151
|
Dager SR, Friedman SD, Petropoulos H, Shaw DW. Imaging Evidence for Pathological Brain Development in Autism Spectrum Disorders. AUTISM : THE INTERNATIONAL JOURNAL OF RESEARCH AND PRACTICE 2008. [DOI: 10.1007/978-1-60327-489-0_17] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
|
152
|
Endo T, Shioiri T, Kitamura H, Kimura T, Endo S, Masuzawa N, Someya T. Altered chemical metabolites in the amygdala-hippocampus region contribute to autistic symptoms of autism spectrum disorders. Biol Psychiatry 2007; 62:1030-7. [PMID: 17631869 DOI: 10.1016/j.biopsych.2007.05.015] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2007] [Revised: 04/13/2007] [Accepted: 05/10/2007] [Indexed: 11/16/2022]
Abstract
BACKGROUND Although several previous studies have been conducted, the neural basis of autism spectrum disorder (ASD) is poorly understood. The objective of the present study was to determine whether individuals with ASD have altered brain chemical metabolites and whether such alterations are related to their autistic symptoms. METHODS N-acetylaspartate (NAA)/creatine (Cr) and choline/Cr ratios in the right medial temporal lobe (MTL), medial prefrontal cortex, and cerebellar vermis were measured in 38 individuals with ASD (mean age = 12.9 years), including 12 with autism, 15 with Asperger's Disorder, and 11 with pervasive developmental disorder not otherwise specified (PDD-NOS), and 16 matched healthy control subjects (mean age = 11.5 years) with proton magnetic resonance spectroscopy. Autistic symptoms were assessed by the Childhood Autistic Rating Scale-Tokyo Version. RESULTS There was a significant group difference for NAA/Cr ratio in the right MTL between the autism, Asperger's Disorder, PDD-NOS, and control groups (p < .001), and the autism group had a significantly lower NAA/Cr ratio compared with the PDD-NOS (p < .001) and control (p < .001) groups. In the ASD group, there was a significant negative correlation between NAA/Cr ratio in the right MTL and their Childhood Autistic Rating Scale-Tokyo Version total scores (r = -.44, p = .01) and subscales of emotional response (r = -.38, p = .02) and listening response (r = -.54, p = .001). CONCLUSIONS The results of the present study suggest that subjects with ASD have abnormalities of neural integrity in the amygdala-hippocampus region that are related to their severity and social impairments.
Collapse
Affiliation(s)
- Taro Endo
- Department of Psychiatry, Niigata University Graduate School of Medical and Dental Science, Niigata City, Niigata, Japan
| | | | | | | | | | | | | |
Collapse
|
153
|
Abstract
The noninvasive localization of the epileptogenic zone continues to be a challenge in many patients that present as candidates for possible epilepsy surgery. Magnetic resonance imaging (MRI) techniques provide accurate anatomical definition, but despite their high resolution, these techniques fail to visualize the pathological neocortical and hippocampal changes in a sizable number of patients with focal pathologies. Further, visualized lesions on MRI may not all produce seizures. One of the keys to the understanding of the epileptogenic zone lies in the recognition of the metabolic alterations that occur in the setting of epileptic seizures. Magnetic resonance spectroscopy (MRS) is a valuable tool that can be used to study the metabolic changes seen in both acute and chronic animal models of epilepsy. Such study allows for the identification of epileptic tissue with high sensitivity and specificity. We present here a review of the use of MRS in animal models of epilepsy.
Collapse
Affiliation(s)
- Girish K Hiremath
- Department of Neurosurgery, Cleveland Clinic Epilepsy Center, Neurological Institute, Cleveland, Ohio 44195, USA
| | | |
Collapse
|
154
|
Rigotti DJ, Inglese M, Gonen O. Whole-brain N-acetylaspartate as a surrogate marker of neuronal damage in diffuse neurologic disorders. AJNR Am J Neuroradiol 2007; 28:1843-9. [PMID: 17921226 DOI: 10.3174/ajnr.a0774] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Proton MR spectroscopy (1H-MR spectroscopy) is a quantitative MR imaging technique often used to complement the sensitivity of conventional MR imaging with specific metabolic information. A key metabolite is the amino acid derivative N-acetylaspartate (NAA), which is almost exclusive to neurons and their processes and is, therefore, an accepted marker of their health and attenuation. Unfortunately, most 1H-MR spectroscopy studies only account for small 1- to 200-cm volumes of interest (VOI), representing less than 20% of the total brain volume. These VOIs have at least 5 additional restrictions: 1) To avoid contamination from subcutaneous and bone marrow lipids, they must be placed away from the skull, thereby missing most of the cortex. 2) They must be image-guided onto MR imaging-visible pathology, subjecting them to the implicit assumption that metabolic changes occur only there. 3) They encounter misregistration errors in serial studies. 4) The time needed to accumulate sufficient signal-intensity quality is often restrictive, and 5) they incur (unknown) T1- and T2-weighting. All these issues are avoided (at the cost of specific localization) by measuring the nonlocalized average NAA concentration over the entire brain. Indeed, whole-brain NAA quantification has been applied to several diffuse neurodegenerative diseases (where specific localization is less important than the total load of the pathology), and the results are presented in this review.
Collapse
Affiliation(s)
- D J Rigotti
- Department of Radiology, New York University School of Medicine, New York, NY10016, USA
| | | | | |
Collapse
|
155
|
Rigotti DJ, Inglese M, Babb JS, Rovaris M, Benedetti B, Filippi M, Grossman RI, Gonen O. Serial whole-brain N-acetylaspartate concentration in healthy young adults. AJNR Am J Neuroradiol 2007; 28:1650-1. [PMID: 17893213 PMCID: PMC8134197 DOI: 10.3174/ajnr.a0712] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Although the concentration of N-acetylaspartate (NAA) is often used as a neuronal integrity marker, its normal temporal variations are not well documented. To assess them over the 1-2 year periods of typical clinical trials, the whole-brain NAA concentration was measured longitudinally, over 4 years, in a cohort of healthy young adults. No significant change (adjusted for both sex and age) was measured either interpersonally or intrapersonally over the entire duration of the study.
Collapse
Affiliation(s)
- D J Rigotti
- Department of Radiology, New York University School of Medicine, New York, NY 10016, USA
| | | | | | | | | | | | | | | |
Collapse
|
156
|
Abstract
Over the past two decades, proton magnetic resonance spectroscopy (proton MRS) of the brain has made the transition from research tool to a clinically useful modality. In this review, we first describe the localization methods currently used in MRS studies of the brain and discuss the technical and practical factors that determine the applicability of the methods to particular clinical studies. We also describe each of the resonances detected by localized solvent-suppressed proton MRS of the brain and discuss the metabolic and biochemical information that can be derived from an analysis of their concentrations. We discuss spectral quantitation and summarize the reproducibility of both single-voxel and multivoxel methods at 1.5 and 3-4 T. We have selected three clinical neurologic applications in which there has been a consensus as to the diagnostic value of MRS and summarize the information relevant to clinical applications. Finally, we speculate about some of the potential technical developments, either in progress or in the future, that may lead to improvements in the performance of proton MRS.
Collapse
Affiliation(s)
- Yael Rosen
- Department of Radiology, Beth Israel Deaconess Medical Center, Harvard Medical School, 02215 Boston, Massachusetts
| | - Robert E. Lenkinski
- Department of Radiology, Beth Israel Deaconess Medical Center, Harvard Medical School, 02215 Boston, Massachusetts
| |
Collapse
|
157
|
Hammen T, Schwarz M, Doelken M, Kerling F, Engelhorn T, Stadlbauer A, Ganslandt O, Nimsky C, Doerfler A, Stefan H. 1H-MR spectroscopy indicates severity markers in temporal lobe epilepsy: correlations between metabolic alterations, seizures, and epileptic discharges in EEG. Epilepsia 2007; 48:263-9. [PMID: 17295619 DOI: 10.1111/j.1528-1167.2006.00856.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
PURPOSE In this study, hippocampal metabolite alterations in (1)H-MR spectroscopy ((1)H-MRS) were correlated to the findings of intensive video-EEG monitoring and duration of seizure symptoms in patients with temporal lobe epilepsy (TLE). METHODS The 14 patients with mesial TLE and no pathological findings in imaging were investigated by (1)H-MRS. Seizures were analyzed by: number of clinical seizures in 24 h, exact duration of clinical symptoms in 24 h, frequency of interictal epileptiform discharges (IEDs) and ictal activity, duration of ictal activity, and IEDs occurring within 24 h in intensive EEG monitoring. Pearson Correlation Coefficient (PCC) was calculated between spectral metabolite alterations and the parameters mentioned above. RESULTS In the analysis, a negative correlation was found between total (t) NAA values and degree of IEDs in EEG (p = 0.04); a positive correlation was found between Cr levels and duration of seizure symptoms registered by video monitoring (p = 0.01). CONCLUSIONS Our study shows that, in some patients, (1)H-MRS is able to refer the severity of TLE. The degree of tNAA reduction in (1)H-MRS, probably indicating neuronal dysfunction, is associated with interictal spiking in intensive EEG monitoring. Duration of seizure symptoms associated with increased Cr peaks probably reflects increased gliosis.
Collapse
Affiliation(s)
- Thilo Hammen
- Center Epilepsy Erlangen, Department of Neurology, University of Erlangen-Nuremberg, Erlangen, Germany
| | | | | | | | | | | | | | | | | | | |
Collapse
|
158
|
Choi JK, Dedeoglu A, Jenkins BG. Application of MRS to mouse models of neurodegenerative illness. NMR IN BIOMEDICINE 2007; 20:216-37. [PMID: 17451183 DOI: 10.1002/nbm.1145] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
The rapid development of transgenic mouse models of neurodegenerative diseases, in parallel with the rapidly expanding growth of MR techniques for assessing in vivo, non-invasive, neurochemistry, offers the potential to develop novel markers of disease progression and therapy. In this review we discuss the interpretation and utility of MRS for the study of these transgenic mouse and rodent models of neurodegenerative diseases such as Alzheimer's (AD), Huntington's (HD) and Parkinson's disease (PD). MRS studies can provide a wealth of information on various facets of in vivo neurochemistry, including neuronal health, gliosis, osmoregulation, energy metabolism, neuronal-glial cycling, and molecular synthesis rates. These data provide information on the etiology, natural history and therapy of these diseases. Mouse models enable longitudinal studies with useful time frames for evaluation of neuroprotection and therapeutic interventions using many of the potential MRS markers. In addition, the ability to manipulate the genome in these models allows better mechanistic understanding of the roles of the observable neurochemicals, such as N-acetylaspartate, in the brain. The argument is made that use of MRS, combined with correlative histology and other MRI techniques, will enable objective markers with which potential therapies can be followed in a quantitative fashion.
Collapse
Affiliation(s)
- Ji-Kyung Choi
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
| | | | | |
Collapse
|
159
|
Vrenken H, Geurts JJG. Gray and normal-appearing white matter in multiple sclerosis: an MRI perspective. Expert Rev Neurother 2007; 7:271-9. [PMID: 17341175 DOI: 10.1586/14737175.7.3.271] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Besides focal white matter lesions, multiple sclerosis brain tissue also displays abnormalities in the gray matter and the normal-appearing white matter. Recent advances in magnetic resonance imaging studies of both types of tissue are discussed. Herein, normal-appearing white matter abnormalities are being found in quantitative magnetic resonance investigations, consistent with a limited degree of axonal damage and/or demyelination, and an increase of glial cells, but the specific nature of the histopathological changes underlying the quantitative magnetic resonance abnormalities remains unclear. Gray matter studies have demonstrated that much of the disease process remains undetected by conventional magnetic resonance imaging. Although newly developed techniques, such as 3D double-inversion recovery, may greatly improve detection of cortical pathology, it remains important to investigate the resultant effects on the cortical tissue alongside this, by studying integrity of normal-appearing cortical tissue through quantitative magnetic resonance studies, as well as the net neurodegenerative effect through measurements of cortical thickness and cortical atrophy (rates). To improve our understanding of normal-appearing white and gray matter changes, their mutual relations, and their relations to clinical changes, further in vivo magnetic resonance imaging studies are required. Specifically, it is proposed that more spatially specific investigations, ideally utilizing subject-specific anatomical information from, for example, diffusion fiber-tracking techniques, could be used to gain more insight into the relations between normal-appearing white matter changes, cortical changes, magnetic resonance visible focal-lesions, and physical and cognitive deficits.
Collapse
Affiliation(s)
- Hugo Vrenken
- MS Center Amsterdam, VU University Medical Center, Department of Physics & Medical Technology, De Boelelaan, Amsterdam, The Netherlands.
| | | |
Collapse
|
160
|
Minati L, Grisoli M, Bruzzone MG. MR spectroscopy, functional MRI, and diffusion-tensor imaging in the aging brain: a conceptual review. J Geriatr Psychiatry Neurol 2007; 20:3-21. [PMID: 17341766 DOI: 10.1177/0891988706297089] [Citation(s) in RCA: 98] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
In vivo magnetic resonance spectroscopy (MRS), functional magnetic resonance imaging (fMRI), and diffusion-tensor imaging (DTI) have recently opened new possibilities for noninvasively assessing the metabolic, functional, and connectivity correlates of aging in research and clinical settings. The purpose of this article is to provide a conceptual review intended for a multidisciplinary audience, covering physical principles and main findings related to normal aging and senile cognitive impairment. This article is divided into 3 sections, dedicated to MRS, to fMRI, and to DTI. The spectroscopy section surveys physiological function of the observable metabolites, concentration changes in normal aging and their interpretation, and correlation with cognitive performance. The functional MRI section surveys the hemispheric asymmetry reduction model from compensation and de-differentiation viewpoints, memory encoding, retrieval and consolidation, inhibitory control, perception and action, resting-state networks, and functional deactivations. The DTI section surveys age-related changes, correlation with behavioral scores, and transition to cognitive impairment.
Collapse
Affiliation(s)
- L Minati
- Scientific Direction Unit, Istituto Nazionale Neurologico Carlo Besta, Milan, Italy.
| | | | | |
Collapse
|
161
|
Abstract
Developmental delay (DD) affects approximately 1% to 3% of all children in the United States. This diagnosis significantly impedes quality of life and full participation in the life of the family, school, and community. In this setting, the clinician's ability to detect, diagnose, and possibly treat the cause for DD in a timely manner depends on a multimodality approach to neuroimaging and a robust understanding of the various imaging algorithms aimed at determining the etiology of disease, structural and/or anatomic defects, functional activity, metabolic profiles, and genetic characteristics. Taken separately and in combination, these features are effectively depicted and analyzed using an array of brain imaging modalities: ultrasound, computed tomography, nuclear medicine, magnetic resonance (MR) spectroscopy, and a growing mix of sophisticated MR imaging (MRI) techniques, including diffusion-weighted imaging, diffusion tensor imaging, perfusion MRI, and functional MRI. Thus, equipped with these advanced imaging capabilities, pediatric neurologists and neuroradiologists are now positioned to diagnose with greater accuracy and speed; this, in turn, results in more effective treatment plans and improved patient outcomes as measured by progress in reaching developmental milestones and in ameliorating secondary conditions such as seizures, poor motor control, incontinence, and impulsivity. The purpose of this article is to present the numerous causes of pediatric DD, describe their respective neuroimaging findings, discuss various neuroimaging approaches for elucidating etiology, and offer specific guidelines for optimizing imaging results in the setting of multimodality imaging capabilities.
Collapse
|
162
|
Gallinat J, Lang UE, Jacobsen LK, Bajbouj M, Kalus P, von Haebler D, Seifert F, Schubert F. Abnormal hippocampal neurochemistry in smokers: evidence from proton magnetic resonance spectroscopy at 3 T. J Clin Psychopharmacol 2007; 27:80-4. [PMID: 17224719 DOI: 10.1097/jcp.0b013e31802dffde] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE In animals, nicotine, the primary psychoactive constituent of tobacco smoke, reduces neurogenesis and increases cell loss in both hippocampus and cortex. Accordingly, tobacco smoking has been linked to reduced performance on cognitive paradigms requiring attention and working memory in humans. However, few prior studies have tested for evidence of structural brain alterations in human tobacco smokers. In this study, proton magnetic resonance spectroscopy was used to assess the effects of chronic smoking on neuronal integrity of the hippocampus and anterior cingulate cortex (ACC). METHODS Absolute concentrations of N-acetylaspartate, total choline (tCho), and total creatine were measured in the left hippocampus and ACC in 13 chronic tobacco smokers and 13 nonsmokers matched for age, sex, and education. RESULTS The N-acetylaspartate concentration was significantly reduced in smokers relative to nonsmokers in the left hippocampus but not in the ACC. There were no group differences in the tCho and total creatine concentrations in either voxel. However, ACC tCho concentration was positively correlated with magnitude of lifetime exposure to tobacco smoke (pack-years). CONCLUSION The results are consistent with prior observations of hippocampal neuronal damage in rodents receiving nicotine and working memory deficits in human tobacco smokers. The positive relationship between tCho and lifetime tobacco exposure suggests that a component of tobacco smoke, presumably nicotine, may increase cortical membrane turnover or modify cell density. Together, these results add to growing evidence that nicotine exerts neurotoxic effects in human brain, although an a priori nature of the findings cannot be ruled out.
Collapse
Affiliation(s)
- Jürgen Gallinat
- Klinik für Psychiatrie und Psychotherapie, Charité Universitätsmedizin, Campus Mitte (PUK Charité SHK), Berlin, Germany.
| | | | | | | | | | | | | | | |
Collapse
|
163
|
Ham BJ, Chey J, Yoon SJ, Sung Y, Jeong DU, Ju Kim S, Sim ME, Choi N, Choi IG, Renshaw PF, Lyoo IK. Decreased N-acetyl-aspartate levels in anterior cingulate and hippocampus in subjects with post-traumatic stress disorder: a proton magnetic resonance spectroscopy study. Eur J Neurosci 2007; 25:324-9. [PMID: 17241294 DOI: 10.1111/j.1460-9568.2006.05253.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The purpose of this study was to investigate the concentration of N-acetyl-aspartate (NAA) in the brain and its relationship with clinical characteristics in patients with post-traumatic stress disorder (PTSD). Proton magnetic resonance spectroscopy was performed in order to measure NAA concentrations in the anterior cingulate cortex (ACC) and bilateral hippocampus in 26 subjects with fire-related PTSD, who were survivors of a subway fire in South Korea, and 25 age- and sex-matched healthy comparison subjects. There were decreased NAA levels in the ACC (t = -3.88, d.f. = 49, P < 0.001) and bilateral hippocampus (right, t = -3.88, d.f. = 49, P < 0.001; left, t = -3.62, d.f. = 49, P < 0.001) in the PTSD group relative to the healthy comparison group. Also, NAA levels of the ACC (r = -0.43, n = 26, P = 0.027) and bilateral hippocampus (right, r = -0.48, n = 26, P = 0.013; left, r = -0.40, n = 26, P = 0.04) were negatively correlated with re-experience symptom scores in subjects with PTSD. In conclusion, our findings suggest that subjects with PTSD had decreased neuronal viabilities in the ACC and bilateral hippocampus, and that these deficits may play an important role in the pathophysiology of PTSD, especially regarding the re-experiencing of traumatic events.
Collapse
Affiliation(s)
- Byung-Joo Ham
- Department of Psychiatry, Hangang Sacred Heart Hospital, Hallym University Medical Center, Seoul, South Korea
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
164
|
Douglas RM, Miyasaka N, Takahashi K, Latuszek-Barrantes A, Haddad GG, Hetherington HP. Chronic intermittent but not constant hypoxia decreases NAA/Cr ratios in neonatal mouse hippocampus and thalamus. Am J Physiol Regul Integr Comp Physiol 2006; 292:R1254-9. [PMID: 17082353 DOI: 10.1152/ajpregu.00404.2006] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Chronic constant hypoxia (CCH) and chronic intermittent hypoxia (CIH) are known to have deleterious effects on the central nervous system. Because of the difference in the pattern of hypoxic exposure, it is possible that the pathological outcome would vary. The N-acetyl aspartate/creatine (NAA/Cr) ratio is a reliable marker of neuronal integrity, and this can be noninvasively measured by proton nuclear magnetic resonance spectroscopy. P2 CD1 mouse pups with their dams were exposed to either CCH, where the Fi(O(2)) was maintained at 11% continuously or to CIH, where the Fi(O(2)) was varied between 21 and 11% every 4 min. P30 mice exposed to intermittent hypoxia for 4 wk demonstrated a significant decrease in the NAA/Cr ratio in the hippocampus and thalamus, which was reversed by a subsequent exposure to 4 wk of normoxia. Meanwhile, mice exposed to 4 wk of constant hypoxia did not demonstrate any differences in their NAA/Cr ratios from controls in these brain regions. These results indicate that an intermittent pattern of hypoxic exposure may have a more adverse effect on neuronal function and integrity than a continuous one. The reversal of NAA/Cr levels to baseline during the return to normoxia indicates that therapeutic strategies targeted at alleviating the intermittent hypoxic stress in diseases, such as obstructive sleep apnea, have the potential for inducing significant neurocognitive recovery in these patients.
Collapse
Affiliation(s)
- Robert M Douglas
- Department of Pediatrics, School of Medicine, University of California-San Diego, 9500 Gilman Dr., La Jolla, CA 92093, USA.
| | | | | | | | | | | |
Collapse
|
165
|
Zhu X, Schuff N, Kornak J, Soher B, Yaffe K, Kramer JH, Ezekiel F, Miller BL, Jagust WJ, Weiner MW. Effects of Alzheimer disease on fronto-parietal brain N-acetyl aspartate and myo-inositol using magnetic resonance spectroscopic imaging. Alzheimer Dis Assoc Disord 2006; 20:77-85. [PMID: 16772742 PMCID: PMC1820860 DOI: 10.1097/01.wad.0000213809.12553.fc] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Previous magnetic resonance (MR) spectroscopy studies of Alzheimer disease (AD) reporting reduced N-acetyl aspartate (NAA) and increased myo-Inositol (mI) used single voxel techniques, which have limited ability to assess the regional distribution of the metabolite abnormalities. The objective of this study was to determine the regional distribution of NAA and mI alterations in AD by using MR spectroscopic imaging. Fourteen patients with AD and 22 cognitively normal elderly were studied using structural MR imaging and MR spectroscopic imaging. Changes of NAA, mI, and various metabolite ratios were measured in frontal and parietal lobe gray matter (GM) and white matter. This study found: (1) when compared with cognitively normal subjects, AD patients had increased mI and mI/creatine (Cr) ratios primarily in parietal lobe GM, whereas frontal lobe GM and white matter were spared; (2) in the same region where mI was increased, AD patients had also decreased NAA and NAA/Cr ratios, replicating previous findings; (3) however, increased mI or mI/Cr ratios did not correlate with decreased NAA or NAA/Cr ratios; and (4) using mI/Cr and NAA/Cr together improved sensitivity and specificity to AD from control as compared with NAA/Cr alone. In conclusion, decreased NAA and increased mI in AD are primarily localized in parietal lobe GM regions. However, the NAA and mI changes are not correlated with each other, suggesting that they represent different processes that might help staging of AD.
Collapse
Affiliation(s)
- Xiaoping Zhu
- Department of Radiology, VA Medical Center, University of California, San Francisco, CA 94121, USA.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
166
|
Eichler F, Tan WH, Shih VE, Grant PE, Krishnamoorthy K. Proton magnetic resonance spectroscopy and diffusion-weighted imaging in isolated sulfite oxidase deficiency. J Child Neurol 2006; 21:801-5. [PMID: 16970890 DOI: 10.1177/08830738060210090601] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Isolated sulfite oxidase deficiency is a rare autosomal recessive disorder of the newborn that can be mistaken for neonatal asphyxia. Diffusion-weighted imaging of the brain demonstrates widespread diffusion restriction, and proton magnetic resonance spectroscopy shows an elevated lactate level, a decrease in the ratio of N-acetylaspartate to creatine, and a rise in the ratio of choline to creatine. This precedes severe cystic encephalomalacia and suggests that the energy failure associated with neuronal dysfunction and myelin disintegration occurs early in isolated sulfite oxidase deficiency.
Collapse
MESH Headings
- Amino Acid Metabolism, Inborn Errors/complications
- Amino Acid Metabolism, Inborn Errors/diagnosis
- Amino Acid Metabolism, Inborn Errors/enzymology
- Amino Acid Metabolism, Inborn Errors/genetics
- Brain Diseases, Metabolic, Inborn/complications
- Brain Diseases, Metabolic, Inborn/diagnosis
- Brain Diseases, Metabolic, Inborn/enzymology
- Brain Diseases, Metabolic, Inborn/genetics
- Diagnosis, Differential
- Diffusion Magnetic Resonance Imaging
- Electroencephalography
- Gene Deletion
- Humans
- Hypoxia-Ischemia, Brain/diagnosis
- Infant
- Infant, Newborn
- Magnetic Resonance Spectroscopy
- Male
- Seizures/enzymology
- Seizures/etiology
- Sulfite Oxidase/deficiency
- Sulfite Oxidase/genetics
Collapse
Affiliation(s)
- Florian Eichler
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, 55 Fruit Street, Boston, MA 02114, USA
| | | | | | | | | |
Collapse
|
167
|
Matalon R, Michals-Matalon K, Surendran S, Tyring SK. Canavan disease: studies on the knockout mouse. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2006; 576:77-93; discussion 361-3. [PMID: 16802706 DOI: 10.1007/0-387-30172-0_6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
Canavan disease (CD) is an autosomal recessive disorder, characterized by spongy degeneration of the brain. Patients with CD have aspartoacylase (ASPA) deficiency, which results accumulation of N-acetylaspartic acid (NAA) in the brain and elevated excretion of urinary NAA. Clinically, patients with CD have macrocephaly, mental retardation and hypotonia. A knockout mouse for CD which was engineered, also has ASPA deficiency and elevated NAA. Molecular studies of the mouse brain showed abnormal expression of multiple genes in addition to ASPA deficiency. Adenoassociated virus mediated gene transfer and stem cell therapy in the knockout mouse are the latest attempts to alter pathophysiology in the CD mouse.
Collapse
Affiliation(s)
- Reuben Matalon
- Department of Pediatrics, University of Texas Medical Branch, Galveston, TX 77555, USA.
| | | | | | | |
Collapse
|
168
|
Cortese BM, Moore GJ, Bailey BA, Jacobson SW, Delaney-Black V, Hannigan JH. Magnetic resonance and spectroscopic imaging in prenatal alcohol-exposed children: preliminary findings in the caudate nucleus. Neurotoxicol Teratol 2006; 28:597-606. [PMID: 16996247 DOI: 10.1016/j.ntt.2006.08.002] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2006] [Revised: 07/23/2006] [Accepted: 08/04/2006] [Indexed: 11/28/2022]
Abstract
Magnetic resonance imaging (MRI) and magnetic resonance spectroscopic imaging (MRSI) offer unique, noninvasive methods of measuring, respectively, in vivo quantitative neuroanatomy and neurochemistry. The main purpose of the present study was to identify and compare the neuroanatomical and neurochemical abnormalities that are associated with prenatal exposure to alcohol in both fetal alcohol syndrome (FAS)-diagnosed children and those diagnosed with fetal alcohol effects (FAE). MR data of three age-, gender- and race-balanced groups of children, FAS-diagnosed, FAE-diagnosed and non-exposed controls, were compared. Effects of prenatal alcohol exposure, regardless of diagnosis, were found in the caudate nucleus. Specifically, a significantly smaller caudate nucleus was found for the FAS and FAE participants compared to the controls. In addition, the metabolite ratio of N-acetyl-aspartate to creatine (NAA/Cr), an indicator of neuronal function, in left caudate nucleus of both the FAS and FAE participants was elevated compared to the control group. Analysis of absolute concentrations revealed that the increase in the ratio of NAA/Cr was due to an increase in NAA alone. Although its exact function in the CNS is unknown, NAA is believed to be a neuronal marker due to its exclusive localization to neurons. Some also speculate a role for NAA in myelination. Elevated NAA in the prenatal alcohol-exposed participants could indicate a lack of normal program cell death, dendritic pruning and/or myelination during development. The present study demonstrates that prenatal alcohol-exposed children, with or without facial dysmorphology, have abnormal brain anatomy and chemistry.
Collapse
Affiliation(s)
- Bernadette M Cortese
- Department of Psychiatry, Pennsylvania State University, College of Medicine Hershey, PA 17033, USA
| | | | | | | | | | | |
Collapse
|
169
|
Hammen T, Kerling F, Schwarz M, Stadlbauer A, Ganslandt O, Keck B, Tomandl B, Dörfler A, Stefan H. Identifying the affected hemisphere by (1)H-MR spectroscopy in patients with temporal lobe epilepsy and no pathological findings in high resolution MRI. Eur J Neurol 2006; 13:482-90. [PMID: 16722973 DOI: 10.1111/j.1468-1331.2006.01293.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Up to 30% of patients with temporal lobe epilepsy (TLE) remain without remarkable changes in MRI. In this study we investigated the role of (1)H-MR spectroscopy ((1)H-MRS) in lateralizing the affected hemisphere in the mentioned patient group. Twenty-two consecutive patients diagnosed with TLE were investigated by high resolution MRI and (1)H-MRS. We examined the incidence and diagnostic accuracy of temporal metabolite alterations determined by Linear Combination of Model Spectra (L C Model) via water reference. Metabolite values of each hemisphere of TLE patients were compared with healthy controls. Results of metabolite alterations were related to intensive video EEG focus localization. Reduction of N-acetylaspartate + N-acetylaspartyl-glutamate (tNAA) in the affected hemisphere revealed identification in six of nine patients (66%) with unilateral TLE. Group comparison revealed a significant reduction of tNAA (6.1+/-0.8*) in the involved temporal lobe compared with controls (6.67+/-0.4*, P=0.026). Choline levels were significantly increased in the affected hemisphere (1.42+/-0.17*) compared with healthy controls (1.22+/-0.17*, P=0.035). The results of our study show that (1)H-MRS is able to identify the affected hemisphere of MRI negative TLE patients and can be used as an additive tool in multimodal focus localization.
Collapse
Affiliation(s)
- T Hammen
- Clinics of Neurology, Epilepsy Center (ZEE), University of Erlangen-Nuremberg, Erlangen, Germany.
| | | | | | | | | | | | | | | | | |
Collapse
|
170
|
Wozniak JR, Lim KO. Advances in white matter imaging: a review of in vivo magnetic resonance methodologies and their applicability to the study of development and aging. Neurosci Biobehav Rev 2006; 30:762-74. [PMID: 16890990 PMCID: PMC2895765 DOI: 10.1016/j.neubiorev.2006.06.003] [Citation(s) in RCA: 212] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Several newer magnetic resonance imaging (MRI) techniques are increasingly being applied to the study of white matter development and pathology across the lifespan. These techniques go beyond traditional macrostructural volumetric methods and provide valuable information about underlying tissue integrity and organization at the microstructural and biochemical levels. We first provide an overview of white matter development and discuss the role of white matter and myelin in cognitive function. We also review available studies of development that have employed traditional volumetric measures. Then, we discuss the contributions of four newer imaging paradigms to our understanding of brain development and aging. These paradigms are Diffusion Tensor Imaging (DTI), Magnetization Transfer Imaging (MTI), T2-Relaxography, and Magnetic Resonance Spectroscopy (MRS). Studies examining brain development during childhood and adulthood as well as studies of the effects of aging are discussed.
Collapse
Affiliation(s)
- Jeffrey R. Wozniak
- Department of Psychiatry, University of Minnesota, F256/2B West, 2450 Riverside Ave., Minneapolis, MN 55454, USA
- Corresponding author. Tel.: +612 273 9741
| | - Kelvin O. Lim
- Drs. T.J. and Ella M. Arneson Endowed Chair, University of Minnesota, F282/2A West, 2450 Riverside Ave., Minneapolis, MN 55454, USA
| |
Collapse
|
171
|
Dickson JM, Wilkinson ID, Howell SJL, Griffiths PD, Grünewald RA. Idiopathic generalised epilepsy: a pilot study of memory and neuronal dysfunction in the temporal lobes, assessed by magnetic resonance spectroscopy. J Neurol Neurosurg Psychiatry 2006; 77:834-40. [PMID: 16574726 PMCID: PMC2117498 DOI: 10.1136/jnnp.2005.086918] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
BACKGROUND The memory deficits in patients with temporal lobe epilepsy (TLE) are associated with epileptogenic lesions of the temporal lobes, especially hippocampal sclerosis. Memory deficits have been extensively studied in TLE, but the presence of pre-existing temporal lobe abnormality has confounded studies on the relationship between memory dysfunction and seizure activity. Idiopathic generalised epilepsy (IGE) is characterised by primary generalised seizures and is found to occur in the absence of any macroscopic brain abnormalities. IGE is therefore ideal for investigations on the effects of seizure activity on memory and cognition. AIM AND METHODS Magnetic resonance spectroscopy (MRS) and neuropsychological testing were used to investigate the relationship between epileptic seizures, memory performance and neuronal dysfunction in the temporal lobes of a group of patients with IGE. 30 patients and 15 healthy controls participated in the study. RESULTS Patients with IGE were found to perform worse than controls on tests of speed of information processing, general cognitive performance and a range of memory tests, including face recognition, word recognition, verbal recall and complex figure recall. The performance of the patient group on the visual recognition and verbal recall sections of the Doors and People Test was found to correlate with MRS ratios of N-acetyl aspartate:choline and N-acetyl aspartate:creatine in the temporal lobes. CONCLUSION This result supports the hypothesis that memory deficits in epilepsy may be due to neuronal dysfunction secondary to epileptic activity itself in the absence of any macroscopic lesions in the temporal lobes.
Collapse
Affiliation(s)
- J M Dickson
- Department of Biomedical Science, University of Sheffield, Sheffield, UK.
| | | | | | | | | |
Collapse
|
172
|
Abstract
Since the 1950s, it has been recognized that a subgroup of multiple sclerosis (MS) patients exists that shows little or no progression in the severity of the disease over time. This group is referred to as 'benign' MS. Although a substantial amount of research in MS indicates a multifactorial background in disease severity, to date it is still difficult to predict whether the course will be benign at onset and it is difficult to find factors that influence the course of the disease over time. Maintaining or restoring neural conduction inside a central nervous system lesion seems to be the essence of staying 'benign'.
Collapse
Affiliation(s)
- G S M Ramsaransing
- Department of Neurology, University Medical Centre Groningen, Groningen, The Netherlands
| | | |
Collapse
|
173
|
Abstract
INTRODUCTION Fabry disease is an X-linked recessive lysosomal storage disease; it is due to alpha-galactosidase A deficiency, and its clinical course shows repeated small artery strokes. METHODS Five patients diagnosed with Fabry disease (mean age +/- SD = 28.2 +/- 11.1 years) and 5 age-matched controls were evaluated with the following magnetic resonance image (MRI) sequences: T1, T2, FLAIR, diffusion, and single voxel spectroscopy at the parietal lobe. RESULTS Conventional images did not reveal alterations. Mean apparent diffusion coefficient (ADC) +/- SD in the corona radiata of patients was 7.8 +/- 0.2 x 10 mm/s, which was significantly higher than for controls: 6.93 +/- 0.49 x 10 mm/s (P < 0.05). At the lenticular nucleus there were no differences in ADC values between patients (7.32 +/- 0.2 x 10 mm/s) and controls (7.2 +/- 0.2 x 10 mm/s). The mean ratio NAA/Cr +/- SD at the parietal lobes was 1.94 +/- 0.2 for patients and 2.1 +/- 0.13 for controls (P = n.s.). DISCUSSION : In a group of young Fabry disease patients with normal MRIs, a significant increment of over 12% in ADC values in the corona radiata was found compared with age-matched controls. The change could reflect increased interstitial water content after the Starling equilibrium under raised cerebral blood flow, which is a known feature of Fabry disease. CONCLUSION Raised ADC values could predate conventional MRI changes in Fabry disease and therefore be a more sensitive marker of disease progression and response to enzymatic replacement therapy.
Collapse
Affiliation(s)
- Juan M Politei
- Neurology Service, Juan A. Fernandez Hospital, Buenos Aires, Argentina.
| | | |
Collapse
|
174
|
Kim EA, Cheong HK, Choi DS, Sakong J, Ryoo JW, Park I, Kang DM. Effect of occupational manganese exposure on the central nervous system of welders: 1H magnetic resonance spectroscopy and MRI findings. Neurotoxicology 2006; 28:276-83. [PMID: 16824604 DOI: 10.1016/j.neuro.2006.05.013] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2005] [Revised: 05/16/2006] [Accepted: 05/16/2006] [Indexed: 11/23/2022]
Abstract
This study investigated the relationship between long-term occupational manganese (Mn) exposure on the regional Mn concentration in the brain, neuronal loss, and neurobehavioral effects on welders. 1H MRS of the basal ganglia (BG) was performed on 20 male welders and 10 age- and gender-matched, non-office, control workers in a shipyard to assess the metabolic change, and the N-acetylaspartate (NAA)/creatine (Cr), choline (Cho)/Cr and NAA/Cho ratios, by the level of Mn exposure. We also assessed the signal intensity of T1-weighted image of magnetic resonance imaging (MRI) on globus pallidus (GP) compared to that of the frontal white matter (pallidal index, PI). The welders had significantly higher signal intensity than the controls. PI showed a significant dose-response relationship with cumulative exposure index (CEI) (r=0.54, p=0.002). CEI and PI showed different relationships with NAA/Cr according to smoking status, and the correlation was evident only in non-smokers (r=-0.73 and -0.57, respectively). There were no significant differences between the welders and the controls in NAA/Cr, Cho/Cr, and NAA/Cho ratios obtained from BG. CEI was positively correlated with simple reaction time. PI was positively correlated with mean sway (MSWAY), sway area (SWAYA), and sway intensity (SWAYI), and negatively correlated with maximum frequency (MAXF). After categorizing the subjects into two groups according to NAA/Cr ratio level, the low NAA/Cr ratio group showed significantly lower score on digit span backward and significantly higher score on MSWAY, SWAYA and SWAYI in regression analysis than the high NAA/Cr ratio group. We speculated that the NAA/Cr ratio of MRS in BG seems to reflect the cumulative effect of Mn exposure on the human brain. Due to uneven distribution of smoking among the welders and the controls, in addition to the small number of subjects in our study, our findings are needed further studies with a larger number of subjects.
Collapse
Affiliation(s)
- Eun A Kim
- Occupational Safety and Health Research Institute, KOSHA, Incheon, Republic of Korea.
| | | | | | | | | | | | | |
Collapse
|
175
|
Poussaint TY, Rodriguez D. Advanced neuroimaging of pediatric brain tumors: MR diffusion, MR perfusion, and MR spectroscopy. Neuroimaging Clin N Am 2006; 16:169-92, ix. [PMID: 16543091 DOI: 10.1016/j.nic.2005.11.005] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
This article highlights the MR imaging techniques of MR perfusion, MR diffusion, and MR spectroscopy in the evaluation of the child with a pediatric brain tumor. These techniques are complementary to conventional MR imaging in providing tumor physiologic information useful for diagnosis and therapy.
Collapse
|
176
|
Hascalik S, Celik O, Sarac K, Alkan A, Mizrak B. Clinical significance of N-acetyl-L-aspartate resonance in ovarian mucinous cystadenoma. Int J Gynecol Cancer 2006; 16:423-6. [PMID: 16445669 DOI: 10.1111/j.1525-1438.2006.00200.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Magnetic resonance spectroscopy (MRS) provides a noninvasive measurement of the biochemistry of living tissue. We report spectroscopy analysis of a 26-year-old woman affected by right ovarian lesion diagnosed as mucinous cystadenoma. MRS was performed by the point-resolved spectroscopy technique with a long echo time (TE) (136 msec). MRS measurements were performed on the two distinct component of the right ovarian tumor. The classification of metabolite peaks area in this study was performed according to the technique described by Okada et al. The features of proton MRS studies are discussed. As well as strongly elevated lactate and N-acetyl-L-aspartate signals, the tumor spectrum showed lipid resonances. Proton MRS imaging may be helpful for the investigation of the underlying pathophysiology of ovarian mucinous cystadenomas.
Collapse
Affiliation(s)
- S Hascalik
- Department of Obstetrics and Gynecology, Medical Faculty, Turgut Ozal Medical Center, Inonu University, 44069 Malatya, Turkey.
| | | | | | | | | |
Collapse
|
177
|
Weber R, Ramos-Cabrer P, Hoehn M. Present status of magnetic resonance imaging and spectroscopy in animal stroke models. J Cereb Blood Flow Metab 2006; 26:591-604. [PMID: 16292254 DOI: 10.1038/sj.jcbfm.9600241] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Magnetic resonance imaging (MRI) is based on a wide variety of physical parameters, which, in principle, can all influence the image contrast conditions. As these diverse variables are validated by independent physiological, metabolic, hemodynamic, and histological techniques, a physiological MRI evolves. This imaging modality has been successfully applied to experimental stroke studies, covering a broad range of raised questions. In the present review, we present an overview of possible physiological criteria to be studied by in vivo MRI and magnetic resonance spectroscopy, and critically analyze the present limits and future potential of the imaging technique for experimental stroke investigations. The documented applications cover the spectrum from morphological-structural details of the lesion to hemodynamic and metabolic alterations, inflammatory reaction, evaluation of thrombolytic treatment, studies on recovery of functional brain activation by functional MRI, and, finally, the most recent applications of exploring stem cells for regenerative therapy.
Collapse
Affiliation(s)
- Ralph Weber
- In-vivo-NMR-Laboratory, Max-Planck-Institute for Neurological Research, Cologne, Germany
| | | | | |
Collapse
|
178
|
Rango M, Bonifati C, Bresolin N. Parkinson's disease and brain mitochondrial dysfunction: a functional phosphorus magnetic resonance spectroscopy study. J Cereb Blood Flow Metab 2006; 26:283-90. [PMID: 16094320 DOI: 10.1038/sj.jcbfm.9600192] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
In spite of several evidences for a mitochondrial impairment in Parkinson's disease (PD), so far it has not been possible to show in vivo mitochondrial dysfunction in the human brain of PD patients. The authors used the high temporal and spatial resolution 31 phosphorus magnetic resonance spectroscopy (31P MRS) technique, which they have previously developed in normal subjects and in patients with mitochondrial diseases to study mitochondrial function by observing high-energy phosphates (HEPs) and intracellular pH (pH) in the visual cortex of 20 patients with PD and 20 normal subjects at rest, during, and after visual activation. In normal subjects, HEPs remained unchanged during activation, but rose significantly (by 16%) during recovery, and pH increased during visual activation with a slow return to rest values. In PD patients, HEPs were within the normal range at rest and did not change during activation, but fell significantly (by 36%) in the recovery period; pH did not reveal a homogeneous pattern with a wide spread of values. Energy unbalance under increased oxidative metabolism requirements, that is, the postactivation phase, discloses a mitochondrial dysfunction that is present in the brain of patients with PD even in the absence of overt clinical manifestations, as in the visual cortex. This is in agreement with our previous findings in patients with mitochondrial disease without clinical central nervous system (CNS) involvement. The heterogeneity of the physicochemical environment (i.e., pH) suggests various degrees of subclinical brain involvement in PD. The combined use of MRS and brain activation is fundamental for the study of brain energetics in patients with PD and may prove an important tool for diagnostic purposes and, possibly, to monitor therapeutic interventions.
Collapse
Affiliation(s)
- Mario Rango
- Department of Neurological Sciences, Parkinson's Disease Center, Maggiore Policlinico Hospital, IRCCS, University of Milan, Milan, Italy.
| | | | | |
Collapse
|
179
|
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.
Collapse
Affiliation(s)
- Antonio Belli
- Victor Horsley Department of Neurosurgery, The National Hospital for Neurology and Neurosurgery, London, UK
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
180
|
Fayed N, Morales H, Modrego PJ, Muñoz-Mingarro J. White matter proton MR spectroscopy in children with isolated developmental delay: does it mean delayed myelination? Acad Radiol 2006; 13:229-35. [PMID: 16428059 DOI: 10.1016/j.acra.2005.10.016] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2005] [Revised: 10/07/2005] [Accepted: 10/07/2005] [Indexed: 11/20/2022]
Abstract
RATIONALE AND OBJECTIVES Isolated developmental delay (IDD) is a common disorder in preschool and school-age children. Conventional magnetic resonance imaging (MRI) usually does not disclose abnormalities, but a myelination delay is suspected as causative or associated factor. N-acetyl-aspartate is a surrogate marker of neuronal integrity but also of axonal integrity. The goal of our study is to determine whether magnetic resonance spectroscopy (MRS) is able to detect alterations in the white matter supporting the hypothesis of delayed myelination in children with IDD and normal MRI. MATERIALS AND METHODS In this cross-sectional study, we enrolled 12 consecutive children meeting the criteria if IDD and aged between 3 and 12 years (mean 7.25 years) and 11 healthy children as control group (mean age 7.18, range 3-12 years) on whom we performed conventional MRI and MRS. We did not include children with abnormal MRI. Single voxel (8 cm(3)) was placed in the white matter of the left centrum semiovale. The mode of acquisition was probe-p (PRESS technique) with a TR of 2500 milliseconds and a TE of 30 milliseconds. We measured the metabolite concentration of n-acetyl-aspartate (NAA), choline (Ch), creatine (Cr) y myo-inositol (mI), and ratios of NAA, Ch, and mI to creatine. RESULTS In children with IDD, we found a significant decrease of the following ratios: NAA/Cr (P < .016), NAA/Ch (P < .026), and NAA/mI (P < .023) in relation to controls. The mean NAA/Cr ratio in IDD children was 1.92 (SD 0.14), and in controls it was 2.09 (SD 0.14); t = 2.62, fd (freedom degrees) = 21, P < .016. No differences were seen in the remaining ratios. CONCLUSIONS The lower NAA/Cr ratio in children with IDD in relation to controls may be a promising marker of this disorder and supports the hypothesis of delayed myelination. MRS can provide important information in children with neurodevelopmental disorders.
Collapse
Affiliation(s)
- Nicolás Fayed
- Magnetic Resonance Unit, Clínica Quirón, Avda de la Ilustración 12, C39, 50012 Zaragoza, Spain
| | | | | | | |
Collapse
|
181
|
Kado H, Kimura H, Murata T, Nagata K, Kanno I. Depressive psychosis: clinical usefulness of MR spectroscopy data in predicting prognosis. Radiology 2006; 238:248-55. [PMID: 16373773 DOI: 10.1148/radiol.2381041375] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To prospectively assess the usefulness of magnetic resonance (MR) spectroscopy data acquired before the initiation of medical therapy in predicting prognosis in patients with depressive psychosis. MATERIALS AND METHODS All subjects gave written informed consent to an institutional committee for clinical research-approved study protocol. The clinical course after medication in 52 patients with depressive psychosis (age range, 52-78 years; 21 men, 31 women) was investigated. In all patients, MR spectroscopy was performed with a 1.5-T MR imaging unit before the initiation of medical therapy. Cerebrovascular lesions (CVLs), which appear as high-signal-intensity areas on T2-weighted MR images, were evaluated by using the Fazekas rating scale. Patients were classified into two groups on the basis of the ratio of N-acetylaspartate (NAA) to creatine and phosphocreatine (Cr): Patients in group A had an NAA/Cr ratio greater than 1.91, and patients in group B had an NAA/Cr ratio of 1.91 or less. To assess the response of the patients to medication, standard psychiatric tests--the Verbal Associative Fluency Test (VAFT), the Digit Symbol Test (DST), the Mini-Mental State Examination (MMSE), and the Hamilton Depression Rating Scale (HAM-D)--were administered before and after medical therapy was initiated. Mean test scores before and after medication were compared with paired t testing. P < .05 was considered to indicate a significant difference. RESULTS There were 25 patients in group A and 27 in group B. In group A, the mean VAFT and DST scores increased and the mean HAM-D score decreased after medication. There was no significant difference in mean MMSE scores before and after medication (P = .945 for group A and P = .934 for group B). In group B, there were no significant differences in any of the psychiatric test scores before and after medication. The high-signal-intensity area score in group B was significantly higher than that in group A (P = .004). CONCLUSION MR spectroscopy data obtained before the initiation of medical therapy were useful in predicting prognosis in patients with depressive psychosis; this suggests that the combined burden of all CVLs may affect the response to antidepressant medication.
Collapse
Affiliation(s)
- Hirotsugu Kado
- Department of Radiology, Akita Research Institute for Brain and Blood Vessels, 6-10 Kubotamachi, Sensyu, Akita 010-0874, Japan
| | | | | | | | | |
Collapse
|
182
|
Vidal C, Méric P, Provost F, Herzog C, Lasmézas C, Gillet B, Beloeil JC, Dormont D. Preclinical metabolic changes in mouse prion diseases detected by 1H-nuclear magnetic resonance spectroscopy. Neuroreport 2006; 17:89-93. [PMID: 16361957 DOI: 10.1097/01.wnr.0000194389.89536.88] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Magnetic resonance spectroscopy studies in animal models of prion disease are very few and concern terminal stages of infection. In order to study earlier stages of the disease, we used in-vivo magnetic resonance spectroscopy in a mouse model of scrapie and, for the first time, in mice infected with a bovine spongiform encephalopathy strain. In bovine spongiform encephalopathy-infected mice, we observed an increase in myo-inositol preceding clinical signs by 20 days, followed by a decrease in N-acetylaspartate at advanced stages. In scrapie-infected mice, changes in N-acetylaspartate and myo-inositol were detected at the beginning of the symptomatic phase. These results show that magnetic resonance spectroscopy is a valuable tool for detecting subtle metabolic changes associated to gliosis and neuronal dysfunction in prion diseases.
Collapse
Affiliation(s)
- Catherine Vidal
- CEA (Atomic Energy Commission), Laboratory of Neurovirology, Fontenay-aux-Roses, France.
| | | | | | | | | | | | | | | |
Collapse
|
183
|
Baslow MH, Guilfoyle DN. Functions Of N-Acetylaspartate and N-Acetylaspartylglutamate in Brain. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2006; 576:95-112; discussion 361-3. [PMID: 16802707 DOI: 10.1007/0-387-30172-0_7] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- Morris H Baslow
- Nathan S. Kline Institute for Psychiatric Research, 140 Old Orangeburg Road, Orangeburg, New York 10962 USA.
| | | |
Collapse
|
184
|
Geurts JJG, Reuling IEW, Vrenken H, Uitdehaag BMJ, Polman CH, Castelijns JA, Barkhof F, Pouwels PJW. MR spectroscopic evidence for thalamic and hippocampal, but not cortical, damage in multiple sclerosis. Magn Reson Med 2006; 55:478-83. [PMID: 16463353 DOI: 10.1002/mrm.20792] [Citation(s) in RCA: 105] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Gray matter (GM) damage is an important pathophysiological feature in Multiple Sclerosis (MS), and may be related to clinical, including cognitive, deficits. Quantitative single-voxel (1)H-Magnetic Resonance Spectroscopy (TR/TE 6000/20 ms) was performed in 33 MS patients (11 per disease subtype; mean age 48 years, 16 females) and 10 healthy controls (mean age 43 years, 7 females). No overall spectroscopic changes were found in MS cortex. In MS thalamus, a 9% decrease of N-acetyl aspartate (NAA; P=0.005) and a 31% increase of myo-inositol (Ins; P=0.002) were found. A 21% Ins increase was observed (P=0.02) in MS hippocampus. Reduced NAA and increased Ins concentrations are thought to reflect neuro-axonal damage or loss and gliosis, respectively. Significant correlations between Ins concentrations and total-brain T(2) lesion load were found for MS thalamus (r=0.65, P<0.001) and hippocampus (r=0.57, P=0.001). MS thalamic and hippocampal Ins concentrations also correlated with each other (r=0.68; P<0.001). Cortical Gln correlated with thalamic NAA (r=-0.38; P=0.03) in MS. Thalamic and hippocampal Ins increases were most prominent in secondary-progressive (SP) patients (37% and 34%, respectively), whereas the largest thalamic NAA decrease (14%) was found in primary-progressive (PP) patients. In conclusion, thalamic and hippocampal GM pathology are important features of (progressive) MS.
Collapse
Affiliation(s)
- Jeroen J G Geurts
- MS Research Center, Dept. of Radiology, VU University Medical Center, Amsterdam, The Netherlands.
| | | | | | | | | | | | | | | |
Collapse
|
185
|
Ledeen RW, Wang J, Wu G, Lu ZH, Chakraborty G, Meyenhofer M, Tyring SK, Matalon R. Physiological role of N-acetylaspartate: contribution to myelinogenesis. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2006; 576:131-43; discussion 361-3. [PMID: 16802709 DOI: 10.1007/0-387-30172-0_9] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Robert W Ledeen
- Dept. Neurology & Neurosciences, New Jersey Medical School, UMDNJ, 185 So. Orange Ave., Newark, NJ 07103, USA.
| | | | | | | | | | | | | | | |
Collapse
|
186
|
Driscoll I, Howard SR, Stone JC, Monfils MH, Tomanek B, Brooks WM, Sutherland RJ. The aging hippocampus: A multi-level analysis in the rat. Neuroscience 2006; 139:1173-85. [PMID: 16564634 DOI: 10.1016/j.neuroscience.2006.01.040] [Citation(s) in RCA: 158] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2005] [Revised: 01/03/2006] [Accepted: 01/26/2006] [Indexed: 11/23/2022]
Abstract
In the current experiment we conducted a multi-level analysis of age-related characteristics in the hippocampus of young adult (3 months), middle-aged (12 months), and old (24 months) Fisher 344xBrown Norway hybrid (FBNF1) rats. We examined the relationships between aging, hippocampus, and memory using a combination of behavioral, non-invasive magnetic resonance imaging and spectroscopy, and postmortem neuroanatomical measures in the same rats. Aging was associated with functional deficits on hippocampus-dependent memory tasks, accompanied by structural alterations observed both in vivo (magnetic resonance imaging-hippocampal volume) and postmortem (dentate gyrus neuronal density and neurogenesis). Neuronal metabolic integrity, assessed by levels of N-acetylaspartate with magnetic resonance spectroscopy, was however, preserved. Further, our results suggest that neurogenesis (doublecortin) seems to be related to both performance deficits on hippocampus-dependent tasks and hippocampal volume reduction. The observed pattern of age-related alterations closely resembles that previously reported in humans and suggests FBNF1 rats to be a useful model of normal human aging.
Collapse
Affiliation(s)
- I Driscoll
- Canadian Centre for Behavioural Neuroscience, University of Lethbridge, Alberta.
| | | | | | | | | | | | | |
Collapse
|
187
|
Abstract
Among the vast number of metabolites in living tissues, metabolites detectable by in vivo MR spectroscopy are limited to those present in high concentrations, and the actual number is only 10 to 20. None is disease-specific. Interpretation of MRS data, therefore, must be based on general knowledge of biochemical processes in association with pathological changes. Each spectrum is a window on the actual biochemical changes taking place within the living tissues, but the reality entails a wide and confusing variance. Continuous expansion of the knowledge may reduce the uncertainty of interpreting MRS data.
Collapse
Affiliation(s)
- Keiko Imamura
- Department of Radiology, St. Marianna University School of Medicine, 2-16-1 Sugao, Miyamae-ku, Kawasaki 216-8511, Japan.
| |
Collapse
|
188
|
Steen RG, Hamer RM, Lieberman JA. Measurement of brain metabolites by 1H magnetic resonance spectroscopy in patients with schizophrenia: a systematic review and meta-analysis. Neuropsychopharmacology 2005; 30:1949-62. [PMID: 16123764 DOI: 10.1038/sj.npp.1300850] [Citation(s) in RCA: 209] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
A systematic review of the literature identified 64 published English-language papers that used proton (1H) magnetic resonance spectroscopy to measure N-acetylaspartate (NAA) concurrently in healthy controls and in patients with a diagnosis of schizophrenia (SZ). A total of 1209 controls and 1256 patients have been evaluated, with 88% of studies carried out at 1.5 T field strength, and 77% of studies focused on patients with chronic SZ. There is consistent evidence that NAA is reduced in a broad range of tissues in the SZ brain. Broad consensus (> or =10 studies) is emerging that NAA levels are reduced > or =5% in hippocampus and in both cortical gray matter (GM) and white matter (WM) of the frontal lobe. There is no evidence to support a hypothesis that relative NAA levels are reduced to a different degree in frontal lobe GM and WM, nor is there robust evidence of a difference in NAA levels between patients with first-episode and chronic SZ. Study reliability may be a problem, as most studies appear to be underpowered. With simple assumptions about the inherent difference in NAA levels between patients and controls, it can be calculated that a minimum sample size of approximately 39 patients and 39 controls is required for acceptable statistical power. Only three of 64 studies included enough subjects to have 80% power to detect a 10% NAA reduction in patients, and no studies were adequately powered to detect a 5% NAA reduction with 80% power.
Collapse
Affiliation(s)
- R Grant Steen
- Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7160, USA.
| | | | | |
Collapse
|
189
|
Rango M, Canesi M, Ghione I, Farabola M, Righini A, Bresolin N, Antonini A, Pezzoli G. Parkinson's disease, chronic hydrocarbon exposure and striatal neuronal damage: a 1-H MRS study. Neurotoxicology 2005; 27:164-8. [PMID: 16246421 DOI: 10.1016/j.neuro.2005.08.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2004] [Revised: 08/02/2005] [Accepted: 08/25/2005] [Indexed: 10/25/2022]
Abstract
Several patients with Parkinson' s disease (PD) reveal an history of chronic exposure to hydrocarbon-solvents. Chronic exposure to hydrocarbon-solvents has been proposed as a risk factor for more severe forms of PD with earlier onset of symptoms and reduced response to dopaminergic therapy. A direct correlation between disease severity and exposure degree has been previously shown. Seven exposed PD patients (two with low degree exposure and five with high degree exposure), 10 unexposed PD patients matched for sex, age and Hoehn and Yahr scale (=3 in the "on" phase), and 10 unexposed PD patients matched for sex, age and l-dopa daily intake instead of disease severity (Hoehn and Yahr scale=3.5 in the "on" phase) were studied. Twenty normal subjects without previous exposure to hydrocarbon-solvents and matched for age and sex with HPD patients were studied for comparison. The purpose of the study was to assess neuronal degeneration in the striatum of exposed vs unexposed PD patients. The authors investigated whether neuronal damage/loss was detectable in the lentiform nucleus measuring N-acetylaspartate (NAA) levels by 1-H MRS. Multiple single voxel MRS water-suppressed spectra were obtained also from the white matter and the occipital lobe. NAA was normal in the lentiform nucleus of patients with low exposure as well as in patients with no exposure whereas it was decreased in PD patients with high degree exposure. White matter and occipital lobe NAA content was normal both in exposed and unexposed PD patients. Clinical expression is more severe in PD patients with previous high degree solvent exposure because of the associated post-synaptic damage of the nigro-striatal pathway.
Collapse
Affiliation(s)
- M Rango
- Dipartimento di Scienze Neurologiche-Centro per il Morbo di Parkinson, Ospedale Maggiore Policlinico, IRCCS, Università degli Studi di Milano, Milano, Italy.
| | | | | | | | | | | | | | | |
Collapse
|
190
|
Caramanos Z, Narayanan S, Arnold DL. 1H-MRS quantification of tNA and tCr in patients with multiple sclerosis: a meta-analytic review. Brain 2005; 128:2483-506. [PMID: 16230321 DOI: 10.1093/brain/awh640] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Meta-analysis was performed on the results of 75 comparisons from the 30 peer-reviewed publications that used proton magnetic resonance spectroscopy (1H-MRS) or spectroscopic imaging to (i) quantify the mean concentrations of total creatine (tCr, found in neurons, astrocytes and oligodendrocytes), and/or total N-acetyl groups (tNA, found only in neurons), in the lesional and/or non-lesional white matter (WM) and/or the grey matter (GM) of patients with multiple sclerosis (MS) and (ii) compare these values with those in the homologous tissues of normal controls (NC). For mean [tNA] values, there was (i) a large-effect-sized overall decrease in patients' lesional WM relative to NC WM (25 comparisons), (ii) a medium-effect-sized overall decrease in patients' non-lesional WM relative to NC WM (36 comparisons) and (iii) a medium-effect-sized overall decrease in patients' GM relative to NC GM (14 comparisons). Patients' mean [tNA] values were sometimes statistically normal but were never statistically increased. For mean [tCr] values, there was (i) no statistically significant overall change in the patients' lesional WM relative to NC WM (24 comparisons), although statistically significant increases and decreases were sometimes found, (ii) a medium-effect-sized overall increase in patients' non-lesional WM relative to NC WM (33 comparisons) and (iii) no statistically significant overall change in patients' GM relative to NC GM (12 comparisons), although a significant decrease was found in one comparison. Of 41 comparisons with statistically significant changes, 38 combined in a way that would probably result in decreased mean [tNA]/[tCr] ratios such that (i) 66% had statistically decreased mean [tNA] and statistically unchanged mean [tCr] values, (ii) 13% had statistically decreased mean [tNA] and statistically increased mean [tCr] values and (iii) 21% had statistically unchanged mean [tNA] values and statistically increased mean [tCr] values. Of the 25 comparisons that came from studies that also analysed [tNA]/[tCr] ratios, the direction of change in mean [tNA] values and mean [tNA]/[tCr] ratios was concordant in 84%. In comparisons that quantified both [tNA] and [tCr], there was a similar amount of variability in both measures in each of the different tissue types studied, both in patients and NCs. Together, these results suggest that within-voxel tNA/tCr ratios can be interpreted as valid and accurate surrogate measures of 'cerebral tissue integrity'-with decreased tNA/tCr ratios indicating some combination of neuroaxonal disturbance, oligodendroglial disturbance, and astrocytic proliferation. These results also suggest that, although within-voxel tNA/tCr ratios are not perfect indicators of [tNA] content, they do represent a practical compromise to acquiring surrogate measures of within-voxel neuroaxonal integrity.
Collapse
Affiliation(s)
- Zografos Caramanos
- Magnetic Resonance Spectroscopy Unit, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada
| | | | | |
Collapse
|
191
|
Lehnhardt FG, Bock C, Röhn G, Ernestus RI, Hoehn M. Metabolic differences between primary and recurrent human brain tumors: a 1H NMR spectroscopic investigation. NMR IN BIOMEDICINE 2005; 18:371-82. [PMID: 15959923 DOI: 10.1002/nbm.968] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
High-resolution proton magnetic resonance spectroscopy was performed on tissue specimens from 33 patients with astrocytic tumors (22 astrocytomas, 11 glioblastomas) and 13 patients with meningiomas. For all patients, samples of primary tumors and their first recurrences were examined. Increased anaplasia, with respect to malignant transformation, resulting in a higher malignancy grade, was present in 11 recurrences of 22 astrocytoma patients. Spectroscopic features of tumor types, as determined on samples of the primary occurrences, were in good agreement with previous studies. Compared with the respective primary astrocytomas, characteristic features of glioblastomas were significantly increased concentrations of alanine (Ala) (p = 0.005), increased metabolite ratios of glycine (Gly)/total creatine (tCr) (p = 0.0001) and glutamate (Glu)/glutamine (Gln) (p = 0.004). Meningiomas showed increased Ala (p = 0.02) and metabolite ratios [Gly, total choline (tCho), Ala] over tCr (p = 0.001) relative to astrocytomas, and N-acetylaspartate and myo-inositol were absent. Metabolic changes of an evolving tumor were observed in recurrent astrocytomas: owing to their consecutive assessments, more indicators of malignant degeneration were detected in astrocytoma recurrences (e.g. Gly, p = 0.029; tCho, p = 0.034; Glu, p = 0.015; tCho/tCr, p = 0.001) in contrast to the comparison of primary astrocytomas with primary glioblastomas. The present investigation demonstrated a correlation of the tCho-signal with tumor progression. Significantly elevated concentrations of Ala (p = 0.037) and Glu (p = 0.003) and metabolite ratio tCho/tCr (p = 0.005) were even found in recurrent low-grade astrocytomas with unchanged histopathological grading (n = 11). This may be related to an early stage of malignant transformation, not yet detectable morphologically, and emphasizes the high sensitivity of 1H NMR spectroscopy in elucidating characteristics of brain tumor metabolism.
Collapse
|
192
|
Janson CG, Assadi M, Francis J, Bilaniuk L, Shera D, Leone P. Lithium citrate for Canavan disease. Pediatr Neurol 2005; 33:235-43. [PMID: 16194720 DOI: 10.1016/j.pediatrneurol.2005.04.015] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2005] [Revised: 03/03/2005] [Accepted: 04/04/2005] [Indexed: 11/15/2022]
Abstract
Current evidence suggests that the effects of lithium on metabolic and signaling pathways in the brain may vary depending on the specific clinical condition or disease model. For example, lithium increases levels of cerebral N-acetyl aspartate in patients with bipolar disorder but does not appear to affect N-acetyl aspartate levels in normal human subjects. Conversely, lithium significantly decreases whole-brain levels of N-acetyl aspartate in a rat genetic model of Canavan disease in which cerebral N-acetyl aspartate is chronically elevated. While N-acetyl aspartate is a commonly used surrogate marker for neuronal density and correlates with neuronal viability, grossly elevated whole-brain levels of N-acetyl aspartate in Canavan disease are associated with dysmyelination and mental retardation. This report describes the first clinical application of lithium in a human subject with Canavan disease. Spectroscopic and clinical changes were observed over the time period in which lithium was administered, which reversed during a 2-week wash-out period after withdrawal of lithium. This investigation reports decreased N-acetyl aspartate levels in the brain regions tested and magnetic resonance spectroscopic values that are more characteristic of normal development and myelination, suggesting that a larger, controlled trial of lithium may be warranted as supportive therapy for Canavan disease by decreasing abnormally elevated N-acetyl aspartate.
Collapse
Affiliation(s)
- Christopher G Janson
- Department of Neurosurgery and Molecular Genetics, University of Medicine and Dentistry of New Jersey-Robert Wood Johnson Medical School, Camden, USA
| | | | | | | | | | | |
Collapse
|
193
|
Forton DM, Allsop JM, Cox IJ, Hamilton G, Wesnes K, Thomas HC, Taylor-Robinson SD. A review of cognitive impairment and cerebral metabolite abnormalities in patients with hepatitis C infection. AIDS 2005; 19 Suppl 3:S53-63. [PMID: 16251829 DOI: 10.1097/01.aids.0000192071.72948.77] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Numerous studies have reported associations between chronic hepatitis C virus (HCV) infection and fatigue, depression and impairments in health-related quality of life, which are independent of the severity of liver disease. Although there are a large number of potential explanations for these symptoms, including a history of substance abuse and associated personality types, or the effect of the diagnosis of HCV infection itself, there has been recent interest in the possibility of a biological effect of HCV infection on cerebral function. There is emerging evidence of mild, but significant neurocognitive impairment in HCV infection, which cannot be wholly attributed to substance abuse, co-existent depression or hepatic encephalopathy. Impairments are predominantly in the domains of attention, concentration and information processing speed. Furthermore, in-vivo cerebral magnetic resonance spectroscopy studies in patients with hepatitis C and normal liver function have reported elevations in cerebral choline-containing compounds and reductions in N-acetyl aspartate, suggesting that a biological mechanism may underlie the cognitive findings. The recent detection of HCV genetic sequences in post-mortem brain tissue raises the intriguing possibility that HCV infection of the central nervous system may be related to the reported neuropsychological symptoms and cognitive impairment.
Collapse
Affiliation(s)
- Daniel M Forton
- Liver Unit, Division of Medicine, Faculty of Medicine, Imperial College London, St Mary's Hospital Campus, London, UK.
| | | | | | | | | | | | | |
Collapse
|
194
|
Stork C, Renshaw PF. Mitochondrial dysfunction in bipolar disorder: evidence from magnetic resonance spectroscopy research. Mol Psychiatry 2005; 10:900-19. [PMID: 16027739 DOI: 10.1038/sj.mp.4001711] [Citation(s) in RCA: 318] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Magnetic resonance spectroscopy (MRS) affords a noninvasive window on in vivo brain chemistry and, as such, provides a unique opportunity to gain insight into the biochemical pathology of bipolar disorder. Studies utilizing proton ((1)H) MRS have identified changes in cerebral concentrations of N-acetyl aspartate, glutamate/glutamine, choline-containing compounds, myo-inositol, and lactate in bipolar subjects compared to normal controls, while studies using phosphorus ((31)P) MRS have examined additional alterations in levels of phosphocreatine, phosphomonoesters, and intracellular pH. We hypothesize that the majority of MRS findings in bipolar subjects can be fit into a more cohesive bioenergetic and neurochemical model of bipolar illness that is both novel and yet in concordance with findings from complementary methodological approaches. In this review, we propose a hypothesis of mitochondrial dysfunction in bipolar disorder that involves impaired oxidative phosphorylation, a resultant shift toward glycolytic energy production, a decrease in total energy production and/or substrate availability, and altered phospholipid metabolism.
Collapse
Affiliation(s)
- C Stork
- Brain Imaging Center, McLean Hospital, Belmont, MA 02478, USA.
| | | |
Collapse
|
195
|
Glodzik-Sobanska L, Slowik A, Kieltyka A, Kozub J, Sobiecka B, Urbanik A, Szczudlik A. Reduced prefrontal N-acetylaspartate in stroke patients with apathy. J Neurol Sci 2005; 238:19-24. [PMID: 16084528 DOI: 10.1016/j.jns.2005.06.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2004] [Revised: 05/05/2005] [Accepted: 06/02/2005] [Indexed: 11/15/2022]
Abstract
BACKGROUND Although substantial numbers of stroke patients suffer from apathy, its causes are still poorly understood. Previous studies suggest that dysfunction of the frontal lobes is implicated in the pathophysiology of motivation. Our aim was to investigate the association between proton magnetic resonance spectroscopy (H1-MRS) measurements in unaffected frontal lobes and apathy in a group of first-time stroke patients. METHODS 31 patients with a first-time ischemic stroke located outside the frontal lobes and 20 healthy subjects were included in the study. The authors performed single voxel H1-MRS in order to measure the N-acetylaspartate/creatine (NAA)/Cr, glutamate+glutamine (Glx)/Cr, choline (Cho)/Cr and myo-inositol (mI)/Cr ratios in the frontal lobes. Patients were assessed between days 7 and 12 post stroke. Diagnosis of apathy was made on the basis of clinical observation, interview and Apathy Scale. RESULTS 13 out of 31 patients (42%) demonstrated apathy. Patients with apathy had lower NAA/Cr ratios in the right frontal lobe than non-apathetic subjects. The patient group was divided into two subgroups: Those with left hemisphere strokes, and those with right hemisphere strokes. Of these subjects, significantly lowered NAA/Cr ratios were found in the right hemispheres of apathetic patients in the subgroup with left-sided brain lesions. CONCLUSIONS These findings point to the association between apathy and frontal lobe integrity, suggest different reactions of the hemispheres and indicate that changes in the NAA/Cr ratio are related to the apathy.
Collapse
Affiliation(s)
- Lidia Glodzik-Sobanska
- Center for Brain Health, NYU School of Medicine, 550 First Avenue, HN-400, NY 10016-6481, USA.
| | | | | | | | | | | | | |
Collapse
|
196
|
Rovira A. Resonancia magnética craneal en la encefalopatía hepática. RADIOLOGIA 2005. [DOI: 10.1016/s0033-8338(05)72828-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
197
|
Hendriks JJA, Teunissen CE, de Vries HE, Dijkstra CD. Macrophages and neurodegeneration. ACTA ACUST UNITED AC 2005; 48:185-95. [PMID: 15850657 DOI: 10.1016/j.brainresrev.2004.12.008] [Citation(s) in RCA: 187] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2004] [Accepted: 12/09/2004] [Indexed: 12/23/2022]
Abstract
Multiple sclerosis (MS) is a chronic inflammatory demyelinating disease of the central nervous system (CNS). Demyelination is a classical feature of MS lesions, and neurological deficits are often ascribed to the reduced signal conduction by demyelinated axons. However, recent studies emphasize that axonal loss is an important factor in MS pathogenesis and disease progression. Axonal loss is found in association with cellular infiltrates in MS lesions. In this review, we discuss the possible contribution of the innate immune system in this process. In particular, we describe how infiltrated macrophages may contribute to axonal loss in MS and in experimental autoimmune encephalomyelitis (EAE), the animal model for MS. An overview is given of the possible effects of mediators, which are produced by activated macrophages, such as such as pro-inflammatory cytokines, free radicals, glutamate and metalloproteases, on axonal integrity. We conclude that infiltrated macrophages, which are activated to produce pro-inflammatory mediators, may be interesting targets for therapeutic approaches aimed to prevent or reduce axonal loss during exacerbation of inflammation. Interference with the process of infiltration and migration of monocytes across the blood-brain barrier is one of the possibilities to reduce the damage by activated macrophages.
Collapse
Affiliation(s)
- Jerome J A Hendriks
- Department of Molecular Cell Biology and Immunology, VU University Medical Center, Amsterdam, The Netherlands
| | | | | | | |
Collapse
|
198
|
Magnetic resonance spectroscopy of neurodegenerative illness. NEURODEGENER DIS 2005. [DOI: 10.1017/cbo9780511544873.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
|
199
|
Ratai EM, Pilkenton S, Lentz MR, Greco JB, Fuller RA, Kim JP, He J, Cheng LL, González RG. Comparisons of brain metabolites observed by HRMAS 1H NMR of intact tissue and solution 1H NMR of tissue extracts in SIV-infected macaques. NMR IN BIOMEDICINE 2005; 18:242-51. [PMID: 15759297 DOI: 10.1002/nbm.953] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The objective of this study was to compare ex vivo proton high-resolution magic angle spinning magnetic resonance spectra of intact tissue with those spectra obtained by solution (1)H NMR of brain extracts of the same sample. Sixteen brain tissue samples from simian immunodeficiency virus-infected rhesus macaques from both frontal cortex and putamen were evaluated by comparing brain metabolite quantities of N-acetylaspartate (NAA), choline-containing compounds (Cho), myo-inositol (MI), creatine (Cr), lactate (Lac), glutamate (Glu) and acetate (Ace). The ratios of the individual NMR peak areas of all metabolites relative to the creatine peak area were calculated. Linear regression analysis revealed significant correlations between measurements using the two methods. The strength of the correlations varied depending on the metabolite studied. We found highly significant correlations for NAA/Cr (r2 = 0.77; p < 0.0001), NAA + Ace/Cr (r2 = 0.73; p < 0.0001) and MI/Cr (r2 = 0.75; p < 0.0001). We observed somewhat less strong correlations for Glu/Cr (r2 = 0.54; p < 0.002) and Lac/Cr (r2 = 0.54; p < 0.002). There was a substantially weaker correlation for Cho/Cr (r2 = 0.32; p = 0.02). When plotting the metabolite ratios obtained by 1H HRMAS NMR of the intact tissue sample on the ordinate vs 1H NMR of the tissue extract on the abscissa, most metabolites exhibited a slope close to unity, and a positive intercept probably due to macromolecular contributions to the MAS spectra. The slope for Cho/Cr was substantially less than unity. Generally, samples from the frontal cortex showed a better correlation between intact and extracted tissue samples than putamen. This is most prominent in the cases of NAA/Cr and Cho/Cr. We conclude that both methods provide substantially the same information for most major brain metabolites, with the exception of the Cho resonance.
Collapse
Affiliation(s)
- Eva M Ratai
- Massachusetts General Hospital NMR Center and Neuroradiology Division, 149 13th St, Charlestown, MA 02129, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
200
|
Crystal RG, Sondhi D, Hackett NR, Kaminsky SM, Worgall S, Stieg P, Souweidane M, Hosain S, Heier L, Ballon D, Dinner M, Wisniewski K, Kaplitt M, Greenwald BM, Howell JD, Strybing K, Dyke J, Voss H. Clinical protocol. Administration of a replication-deficient adeno-associated virus gene transfer vector expressing the human CLN2 cDNA to the brain of children with late infantile neuronal ceroid lipofuscinosis. Hum Gene Ther 2005; 15:1131-54. [PMID: 15610613 DOI: 10.1089/hum.2004.15.1131] [Citation(s) in RCA: 106] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Late infantile neuronal ceroid lipofuscinosis (LINCL) is a fatal childhood neurodegenerative lysosomal storage disease with no known therapy. There are estimated to be 200 to 300 children in the United States at any one time with the disease. LINCL is a genetic disease resulting from a deficiency of tripeptidyl peptidase I (TPP-I), a proteolytic enzyme encoded by CLN2, the gene that is mutated in individuals with LINCL. The subjects are chronically ill, with a progressive CNS disorder that invariably results in death, typically by age 8 to 12 years. The strategy of this clinical study is based on the concept that persistent expression in the CNS of the normal CLN2 cDNA with production of sufficient amounts of TPP-I should prevent further loss of neurons, and hence limit disease progression. To assess this concept, an adeno-associated virus vector (AAV2CUh-CLN2) will be used to transfer to and express the human CLN2 cDNA in the brain of children with LINCL. The vector consists of the AAV2 capsid enclosing the 4278-base single-stranded genome consisting of the two inverted terminal repeats of AAV serotype 2 and an expression cassette composed of the human cytomegalovirus (CMV) enhancer, the chicken beta-actin promoter/splice donor and 5' end of the intron, the 3' end of the rabbit P-globin intron and splice acceptor, the human CLN2 cDNA with an optimized Kozak translation initiation signal, and the polyadenylation/transcription stop codon from rabbit 3-globin. The proposed study will include 10 individuals and will be divided into two parts. Group A, to be studied first, will include four individuals with the severe form of the disease. Group B of the trial will include six individuals with a moderate form of the disease. After direct intracranial administration of the vector, there will be neurological assessment based on the LINCL clinical rating scale and magnetic resonance imaging/magnetic resonance spectroscopy assessment of the brain in regions of vector administration. The data generated will help evaluate two hypotheses: (1) that it is safe to carry out direct intracranial administration of the AAV2cuhCLN2 vector to the CNS of individuals with LINCL, and (2) that administration of the AAV2cuhCLN2 vector will slow down or halt the progression of the disease in the central nervous system.
Collapse
Affiliation(s)
- Ronald G Crystal
- Department of Genetic Medicine, Weill Medical College of Cornell University, New York, NY 10021, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|