurotrauma 2001; 18:241-6. [PMID: 11284545 DOI: 10.1089/08977150151070856] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Magnetic resonance spectroscopy (MRS) studies on traumatic brain injury (TBI) have shown that the neuronal metabolite N-acetylaspartate (NAA) may be reduced in regions of brain remote from sites of focal injury. Such reductions have generally been attributed to diffuse axonal injury (DAI) or neuron death. The aim of the present study was to investigate the contribution of metabolic depression, in the absence of DAI or cell death, to remote NAA reduction after TBI. The right sensorimotor cortices of adult rats were injured by weight drop. Two and six days later, tissue slices from the ipsilateral occipital cortex, or from the same region in uninjured rats, were superfused and examined by 1H-MRS. The occipital cortex has been shown to have negligible DAI or cell death but marked transient metabolic depression in this model of TBI. Two days after injury, the ratio of the NAA peak height to the total creatine peak height (NAA/TCr) was 14% lower than in control samples. Six days after injury, NAA/TCr recovered to within 7% of the control value. The time course of NAA/TCr decrease and recovery was similar to the time courses of widespread depression and recovery of 2-deoxyglucose uptake and mitochondrial alpha-glycerophosphate dehydrogenase activity measured previously in this model of TBI. Together, these results suggest that at least one component of remote NAA depression after TBI may be associated with a widespread and reversible metabolic depression that is unrelated to either DAI or cell death.
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Affiliation(s)
- C Gasparovic
- Department of Neurosciences, University of New Mexico School of Medicine, Albuquerque 87131, USA.
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Wennerberg AB, Jonsson T, Forssberg H, Li TQ. Current awareness in NMR in biomedicine. NMR IN BIOMEDICINE 2001; 14:48-53. [PMID: 11252040 DOI: 10.1002/nbm.667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
In order to keep subscribers up-to-date with the latest developments in their field, John Wiley & Sons are providing a current awareness service in each issue of the journal. The bibliography contains newly published material in the field of NMR in biomedicine. Each bibliography is divided into 9 sections: 1 Books, Reviews ' Symposia; 2 General; 3 Technology; 4 Brain and Nerves; 5 Neuropathology; 6 Cancer; 7 Cardiac, Vascular and Respiratory Systems; 8 Liver, Kidney and Other Organs; 9 Muscle and Orthopaedic. Within each section, articles are listed in alphabetical order with respect to author. If, in the preceding period, no publications are located relevant to any one of these headings, that section will be omitted.
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Affiliation(s)
- A B Wennerberg
- Department of KARO, Division of Diagnostic Radiology, Karolinska Institutet, Huddinge University Hospital, SE-141 86 Stockholm, Sweden
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