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Frye RE, Rincon N, McCarty PJ, Brister D, Scheck AC, Rossignol DA. Biomarkers of mitochondrial dysfunction in autism spectrum disorder: A systematic review and meta-analysis. Neurobiol Dis 2024; 197:106520. [PMID: 38703861 DOI: 10.1016/j.nbd.2024.106520] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2024] [Revised: 04/27/2024] [Accepted: 04/29/2024] [Indexed: 05/06/2024] Open
Abstract
Autism spectrum disorder (ASD) is a neurodevelopmental disorder affecting 1 in 36 children and is associated with physiological abnormalities, most notably mitochondrial dysfunction, at least in a subset of individuals. This systematic review and meta-analysis discovered 204 relevant articles which evaluated biomarkers of mitochondrial dysfunction in ASD individuals. Significant elevations (all p < 0.01) in the prevalence of lactate (17%), pyruvate (41%), alanine (15%) and creatine kinase (9%) were found in ASD. Individuals with ASD had significant differences (all p < 0.01) with moderate to large effect sizes (Cohen's d' ≥ 0.6) compared to controls in mean pyruvate, lactate-to-pyruvate ratio, ATP, and creatine kinase. Some studies found abnormal TCA cycle metabolites associated with ASD. Thirteen controlled studies reported mitochondrial DNA (mtDNA) deletions or variations in the ASD group in blood, peripheral blood mononuclear cells, lymphocytes, leucocytes, granulocytes, and brain. Meta-analyses discovered significant differences (p < 0.01) in copy number of mtDNA overall and in ND1, ND4 and CytB genes. Four studies linked specific mtDNA haplogroups to ASD. A series of studies found a subgroup of ASD with elevated mitochondrial respiration which was associated with increased sensitivity of the mitochondria to physiological stressors and neurodevelopmental regression. Lactate, pyruvate, lactate-to-pyruvate ratio, carnitine, and acyl-carnitines were associated with clinical features such as delays in language, social interaction, cognition, motor skills, and with repetitive behaviors and gastrointestinal symptoms, although not all studies found an association. Lactate, carnitine, acyl-carnitines, ATP, CoQ10, as well as mtDNA variants, heteroplasmy, haplogroups and copy number were associated with ASD severity. Variability was found across biomarker studies primarily due to differences in collection and processing techniques as well as the intrinsic heterogeneity of the ASD population. Several studies reported alterations in mitochondrial metabolism in mothers of children with ASD and in neonates who develop ASD. Treatments targeting mitochondria, particularly carnitine and ubiquinol, appear beneficial in ASD. The link between mitochondrial dysfunction in ASD and common physiological abnormalities in individuals with ASD including gastrointestinal disorders, oxidative stress, and immune dysfunction is outlined. Several subtypes of mitochondrial dysfunction in ASD are discussed, including one related to neurodevelopmental regression, another related to alterations in microbiome metabolites, and another related to elevations in acyl-carnitines. Mechanisms linking abnormal mitochondrial function with alterations in prenatal brain development and postnatal brain function are outlined. Given the multisystem complexity of some individuals with ASD, this review presents evidence for the mitochondria being central to ASD by contributing to abnormalities in brain development, cognition, and comorbidities such as immune and gastrointestinal dysfunction as well as neurodevelopmental regression. A diagnostic approach to identify mitochondrial dysfunction in ASD is outlined. From this evidence, it is clear that many individuals with ASD have alterations in mitochondrial function which may need to be addressed in order to achieve optimal clinical outcomes. The fact that alterations in mitochondrial metabolism may be found during pregnancy and early in the life of individuals who eventually develop ASD provides promise for early life predictive biomarkers of ASD. Further studies may improve the understanding of the role of the mitochondria in ASD by better defining subgroups and understanding the molecular mechanisms driving some of the unique changes found in mitochondrial function in those with ASD.
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Affiliation(s)
- Richard E Frye
- Autism Discovery and Treatment Foundation, Phoenix, AZ, USA; Southwest Autism Research and Resource Center, Phoenix, AZ, USA; Rossignol Medical Center, Phoenix, AZ, USA.
| | | | - Patrick J McCarty
- Tulane University School of Medicine, New Orleans, LA 70113, United States of America.
| | | | - Adrienne C Scheck
- Autism Discovery and Treatment Foundation, Phoenix, AZ, USA; Department of Child Health, University of Arizona College of Medicine - Phoenix, Phoenix, AZ 85004, United States of America.
| | - Daniel A Rossignol
- Autism Discovery and Treatment Foundation, Phoenix, AZ, USA; Rossignol Medical Center, Aliso Viejo, CA, USA
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Du Y, Chen L, Yan MC, Wang YL, Zhong XL, Xv CX, Li YB, Cheng Y. Neurometabolite levels in the brains of patients with autism spectrum disorders: A meta-analysis of proton magnetic resonance spectroscopy studies (N = 1501). Mol Psychiatry 2023; 28:3092-3103. [PMID: 37117459 DOI: 10.1038/s41380-023-02079-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 04/12/2023] [Accepted: 04/14/2023] [Indexed: 04/30/2023]
Abstract
Evidence suggests that neurometabolite alterations may be involved in the pathophysiology of autism spectrum disorders (ASDs). We performed a meta-analysis of proton magnetic resonance spectroscopy (1H-MRS) studies to examine the neurometabolite levels in the brains of patients with ASD. A systematic search of PubMed and Web of Science identified 54 studies for the meta-analysis. A random-effects meta-analysis demonstrated that compared with the healthy controls, patients with ASD had lower N-acetyl-aspartate-containing compound (NAA) and choline-containing compound (Cho) levels and NAA/(creatine-containing compound) Cr ratios in the gray matter and lower NAA and glutamate + glutamine (Glx) levels in the white matter. Furthermore, NAA and gamma-aminobutyric acid (GABA) levels, NAA/Cr ratios, and GABA/Cr ratios were significantly decreased in the frontal cortex of patients with ASD, whereas glutamate (Glu) levels were increased in the prefrontal cortex. Additionally, low NAA levels and GABA/Cr ratios in the temporal cortex, low NAA levels and NAA/Cr ratios in the parietal and dorsolateral prefrontal cortices, and low NAA levels in the cerebellum and occipital cortex were observed in patients with ASD. Meta-regression analysis revealed that age was positively associated with effect size in studies analyzing the levels of gray matter NAA and white matter Glx. Taken together, these results provide strong clinical evidence that neurometabolite alterations in specific brain regions are associated with ASD and age is a confounding factor for certain neurometabolite levels in patients with ASD.
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Affiliation(s)
- Yang Du
- Key Laboratory of Ethnomedicine of Ministry of Education, Center on Translational Neuroscience, College of Life and Environmental Sciences, Minzu University of China, Beijing, China
| | - Lei Chen
- Key Laboratory of Ethnomedicine of Ministry of Education, Center on Translational Neuroscience, College of Life and Environmental Sciences, Minzu University of China, Beijing, China
| | - Mei-Chen Yan
- Key Laboratory of Ethnomedicine of Ministry of Education, Center on Translational Neuroscience, College of Life and Environmental Sciences, Minzu University of China, Beijing, China
| | - Yan-Li Wang
- Key Laboratory of Ethnomedicine of Ministry of Education, Center on Translational Neuroscience, College of Life and Environmental Sciences, Minzu University of China, Beijing, China
| | - Xiao-Lin Zhong
- Key Laboratory of Ethnomedicine of Ministry of Education, Center on Translational Neuroscience, College of Life and Environmental Sciences, Minzu University of China, Beijing, China
| | - Chen-Xi Xv
- Key Laboratory of Ethnomedicine of Ministry of Education, Center on Translational Neuroscience, College of Life and Environmental Sciences, Minzu University of China, Beijing, China
| | - Yao-Bo Li
- Key Laboratory of Ethnomedicine of Ministry of Education, Center on Translational Neuroscience, College of Life and Environmental Sciences, Minzu University of China, Beijing, China
| | - Yong Cheng
- Key Laboratory of Ethnomedicine of Ministry of Education, Center on Translational Neuroscience, College of Life and Environmental Sciences, Minzu University of China, Beijing, China.
- Institute of National Security, Minzu University of China, Beijing, China.
- NHC Key Laboratory of Birth Defect Research, Prevention, and Treatment (Hunan Provincial Maternal and Child Health-Care Hospital), Changsha, Hunan, China.
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Changes in the Cerebrospinal Fluid and Plasma Lipidome in Patients with Rett Syndrome. Metabolites 2022; 12:metabo12040291. [PMID: 35448478 PMCID: PMC9026385 DOI: 10.3390/metabo12040291] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 03/23/2022] [Accepted: 03/24/2022] [Indexed: 01/27/2023] Open
Abstract
Rett syndrome (RTT) is defined as a rare disease caused by mutations of the methyl-CpG binding protein 2 (MECP2). It is one of the most common causes of genetic mental retardation in girls, characterized by normal early psychomotor development, followed by severe neurologic regression. Hitherto, RTT lacks a specific biomarker, but altered lipid homeostasis has been found in RTT model mice as well as in RTT patients. We performed LC-MS/MS lipidomics analysis to investigate the cerebrospinal fluid (CSF) and plasma composition of patients with RTT for biochemical variations compared to healthy controls. In all seven RTT patients, we found decreased CSF cholesterol levels compared to age-matched controls (n = 13), whereas plasma cholesterol levels were within the normal range in all 13 RTT patients compared to 18 controls. Levels of phospholipid (PL) and sphingomyelin (SM) species were decreased in CSF of RTT patients, whereas the lipidomics profile of plasma samples was unaltered in RTT patients compared to healthy controls. This study shows that the CSF lipidomics profile is altered in RTT, which is the basis for future (functional) studies to validate selected lipid species as CSF biomarkers for RTT.
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Ford TC, Crewther DP. A Comprehensive Review of the (1)H-MRS Metabolite Spectrum in Autism Spectrum Disorder. Front Mol Neurosci 2016; 9:14. [PMID: 27013964 PMCID: PMC4783404 DOI: 10.3389/fnmol.2016.00014] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Accepted: 02/16/2016] [Indexed: 01/11/2023] Open
Abstract
Neuroimaging studies of neuropsychiatric behavior biomarkers across spectrum disorders are typically based on diagnosis, thus failing to account for the heterogeneity of multi-dimensional spectrum disorders such as autism (ASD). Control group trait phenotypes are also seldom reported. Proton magnetic resonance spectroscopy (1H-MRS) measures the abundance of neurochemicals such as neurotransmitters and metabolites and hence can probe disorder phenotypes at clinical and sub-clinical levels. This detailed review summarizes and critiques the current 1H-MRS research in ASD. The literature reports reduced N-acetylaspartate (NAA), glutamate and glutamine (Glx), γ-aminobutyric acid (GABA), creatine and choline, and increased glutamate for children with ASD. Adult studies are few and results are inconclusive. Overall, the literature has several limitations arising from differences in 1H-MRS methodology and sample demographics. We argue that more consistent methods and greater emphasis on phenotype studies will advance understanding of underlying cortical metabolite disturbance in ASD, and the detection, diagnosis, and treatment of ASD and other multi-dimensional psychiatric disorders.
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Affiliation(s)
- Talitha C Ford
- Faculty of Health, Arts and Design, Centre for Human Psychopharmacology, Swinburne University of Technology Melbourne, VIC, Australia
| | - David P Crewther
- Faculty of Health, Arts and Design, Centre for Human Psychopharmacology, Swinburne University of Technology Melbourne, VIC, Australia
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Baruth JM, Wall CA, Patterson MC, Port JD. Proton Magnetic Resonance Spectroscopy as a Probe into the Pathophysiology of Autism Spectrum Disorders (ASD): A Review. Autism Res 2013; 6:119-33. [DOI: 10.1002/aur.1273] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2012] [Accepted: 12/08/2012] [Indexed: 12/25/2022]
Affiliation(s)
- Joshua M. Baruth
- Department of Psychiatry and Psychology; Mayo Clinic; Rochester; Minnesota
| | | | - Marc C. Patterson
- Departments of Neurology, Pediatric and Adolescent Medicine and Medical Genetics; Mayo Clinic Children's Center; Rochester; Minnesota
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Ipser JC, Syal S, Bentley J, Adnams CM, Steyn B, Stein DJ. 1H-MRS in autism spectrum disorders: a systematic meta-analysis. Metab Brain Dis 2012; 27:275-87. [PMID: 22426803 DOI: 10.1007/s11011-012-9293-y] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/18/2011] [Accepted: 02/24/2012] [Indexed: 10/28/2022]
Abstract
We conducted a systematic review and meta-analysis of proton magnetic resonance spectroscopy (1H-MRS) studies comparing autism spectrum disorder (ASD) patients with healthy controls, with the aim of profiling ASD-associated changes in the metabolites N-acetyl-aspartate (NAA) and Creatine (Cr). Meta-regression models of NAA and Cr levels were employed, using data from 20 eligible studies (N = 852), to investigate age-dependent differences in both global brain and region-specific metabolite levels, while controlling for measurement method (Cr-ratio versus absolute concentrations). Decreased NAA concentrations that were specific to children were found for whole-brain grey and white matter. In addition, a significant decrease in NAA was evident across age categories in the parietal cortex, the cerebellum, and the anterior cingulate cortex. Higher levels of Cr were observed for ASD adults than children in global grey matter, with specific increases for adults in the temporal lobe and decreased Cr in the occipital lobe in children. No differences were found for either NAA or Cr in the frontal lobes. These data provide some evidence that ASD is characterized by age-dependent fluctuations in metabolite levels across the whole brain and at the level of specific regions thought to underlie ASD-associated behavioural and affective deficits. Differences in Cr as a function of age and brain region suggests caution in the interpretation of Cr-based ratio measures of metabolites. Despite efforts to control for sources of heterogeneity, considerable variability in metabolite levels was observed in frontal and temporal regions, warranting further investigation.
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Affiliation(s)
- Jonathan C Ipser
- Department of Psychiatry and Mental Health, University of Cape Town, Cape Town, South Africa.
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Elevated glutamatergic compounds in pregenual anterior cingulate in pediatric autism spectrum disorder demonstrated by 1H MRS and 1H MRSI. PLoS One 2012; 7:e38786. [PMID: 22848344 PMCID: PMC3407186 DOI: 10.1371/journal.pone.0038786] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2011] [Accepted: 05/10/2012] [Indexed: 11/19/2022] Open
Abstract
Recent research in autism spectrum disorder (ASD) has aroused interest in anterior cingulate cortex and in the neurometabolite glutamate. We report two studies of pregenual anterior cingulate cortex (pACC) in pediatric ASD. First, we acquired in vivo single-voxel proton magnetic resonance spectroscopy ((1)H MRS) in 8 children with ASD and 10 typically developing controls who were well matched for age, but with fewer males and higher IQ. In the ASD group in midline pACC, we found mean 17.7% elevation of glutamate + glutamine (Glx) (p<0.05) and 21.2% (p<0.001) decrement in creatine + phosphocreatine (Cr). We then performed a larger (26 subjects with ASD, 16 controls) follow-up study in samples now matched for age, gender, and IQ using proton magnetic resonance spectroscopic imaging ((1)H MRSI). Higher spatial resolution enabled bilateral pACC acquisition. Significant effects were restricted to right pACC where Glx (9.5%, p<0.05), Cr (6.7%, p<0.05), and N-acetyl-aspartate + N-acetyl-aspartyl-glutamate (10.2%, p<0.01) in the ASD sample were elevated above control. These two independent studies suggest hyperglutamatergia and other neurometabolic abnormalities in pACC in ASD, with possible right-lateralization. The hyperglutamatergic state may reflect an imbalance of excitation over inhibition in the brain as proposed in recent neurodevelopmental models of ASD.
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8
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Halbach NSJ, Smeets EEJ, Bierau J, Keularts IMLW, Plasqui G, Julu POO, Engerström IW, Bakker JA, Curfs LMG. Altered carbon dioxide metabolism and creatine abnormalities in rett syndrome. JIMD Rep 2011; 3:117-24. [PMID: 23430883 PMCID: PMC3509869 DOI: 10.1007/8904_2011_76] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2010] [Revised: 06/24/2011] [Accepted: 07/04/2011] [Indexed: 03/23/2024] Open
Abstract
Despite their good appetite, many females with Rett syndrome (RTT) meet the criteria for moderate to severe malnutrition. Although feeding difficulties may play a part in this, other constitutional factors such as altered metabolic processes are suspected. Irregular breathing is a common clinical feature, leading to chronic respiratory alkalosis or acidosis. We assumed that these changes in intracellular pH cause disturbances in the metabolic equilibrium, with important nutritional consequences. The study population consisted of a group of thirteen well-defined RTT girls with extended clinical, molecular and neurophysiological assessments. Despite normal levels of total dietary energy and protein intakes, malnutrition was confirmed based on significantly low fat-free mass index (FFMI) values. Biochemical screening of multiple metabolic pathways showed significantly elevated plasma creatine concentrations and increased urinary creatine/creatinine ratio in five RTT girls. Four girls, 10 years and older, were forceful breathers, one 13-year-old girl had an undetermined cardiorespiratory phenotype. An isolated increase of the urinary creatine/creatinine ratio was seen in two girls, a 9-year old forceful and a 4-year old feeble breather. Given that the young girls are feeble breathers and the older girls are forceful breathers, it is impossible to determine whether the elevated creatine concentrations are due to increasing age or cardiorespiratory phenotype. Furthermore, MeCP2 deficiency may cause epigenetic aberrations affecting the expression of the creatine-transporter gene, which is located at Xq28. Further studies are required to confirm these findings and to provide greater insight into the pathogenesis of the abnormal creatine metabolism in RTT.
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Affiliation(s)
- Nicky S J Halbach
- Department of Clinical Genetics, Maastricht University Medical Centre, P. Debeyelaan 25, 5800, 6202, AZ, Maastricht, The Netherlands,
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9
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Vasconcelos MM, Brito AR, Domingues RC, da Cruz LCH, Gasparetto EL, Werner J, Gonçalves JPS. Proton magnetic resonance spectroscopy in school-aged autistic children. J Neuroimaging 2009; 18:288-95. [PMID: 18304036 DOI: 10.1111/j.1552-6569.2007.00200.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
PURPOSE This study aims to assess cerebral metabolites in school-aged autistic patients through proton magnetic resonance spectroscopy. METHODS This case-control study included 10 right-handed male children (median age, 9.53 years +/- 1.80) with autism according to DSM-IV criteria, and 10 healthy age- and sex-matched healthy controls (median age, 8.52 years +/- 1.42). Imaging was performed on a 1.5-T scanner utilizing a single voxel point-resolved spectroscopy (PRESS) technique (TR = 1,500 ms, TE = 30 ms). Four cerebral areas were evaluated: bilateral anterior cingulate, left striatum, left cerebellar hemisphere, and left frontal lobe. Peak areas and ratios to creatine (Cr) of N-acetylaspartate (NAA), choline (Cho), and myo-inositol (mI) were analyzed. RESULTS Compared with controls, autistic children showed a significant increase in mI (P= .021) and Cho (P= .042) peak areas in anterior cingulate and in mI/Cr ratio in anterior cingulate (P= .037) and left striatum (P= .035). The remaining metabolites and ratios were not significantly different between the 2 groups. CONCLUSIONS This study found a statistically significant increase in myo-inositol and choline in anterior cingulate and left striatum of autistic children compared with controls. In contrast to previous studies, NAA peak area and NAA/Cr and NAA/Cho ratios had no statistically significant decrease in any of the 4 brain regions.
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Affiliation(s)
- Marcio Moacyr Vasconcelos
- Departamento Materno-Infantil, Hospital Universitário Antônio Pedro, Universidade Federal Fluminense, Rio de Janeiro, Brazil.
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10
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Ward BC, Kolodny NH, Nag N, Berger-Sweeney JE. Neurochemical changes in a mouse model of Rett syndrome: changes over time and in response to perinatal choline nutritional supplementation. J Neurochem 2008; 108:361-71. [PMID: 19012748 DOI: 10.1111/j.1471-4159.2008.05768.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Rett syndrome (RTT), the second leading cause of mental retardation in girls, is caused by mutations in the X-linked gene for methyl-CpG-binding protein 2 (MeCP2), a transcriptional repressor. In addition to well-documented neuroanatomical and behavioral deficits, RTT is characterized by reduced markers of cholinergic activity and general neuronal health. Previously, we have shown that early postnatal choline (Cho) supplementation improves behavioral and neuroanatomical symptoms in a mouse model of RTT (Mecp2(1lox) mice). In this study, we use NMR spectroscopy to quantify the relative amounts of Cho, Glutamate (Glu), Glutamine (Gln), and N-acetyl aspartate (NAA) in the brains of wild type and mutant mice at 21, 35, and 42 days of age and in mice receiving postnatal Cho supplementation. We find that the mutant mice have reduced levels of Cho, Glu, and NAA, but elevated Gln levels, compared with their wild type littermates. These differences emerge at different developmental ages. Cho supplementation increases NAA levels, a marker of neuronal integrity, but has no effect on Cho, Glu, or Gln. These data suggest that postnatal nutritional supplementation may improve neuronal function and could serve as a therapeutic agent for human RTT patients.
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Affiliation(s)
- Bonnie C Ward
- Department of Biological Sciences, Wellesley College, Wellesley, MA 02481, USA
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Gabis L, Wei Huang, Azizian A, DeVincent C, Tudorica A, Kesner-Baruch Y, Roche P, Pomeroy J. 1H-magnetic resonance spectroscopy markers of cognitive and language ability in clinical subtypes of autism spectrum disorders. J Child Neurol 2008; 23:766-74. [PMID: 18487520 DOI: 10.1177/0883073808315423] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
This study assessed metabolic functioning of regional brain areas to address whether there is a neurometabolic profile reflecting the underlying neuropathology in individuals with autism spectrum disorders, and if varied profiles correlate with the clinical subtypes. Thirteen children (7-16 years) with autism spectrum disorders and 8 typically developing children were compared on (1)H-magnetic resonance spectroscopy data collected from hippocampus-amygdala and cerebellar regions. The autism spectrum disorder group had significantly lower N-acetyl-aspartate/creatine ratios bilaterally in the hippocampus-amygdala but not cerebellum, whereas myo-inositol/creatine was significantly increased in all measured regions. Choline/creatine was also significantly elevated in the left hippocampus-amygdala and cerebellar regions of children with autism spectrum disorder. Comparisons within the autism spectrum disorder group when clinically subdivided by history of speech delay revealed significant metabolic ratio differences. Magnetic resonance spectroscopy can provide important information regarding abnormal brain metabolism and clinical classification in autism spectrum disorders.
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Affiliation(s)
- Lidia Gabis
- Weinberg Child Development Center, Safra Children's Hospital, Tel Hashomer, Israel.
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Nag N, Ward B, Berger-Sweeney JE. Nutritional factors in a mouse model of Rett syndrome. Neurosci Biobehav Rev 2008; 33:586-92. [PMID: 18479749 DOI: 10.1016/j.neubiorev.2008.03.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2007] [Revised: 03/07/2008] [Accepted: 03/19/2008] [Indexed: 11/17/2022]
Abstract
Environmental factors such as nutrition and housing can influence behavioral and anatomical characteristics of several neurological disorders, including Rett syndrome (RTT). RTT is associated with mutations in the X-linked gene encoding MeCP2, a transcriptional repressor that binds methylated DNA. While direct genetic intervention in humans is impossible at this time, motor and cognitive deficits in RTT may be ameliorated through manipulations of epigenetic/environmental factors. For example, studies in rodents suggest that choline nutrient supplementation during critical periods of brain development enhances cholinergic neurotransmission, alters neuronal size and distribution, and facilitates performance of memory and motoric tasks. Recent work in a mouse model of RTT shows that enhancing maternal nutrition through choline supplementation improves both anatomical and behavioral symptoms in the mutant offspring. We describe here cellular and molecular mechanisms that may underlie this specific enhancement and may provide more general insights into mechanisms underlying gene-environment interactions in neurological disorders.
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Affiliation(s)
- Nupur Nag
- Department of Biological Sciences, Wellesley College, 106 Central Street, Wellesley, MA 02481, United States
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13
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Oner O, Devrimci-Ozguven H, Oktem F, Yagmurlu B, Baskak B, Munir KM. Proton MR spectroscopy: higher right anterior cingulate N-acetylaspartate/choline ratio in Asperger syndrome compared with healthy controls. AJNR Am J Neuroradiol 2007; 28:1494-8. [PMID: 17846198 PMCID: PMC3166641 DOI: 10.3174/ajnr.a0625] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE One former study reported higher prefrontal N-acetylaspartate (NAA) levels in patients with Asperger syndrome (AS). The objective of the current study was to test the hypothesis that patients with AS would have higher dorsolateral prefrontal and anterior cingulate cortex NAA/creatine (Cr) and that NAA/Cr would be correlated with symptom severity. MATERIALS AND METHODS NAA/choline (Cho), NAA/Cr, and Cho/Cr values revealed by (1)H-MR spectroscopy in 14 right-handed male patients with AS (6 medicated with risperidone), 17-38 years of age, diagnosed by the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, criteria were compared with those of 21 right-handed male controls frequency-matched by age and intelligence quotient scores. RESULTS Patients with AS had significantly higher anterior cingulate NAA/Cho levels (z = -2.18, P = .028); there was a statistical trend for higher anterior cingulate NAA/Cr (z = -1.81, P = .069) that was significant when only the unmedicated patients with AS were taken into account (z = -1.95, P = .050). There were no significant differences in dorsolateral prefrontal MR spectroscopy values. CONCLUSIONS Our findings show that individuals with AS had higher NAA/Cho levels in the right anterior cingulate compared with healthy controls and that higher anterior cingulate NAA/Cho levels were correlated with higher Yale-Brown Obsessive Compulsive Scale total scores.
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Affiliation(s)
- O Oner
- Child Psychiatry Department, SB Ankara Diskapi Children's Hospital, Ankara, Turkey.
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Abstract
Since the birth of functional magnetic resonance imaging (fMRI)-a noninvasive tool able to visualize brain function-now 15 years ago, several clinical applications have emerged. fMRI follows from the neurovascular coupling between neuronal electrical activity and cerebrovascular physiology that leads to three effects that can contribute to the fMRI signal: an increase in the blood flow velocity, in the blood volume and in the blood oxygenation level. The latter effect, gave the technique the name blood oxygenation level dependent (BOLD) fMRI. One of the major clinical uses is presurgical fMRI in patients with brain abnormalities. The goals of presurgical fMRI are threefold: 1) assessing the risk of neurological deficit that follows a surgical procedure, 2) selecting patients for invasive intraoperative mapping, and 3) guiding of the surgical procedure itself. These are reviewed here. Unfortunately, randomized trials or outcome studies that definitively show benefits to the final outcome of the patient when applying fMRI presurgically have not been performed. Therefore, fMRI has not yet reached the status of clinical acceptance. The final purpose of this article is to define a roadmap of future research and developments in order to tilt pre-surgical fMRI to the status of clinical validity and acceptance.
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Affiliation(s)
- Stefan Sunaert
- Department of Radiology, University Hospital of the Catholic University of Leuven, Leuven, Belgium.
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Zeegers M, van der Grond J, van Daalen E, Buitelaar J, van Engeland H. Proton magnetic resonance spectroscopy in developmentally delayed young boys with or without autism. J Neural Transm (Vienna) 2006; 114:289-95. [PMID: 16715207 DOI: 10.1007/s00702-006-0501-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2005] [Accepted: 02/07/2006] [Indexed: 11/30/2022]
Abstract
OBJECTIVE The aim of the present study is to investigate whether brain metabolism of boys with autism spectrum disorder (ASD) is altered compared to boys with a developmental delay without autism if corrected for patient age and developmental level. STUDY DESIGN 25 boys with ASD (with or without concurrent mental retardation) and 12 boys without ASD with mental retardation or language disorder underwent proton magnetic resonance spectroscopy. All analyses were performed with chronological age and developmental level as independent variables. RESULTS No metabolic differences were found between boys with ASD and without ASD. CONCLUSIONS Our findings do not replicate previous reports of differences in NAA, Cho and Cr levels in ASD.
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Affiliation(s)
- M Zeegers
- Department of Child and Adolescent Psychiatry, Rudolf Magnus Institute of Neuroscience, University Medical Center Utrecht, Utrecht, The Netherlands.
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Gulati S, Shah T, Menon S, Jayasundar R, Kalra V. Magnetic resonance spectroscopy in pediatric neurology. Indian J Pediatr 2003; 70:317-25. [PMID: 12793309 DOI: 10.1007/bf02723588] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
In the last three decades a range of non-invasive biophysical techniques have been developed, of which Magnetic Resonance (MR) has proved to be the most versatile. Its non-invasive and safe nature has made it the most important diagnostic and research tool in clinical medicine. MR Spectroscopy (MRS) is the only technique in clinical medicine that provides non-invasive access to living chemistry in situ. This article focuses mainly on proton MRS in brain and also phosphorus MRS in calf muscle, with particular reference to the pediatric population, the normal spectrum and its use in various disease conditions in the practice of pediatric neurology. Few representative case studies among different disease groups have also been detailed.
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Affiliation(s)
- Sheffali Gulati
- Department of Pediatrics, All India Institute of Medical Sciences, New Delhi, India
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Gökcay A, Kitis O, Ekmekci O, Karasoy H, Sener RN. Proton MR spectroscopy in Rett syndrome. Comput Med Imaging Graph 2002; 26:271-5. [PMID: 12074922 DOI: 10.1016/s0895-6111(02)00016-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Seven patients (mean age 7.7yr) with Rett syndrome, a condition with progressive regression of psychomotor development are included in this study. Proton MR spectroscopy images were obtained with the multivoxel chemical-shift imaging mode (TR=1500ms, TE=40ms). Spectra from 224 voxels in the brain parenchyma were studied. N-acetyl aspartate (NAA), creatine (Cr), choline (Cho), and myoinositol (mI) peaks were quantitatively evaluated, and NAA/Cr, NAA/Cho, and Cho/Cr, mI/Cr ratios were calculated. Five age-matched normal cases were available as controls. In three patients with Rett syndrome spectroscopy findings were normal, and the metabolite ratios were similar to control cases. In the remaining four patients with the syndrome prominent decrease of the NAA peak was the main finding resulting in decreases in NAA/Cr (1.14+/-17), and NAA/Cho (1.08+/-27) ratios (p<0.0001). Cho/Cr ratios (0.93+/-26), and mI/Cr ratios (0.88+/-36) were normal compared to controls. There was no correlation between spectroscopic changes and clinical status of the patients. The findings suggested that not only reduced neuronal-dendritic arborizations but also decreased neuronal function could contribute to spectroscopy changes in Rett syndrome.
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Affiliation(s)
- A Gökcay
- Department of Neurology, Ege University Hospital, Bornova, Izmir 35100, Turkey
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Sokol DK, Dunn DW, Edwards-Brown M, Feinberg J. Hydrogen proton magnetic resonance spectroscopy in autism: preliminary evidence of elevated choline/creatine ratio. J Child Neurol 2002; 17:245-9. [PMID: 12088077 DOI: 10.1177/088307380201700401] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Hydrogen proton magnetic resonance spectroscopy is only beginning to be studied in autistic individuals. We report an association between hydrogen proton magnetic resonance spectroscopy choline/creatine ratios and severity of autism as measured by the Children's Autistic Rating Scale (Pearson r = .657, P = .04) in 10 autistic children. Hydrogen proton magnetic resonance spectroscopy choline/creatine ratio measures the concentration of cytosolic choline including free choline used in the synthesis of acetylcholine. Elevation in this ratio has been interpreted as a result of membrane degradation such as caused by a tumor or, alternatively, as a result of choline synthesis associated with increased cellular proliferation. Recent neuropathologic evidence has implicated disruption of acetylcholine transmission in the brains of autistic adults. A case-controlled study of hydrogen proton magnetic resonance spectroscopy choline/creatine ratios is warranted.
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Affiliation(s)
- Deborah K Sokol
- Department of Neurology, Indiana University School of Medicine, Indianapolis, USA.
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19
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Abstract
We studied the in vivo cerebral metabolites and documented the presence of MECP2 gene mutations in six Chinese females with Rett syndrome. Magnetic resonance spectroscopy spectra from the frontal lobe (gray and white matter) and deep gray nuclei (basal ganglia and thalamus) of either side were obtained. N-acetylaspartate/total creatine, choline/total creatine, and N-acetylaspartate/choline ratios were analyzed and compared with six healthy age-matched female control subjects. MECP2 gene mutation was identified in four patients; one patient had polymorphism and one patient did not have gene mutation. N-acetylaspartate/total creatine of the frontal lobe of all patients (mean: 2.63, S.D. = 0.33) was decreased compared with age-matched control subjects (mean: 3.15, S.D. = 0.27), and the difference was statistically significant (P = 0.017) with a mean difference of 0.52 (95% CI = 0.68-0.36). The difference in all other metabolite ratios in the frontal lobe and deep gray nuclei were not statistically significant compared with age-matched control subjects. Mild frontal lobe and anterior temporal lobe atrophy was present in three patients. Proton-magnetic resonance spectroscopy is a sensitive method capable of detecting the biochemical changes in Rett syndrome and is able to detect changes before conventional magnetic resonance imaging. Our preliminary results suggest that reduction in N-acetylaspartate/total creatine ratio may not be related to the MECP2 mutation.
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Affiliation(s)
- Pek Lan Khong
- Department of Diagnostic Radiology, Queen Mary Hospital, the University of Hong Kong, Hong Kong
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20
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Abstract
The Rett syndrome (RS) is a peculiar, sporadic, atrophic disorder, almost entirely confined to females. After the first six months of life there is developmental slowing with reduced communication and head growth for about one year. This is followed by a rapid destructive stage with severe dementia and loss of hand skills (with frequent hand wringing), apraxia and ataxia, autistic features and irregular breathing with hyperventilation. Seizures often supervene. Subsequently there is some stabilization in a pseudo-stationary stage during the preschool to school years, associated with more emotional contact but also abnormalities of the autonomic and skeletal systems. After the age of 15-20 years, a late motor deterioration occurs with dystonia and frequent spasticity but seizures become milder. RS has generally been considered an X-linked disorder in which affected females represent a new mutation, with male lethality. Linkage studies suggested a critical region at Xq28. In 1999, mutations in the gene MECP2 encoding X-linked methyl cytosine-binding protein 2 (MeCP2) were found in a proportion of Rett girls. This protein can bind methylated DNA. Analyses are leading to much further investigation of mutants and their effects on genes. Neuropathological and electrophysiological studies of RS are described. Description of neurometabolic factors includes reduced levels of dopamine, serotonin, noradrenaline and choline acetyltransferase (ChAT) in brain, also estimation of nerve growth factors, endorphin, substance P, glutamate and other amino acids and their receptor levels. The results of neuroimaging are surveyed, including volumetric magnetic resonance imaging (MRI) and positron emission tomography (PET).
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Affiliation(s)
- H G Dunn
- Division of Neurology, British Columbia's Children's Hospital, Vancouver, BC, Canada
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21
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Rumsey JM, Ernst M. Functional neuroimaging of autistic disorders. MENTAL RETARDATION AND DEVELOPMENTAL DISABILITIES RESEARCH REVIEWS 2000; 6:171-9. [PMID: 10982494 DOI: 10.1002/1098-2779(2000)6:3<171::aid-mrdd4>3.0.co;2-n] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Functional neuroimaging methods hold promise for elucidating the neurobiology of autistic disorders, yet they present difficult practical and scientific challenges when applied to these complex and heterogeneous syndromes. Single-state studies of brain metabolism and blood flow thus far have failed to yield consistent findings, but suggest considerable variability in regional patterns of cerebral synaptic activity. Patients with idiopathic autism are less likely to show abnormalities than are patients with comorbid illness or epilepsy. Activation studies have begun to suggest alterations in brain organization for language and cognition. Neurotransmitter studies using positron emission tomography (PET) suggest abnormalities of serotonergic and dopaminergic function. Studies using magnetic resonance spectroscopy (MRS) have begun to document metabolic deficits in the frontal cortex and cerebellum. A single study using magnetoencephalography suggests a high incidence of epileptiform activity in children with autistic regression. Research needs include well-controlled developmental studies, particularly of young subjects and relatively homogeneous subgroups, which balance scientific rigor with ethical constraints. Investigations of the serotonergic and dopaminergic systems, limbic-based memory and emotional systems, and the role of epileptiform activity in autism represent priorities for future research.
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Affiliation(s)
- J M Rumsey
- Clinical Neuroscience Branch, National Institute of Mental Health, Bethesda, Maryland 20892, USA.
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22
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Abstract
Rett syndrome, a neurodevelopmental disorder predominantly affecting girls, is characterized by regression of psychomotor development, communication dysfunction, and hand stereotypies. Brain morphologic studies demonstrate increased neuronal packing density and reduced dendritic arborizations, suggesting an arrest or interruption of normal maturation. Numerous neurotransmitter systems have been implicated. Among these, cerebrospinal fluid glutamate levels are elevated and glutamate receptors, particularly in putamen, are reduced. Therefore, 1H spectroscopy at 4.1 Tesla was used to evaluate glutamate, creatine, and N-acetylaspartate in six girls with Rett syndrome and four normal sibling controls. The ratio of creatine to N-acetylaspartate was significantly elevated in white matter, primarily reflecting reduced N-acetylaspartate levels, and normal in gray matter. The glutamate to N-acetylaspartate ratio was elevated in gray matter and normal in white matter. These findings are consistent with previous neuropathologic and neurochemical findings and indicate the feasibility of imaging these metabolites in vivo.
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Affiliation(s)
- J W Pan
- Center for Nuclear Imaging Research, University of Alabama at Birmingham, USA
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