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Jett S, Boneu C, Zarate C, Carlton C, Kodancha V, Nerattini M, Battista M, Pahlajani S, Williams S, Dyke JP, Mosconi L. Systematic review of 31P-magnetic resonance spectroscopy studies of brain high energy phosphates and membrane phospholipids in aging and Alzheimer's disease. Front Aging Neurosci 2023; 15:1183228. [PMID: 37273652 PMCID: PMC10232902 DOI: 10.3389/fnagi.2023.1183228] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Accepted: 05/02/2023] [Indexed: 06/06/2023] Open
Abstract
Many lines of evidence suggest that mitochondria have a central role in aging-related neurodegenerative diseases, such as Alzheimer's disease (AD). Mitochondrial dysfunction, cerebral energy dysmetabolism and oxidative damage increase with age, and are early event in AD pathophysiology and may precede amyloid beta (Aβ) plaques. In vivo probes of mitochondrial function and energy metabolism are therefore crucial to characterize the bioenergetic abnormalities underlying AD risk, and their relationship to pathophysiology and cognition. A majority of the research conducted in humans have used 18F-fluoro-deoxygluose (FDG) PET to image cerebral glucose metabolism (CMRglc), but key information regarding oxidative phosphorylation (OXPHOS), the process which generates 90% of the energy for the brain, cannot be assessed with this method. Thus, there is a crucial need for imaging tools to measure mitochondrial processes and OXPHOS in vivo in the human brain. 31Phosphorus-magnetic resonance spectroscopy (31P-MRS) is a non-invasive method which allows for the measurement of OXPHOS-related high-energy phosphates (HEP), including phosphocreatine (PCr), adenosine triphosphate (ATP), and inorganic phosphate (Pi), in addition to potential of hydrogen (pH), as well as components of phospholipid metabolism, such as phosphomonoesters (PMEs) and phosphodiesters (PDEs). Herein, we provide a systematic review of the existing literature utilizing the 31P-MRS methodology during the normal aging process and in patients with mild cognitive impairment (MCI) and AD, with an additional focus on individuals at risk for AD. We discuss the strengths and limitations of the technique, in addition to considering future directions toward validating the use of 31P-MRS measures as biomarkers for the early detection of AD.
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Affiliation(s)
- Steven Jett
- Department of Neurology, Weill Cornell Medical College, New York, NY, United States
| | - Camila Boneu
- Department of Neurology, Weill Cornell Medical College, New York, NY, United States
| | - Camila Zarate
- Department of Neurology, Weill Cornell Medical College, New York, NY, United States
| | - Caroline Carlton
- Department of Neurology, Weill Cornell Medical College, New York, NY, United States
| | - Vibha Kodancha
- Department of Neurology, Weill Cornell Medical College, New York, NY, United States
| | - Matilde Nerattini
- Department of Neurology, Weill Cornell Medical College, New York, NY, United States
- Nuclear Medicine Unit, Department of Experimental and Clinical Biomedical Sciences, University of Florence, Florence, Italy
| | - Michael Battista
- Department of Neurology, Weill Cornell Medical College, New York, NY, United States
| | - Silky Pahlajani
- Department of Neurology, Weill Cornell Medical College, New York, NY, United States
- Department of Radiology, Weill Cornell Medical College, New York, NY, United States
| | - Schantel Williams
- Department of Neurology, Weill Cornell Medical College, New York, NY, United States
| | - Jonathan P. Dyke
- Department of Radiology, Weill Cornell Medical College, New York, NY, United States
| | - Lisa Mosconi
- Department of Neurology, Weill Cornell Medical College, New York, NY, United States
- Department of Radiology, Weill Cornell Medical College, New York, NY, United States
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Jett S, Dyke JP, Boneu Yepez C, Zarate C, Carlton C, Schelbaum E, Jang G, Pahlajani S, Williams S, Diaz Brinton R, Mosconi L. Effects of sex and APOE ε4 genotype on brain mitochondrial high-energy phosphates in midlife individuals at risk for Alzheimer's disease: A 31Phosphorus MR spectroscopy study. PLoS One 2023; 18:e0281302. [PMID: 36787293 PMCID: PMC9928085 DOI: 10.1371/journal.pone.0281302] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Accepted: 01/19/2023] [Indexed: 02/15/2023] Open
Abstract
Age, female sex, and APOE epsilon 4 (APOE4) genotype are the three greatest risk factors for late-onset Alzheimer's disease (AD). The convergence of these risks creates a hypometabolic AD-risk profile unique to women, which may help explain their higher lifetime risk of AD. Less is known about APOE4 effects in men, although APOE4 positive men also experience an increased AD risk. This study uses 31Phosphorus Magnetic Resonance Spectroscopy (31P-MRS) to examine effects of sex and APOE4 status on brain high-energy phosphates [adenosine triphosphate (ATP), phosphocreatine (PCr), inorganic phosphate (Pi)] and membrane phospholipids [phosphomonoesters (PME), phosphodiesters (PDE)] in 209 cognitively normal individuals at risk for AD, ages 40-65, 80% female, 46% APOE4 carriers (APOE4+). Women exhibited lower PCr/ATP and PCr/Pi levels than men in AD-vulnerable regions, including frontal, posterior cingulate, lateral and medial temporal cortex (multi-variable adjusted p≤0.037). The APOE4+ group exhibited lower PCr/ATP and PCr/Pi in frontal regions as compared to non-carriers (APOE4-) (multi-variable adjusted p≤0.005). Sex by APOE4 status interactions were observed in frontal regions (multi-variable adjusted p≤0.046), where both female groups and APOE4+ men exhibited lower PCr/ATP and PCr/Pi than APOE4- men. Among men, APOE4 homozygotes exhibited lower frontal PCr/ATP than heterozygotes and non-carriers. There were no significant effects of sex or APOE4 status on Pi/ATP and PME/PDE measures. Among midlife individuals at risk for AD, women exhibit lower PCr/ATP (e.g. higher ATP utilization) and lower PCr/Pi (e.g. higher energy demand) than age-controlled men, independent of APOE4 status. However, a double dose of APOE4 allele shifted men's brains to a similar metabolic range as women's brains. Examination of brain metabolic heterogeneity can support identification of AD-specific pathways within at-risk subgroups, further advancing both preventive and precision medicine for AD.
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Affiliation(s)
- Steven Jett
- Department of Neurology, Weill Cornell Medicine, New York, New York, United States of America
| | - Jonathan P. Dyke
- Department of Radiology, Weill Cornell Medicine, New York, New York, United States of America
| | - Camila Boneu Yepez
- Department of Neurology, Weill Cornell Medicine, New York, New York, United States of America
| | - Camila Zarate
- Department of Neurology, Weill Cornell Medicine, New York, New York, United States of America
| | - Caroline Carlton
- Department of Neurology, Weill Cornell Medicine, New York, New York, United States of America
| | - Eva Schelbaum
- Department of Neurology, Weill Cornell Medicine, New York, New York, United States of America
| | - Grace Jang
- Department of Neurology, Weill Cornell Medicine, New York, New York, United States of America
| | - Silky Pahlajani
- Department of Neurology, Weill Cornell Medicine, New York, New York, United States of America
- Department of Radiology, Weill Cornell Medicine, New York, New York, United States of America
| | - Schantel Williams
- Department of Neurology, Weill Cornell Medicine, New York, New York, United States of America
| | - Roberta Diaz Brinton
- Department of Pharmacology, University of Arizona, Tucson, Arizona, United States of America
- Department of Neurology, University of Arizona, Tucson, Arizona, United States of America
| | - Lisa Mosconi
- Department of Neurology, Weill Cornell Medicine, New York, New York, United States of America
- Department of Radiology, Weill Cornell Medicine, New York, New York, United States of America
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Jett S, Dyke JP, Andy C, Schelbaum E, Jang G, Boneu Yepez C, Pahlajani S, Diaz I, Diaz Brinton R, Mosconi L. Sex and menopause impact 31P-Magnetic Resonance Spectroscopy brain mitochondrial function in association with 11C-PiB PET amyloid-beta load. Sci Rep 2022; 12:22087. [PMID: 36543814 PMCID: PMC9772209 DOI: 10.1038/s41598-022-26573-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Accepted: 12/16/2022] [Indexed: 12/24/2022] Open
Abstract
Increasing evidence implicates sex and endocrine aging effects on brain bioenergetic aging in the greater lifetime risk of Alzheimer's disease (AD) in women. We conducted 31Phosphorus Magnetic Resonance Spectroscopy (31P-MRS) to assess the impact of sex and menopause on brain high-energy phosphates [adenosine triphosphate (ATP), phosphocreatine (PCr), inorganic phosphate (Pi)] and membrane phospholipids [phosphomonoesters/phosphodiesters (PME/PDE)] in 216 midlife cognitively normal individuals at risk for AD, 80% female. Ninety-seven participants completed amyloid-beta (Aβ) 11C-PiB PET. Women exhibited higher ATP utilization than men in AD-vulnerable frontal, posterior cingulate, fusiform, medial and lateral temporal regions (p < 0.001). This profile was evident in frontal cortex at the pre-menopausal and peri-menopausal stage and extended to the other regions at the post-menopausal stage (p = 0.001). Results were significant after multi-variable adjustment for age, APOE-4 status, midlife health indicators, history of hysterectomy/oophorectomy, use of menopause hormonal therapy, and total intracranial volume. While associations between ATP/PCr and Aβ load were not significant, individuals with the highest Aβ load were post-menopausal and peri-menopausal women with ATP/PCr ratios in the higher end of the distribution. No differences in Pi/PCr, Pi/ATP or PME/PDE were detected. Outcomes are consistent with dynamic bioenergetic brain adaptations that are associated with female sex and endocrine aging.
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Affiliation(s)
- Steven Jett
- Department of Neurology, Weill Cornell Medicine, New York, NY, 10021, USA
| | - Jonathan P Dyke
- Department of Radiology, Weill Cornell Medicine, New York, NY, USA
| | - Caroline Andy
- Department of Population Health Sciences, Weill Cornell Medicine, New York, NY, USA
| | - Eva Schelbaum
- Department of Neurology, Weill Cornell Medicine, New York, NY, 10021, USA
| | - Grace Jang
- Department of Neurology, Weill Cornell Medicine, New York, NY, 10021, USA
| | - Camila Boneu Yepez
- Department of Neurology, Weill Cornell Medicine, New York, NY, 10021, USA
| | - Silky Pahlajani
- Department of Neurology, Weill Cornell Medicine, New York, NY, 10021, USA
- Department of Radiology, Weill Cornell Medicine, New York, NY, USA
| | - Ivan Diaz
- Department of Population Health Sciences, Weill Cornell Medicine, New York, NY, USA
| | - Roberta Diaz Brinton
- Department of Pharmacology, University of Arizona, Tucson, AZ, USA
- Department of Neurology, University of Arizona, Tucson, AZ, USA
| | - Lisa Mosconi
- Department of Neurology, Weill Cornell Medicine, New York, NY, 10021, USA.
- Department of Radiology, Weill Cornell Medicine, New York, NY, USA.
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Parasoglou P, Osorio RS, Khegai O, Kovbasyuk Z, Miller M, Ho A, Dehkharghani S, Wisniewski T, Convit A, Mosconi L, Brown R. Phosphorus metabolism in the brain of cognitively normal midlife individuals at risk for Alzheimer's disease. NEUROIMAGE. REPORTS 2022; 2:100121. [PMID: 36532654 PMCID: PMC9757821 DOI: 10.1016/j.ynirp.2022.100121] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
BACKGROUND Neurometabolic abnormalities and amyloid-beta plaque deposition are important early pathophysiologic changes in Alzheimer's disease (AD). This study investigated the relationship between high-energy phosphorus-containing metabolites, glucose uptake, and amyloid plaque using phosphorus magnetic resonance spectroscopy (31P-MRS) and positron emission tomography (PET). METHODS We measured 31P-MRS, fluorodeoxyglucose (FDG)-PET, and Pittsburgh Compound B (PiB)-PET in a cohort of 20 cognitively normal middle-aged adults at risk for AD. We assessed 31P-MRS reliability by scanning a separate cohort of 13 healthy volunteers twice each. We calculated the coefficient-of-variation (CV) of metabolite ratios phosphocreatine-to-adenosine triphosphate (PCr/α-ATP), inorganic phosphate (Pi)-to-α-ATP, and phosphomonoesters-to-phosphodiesters (PME/PDE), and pH in pre-defined brain regions. We performed linear regression analysis to determine the relationship between 31P measurements and tracer uptake, and Dunn's multiple comparison tests to investigate regional differences in phosphorus metabolism. Finally, we performed linear regression analysis on 31P-MRS measurements in both cohorts to investigate the relationship of phosphorus metabolism with age. RESULTS Most regional 31P metabolite ratio and pH inter- and intra-day CVs were well below 10%. There was an inverse relationship between FDG-SUV levels and metabolite ratios PCr/α-ATP, Pi/α-ATP, and PME/PDE in several brain regions in the AD risk group. There were also several regional differences among 31P metabolites and pH in the AD risk group including elevated PCr/α-ATP, depressed PME/PDE, and elevated pH in the temporal cortices. Increased PCr/α-ATP throughout the brain was associated with aging. CONCLUSIONS Phosphorus spectroscopy in the brain can be performed with high repeatability. Phosphorus metabolism varies with region and age, and is related to glucose uptake in adults at risk for AD. Phosphorus spectroscopy may be a valuable approach to study early changes in brain energetics in high-risk populations.
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Affiliation(s)
- Prodromos Parasoglou
- Center for Advanced Imaging Innovation and Research, Department of Radiology, New York University Grossman School of Medicine, New York, NY, USA
| | - Ricardo S. Osorio
- Department of Psychiatry, New York University School of Medicine, New York, NY, USA
| | - Oleksandr Khegai
- Center for Advanced Imaging Innovation and Research, Department of Radiology, New York University Grossman School of Medicine, New York, NY, USA
| | - Zanetta Kovbasyuk
- Department of Psychiatry, New York University School of Medicine, New York, NY, USA
| | - Margo Miller
- Department of Psychiatry, New York University School of Medicine, New York, NY, USA
| | - Amanda Ho
- Center for Advanced Imaging Innovation and Research, Department of Radiology, New York University Grossman School of Medicine, New York, NY, USA
| | - Seena Dehkharghani
- Center for Advanced Imaging Innovation and Research, Department of Radiology, New York University Grossman School of Medicine, New York, NY, USA
- Department of Neurology, Center for Cognitive Neurology, New York University Grossman School of Medicine, New York, NY, USA
| | - Thomas Wisniewski
- Department of Psychiatry, New York University School of Medicine, New York, NY, USA
- Department of Neurology, Center for Cognitive Neurology, New York University Grossman School of Medicine, New York, NY, USA
- Department of Pathology, New York University Grossman School of Medicine, New York, NY, USA
| | - Antonio Convit
- Department of Psychiatry, New York University School of Medicine, New York, NY, USA
- Nathan S Kline Institute for Psychiatric Research, Orangeburg, NY, USA
| | - Lisa Mosconi
- Department of Neurology, Weill Cornell Medical College, New York, NY, USA
- Department of Radiology, Weill Cornell Medical College, New York, NY, USA
| | - Ryan Brown
- Center for Advanced Imaging Innovation and Research, Department of Radiology, New York University Grossman School of Medicine, New York, NY, USA
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Mitochondrial dysfunction, oxidative stress, neuroinflammation, and metabolic alterations in the progression of Alzheimer's disease: A meta-analysis of in vivo magnetic resonance spectroscopy studies. Ageing Res Rev 2021; 72:101503. [PMID: 34751136 DOI: 10.1016/j.arr.2021.101503] [Citation(s) in RCA: 91] [Impact Index Per Article: 30.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2021] [Revised: 10/19/2021] [Accepted: 10/25/2021] [Indexed: 12/13/2022]
Abstract
Accumulating evidence demonstrates that metabolic changes in the brain associated with neuroinflammation, oxidative stress, and mitochondrial dysfunction play an important role in the pathophysiology of mild cognitive impairment (MCI) and Alzheimer's disease (AD). However, the neural signatures associated with these metabolic alterations and underlying molecular mechanisms are still elusive. Accordingly, we reviewed the literature on in vivo human brain 1H and 31P-MRS studies and use meta-analyses to identify patterns of brain metabolic alterations in MCI and AD. 40 and 39 studies on MCI and AD, respectively, were classified according to brain regions. Our results indicate decreased N-acetyl aspartate and creatine but increased myo-inositol levels in both MCI and AD, decreased glutathione level in MCI as well as disrupted energy metabolism in AD. In addition, the hippocampus shows the strongest alterations in most of these metabolites. This meta-analysis also illustrates progressive metabolite alterations from MCI to AD. Taken together, it suggests that 1) neuroinflammation and oxidative stress may occur in the early stages of AD, and likely precede neuron loss in its progression; 2) the hippocampus is a sensitive region of interest for early diagnosis and monitoring the response of interventions; 3) targeting bioenergetics associated with neuroinflammation/oxidative stress is a promising approach for treating AD.
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Mecheri G, Marie-Cardine M, Sappey-Marinier D, Bonmartin H, Albrand G, Ferry G, Coppard-Meyer N, Courpron P. In vivo hippocampal 31P NMR metabolites in Alzheimer's disease and ageing. Eur Psychiatry 2020; 12:140-8. [DOI: 10.1016/s0924-9338(97)80203-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/1996] [Accepted: 03/11/1997] [Indexed: 11/16/2022] Open
Abstract
SummaryMemory loss is the most common early symptom of Alzheimer's disease (AD). For this study, we chose the hippocampi as regions of interest. The hippocampus, which is closely associated with memory processing, is known to be vulnerable to damage in the early stage of AD. We considered both inter-group (patients vs controls) and intra-group (right vs left hippocampus) comparisons. We examined seven patients meeting the DSM-III-R criteria of senile dementia and the National Institute of Neurological and Communicative Disorders and Stroke-Alzheimer's Disease and Related Disorders Association (NINCDS — ADRDA) criteria of probable AD, and II aged controls. This study focused on the measurement of phosphorus 31 (31P) Nuclear Magnetic Resonance (NMR) spectroscopy metabolites in each hippocampus. We found significant differences in phosphorus metabolites for both intra-group comparison (pH shifted towards relative alkalosis in the left hippocampus of patients) and inter-group consideration (reduced phosphodiesters [Pde]and elevated gamma adenosine triphosphate (ATP) in the right hippocampus, higher inorganic phosphate (pHi) in the left hippocampus for patients as compared to controls). We suggest energy failure and membrane functional breakdown in patients compared to aged controls.
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Rijpma A, van der Graaf M, Meulenbroek O, Olde Rikkert MGM, Heerschap A. Altered brain high-energy phosphate metabolism in mild Alzheimer's disease: A 3-dimensional 31P MR spectroscopic imaging study. NEUROIMAGE-CLINICAL 2018; 18:254-261. [PMID: 29876246 PMCID: PMC5987799 DOI: 10.1016/j.nicl.2018.01.031] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Revised: 12/15/2017] [Accepted: 01/24/2018] [Indexed: 12/20/2022]
Abstract
In Alzheimer's disease (AD), defects in essential metabolic processes for energy supply and phospholipid membrane function have been implicated in the pathological process. However, post-mortem investigations are generally limited to late stage disease and prone to tissue decay artifacts. In vivo assessments of high energy phosphates, tissue pH and phospholipid metabolites are possible by phosphorus MR spectroscopy (31P–MRS), but so far only small studies, mostly focusing on single brain regions, have been performed. Therefore, we assessed phospholipid and energy metabolism in multiple brain regions of 31 early stage AD patients and 31 age- and gender-matched controls using 31P–MRS imaging. An increase of phosphocreatine (PCr) was found in AD patients compared with controls in the retrosplenial cortex, and both hippocampi, but not in the anterior cingulate cortex. While PCr/inorganic phosphate and pH were also increased in AD, no changes were found for phospholipid metabolites. This study showed that PCr levels are specifically increased in regions that show early degeneration in AD. Together with an increased pH, this indicates an altered energy metabolism in mild AD. Phosphocreatine and pH are increased in mild Alzheimer's disease. Phosphocreatine increase occurs in early affected brain regions. Brain energy metabolism may be altered in mild Alzheimer's disease. Phospholipid and energy metabolites as well as pH, differ across brain regions.
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Key Words
- 1H, proton
- 31P–MRS, phosphorus magnetic resonance spectroscopy
- AC, anterior commissure
- ACC, anterior cingulate cortex
- AD, Alzheimer's disease
- ADP, adenosine diphosphate
- ATP, adenosine triphosphate
- Alzheimer's disease
- CK, creatine kinase
- CSF, cerebrospinal fluid
- Cr, creatine
- Dementia
- Energy metabolism
- GM, grey matter
- GPCh, glycerophosphocholine
- GPEth, glycerophosphoethanolamine
- HL, left hippocampus
- HR, right hippocampus
- LS, least square
- MCI, mild cognitive impairment
- MMSE, Mini Mental State Examination
- MRSI, magnetic resonance spectroscopic imaging
- NAD(H), nicotinamide adenine dinucleotide
- OXPHOS, oxidative phosphorylation
- PC, posterior commissure
- PCh, phosphocholine
- PCr, phosphocreatine
- PDE, phosphodiesters
- PEth, phosphoethanolamine
- PME, phosphomonoesters
- Phospholipid metabolism
- Phosphorus magnetic resonance spectroscopic imaging
- Pi, inorganic phosphate
- ROI, region of interest
- RSC, retrosplenial cortex
- WM, white matter
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Affiliation(s)
- Anne Rijpma
- Department of Geriatric Medicine, Radboud university medical center, Nijmegen, The Netherlands; Radboudumc Alzheimer Center, Donders Institute for Brain, Cognition and Behaviour, Radboud university medical center, Nijmegen, The Netherlands.
| | - Marinette van der Graaf
- Department of Radiology and Nuclear Medicine, Radboud university medical center, Nijmegen, The Netherlands; Department of Paediatrics, Radboud university medical center, Nijmegen, The Netherlands
| | - Olga Meulenbroek
- Department of Geriatric Medicine, Radboud university medical center, Nijmegen, The Netherlands; Radboudumc Alzheimer Center, Donders Institute for Brain, Cognition and Behaviour, Radboud university medical center, Nijmegen, The Netherlands
| | - Marcel G M Olde Rikkert
- Department of Geriatric Medicine, Radboud university medical center, Nijmegen, The Netherlands; Radboudumc Alzheimer Center, Donders Institute for Brain, Cognition and Behaviour, Radboud university medical center, Nijmegen, The Netherlands
| | - Arend Heerschap
- Department of Radiology and Nuclear Medicine, Radboud university medical center, Nijmegen, The Netherlands
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Lee BY, Zhu XH, Woo MK, Adriany G, Schillak S, Chen W. Interleaved 31 P MRS imaging of human frontal and occipital lobes using dual RF coils in combination with single-channel transmitter-receiver and dynamic B 0 shimming. NMR IN BIOMEDICINE 2018; 31:10.1002/nbm.3842. [PMID: 29073724 PMCID: PMC5736151 DOI: 10.1002/nbm.3842] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Revised: 09/10/2017] [Accepted: 09/14/2017] [Indexed: 06/01/2023]
Abstract
In vivo 31 P magnetic resonance spectroscopy (MRS) provides a unique tool for the non-invasive study of brain energy metabolism and mitochondrial function. The assessment of bioenergetic impairment in different brain regions is essential to understand the pathophysiology and progression of human brain diseases. This article presents a simple and effective approach which allows the interleaved measurement of 31 P spectra and imaging from two distinct human brain regions of interest with dynamic B0 shimming capability. A transistor-transistor logic controller was employed to actively switch the single-channel X-nuclear radiofrequency (RF) transmitter-receiver between two 31 P RF surface coils, enabling the interleaved acquisition of two 31 P free induction decays (FIDs) from human occipital and frontal lobes within the same repetition time. Linear gradients were incorporated into the RF pulse sequence to perform the first-order dynamic shimming to further improve spectral resolution. The overall results demonstrate that the approach provides a cost-effective and time-efficient solution for reliable 31 P MRS measurement of cerebral phosphate metabolites and adenosine triphosphate (ATP) metabolic fluxes from two human brain regions with high detection sensitivity and spectral quality at 7 T. The same design concept can be extended to acquire multiple spectra from more than two brain regions or can be employed for other magnetic resonance applications beyond the 31 P spin.
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Affiliation(s)
- Byeong-Yeul Lee
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota Medical School, Minneapolis, MN 55455
| | - Xiao-Hong Zhu
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota Medical School, Minneapolis, MN 55455
| | - Myung Kyun Woo
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota Medical School, Minneapolis, MN 55455
| | - Gregor Adriany
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota Medical School, Minneapolis, MN 55455
| | | | - Wei Chen
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota Medical School, Minneapolis, MN 55455
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The medical food Souvenaid affects brain phospholipid metabolism in mild Alzheimer's disease: results from a randomized controlled trial. ALZHEIMERS RESEARCH & THERAPY 2017; 9:51. [PMID: 28747210 PMCID: PMC5530581 DOI: 10.1186/s13195-017-0286-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Accepted: 07/10/2017] [Indexed: 11/21/2022]
Abstract
Background Synaptic dysfunction contributes to cognitive impairment in Alzheimer’s disease and may be countered by increased intake of nutrients that target brain phospholipid metabolism. In this study, we explored whether the medical food Souvenaid affects brain phospholipid metabolism in patients with Alzheimer’s disease. Methods Thirty-four drug-naive patients with mild Alzheimer’s disease (Mini Mental State Examination score ≥20) were enrolled in this exploratory, double-blind, randomized controlled study. Before and after 4-week intervention with Souvenaid or an isocaloric control product, phosphorus and proton magnetic resonance spectroscopy (MRS) was performed to assess surrogate measures of phospholipid synthesis and breakdown (phosphomonoesters [PME] and phosphodiesters [PDEs]), neural integrity (N-acetyl aspartate), gliosis (myo-inositol), and choline metabolism (choline-containing compounds [tCho]). The main outcome parameters were PME and PDE signal intensities and the PME/PDE ratio. Results MRS data from 33 patients (60–86 years old; 42% males; Souvenaid arm n = 16; control arm n = 17) were analyzed. PME/PDE and tCho were higher after 4 weeks of Souvenaid compared with control (PME/PDE least squares [LS] mean difference [95% CI] 0.18 [0.06–0.30], p = 0.005; tCho LS mean difference [95% CI] 0.01 [0.00–0.02], p = 0.019). No significant differences were observed in the other MRS outcome parameters. Conclusions MRS reveals that Souvenaid affects brain phospholipid metabolism in mild Alzheimer’s disease, in line with findings in preclinical studies. Trial registration Netherlands Trial Register, NTR3346. Registered on 13 March 2012. Electronic supplementary material The online version of this article (doi:10.1186/s13195-017-0286-2) contains supplementary material, which is available to authorized users.
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Doert A, Pilatus U, Zanella F, Müller WE, Eckert GP. ¹H- and ¹³C-NMR spectroscopy of Thy-1-APPSL mice brain extracts indicates metabolic changes in Alzheimer's disease. J Neural Transm (Vienna) 2015; 122:541-50. [PMID: 25742870 DOI: 10.1007/s00702-015-1387-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2014] [Accepted: 02/22/2015] [Indexed: 01/17/2023]
Abstract
Biochemical alterations underlying the symptoms and pathomechanisms of Alzheimer's disease (AD) are not fully understood. However, alterations of glucose metabolism and mitochondrial dysfunction certainly play an important role. (1)H- and (13)C-NMR spectroscopy exhibits promising results in providing information about those alterations in vivo in patients and animals, especially regarding the mitochondrial tricarboxylic acid (TCA) cycle. Accordingly, transgenic mice expressing mutant human amyloid precursor protein (APP(SL))-serving as a model of neuropathological changes in AD-were examined with in vitro 1D (1)H- and 2D (1)H-(13)C-HSQC-NMR spectroscopy after oral administration of 1-(13)C-glucose and acquisition of brain material after 30 min. Perchloric acid extracts were measured using a 500 MHz spectrometer, providing more detailed information compared to in vivo spectra achievable nowadays. Area under curve (AUC) data of metabolite peaks were obtained and normalized in relation to the creatine signal, serving as internal reference. Besides confirming well-known metabolic alterations in AD like decreased N-acetylaspartate (NAA)/Creatine (Cr) ratio, new findings such as a decrease in phosphorylcholine (PC) are presented. Glutamate (Glu) and glutamine (Gln) concentrations were decreased while γ-aminobutyric acid (GABA) was elevated in Thy1-APP(SL) mice. (13)C-NMR spectroscopy revealed a shift in the Glx-2/Glx-4-ratio-where Glx represents a combined Glu/Gln-signal-towards Glx-2 in AD. These findings correlated well with the NAA/Cr-ratio. The Gln-4/Glu-4-ratio is altered in favor of Glu. Our findings suggest that glutamine synthetase (GS), which is predominantly present in glial cells may be impaired in the brain of Thy1-APP(SL) transgenic mice. Since GS is an ATP-dependent enzyme, mitochondrial dysfunction might contribute to reduced activity, which might also account for the increased metabolism of glutamate via the GABA shunt, a metabolic pathway to bypass intra-mitochondrial α-ketoglutarate-dehydrogenase, resulting in elevated GABA levels.
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Affiliation(s)
- A Doert
- Institute of Neuroradiology, Goethe-University Hospital, Frankfurt, Germany
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11
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Yan X, Xue R, Zhang X. A monopole/loop dual-tuned RF coil for ultrahigh field MRI. Quant Imaging Med Surg 2014; 4:225-31. [PMID: 25202657 DOI: 10.3978/j.issn.2223-4292.2014.08.03] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Accepted: 08/06/2014] [Indexed: 01/27/2023]
Abstract
Proton and heteronuclear MRI/MRS using dual-tuned (DT) coils could provide both anatomical and metabolic images without repositioning the subject. However, it is technologically challenging to attain sufficiently electromagnetic (EM) decoupling between the heteronuclear channel and proton channel, and keep the imaging areas and profiles of two nuclear channels highly matched. In this study, a hybrid monopole/loop technique was proposed for DT coil design and this technique was validated by implementing and testing a DT (1)H/(23)Na coil for MR imaging at 7T. The RF fields of the monopole ((1)H channel) and regular L/C loop ((23)Na channel) were orthogonal and intrinsically EM decoupled. Bench measurement results demonstrated the isolation between the two nuclear channels was better than -28 dB at both nuclear frequencies. Compared with the conventional DT coil using trap circuits, the monopole/loop DT coil had higher MR sensitivity for sodium imaging. The experimental results indicated that the monopole/loop technique might be a simple and efficient design for multinuclear imaging at ultrahigh fields. Additionally, the proposed DT coils based on the monopole/loop technique can be used as building blocks in designing multichannel DT coil arrays.
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Affiliation(s)
- Xinqiang Yan
- 1 State Key Laboratory of Brain and Cognitive Science, Beijing MRI Center for Brain Research, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China ; 2 Key Laboratory of Nuclear Radiation and Nuclear Energy Technology, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China ; 3 Beijing Engineering Research Center of Radiographic Techniques and Equipment, Beijing 100049, China ; 4 Beijing Institute for Brain Disorders, Beijing 100053, China ; 5 Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, California 94158, USA ; 6 UCSF/UC Berkeley Joint Graduate Group in Bioengineering, San Francisco, California 94158, USA
| | - Rong Xue
- 1 State Key Laboratory of Brain and Cognitive Science, Beijing MRI Center for Brain Research, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China ; 2 Key Laboratory of Nuclear Radiation and Nuclear Energy Technology, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China ; 3 Beijing Engineering Research Center of Radiographic Techniques and Equipment, Beijing 100049, China ; 4 Beijing Institute for Brain Disorders, Beijing 100053, China ; 5 Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, California 94158, USA ; 6 UCSF/UC Berkeley Joint Graduate Group in Bioengineering, San Francisco, California 94158, USA
| | - Xiaoliang Zhang
- 1 State Key Laboratory of Brain and Cognitive Science, Beijing MRI Center for Brain Research, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China ; 2 Key Laboratory of Nuclear Radiation and Nuclear Energy Technology, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China ; 3 Beijing Engineering Research Center of Radiographic Techniques and Equipment, Beijing 100049, China ; 4 Beijing Institute for Brain Disorders, Beijing 100053, China ; 5 Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, California 94158, USA ; 6 UCSF/UC Berkeley Joint Graduate Group in Bioengineering, San Francisco, California 94158, USA
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12
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Lu M, Chen W, Zhu XH. Field dependence study of in vivo brain (31) P MRS up to 16.4 T. NMR IN BIOMEDICINE 2014; 27:1135-41. [PMID: 25070004 PMCID: PMC4180101 DOI: 10.1002/nbm.3167] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2014] [Revised: 06/16/2014] [Accepted: 06/17/2014] [Indexed: 05/05/2023]
Abstract
In vivo (31) P MRS provides a unique tool for studying bioenergetics of living organs. Although its utility has been limited by the relatively low (31) P NMR sensitivity, increasing magnetic field strength (B0 ) could significantly improve the quality and reliability of the (31) P MR spectra for biomedical research. To quantitatively understand the field dependence of in vivo (31) P MRS for brain applications, (31) P NMR sensitivity of phosphocreatine (PCr) in rat brains was measured and compared at 9.4 T and 16.4 T. Additionally, the linewidths and T1 relaxation times of PCr and adenosine triphosphate (ATP) resonances obtained from human and animal brains over a wide B0 range from 4 T, 7 T, and 9.4 T to 16.4 T were examined and their field dependences were quantified. The results indicate an approximate 1.74-fold (31) P signal-to-noise ratio (SNR) gain for PCr at 16.4 T compared with 9.4 T. An approximate power 1.4 dependence of (31) P SNR on B0 was concluded. Substantial improvements in spectral resolution and significantly shortened T1 values of brain PCr and ATP were observed at high/ultrahigh fields, contributing to an additional sensitivity gain and spectral improvement. In summary, the overall findings from this study suggest that in vivo (31) P MRS should greatly benefit from high/ultrahigh fields for noninvasive assessment of altered bioenergetics and metabolic processes associated with brain function and neurological diseases.
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Affiliation(s)
- Ming Lu
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota Medical School, Minneapolis, Minnesota 55455, USA
| | - Wei Chen
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota Medical School, Minneapolis, Minnesota 55455, USA
| | - Xiao-Hong Zhu
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota Medical School, Minneapolis, Minnesota 55455, USA
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13
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Tenório T, Lopes DCN, Silva AM, Ramos JM, Buarque CD. Experimental and theoretical investigation of [Al(PCr)(H2O)] complex in aqueous solution. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2014; 118:260-270. [PMID: 24051299 DOI: 10.1016/j.saa.2013.08.073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2013] [Revised: 08/10/2013] [Accepted: 08/15/2013] [Indexed: 06/02/2023]
Abstract
Phosphocreatine is a phosphorylated creatine molecule synthesized in the liver and transported to muscle cells where it is used for the temporary storage of energy. In Alzheimer's disease, the capture of glucose by cells is impaired, which negatively affects the Krebs cycle, leading to problems with the generation of phosphocreatine. Furthermore, the creatine-phosphocreatine system, regulated by creatine kinase, is affected in the brains of Alzheimer's disease patients. Aluminum ions are associated with Alzheimer's disease. Al(III) decreases cell viability and increases the fluidity of the plasma membrane, profoundly altering cell morphology. In this study, one of the complexes formed by Al(III) and phosphocreatine in aqueous solution was investigated by potentiometry, (31)P and (27)Al NMR, Raman spectroscopy and density functional theory (DFT) calculations. The log KAlPCr value was 11.37±0.03. Phosphocreatine should act as a tridentate ligand in this complex. The (27)Al NMR peak at 48.92ppm indicated a tetrahedral molecule. The fourth position in the arrangement was occupied by a coordinated water molecule. Raman spectroscopy, (31)P NMR and DFT calculations (DFT:B3LYP/6-311++G(**)) indicated that the donor atoms are oxygen in the phosphate group, the nitrogen of the guanidine group and the oxygen of the carboxylate group. Mulliken charges, NBO charges, frontier molecular orbitals, electrostatic potential contour surfaces and mapped electrostatic potential were also examined.
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Affiliation(s)
- Thaís Tenório
- Department of Chemistry, Pontifícia Universidade Católica do Rio de Janeiro, Rua Marquês de São Vicente, 225, Edifício Cardeal Leme, 6° andar, sala 671L, 22453-900 Rio de Janeiro, RJ, Brazil.
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14
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Pang Y, Zhang X, Xie Z, Wang C, Vigneron DB. Common-mode differential-mode (CMDM) method for double-nuclear MR signal excitation and reception at ultrahigh fields. IEEE TRANSACTIONS ON MEDICAL IMAGING 2011; 30:1965-73. [PMID: 21693414 PMCID: PMC3277813 DOI: 10.1109/tmi.2011.2160192] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Double-tuned radio-frequency (RF) coils for heteronuclear mangentic resonance (MR) require sufficient electromagnetic isolation between the two resonators operating at two Larmor frequencies and independent tuning in order to attain highly efficient signal acquisition at each frequency. In this work, a novel method for double-tuned coil design at 7T based on the concept of common-mode differential-mode (CMDM) was developed and tested. Common mode (CM) and differential mode (DM) currents exist within two coupled parallel transmission lines, e.g., microstrip lines, yielding two different current distributions. The electromagnetic (EM) fields of the CM and DM are orthogonal to each other, and thus, the two modes are intrinsically EM decoupled. The modes can be tuned independently to desired frequencies, thus satisfying the requirement of dual-frequency MR applications. To demonstrate the feasibility and efficiency of the proposed CMDM technique, CMDM surface coils and volume coils using microstrip transmission line for (1)H and (13)C MRI/MRSI were designed, constructed, and tested at 7T. Bench test results showed that the isolations between the two frequency channels of the CMDM surface coil and volume coil were better than -30 and -25 dB, respectively. High quality MR phantom images were also obtained using the CMDM coils. The performance of the CMDM technique was validated through a comparison with the conventional two-pole design method at 7T. The proposed CMDM technique can be also implemented by using other coil techniques such as lumped element method, and can be applied to designing double-tuned parallel imaging coil arrays. Furthermore, if the two resonant modes of a CMDM coil were tuned to the same frequency, the CMDM coil becomes a quadrature coil due to the intrinsic orthogonal field distribution of CM and DM.
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Affiliation(s)
- Yong Pang
- Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA 94158 USA
| | - Xiaoliang Zhang
- Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA 94158 USA, and with UCSF/UC Berkeley Joint Graduate Group in Bioengineering, San Francisco, CA 94720 USA, and also with the California Institute for Quantitative Biosciences (QB3), San Francisco, CA 94158 USA
| | - Zhentian Xie
- Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA 94158 USA
| | - Chunsheng Wang
- Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA 94158 USA
| | - Daniel. B. Vigneron
- Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA 94158 USA, and with UCSF/UC Berkeley Joint Graduate Group in Bioengineering, San Francisco, CA 94720 USA, and also with the California Institute for Quantitative Biosciences (QB3), San Francisco, CA 94158 USA
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15
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Soher BJ, Doraiswamy PM, Charles HC. A Review of 1H MR Spectroscopy Findings in Alzheimer's Disease. Neuroimaging Clin N Am 2005; 15:847-52, xi. [PMID: 16443495 DOI: 10.1016/j.nic.2005.09.013] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Hydrogen-1 MR spectroscopy (MRS) studies demonstrate metabolic differences between patients who have Alzheimer's disease (AD) and cognitive normal age-matched controls. Clinical MRS also shows regional variations in metabolites between patients who have AD and those who have other dementias. Single-voxel and volumetric standard MRS techniques and automated data processing software are available for clinical MR scanners. Improvements in specificity and sensitivity of AD diagnosis, using MRS techniques as an adjunct to clinical imaging, are under evaluation. Multiparametric data analyses show, however, that metabolite changes correlate with in-vitro, postmortem, and metabolic changes and to changes in or predictions of cognitive scores.
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Affiliation(s)
- Brian J Soher
- Center for Advanced MR Development, Department of Radiology, Duke University Medical Center, Durham, NC 27710, USA.
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16
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Okada K, Yamaguchi T, Komatsu K, Matsuki T, Gotouda A, Minowa K, Inoue N. The influence of tissue blood flow volume on energy metabolism in masseter muscles. Cranio 2005; 23:166-73. [PMID: 16128350 DOI: 10.1179/crn.2005.024] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
This study investigated the energy metabolism of masseter muscles by 31P-Magnetic Resonance Spectroscopy (MRS) during increased blood flow induced by hot pack application to clarify the influence of changes in blood flow on muscle fatigue. Twelve healthy subjects with no history of muscle pain in the masticatory system participated in this study. The 31P-MRS measurements were performed before and after hot pack application and the ratio of phosphocreatine (PCr) acting as the energy source to reproduce ATP to beta-ATP, the PCr/beta-ATP ratio, was analyzed. Results showed that PCr/beta-ATP ratios increased significantly by an average of 22.4% after the hot pack application. The results suggest that changes in blood flow volume influence the energy metabolism in masseter muscles and that blood flow increases due to the hot pack cause higher energy levels in masseter muscles and offer an advantageous condition for preventing and relieving muscle fatigue.
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Affiliation(s)
- Kazuki Okada
- Dept. of Gnathofunctional Medicine, Graduate School of Dental Medicine, Hokkaido University, West 7 North 13, Kita-ku, Sapporo 060-8586, Japan.
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17
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Forlenza OV, Wacker P, Nunes PV, Yacubian J, Castro CC, Otaduy MCG, Gattaz WF. Reduced phospholipid breakdown in Alzheimer's brains: a 31P spectroscopy study. Psychopharmacology (Berl) 2005; 180:359-65. [PMID: 15700180 DOI: 10.1007/s00213-005-2168-8] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2004] [Accepted: 12/20/2004] [Indexed: 12/13/2022]
Abstract
BACKGROUND Abnormalities of membrane phospholipid metabolism have been described in Alzheimer's disease (AD). We investigated, with the aid of (31)P magnetic resonance spectroscopy, the in vivo intracerebral availability of phosphomonoesters (PME) and phosphodiesters (PDE) in patients with AD. METHODS Eighteen outpatients with mild or moderate probable AD and 16 nondemented elderly volunteers were assessed with the Cambridge Examination for Mental Disorders of the Elderly (CAMDEX) and its cognitive subscale of the CAMDEX schedule (CAMCOG). Scans were performed on a 1.5 T magnetic resonance imager addressing a 40-cm(3) voxel in the left prefrontal cortex. Main outcome measures were mean relative peak areas of PME and PDE, which provide an estimate of membrane phospholipid metabolism. RESULTS PME resonance and the PME/PDE ratio were increased in AD patients as compared to controls (p<0.05). PME was negatively correlated with global cognitive performance as shown by the Mini-Mental State Examination (r(s)=-0.36, p=0.05) and CAMCOG scores (r(s)=-0.49, p=0.007), as well as with discrete neuropsychological functions, namely, memory (r(s)=-0.53, p=0.004), visual perception (r(s)=-0.54, p=0.003), orientation (r(s)=-0.36, p=0.05), and abstract thinking (r(s)=-0.48, p=0.01). CONCLUSIONS We provide evidence of reduced membrane phospholipid breakdown in the prefrontal cortex of mild and moderately demented AD patients. These abnormalities correlate with neuropsychological deficits that are characteristic of AD.
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Affiliation(s)
- Orestes V Forlenza
- Laboratory of Neuroscience (LIM-27) Department and Institute of Psychiatry, Faculty of Medicine, University of São Paulo, Rua Doutor Ovídio Pires de Campos 785, 05403-010, São Paulo, SP, Brazil
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18
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Abstract
The neurophysiological basis of cognition is relatively unexplained, with most studies reporting weak relationships between cognition and measures of brain function, such as event-related potentials, brain size and cerebral blood flow. Magnetic resonance spectroscopy (MRS) is an in vivo method used to detect neurochemicals within the brain that are relevant to certain brain processes. The most widely used methods are 1H-MRS and 31P-MRS, which detect compounds that contain hydrogen and phosphorus, respectively. Recent studies have shown that the absolute concentrations or ratios of these neurochemicals, in particular N-acetyl aspartate (NAA), which is associated with neuronal viability, correlate with performance on neuropsychological tests or other measures of cognitive function in normal subjects. Many studies in adults and children have shown a relationship between neurometabolite values and cognitive status or extent of cognitive dysfunction in various neurological and neuropsychiatric disorders. We review these studies and conclude that MRS has potential applications for the study of cognitive processes in health and disease and may be used clinically for differential diagnosis, the early detection of pathology and the examination of longitudinal change.
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Affiliation(s)
- Amy J Ross
- School of Psychiatry, University of New South Wales, Kensington, New South Wales 2033, Australia.
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19
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Abstract
Alzheimer's disease (AD) is the most common age-related neurodegenerative disorder. Behavioural, cognitive and memory dysfunctions are characteristic symptoms of AD. The formation of amyloid plaques is currently considered as the key event of AD. Other histological hallmarks of the disease are the formation of fibrillary tangles, astrocytosis, and loss of certain neuronal systems in cortical areas of the brain. A great number of possible aetiologic and pathogenetic factors of AD have been published in the course of the last two decades. Among the toxic factors, which have been considered to contribute to the symptoms and progression of AD, ammonia deserves special interest for the following reasons: (a) Ammonia is formed in nearly all tissues and organs of the vertebrate organism; it is the most common endogenous neurotoxic compounds. Its effects on glutamatergic and GABAergic neuronal systems, the two prevailing neuronal systems of the cortical structures, are known for many years. (b) The impairment of ammonia detoxification invariably leads to severe pathology. Several symptoms and histologic aberrations of hepatic encephalopathy (HE), of which ammonia has been recognised as a pathogenetic factor, resemble those of AD. (c) The excessive formation of ammonia in the brains of AD patients has been demonstrated, and it has been shown that some AD patients exhibit elevated blood ammonia concentrations. (d) There is evidence for the involvement of aberrant lysosomal processing of beta-amyloid precursor protein (beta-APP) in the formation of amyloid deposits. Ammonia is the most important natural modulator of lysosomal protein processing. (e) Inflammatory processes and activation of microglia are widely believed to be implicated in the pathology of AD. Ammonia is able to affect the characteristic functions of microglia, such as endocytosis, and cytokine production. Based on these facts, an ammonia hypothesis of AD has first been suggested in 1993. In the present review old and new observations are discussed, which are in support of the notion that ammonia is a factor able to produce symptoms of AD and to affect the progression of the disease.
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Affiliation(s)
- Nikolaus Seiler
- Laboratory of Nutritional Oncology, Institut de Recherche Contre les Cancers de l'Appareil Digestif, Strasbourg, France.
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20
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Ljungberg M, Starck G, Vikhoff-Baaz B, Alpsten M, Ekholm S, Forssell-Aronsson E. The magnitude of signal errors introduced by ISIS in quantitative 31P MRS. MAGMA (NEW YORK, N.Y.) 2002; 14:30-8. [PMID: 11796250 DOI: 10.1007/bf02668184] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
It is well known that the quality of a quantitative 31P MRS measurement relies largely on the performance of the volume selection method, and that image selected in vivo spectroscopy (ISIS) suffers from contaminating signal caused mostly by T1 smearing. However, these signal errors and their magnitude are seldom addressed in clinical studies. The aim of this study was therefore to investigate the magnitude of signal errors in 31P MRS when using ISIS. The results from the measurements with a homogeneous head phantom are as follows: at low TR/T1 ratios the contamination increases rapidly, especially for small (<27 cm3) VOI sizes; at TR/T1=1, the signal from a 27 cm3 VOI was 20% too high, and from an 8 cm3 VOI 150% too high. The signal obtained from different VOI positions varied between 80 and 127%. The signal varied linearly with the 31P concentration in the object. However, a too high signal was obtained when the concentration was lower in the region of interest (inner container) than in the rest of the phantom. The agreement between the simulations and measurements shows that the results of this study are generally applicable to the measurement geometry and the ISIS experiment order rather than being specific for the MR system studied. The errors obtained both experimentally and in computer simulations are too large to be ignored in clinical studies using the ISIS pulse sequence.
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Affiliation(s)
- Maria Ljungberg
- Department of Radiation Physics, Göteborg University, Sahlgrenska University Hospital, 413 45, Göteborg, Sweden.
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21
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Hsu YY, Du AT, Schuff N, Weiner MW. Magnetic resonance imaging and magnetic resonance spectroscopy in dementias. J Geriatr Psychiatry Neurol 2001; 14:145-66. [PMID: 11563438 PMCID: PMC1857299 DOI: 10.1177/089198870101400308] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
This article reviews recent studies of magnetic resonance imaging and magnetic resonance spectroscopy in dementia, including Alzheimer's disease, frontotemporal dementia, dementia with Lewy bodies, idiopathic Parkinson's disease, Huntington's disease, and vascular dementia. Magnetic resonance imaging and magnetic resonance spectroscopy can detect structural alteration and biochemical abnormalities in the brain of demented subjects and may help in the differential diagnosis and early detection of affected individuals, monitoring disease progression, and evaluation of therapeutic effect.
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Affiliation(s)
- Y Y Hsu
- Magnetic Resonance Unit, Department of Veterans Affairs Medical Center, San Francisco 94121, USA
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22
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Pettegrew JW, Klunk WE, Panchalingam K, McClure RJ, Stanley JA. Molecular insights into neurodevelopmental and neurodegenerative diseases. Brain Res Bull 2000; 53:455-69. [PMID: 11137004 DOI: 10.1016/s0361-9230(00)00376-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Magnetic resonance spectroscopy (MRS) is a non-invasive physical technique that is routinely used to determine the quantity and structure of organic molecules in solution. Technical advances that have expanded the usefulness of this technique include: (1) high resolution MRS to identify and quantify individual molecules present in complex mixtures of tissue extracts; (2) in vivo MRS techniques to non-invasively monitor metabolites in humans; (3) structure determination of proteins of moderate size; and (4) improved structure characterization of solids and liquid crystals, such as the detection of phase changes in membranes. The focus of this review is on the first two technical advances mentioned above. The strengths of MRS as a research tool to investigate molecular alterations in disease states include ease of sample preparation, minimum sample manipulation, avoidance of the preparation of derivatives, and the ability to analyze an unfractionated sample. The strengths of MRS in the clinic are its ability to measure neuronal metabolite levels non-invasively in humans and its potential for disease diagnosis, monitoring disease progression, and assessing the efficacy of experimental therapies.
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Affiliation(s)
- J W Pettegrew
- Department of Psychiatry, School of Medicine, Neurophysics Laboratory, University of Pittsburgh, Pittsburgh, PA 15213, USA.
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23
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Abstract
The goal of this review is to present a comprehensive survey of the many intriguing facets of creatine (Cr) and creatinine metabolism, encompassing the pathways and regulation of Cr biosynthesis and degradation, species and tissue distribution of the enzymes and metabolites involved, and of the inherent implications for physiology and human pathology. Very recently, a series of new discoveries have been made that are bound to have distinguished implications for bioenergetics, physiology, human pathology, and clinical diagnosis and that suggest that deregulation of the creatine kinase (CK) system is associated with a variety of diseases. Disturbances of the CK system have been observed in muscle, brain, cardiac, and renal diseases as well as in cancer. On the other hand, Cr and Cr analogs such as cyclocreatine were found to have antitumor, antiviral, and antidiabetic effects and to protect tissues from hypoxic, ischemic, neurodegenerative, or muscle damage. Oral Cr ingestion is used in sports as an ergogenic aid, and some data suggest that Cr and creatinine may be precursors of food mutagens and uremic toxins. These findings are discussed in depth, the interrelationships are outlined, and all is put into a broader context to provide a more detailed understanding of the biological functions of Cr and of the CK system.
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Affiliation(s)
- M Wyss
- F. Hoffmann-La Roche, Vitamins and Fine Chemicals Division, Basel, Switzerland.
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24
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Brewer GJ, Wallimann TW. Protective effect of the energy precursor creatine against toxicity of glutamate and beta-amyloid in rat hippocampal neurons. J Neurochem 2000; 74:1968-78. [PMID: 10800940 DOI: 10.1046/j.1471-4159.2000.0741968.x] [Citation(s) in RCA: 169] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The loss of ATP, which is needed for ionic homeostasis, is an early event in the neurotoxicity of glutamate and beta-amyloid (A(beta)). We hypothesize that cells supplemented with the precursor creatine make more phosphocreatine (PCr) and create larger energy reserves with consequent neuroprotection against stressors. In serum-free cultures, glutamate at 0.5-1 mM was toxic to embryonic hippocampal neurons. Creatine at >0.1 mM greatly reduced glutamate toxicity. Creatine (1 mM) could be added as late as 2 h after glutamate to achieve protection at 24 h. In association with neurotoxic protection by creatine during the first 4 h, PCr levels remained constant, and PCr/ATP ratios increased. Morphologically, creatine protected against glutamate-induced dendritic pruning. Toxicity in embryonic neurons exposed to A(beta) (25-35) for 48 h was partially prevented by creatine as well. During the first 6 h of treatment with A(beta) plus creatine, the molar ratio of PCr/ATP in neurons increased from 15 to 60. Neurons from adult rats were also partially protected from a 24-h exposure to A(beta) (25-35) by creatine, but protection was reduced in neurons from old animals. These results suggest that fortified energy reserves are able to protect neurons against important cytotoxic agents. The oral availability of creatine may benefit patients with neurodegenerative diseases.
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Affiliation(s)
- G J Brewer
- Department of Medical Microbiology/Immunology, Southern Illinois University School of Medicine, Springfield, Illinois 62794-9626, USA.
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25
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Moore CM, Frederick BB, Renshaw PF. Brain biochemistry using magnetic resonance spectroscopy: relevance to psychiatric illness in the elderly. J Geriatr Psychiatry Neurol 2000; 12:107-17. [PMID: 10593699 DOI: 10.1177/089198879901200304] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Magnetic resonance spectroscopy (MRS) allows for the noninvasive study of cerebral biochemistry. It has been used to investigate cerebral metabolic changes associated with mental illness in vivo and in vitro. In this review, we will discuss the application of MRS to psychiatric illness in the elderly. Following a brief description of the basic principles of MRS, the use of phosphorus (31P) and proton (1H) MRS to enable a better understanding of normal brain aging, dementia (Alzheimer's disease, multiple subcortical infarct dementia, Down syndrome, frontotemporal dementia, vascular dementia, age-associated memory impairment, and other dementias), major depression, and electroconvulsive therapy is detailed.
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Affiliation(s)
- C M Moore
- Brain Imaging Center, McLean Hospital, Belmont, Massachusetts 02478, USA
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26
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Lazeyras F, Charles HC, Tupler LA, Erickson R, Boyko OB, Krishnan KR. Metabolic brain mapping in Alzheimer's disease using proton magnetic resonance spectroscopy. Psychiatry Res 1998; 82:95-106. [PMID: 9754452 DOI: 10.1016/s0925-4927(98)00010-9] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Alzheimer's disease (AD) is a progressive disorder associated with disruption of neuronal function and neuronal loss. N-acetylaspartate (NAA) is a marker of neuronal content and can be assessed using proton (1H) magnetic resonance spectroscopy (MRS). We utilized 1H-MRS (two-dimensional chemical-shift imaging) to assess amplitudes and areas of NAA, as well as choline moieties (Cho), creatine (Cr) and myo-inositol (mI), in 15 AD patients compared with 14 control subjects. Voxels were classified as predominantly cortical gray matter (CGM), subcortical gray matter (SGM), or white matter (WM). Compared with control subjects, AD patients exhibited decreased NAA/Cho and NAA/Cr amplitudes, whereas an increase was observed in Cho/Cr and in amplitude ratios involving mI. Area ratios were significant in the same direction for NAA/Cho, NAA/Cr, mI/Cr and mI/NAA. No significant effects of tissue type were observed; however, significant group x tissue type interactions were noted for Cho/Cr and mI/Cr amplitudes. Our study confirms that 1H-MRS can identify distinct physicochemical alterations in AD patients, reflecting membrane changes and diminished neuronal function. These alterations can be used as longitudinal markers for the disease.
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Affiliation(s)
- F Lazeyras
- Department of Radiology, Duke University Medical Center, Durham, NC 27710, USA
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27
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Mason GF, Chu WJ, Vaughan JT, Ponder SL, Twieg DB, Adams D, Hetherington HP. Evaluation of 31P metabolite differences in human cerebral gray and white matter. Magn Reson Med 1998; 39:346-53. [PMID: 9498589 DOI: 10.1002/mrm.1910390303] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
31P NMR is commonly used to study brain energetics in health and disease. Due to sensitivity constraints, the NMR measurements are typically made in volumes that do not contain pure gray or white matter. For accurate evaluation of abnormalities in brain metabolite levels, it is necessary to consider the differences in normal levels of 31P metabolites in gray and white matter. In this study, voxels from a three-dimensional spectroscopic image acquisition were analyzed for their dependence on tissue type to assess differences in metabolite levels between gray and white matter. Specifically, gray matter was found to have significantly higher ratios of phosphocreatine (PCr) to gamma-ATP and PCr to the total 31P metabolite signal, whereas pH and the ratio of PCr to inorganic phosphate (Pi) were found to differ insignificantly between gray and white matter. Thus, tissue type can be an important factor to consider for alterations in bioenergetics by 31P NMR spectroscopic studies of the brain.
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Affiliation(s)
- G F Mason
- Department of Medicine, Center for Nuclear Imaging Research, University of Alabama at Birmingham, USA
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28
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Pettegrew JW, Klunk WE, Panchalingam K, McClure RJ, Stanley JA. Magnetic resonance spectroscopic changes in Alzheimer's disease. Ann N Y Acad Sci 1997; 826:282-306. [PMID: 9329700 DOI: 10.1111/j.1749-6632.1997.tb48480.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
In vitro and in vivo 31P magnetic resonance (MR) spectroscopy studies of Alzheimer's disease (AD) brain have revealed alterations in membrane phospholipid metabolism and high-energy phosphate metabolism. Mildly demented AD patients compared with control subjects have increased levels of phosphomonoesters, decreased levels of phosphocreatine and probably adenosine diphosphate and an increased oxidative metabolic rate. As the dementia worsens, levels of phosphomonoesters decrease and levels of phosphocreatine and adenosine di-phosphate increase. The changes in oxidative metabolic rate suggest that the AD brain is under energetic stress. The phosphomonoester findings support our in vitro findings and implicate basic defects in membrane metabolism in AD brain. MR spectroscopy provides new diagnostic insights and a noninvasive method to follow the progression of the disease and the metabolic response to therapeutic interventions.
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Affiliation(s)
- J W Pettegrew
- Department of Psychiatry, University of Pittsburgh, Pennsylvania 15213, USA
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29
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Reglinski J, Watson ID. An analytical perspective of NMR spectroscopy of biological fluids and cells. Ann Clin Biochem 1996; 33 ( Pt 4):290-307. [PMID: 8836387 DOI: 10.1177/000456329603300404] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- J Reglinski
- Department of Pure and Applied Chemistry, Strathclyde University, Glasgow
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30
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Xu CJ, Klunk WE, Kanfer JN, Xiong Q, Miller G, Pettegrew JW. Phosphocreatine-dependent glutamate uptake by synaptic vesicles. A comparison with atp-dependent glutamate uptake. J Biol Chem 1996; 271:13435-40. [PMID: 8662761 DOI: 10.1074/jbc.271.23.13435] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
ATP-dependent uptake of glutamate into synaptic vesicles has been well documented. Stimulation of glutamate uptake into synaptic vesicles by other high-energy phosphates has not been described. In this paper, we examine the stimulation of phosphocreatine (PCr)-induced glutamate uptake and determine whether this stimulation is secondary to conversion of PCr to ATP. We found the following. 1) PCr stimulates glutamate uptake into synaptic vesicles in the absence of added ATP. 2) At a glutamate concentration of 50 microM, no concentration of added ATP could produce the degree of stimulation seen in the presence of PCr. 3) 0.5 mM iodoacetamide completely inhibits synaptic vesicle creatine kinase activity but does not inhibit PCr-stimulated glutamate uptake. 4) PCr-dependent glutamate uptake, unlike ATP-dependent uptake, is not magnesium- or chloride-dependent. 5) 0.5 mM N-ethylmaleimide, a selective H+-ATPase inhibitor, completely inhibits ATP-dependent glutamate uptake but only slightly inhibits PCr-dependent glutamate uptake. 6) PCr-dependent glutamate uptake is sensitive to valinomycin, a K+/H+ translocator, whereas the ATP-dependent uptake is not. Therefore, it appears that in addition to the well-known ATP-dependent glutamate uptake system, there is a previously unreported PCr-dependent glutamate uptake system in synaptic vesicles. The total glutamate uptake by synaptic vesicles is likely the sum of both ATP- and PCr-dependent glutamate uptake.
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Affiliation(s)
- C J Xu
- Laboratory of Neurophysics, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania 15213, USA
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31
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Klunk WE, Xu C, Panchalingam K, McClure RJ, Pettegrew JW. Quantitative 1H and 31P MRS of PCA extracts of postmortem Alzheimer's disease brain. Neurobiol Aging 1996; 17:349-57. [PMID: 8725895 DOI: 10.1016/0197-4580(96)00035-8] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Several previous studies have shown metabolic abnormalities in perchloric acid extracts of postmortem Alzheimer's disease (AD) brain by both proton (1H) and phosphorus-31 (31P) magnetic resonance spectroscopy (MRS). In all of these studies the results were expressed in relative terms, in units of mol percent. The results of this study, expressed in the absolute units of mumol/g wet weight, verify the previous 1H and 31P MRS studies. Absolute increases were found for myo-inositol, aspartate, L-glutamate, alanine, phosphocholine, and the phosphodiesters,. Absolute decreases were found for phosphoethanolamine and N-acetyl-l-aspartate. Many of these changes also were observed in non-AD dementia brain extracts, but changes in myo-inositol, inositol-l-phosphate, aspartate, and L-glutamate appeared to be more specific for AD in extracts of many brain areas. These results suggest that compounds related to membrane degradation and excitatory neuro-transmission increase in Alzheimer's disease while compounds related to neuronal integrity and inhibitory neurotransmission are decreased.
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Affiliation(s)
- W E Klunk
- Department of Psychiatry, University of Pittsburgh School of Medicine, PA 15261, USA
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32
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Abstract
The prevalence of dementia is expected to increase markedly as our population ages. Although only a minority of cases currently are found to have treatable causes, the personal and financial costs of misdiagnosis are great. Furthermore, progress in developing effective therapy hinges on accurate diagnosis. This article reviews the current state of diagnostic testing in the diagnosis of dementia.
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Affiliation(s)
- T A Sandson
- Department of Neurology, Harvard Medical School, Boston, Massachusetts, USA
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33
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Newberg AB, Alavi A. The study of neurological disorders using positron emission tomography and single photon emission computed tomography. J Neurol Sci 1996; 135:91-108. [PMID: 8867064 DOI: 10.1016/0022-510x(95)00289-e] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- A B Newberg
- Department of Radiology, University of Pennsylvania, Philadelphia 19104, USA
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34
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Gilberto González R. Molecular and functional magnetic resonance neuroimaging for the study of dementia. Ann N Y Acad Sci 1996; 777:37-48. [PMID: 8624115 DOI: 10.1111/j.1749-6632.1996.tb34399.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The living brain's structure, function, and underlying chemistry are increasingly being revealed in sharpened detail by the extraordinary evolution of magnetic resonance (MR) technology. Recent years have ushered in a wealth of new information about neurophysiology and pathological states owing to such technologies as functional MR imaging (fMRI), MR spectroscopy (MRS), and MR spectroscopic imaging (MRSI). These advances are of substantial benefit in the study of the dementias, especially Alzheimer's disease (AD). One primary objective of our laboratory at the Massachusetts General Hospital NMR Center is to utilize these extant and emerging MR technologies to further understanding of the human brain as it undergoes assault by AD. Our approach is guided by the belief that the pathological states observed in the AD brain must be accompanied by structural, chemical and/or physiological changes that can be made visible in an in vivo MR study. Quantitative measurements by MRI medical temporal lobe structures have been shown to be abnormal by several groups including our own. This use of MRI will be reviewed by others. In this paper, I will review recent advances in the application of MR for the study of chemical and functional brain abnormalities in dementia, and in particular to the investigation of AD.
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35
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Smith CD. Quantitative computed tomography and magnetic resonance imaging in aging and Alzheimer's disease. A review. J Neuroimaging 1996; 6:44-53. [PMID: 8555663 DOI: 10.1111/jon19966144] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
In recent aging research, quantitative techniques have been used to overcome limitations of qualitative interpretation of magnetic resonance and computed tomographic imaging. The purpose of this review is to summarize imaging results emphasizing quantitative studies using these two modalities in human aging. Magnetic resonance spectroscopy is viewed as an extension of imaging, and results of in vivo spectroscopic studies are included. Because Alzheimer's disease (AD) is closely related to aging, a discussion of quantitative imaging techniques that may distinguish normal elderly from patients with AD is included.
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Affiliation(s)
- C D Smith
- Department of Neurology, University of Kentucky College of Medicine, Lexington 40536, USA
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36
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Cady EB, Wylezinska M, Penrice J, Lorek A, Amess P. Quantitation of phosphorus metabolites in newborn human brain using internal water as reference standard. Magn Reson Imaging 1996; 14:293-304. [PMID: 8725195 DOI: 10.1016/0730-725x(95)02101-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
A new method for noninvasive, in vivo quantitation of cerebral phosphorus (31P) metabolites is described. The technique employs point-resolved spectroscopy (PRESS) to obtain both 31P-metabolite and proton (1H) water spectra: brain water is used as an internal concentration reference. Spin-spin relaxation times (T2s) of cerebral 31P metabolites are much longer than the minimum echo time (TE) usable on a spectrometer equipped with actively shielded gradient coils. With short-TE (approximately 10 ms) 31P PRESS, T2 relaxation is minimal and phase modulation of the nucleotide triphosphate (NTP) multiplets can be accounted for 1H water spectra were acquired using several TEs so that extra- and intracellular water signals could be separated from that due to cerebrospinal fluid. Prior calibration of the 31P and 1H spectrometer channels and an assumed brain-water concentration enabled estimations of metabolite concentrations. Using this method, mean 31P metabolite concentrations in the brains of eight normal infants of gestational plus postnatal age 34 to 39 wk were: phosphomonoester (PME) 5.6 (SD 0.9); inorganic phosphate 1.4 (0.4); mobile phosphodiester 2.3 (0.6); phosphocreatine 2.9 (0.3); nucleotide triphosphate 2.8 (0.6); and total mobile phosphate 21.4 (2.8) mmol/kg wet.
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Affiliation(s)
- E B Cady
- Department of Medical Physics and Bio-Engineering, University College London Hospitals NHS Trust, UK
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37
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Smith CD, Pettigrew LC, Avison MJ, Kirsch JE, Tinkhtman AJ, Schmitt FA, Wermeling DP, Wekstein DR, Markesberry WR. Frontal lobe phosphorus metabolism and neuropsychological function in aging and in Alzheimer's disease. Ann Neurol 1995; 38:194-201. [PMID: 7654066 DOI: 10.1002/ana.410380211] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
31P Magnetic resonance spectroscopy of the frontal lobe was performed in 17 patients with Alzheimer's disease (AD), 8 elderly controls (EC), and 17 young controls (YC). The phosphocreatine/inorganic phosphate (PCr/Pi) ratio in AD (2.32 +/- 0.26 SD) was significantly lower than in EC (2.65 +/- 0.41). In AD patients, a correlation was observed between the PCr/Pi ratio and the dementia rating scale (r = -0.50, p = 0.04). A significant positive correlation between PCr/Pi ratio and age was observed in both AD (r = 0.67, p = 0.003) and YC (r = 0.63, p = 0.006) groups, however, suggesting caution in interpretation of this ratio in AD. We did not find differences between AD, EC, or YC in any other spectroscopic measure. A significant sex difference in the phosphomonoester/phosphodiester ratio (PME/PDE) ratio was observed in AD brain. Females had a lower PME/PDE ratio than males.
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Affiliation(s)
- C D Smith
- Magnetic Resonanance Imaging and Spectroscopy Center, University of Kentucky College of Medicine, Lexington 40536, USA
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38
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Passe TJ, Charles HC, Rajagopalan P, Krishnan KR. Nuclear magnetic resonance spectroscopy: a review of neuropsychiatric applications. Prog Neuropsychopharmacol Biol Psychiatry 1995; 19:541-63. [PMID: 8588055 DOI: 10.1016/0278-5846(95)00101-z] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
1. Magnetic resonance spectroscopy (MRS) is a powerful new neuropsychiatric research tool which allows for the noninvasive investigation of in vivo biochemistry. This review focuses on the recent applications of MRS to in vivo neuropsychiatric research. 2. The history of MRS as it has progressed from an in vitro method of biochemical analysis to its current in vivo research uses is presented. 3. A brief overview of the physical principles of MRS, including methods for spectral localization, is discussed. 4. Applications of the different MRS modalities (1H, 31P, 19F, 7Li, 13C and 23Na) to various neuropsychiatric disorders such as Alzheimer's disease, schizophrenia, affective disorders, acquired immunodeficiency disease, etc. are reviewed. The study of both fluorinated neuroleptics and the antidepressant fluoxetine using 19F MRS are discussed in greater detail. 5. Finally, potential future neuropsychiatric applications of MRS and specifically 19F MRS are presented.
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Affiliation(s)
- T J Passe
- Department of Psychiatry, Duke University Medical Center, Durham, NC, USA
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39
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Laakso MP, Soininen H, Partanen K, Helkala EL, Hartikainen P, Vainio P, Hallikainen M, Hänninen T, Riekkinen PJ. Volumes of hippocampus, amygdala and frontal lobes in the MRI-based diagnosis of early Alzheimer's disease: correlation with memory functions. JOURNAL OF NEURAL TRANSMISSION. PARKINSON'S DISEASE AND DEMENTIA SECTION 1995; 9:73-86. [PMID: 7605591 DOI: 10.1007/bf02252964] [Citation(s) in RCA: 201] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
We studied the usefulness of measuring volumes of the hippocampus, amygdala and frontal lobes with coronal magnetic resonance imaging (MRI) scans in the diagnosis of early Alzheimer's disease (AD). We examined 32 patients diagnosed according to the NINCDS-ADRDA criteria of probable AD and 16 age-matched healthy cognitively normal controls. The AD patients had mild dementia with a mean score of 22.8 in the Mini-Mental Status Examination (MMSE). We used a 1.5 T magnetic resonance imager and normalized the volumes for brain area. The AD patients had significantly smaller volumes of the right and the left hippocampus (-38%) (ANOVA, p < 0.0001) and the left frontal lobe (-16%, p < 0.05) compared to controls. The reductions in volumes of the right frontal lobe (-13%), the right amygdala (-14%) or the left amygdala (-18%) were not statistically significant. In the discriminant function analysis which included the volumes of the hippocampus, amygdala, and the frontal lobes and age, the volumes of the left and right hippocampus, the left and right frontal lobe, and the right amygdala entered the model and we could correctly classify 92% of the subjects into AD and control groups (Chi-square 42.6, df 5, p < 0.001). By using the volumes of the hippocampus, the frontal lobes or the amygdala on their alone, the correct classification was achieved in 88%, 65% and 58% of the subjects, respectively. In addition, in AD patients the volumes of the left hippocampus correlated significantly with the MMSE score and with immediate and delayed verbal memory; the smaller the volume the more impaired was their performance. Our data indicate that measurements of volumes of the hippocampus might be useful in diagnosis of early AD.
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Affiliation(s)
- M P Laakso
- Department of Neurology, University Hospital, Kuopio, Finland
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40
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McClure RJ, Kanfer JN, Panchalingam K, Klunk WE, Pettegrew JW. Alzheimer's disease: membrane-associated metabolic changes. Ann N Y Acad Sci 1994; 747:110-24. [PMID: 7847665 DOI: 10.1111/j.1749-6632.1994.tb44404.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- R J McClure
- Department of Psychiatry, University of Pittsburgh, Pennsylvania 15213
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41
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Vion-Dury J, Meyerhoff DJ, Cozzone PJ, Weiner MW. What might be the impact on neurology of the analysis of brain metabolism by in vivo magnetic resonance spectroscopy? J Neurol 1994; 241:354-71. [PMID: 7931430 DOI: 10.1007/bf02033352] [Citation(s) in RCA: 106] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
In vivo nuclear magnetic resonance spectroscopy (MRS) of the human brain is a recently developed technique which allows to assay noninvasively in vivo key molecules of brain metabolism. After a review of the origin of the signals detected by phosphorus and proton MRS of human brain, the impact of MRS on clinical neurology is examined. MRS of the brain does not purport to be a metabolic "biopsy", but unique applications for brain MRS are (1) quantitating the oxidative state of the brain and defining neuronal death, (2) assessing and mapping neuron damage, (3) evaluating membrane alterations, and (4) characterizing encephalopathies. In the near future brain MRS will be performed routinely after conventional MRI, as a valuable metabolic (and functional) complement to the anatomical evaluation of cerebral pathologies, particularly the toxic, metabolic and infectious encephalopathies.
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42
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Klunk WE, Xu CJ, Panchalingam K, McClure RJ, Pettegrew JW. Analysis of magnetic resonance spectra by mole percent: comparison to absolute units. Neurobiol Aging 1994; 15:133-40. [PMID: 8159259 DOI: 10.1016/0197-4580(94)90153-8] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
A variety of metabolites present in perchloric acid extracts of brain tissue were measured by 1H and 31P magnetic resonance spectroscopy (MRS) and HPLC in the same tissue sample and the MRS results were expressed both in terms of mole % and mumole/g based on an internal standard. The levels of 16 metabolites were compared by linear regression analysis and the mole % results were found to correlate very well with the results expressed as mumole/g. To compare the two units under typical experimental conditions, the percent change in metabolites in a group of Alzheimer's disease brains was compared to a control group using both units. The results were essentially identical for the mole % and mumole/g methods. We conclude that the use of the mole % method of expressing MRS data yields results which are equivalent to those expressed in absolute units and suggest that, for in vivo MRS studies, use of the mole % method is preferable because fewer artifacts, such as partial volume effects, are introduced.
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Affiliation(s)
- W E Klunk
- Department of Psychiatry, University of Pittsburgh School of Medicine, PA 15261
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43
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Pettegrew JW, Panchalingam K, Klunk WE, McClure RJ, Muenz LR. Alterations of cerebral metabolism in probable Alzheimer's disease: a preliminary study. Neurobiol Aging 1994; 15:117-32. [PMID: 8159258 DOI: 10.1016/0197-4580(94)90152-x] [Citation(s) in RCA: 132] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Previous in vitro and in vivo 31P MRS studies of Alzheimer's disease patients have revealed alterations in membrane phospholipid metabolism and PET studies have shown alterations in glucose and oxidative metabolism. This study of probable Alzheimer's disease patients demonstrates severity dependent alterations in measures of both high-energy phosphate and membrane phospholipid metabolism. Mildly demented Alzheimer's patients compared to the controls, have increases in the levels of phosphomonoesters, decreases in the levels of phosphocreatine and probably adenosine diphosphate, and an increased oxidative metabolic rate. As the dementia worsens, the levels of phosphocreatine and adenosine diphosphate increase, the levels of phosphomonoesters decrease, and the oxidative metabolic rate decreases. The phosphomonoester findings replicate previous findings and provide a new dimension to the molecular pathology of Alzheimer's disease, implicating basic defects in membrane metabolism. The changes in oxidative metabolic rate suggest the AD brain is under energetic stress. The changes in energy metabolites with increasing dementia could be a consequence of nerve terminal degeneration and are consistent with previous PET findings. 31P MRS provides new diagnostic and metabolic insights into this disease and would be a noninvasive method to follow the progression of the disease and the metabolic response to therapeutic interventions.
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Affiliation(s)
- J W Pettegrew
- Department of Psychiatry, University of Pittsburgh, School of Medicine, PA 15213
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44
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45
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Longo R, Giorgini A, Magnaldi S, Pascazio L, Ricci C. Alzheimer's disease histologically proven studied by MRI and MRS: two cases. Magn Reson Imaging 1993; 11:1209-15. [PMID: 8271908 DOI: 10.1016/0730-725x(93)90249-d] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Two patients affected by severe Alzheimer's disease (AD) were investigated by MRI and image-guided 31P MRS. In one case, 1H MRS was additionally performed. In both cases the diagnosis of AD was confirmed, post mortem, by the pathologist. The spectral parameters of the 31P MR spectra were estimated by fitting the 31P MR signals in the time domain. Our 31P MRS results suggest that it is possible to detect the membrane catabolism, as indexed with the level of PDE resonances visible in in vivo 31P MRS, at least in severe AD cases. The 1H spectrum from AD brain showed a marked decrease of NAA signal respect to choline.
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Affiliation(s)
- R Longo
- Istituto di Radiologia, Università degli Studi di Trieste, Italy
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