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Levy KA, Weisz ED, Jongens TA. Loss of neurexin-1 in Drosophila melanogaster results in altered energy metabolism and increased seizure susceptibility. Hum Mol Genet 2022; 31:3422-3438. [PMID: 35617143 PMCID: PMC9558836 DOI: 10.1093/hmg/ddac115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 04/28/2022] [Accepted: 05/09/2022] [Indexed: 12/04/2022] Open
Abstract
Although autism is typically characterized by differences in language, social interaction and restrictive, repetitive behaviors, it is becoming more well known in the field that alterations in energy metabolism and mitochondrial function are comorbid disorders in autism. The synaptic cell adhesion molecule, neurexin-1 (NRXN1), has previously been implicated in autism, and here we show that in Drosophila melanogaster, the homologue of NRXN1, called Nrx-1, regulates energy metabolism and nutrient homeostasis. First, we show that Nrx-1-null flies exhibit decreased resistance to nutrient deprivation and heat stress compared to controls. Additionally, Nrx-1 mutants exhibit a significantly altered metabolic profile characterized by decreased lipid and carbohydrate stores. Nrx-1-null Drosophila also exhibit diminished levels of nicotinamide adenine dinucleotide (NAD+), an important coenzyme in major energy metabolism pathways. Moreover, loss of Nrx-1 resulted in striking abnormalities in mitochondrial morphology in the flight muscle of Nrx-1-null Drosophila and impaired flight ability in these flies. Further, following a mechanical shock Nrx-1-null flies exhibited seizure-like activity, a phenotype previously linked to defects in mitochondrial metabolism and a common symptom of patients with NRXN1 deletions. The current studies indicate a novel role for NRXN1 in the regulation of energy metabolism and uncover a clinically relevant seizure phenotype in Drosophila lacking Nrx-1.
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Affiliation(s)
- Kyra A Levy
- Department of Genetics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA.,Neuroscience Graduate Group, University of Pennsylvania, Philadelphia, PA 19104, USA.,Autism Spectrum Program of Excellence, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Eliana D Weisz
- Department of Genetics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA.,Autism Spectrum Program of Excellence, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Thomas A Jongens
- Department of Genetics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA.,Autism Spectrum Program of Excellence, University of Pennsylvania, Philadelphia, PA 19104, USA
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Tan Z, Wei H, Song X, Mai W, Yan J, Ye W, Ling X, Hou L, Zhang S, Yan S, Xu H, Wang L. Positron Emission Tomography in the Neuroimaging of Autism Spectrum Disorder: A Review. Front Neurosci 2022; 16:806876. [PMID: 35495051 PMCID: PMC9043810 DOI: 10.3389/fnins.2022.806876] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 03/14/2022] [Indexed: 12/11/2022] Open
Abstract
Autism spectrum disorder (ASD) is a basket term for neurodevelopmental disorders characterized by marked impairments in social interactions, repetitive and stereotypical behaviors, and restricted interests and activities. Subtypes include (A) disorders with known genetic abnormalities including fragile X syndrome, Rett syndrome, and tuberous sclerosis and (B) idiopathic ASD, conditions with unknown etiologies. Positron emission tomography (PET) is a molecular imaging technology that can be utilized in vivo for dynamic and quantitative research, and is a valuable tool for exploring pathophysiological mechanisms, evaluating therapeutic efficacy, and accelerating drug development in ASD. Recently, several imaging studies on ASD have been published and physiological changes during ASD progression was disclosed by PET. This paper reviews the specific radioligands for PET imaging of critical biomarkers in ASD, and summarizes and discusses the similar and different discoveries in outcomes of previous studies. It is of great importance to identify general physiological changes in cerebral glucose metabolism, cerebral blood flow perfusion, abnormalities in neurotransmitter systems, and inflammation in the central nervous system in ASD, which may provide excellent points for further ASD research.
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Affiliation(s)
- Zhiqiang Tan
- Center of Cyclotron and PET Radiopharmaceuticals, Department of Nuclear Medicine and PET/CT-MRI Center, The First Affiliated Hospital of Jinan University, Guangzhou, China
| | - Huiyi Wei
- Center of Cyclotron and PET Radiopharmaceuticals, Department of Nuclear Medicine and PET/CT-MRI Center, The First Affiliated Hospital of Jinan University, Guangzhou, China
| | - Xiubao Song
- Department of Rehabilitation Medicine, The First Affiliated Hospital of Jinan University, Jinan University, Guangzhou, China
| | - Wangxiang Mai
- Department of Rehabilitation Medicine, The First Affiliated Hospital of Jinan University, Jinan University, Guangzhou, China
| | - Jiajian Yan
- Department of Rehabilitation Medicine, The First Affiliated Hospital of Jinan University, Jinan University, Guangzhou, China
| | - Weijian Ye
- Center of Cyclotron and PET Radiopharmaceuticals, Department of Nuclear Medicine and PET/CT-MRI Center, The First Affiliated Hospital of Jinan University, Guangzhou, China
| | - Xueying Ling
- Center of Cyclotron and PET Radiopharmaceuticals, Department of Nuclear Medicine and PET/CT-MRI Center, The First Affiliated Hospital of Jinan University, Guangzhou, China
| | - Lu Hou
- Center of Cyclotron and PET Radiopharmaceuticals, Department of Nuclear Medicine and PET/CT-MRI Center, The First Affiliated Hospital of Jinan University, Guangzhou, China
| | - Shaojuan Zhang
- Center of Cyclotron and PET Radiopharmaceuticals, Department of Nuclear Medicine and PET/CT-MRI Center, The First Affiliated Hospital of Jinan University, Guangzhou, China
| | - Sen Yan
- Guangdong-Hongkong-Macau Institute of CNS Regeneration, Ministry of Education CNS Regeneration Collaborative Joint Laboratory, Jinan University, Guangzhou, China
| | - Hao Xu
- Center of Cyclotron and PET Radiopharmaceuticals, Department of Nuclear Medicine and PET/CT-MRI Center, The First Affiliated Hospital of Jinan University, Guangzhou, China
- *Correspondence: Hao Xu,
| | - Lu Wang
- Center of Cyclotron and PET Radiopharmaceuticals, Department of Nuclear Medicine and PET/CT-MRI Center, The First Affiliated Hospital of Jinan University, Guangzhou, China
- Lu Wang,
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Ouellette J, Lacoste B. From Neurodevelopmental to Neurodegenerative Disorders: The Vascular Continuum. Front Aging Neurosci 2021; 13:749026. [PMID: 34744690 PMCID: PMC8570842 DOI: 10.3389/fnagi.2021.749026] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Accepted: 09/13/2021] [Indexed: 12/12/2022] Open
Abstract
Structural and functional integrity of the cerebral vasculature ensures proper brain development and function, as well as healthy aging. The inability of the brain to store energy makes it exceptionally dependent on an adequate supply of oxygen and nutrients from the blood stream for matching colossal demands of neural and glial cells. Key vascular features including a dense vasculature, a tightly controlled environment, and the regulation of cerebral blood flow (CBF) all take part in brain health throughout life. As such, healthy brain development and aging are both ensured by the anatomical and functional interaction between the vascular and nervous systems that are established during brain development and maintained throughout the lifespan. During critical periods of brain development, vascular networks remodel until they can actively respond to increases in neural activity through neurovascular coupling, which makes the brain particularly vulnerable to neurovascular alterations. The brain vasculature has been strongly associated with the onset and/or progression of conditions associated with aging, and more recently with neurodevelopmental disorders. Our understanding of cerebrovascular contributions to neurological disorders is rapidly evolving, and increasing evidence shows that deficits in angiogenesis, CBF and the blood-brain barrier (BBB) are causally linked to cognitive impairment. Moreover, it is of utmost curiosity that although neurodevelopmental and neurodegenerative disorders express different clinical features at different stages of life, they share similar vascular abnormalities. In this review, we present an overview of vascular dysfunctions associated with neurodevelopmental (autism spectrum disorders, schizophrenia, Down Syndrome) and neurodegenerative (multiple sclerosis, Huntington's, Parkinson's, and Alzheimer's diseases) disorders, with a focus on impairments in angiogenesis, CBF and the BBB. Finally, we discuss the impact of early vascular impairments on the expression of neurodegenerative diseases.
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Affiliation(s)
- Julie Ouellette
- Ottawa Hospital Research Institute, Neuroscience Program, Ottawa, ON, Canada
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Baptiste Lacoste
- Ottawa Hospital Research Institute, Neuroscience Program, Ottawa, ON, Canada
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
- University of Ottawa Brain and Mind Research Institute, Ottawa, ON, Canada
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4
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Cerasa A, Ruta L, Marino F, Biamonti G, Pioggia G. Brief Report: Neuroimaging Endophenotypes of Social Robotic Applications in Autism Spectrum Disorder. J Autism Dev Disord 2020; 51:2538-2542. [PMID: 32945987 DOI: 10.1007/s10803-020-04708-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
A plethora of neuroimaging studies have focused on the discovery of potential neuroendophenotypes useful to understand the etiopathogenesis of autism and predict treatment response. Social robotics has recently been proposed as an effective tool to strengthen the current treatments in children with autism. However, the high clinical heterogeneity characterizing this disorder might interfere with behavioral effects. Neuroimaging is set to overcome these limitations by capturing the level of heterogeneity. Here, we provide a preliminary evaluation of the neural basis of social robotics and how extracting neural hallmarks useful to design more effective behavioral applications. Despite the endophenotype-oriented neuroimaging research approach is in its relative infancy, this preliminary evidence encourages innovation to address its current limitations.
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Affiliation(s)
- Antonio Cerasa
- Institute for Biomedical Research and Innovation (IRIB), National Research Council, C/Da Burga, Cosenza, Mangone, 87050, Italy.
- S. Anna Institute, Crotone, 88900, Italy.
| | - Liliana Ruta
- Institute for Biomedical Research and Innovation (IRIB), Nationasssl Research Council, Messina, 98164, Italy
| | - Flavia Marino
- Institute for Biomedical Research and Innovation (IRIB), Nationasssl Research Council, Messina, 98164, Italy
| | - Giuseppe Biamonti
- Institute for Biomedical Research and Innovation (IRIB), National Research Council, C/Da Burga, Cosenza, Mangone, 87050, Italy
- Institute for Biomedical Research and Innovation (IRIB), Nationasssl Research Council, Messina, 98164, Italy
| | - Giovanni Pioggia
- Institute for Biomedical Research and Innovation (IRIB), Nationasssl Research Council, Messina, 98164, Italy
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Prevalence and Characteristics of Sensory Processing Abnormalities and its Correlation with FDG-PET Findings in Children with Autism. Indian J Pediatr 2019; 86:1036-1042. [PMID: 31612302 DOI: 10.1007/s12098-019-03061-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Accepted: 08/09/2019] [Indexed: 10/25/2022]
Abstract
OBJECTIVE To study the prevalence and characteristics of Sensory processing abnormalities (SPAs) in children with autism and to study if there is any correlation between sensory processing abnormalities with FDG-PET findings in children with severe autism. METHODS One hundred children, aged 3-12 y, diagnosed as Autistic spectrum disorder; ASD (DSM-V) and 100 age and sex matched controls were studied. SPAs were detected using Short sensory profile (SSP) questionnaire. Children with progressive neurological diseases, active epilepsy and structural brain abnormalities were excluded. On Childhood Autism rating scale, 30 children had severe and 70 had mild-moderate autism. The pattern of sensory processing abnormalities in children with severe ASD was compared with mild-moderate ASD. FDG-PET scan was done in children with severe autism and correlated with SPAs. RESULTS All children with severe autism had sensory processing abnormalities as compared to only 40% children with mild-moderate autism. Underresponsiveness/seeking-sensation was affected in all children with severe ASD and 82% had movement sensitivity. In children with mild-moderate ASD, 45% had auditory filtering, 30% had movement sensitivity and 27% had underresponsiveness/seeking-sensation. FDG-PET was abnormal in 17% of children with severe autism. Diffuse cerebral/ temporal lobe hypometabolism, increased bilateral frontal lobe uptake and moderate reduction in parietal lobe (Lt > Rt) was observed. CONCLUSIONS All patients with severe autism had SPAs. However, they did not correlate with FDG-PET findings.
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Pan YH, Wu N, Yuan XB. Toward a Better Understanding of Neuronal Migration Deficits in Autism Spectrum Disorders. Front Cell Dev Biol 2019; 7:205. [PMID: 31620440 PMCID: PMC6763556 DOI: 10.3389/fcell.2019.00205] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2019] [Accepted: 09/06/2019] [Indexed: 11/13/2022] Open
Abstract
Newborn neurons in developing brains actively migrate from germinal zones to designated regions before being wired into functional circuits. The motility and trajectory of migrating neurons are regulated by both extracellular factors and intracellular signaling cascades. Defects in the molecular machinery of neuronal migration lead to mis-localization of affected neurons and are considered as an important etiology of multiple developmental disorders including epilepsy, dyslexia, schizophrenia (SCZ), and autism spectrum disorders (ASD). However, the mechanisms that link neuronal migration deficits to the development of these diseases remain elusive. This review focuses on neuronal migration deficits in ASD. From a translational perspective, we discuss (1) whether neuronal migration deficits are general neuropathological characteristics of ASD; (2) how the phenotypic heterogeneity of neuronal migration disorders is generated; (3) how neuronal migration deficits lead to functional defects of brain circuits; and (4) how therapeutic intervention of neuronal migration deficits can be a potential treatment for ASD.
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Affiliation(s)
- Yi-Hsuan Pan
- Key Laboratory of Brain Functional Genomics (Ministry of Education and Shanghai), Institute of Brain Functional Genomics, School of Life Sciences and the Collaborative Innovation Center for Brain Science, East China Normal University, Shanghai, China
| | - Nan Wu
- Key Laboratory of Brain Functional Genomics (Ministry of Education and Shanghai), Institute of Brain Functional Genomics, School of Life Sciences and the Collaborative Innovation Center for Brain Science, East China Normal University, Shanghai, China
| | - Xiao-Bing Yuan
- Key Laboratory of Brain Functional Genomics (Ministry of Education and Shanghai), Institute of Brain Functional Genomics, School of Life Sciences and the Collaborative Innovation Center for Brain Science, East China Normal University, Shanghai, China.,Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD, United States
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7
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MRI or not to MRI! Should brain MRI be a routine investigation in children with autistic spectrum disorders? Acta Neurol Belg 2015; 115:351-4. [PMID: 25344829 DOI: 10.1007/s13760-014-0384-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2014] [Accepted: 10/17/2014] [Indexed: 10/24/2022]
Abstract
To evaluate the routine usage of Magnetic Resonance Imaging (MRI) of brain and estimate the prevalence of brain abnormalities in children presenting to the Neurodevelopment Clinic of Al-Khadra Hospital (NDC-KH), Tripoli, Libya with autistic spectrum disorders (ASD). The records of all children with ASD presented to NDC-KH over 4-year period (from January 2009 to December 2012) were reviewed. All MRIs were acquired with a 1.5-T Philips (3-D T1, T2, FLAIR coronal and axial sequences). MRIs were reported to be normal, abnormal or no significant abnormalities by a consultant neuroradiologist. One thousand and seventy-five children were included in the study. Seven hundred and eighty-two children (72.7 %) had an MRI brain of whom 555 (71 %) were boys. 26 children (24 males and 2 females) (3.3 %) demonstrated MRI abnormalities (8 leukodystrophic changes, 4 periventricular leukomalacia, 3 brain atrophy, 2 tuberous sclerosis, 2 vascular changes, 1 pineoblastoma, 1 cerebellar angioma, 1 cerebellar hypoplasia, 3 agenesis of corpus callosum, 1 neuro-epithelial cyst). An unexpectedly high rate of MRI abnormalities was found in the first large series of clinical MRI investigations in children with autism. These results could contribute to further research into the pathogenesis of autistic spectrum disorder.
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8
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Zürcher NR, Bhanot A, McDougle CJ, Hooker JM. A systematic review of molecular imaging (PET and SPECT) in autism spectrum disorder: current state and future research opportunities. Neurosci Biobehav Rev 2015; 52:56-73. [PMID: 25684726 DOI: 10.1016/j.neubiorev.2015.02.002] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Revised: 02/02/2015] [Accepted: 02/03/2015] [Indexed: 10/24/2022]
Abstract
Non-invasive positron emission tomography (PET) and single-photon emission computed tomography (SPECT) are techniques used to quantify molecular interactions, biological processes and protein concentration and distribution. In the central nervous system, these molecular imaging techniques can provide critical insights into neurotransmitter receptors and their occupancy by neurotransmitters or drugs. In recent years, there has been an increase in the number of studies that have investigated neurotransmitters in autism spectrum disorder (ASD), while earlier studies mostly focused on cerebral blood flow and glucose metabolism. The underlying and contributing mechanisms of ASD are largely undetermined and ASD diagnosis relies on the behavioral phenotype. Discovery of biochemical endophenotypes would represent a milestone in autism research that could potentially lead to ASD subtype stratification and the development of novel therapeutic drugs. This review characterizes the prior use of molecular imaging by PET and SPECT in ASD, addresses methodological challenges and highlights areas of future opportunity for contributions from molecular imaging to understand ASD pathophysiology.
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Affiliation(s)
- Nicole R Zürcher
- A.A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA, USA; Harvard Medical School, Harvard, Boston, MA, USA
| | - Anisha Bhanot
- A.A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA, USA
| | - Christopher J McDougle
- Lurie Center for Autism, Department of Pediatrics, MassGeneral Hospital for Children, Lexington, MA, USA; Department of Psychiatry, Harvard Medical School, Boston, MA, USA
| | - Jacob M Hooker
- A.A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA, USA; Harvard Medical School, Harvard, Boston, MA, USA.
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Autologous bone marrow mononuclear cell therapy for autism: an open label proof of concept study. Stem Cells Int 2013; 2013:623875. [PMID: 24062774 PMCID: PMC3767048 DOI: 10.1155/2013/623875] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2013] [Revised: 06/24/2013] [Accepted: 07/07/2013] [Indexed: 12/13/2022] Open
Abstract
Cellular therapy is an emerging therapeutic modality with a great potential for the treatment of autism. Recent findings show that the major underlying pathogenetic mechanisms of autism are hypoperfusion and immune alterations in the brain. So conceptually, cellular therapy which facilitates counteractive processes of improving perfusion by angiogenesis and balancing inflammation by immune regulation would exhibit beneficial clinical effects in patients with autism. This is an open label proof of concept study of autologous bone marrow mononuclear cells (BMMNCs) intrathecal transplantation in 32 patients with autism followed by multidisciplinary therapies. All patients were followed up for 26 months (mean 12.7). Outcome measures used were ISAA, CGI, and FIM/Wee-FIM scales. Positron Emission Tomography-Computed Tomography (PET-CT) scan recorded objective changes. Out of 32 patients, a total of 29 (91%) patients improved on total ISAA scores and 20 patients (62%) showed decreased severity on CGI-I. The difference between pre- and postscores was statistically significant (P < 0.001) on Wilcoxon matched-pairs signed rank test. On CGI-II 96% of patients showed global improvement. The efficacy was measured on CGI-III efficacy index. Few adverse events including seizures in three patients were controlled with medications. The encouraging results of this leading clinical study provide future directions for application of cellular therapy in autism.
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Essa MM, Subash S, Braidy N, Al-Adawi S, Lim CK, Manivasagam T, Guillemin GJ. Role of NAD(+), Oxidative Stress, and Tryptophan Metabolism in Autism Spectrum Disorders. Int J Tryptophan Res 2013; 6:15-28. [PMID: 23922500 PMCID: PMC3729335 DOI: 10.4137/ijtr.s11355] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Autism spectrum disorder (ASD) is a pervasive neuro-developmental disorder characterized by impaired social interaction, reduced/absent verbal and non-verbal communication, and repetitive behavior during early childhood. The etiology of this developmental disorder is poorly understood, and no biomarkers have been identified. Identification of novel biochemical markers related to autism would be advantageous for earlier clinical diagnosis and intervention. Studies suggest that oxidative stress-induced mechanisms and reduced antioxidant defense, mitochondrial dysfunction, and impaired energy metabolism (NAD(+), NADH, ATP, pyruvate, and lactate), are major causes of ASD. This review provides renewed insight regarding current autism research related to oxidative stress, mitochondrial dysfunction, and altered tryptophan metabolism in ASD.
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Affiliation(s)
- Musthafa Mohamed Essa
- Dept of Food Science and Nutrition, College of Agriculture and Marine Sciences, Sultan Qaboos University, Oman. ; School of Medical Sciences, Department of Pharmacology, Faculty of Medicine, University of NSW, Sydney, Australia
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Geier DA, Kern JK, Davis G, King PG, Adams JB, Young JL, Geier MR. A prospective double-blind, randomized clinical trial of levocarnitine to treat autism spectrum disorders. Med Sci Monit 2011; 17:PI15-23. [PMID: 21629200 PMCID: PMC3539542 DOI: 10.12659/msm.881792] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Background L-carnitine was proposed as a potential treatment for patients diagnosed with an autism spectrum disorder to improve mitochondrial dysfunction, but no prior randomized controlled trials have been conducted. Material/Methods Thirty subjects diagnosed with an ASD were randomly assigned to receive a standardized regimen (50 mg L-carnitine/kg bodyweight/day) of liquid L-carnitine (n=19) or placebo (n=11) for 3-months. Measures included changes in professionally completed Childhood Autism Rating Scale (CARS), hand muscle testing, and modified clinical global impression (CGI) forms; parent completed Autism Treatment Evaluation Checklist (ATEC), treatment adherence measurement (TAM), frequency and intensity of side effect rating (FISER)/global rating of side effect burden (GRSEB)/patient report of incidence of side effects (PRISE) forms; and lab testing. Results Significant improvements were observed in CARS (−2.03, 95% CI=−3.7 to −0.31), CGI (−0.69, 95% CI=−1.1 to −0.06), and ATEC scores. Significant correlations between changes in serum free-carnitine levels and positive clinical changes were observed for hand muscle strength (R2=0.23, P=0.046), cognitive scores (R2=0.27, P=0.019), and CARS scores (R2=0.20, P=0.047). Study subjects were protocol-compliant (average adherence was >85%) and generally well-tolerated the L-carnitine therapy given. Conclusions L-carnitine therapy (50 mg/kilogram-bodyweight/day) administered for 3-months significantly improved several clinical measurements of ASD severity, but subsequent studies are recommended.
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Affiliation(s)
- David A Geier
- The Institute of Chronic Illnesses, Inc., Silver Spring, MD, USA.
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Palmieri L, Persico AM. Mitochondrial dysfunction in autism spectrum disorders: cause or effect? BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2010; 1797:1130-7. [PMID: 20441769 DOI: 10.1016/j.bbabio.2010.04.018] [Citation(s) in RCA: 112] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 02/25/2010] [Revised: 04/15/2010] [Accepted: 04/26/2010] [Indexed: 12/12/2022]
Abstract
Autism Spectrum Disorders encompass severe developmental disorders characterized by variable degrees of impairment in language, communication and social skills, as well as by repetitive and stereotypic patterns of behaviour. Substantial percentages of autistic patients display peripheral markers of mitochondrial energy metabolism dysfunction, such as (a) elevated lactate, pyruvate, and alanine levels in blood, urine and/or cerebrospinal fluid, (b) serum carnitine deficiency, and/or (c) enhanced oxidative stress. These biochemical abnormalities are accompanied by highly heterogeneous clinical presentations, which generally (but by no means always) encompass neurological and systemic symptoms relatively unusual in idiopathic autistic disorder. In some patients, these abnormalities have been successfully explained by the presence of specific mutations or rearrangements in their mitochondrial or nuclear DNA. However, in the majority of cases, abnormal energy metabolism cannot be immediately linked to specific genetic or genomic defects. Recent evidence from post-mortem studies of autistic brains points toward abnormalities in mitochondrial function as possible downstream consequences of dysreactive immunity and altered calcium (Ca(2+)) signalling.
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Affiliation(s)
- Luigi Palmieri
- Laboratory of Biochemistry and Molecular Biology, Department of Pharmaco-Biology, University of Bari, Via Orabona 4, 70125, Bari, Italy.
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Boddaert N, Zilbovicius M, Philipe A, Robel L, Bourgeois M, Barthélemy C, Seidenwurm D, Meresse I, Laurier L, Desguerre I, Bahi-Buisson N, Brunelle F, Munnich A, Samson Y, Mouren MC, Chabane N. MRI findings in 77 children with non-syndromic autistic disorder. PLoS One 2009; 4:e4415. [PMID: 19204795 PMCID: PMC2635956 DOI: 10.1371/journal.pone.0004415] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2008] [Accepted: 11/21/2008] [Indexed: 11/19/2022] Open
Abstract
Background The clinical relevance of MR scanning in children with autism is still an open question and must be considered in light of the evolution of this technology. MRI was judged to be of insufficient value to be included in the standard clinical evaluation of autism according to the guidelines of the American Academy of Neurology and Child Neurology Society in 2000 [1]. However, this statement was based on results obtained from small samples of patients and, more importantly, included mostly insufficient MRI sequences. Our main objective was to evaluate the prevalence of brain abnormalities in a large group of children with a non-syndromic autistic disorder (AD) using T1, T2 and FLAIR MRI sequences. Methodology MRI inspection of 77 children and adolescents with non-syndromic AD (mean age 7.4±3.6) was performed. All met the DSM-IV and ADI –R criteria for autism. Based on recommended clinical and biological screenings, we excluded patients with infectious, metabolic or genetic diseases, seizures or any other neurological symptoms. Identical MRI inspections of 77 children (mean age 7.0±4.2) without AD, developmental or neurological disorders were also performed. All MRIs were acquired with a 1.5-T Signa GE (3-D T1-FSPGR, T2, FLAIR coronal and axial sequences). Two neuroradiologists independently inspected cortical and sub-cortical regions. MRIs were reported to be normal, abnormal or uninterpretable. Principal Findings MRIs were judged as uninterpretable in 10% (8/77) of the cases. In 48% of the children (33/69 patients), abnormalities were reported. Three predominant abnormalities were observed, including white matter signal abnormalities (19/69), major dilated Virchow–Robin spaces (12/69) and temporal lobe abnormalities (20/69). In all, 52% of the MRIs were interpreted as normal (36/69 patients). Conclusions An unexpectedly high rate of MRI abnormalities was found in the first large series of clinical MRI investigations in non-syndromic autism. These results could contribute to further etiopathogenetic research into autism.
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Affiliation(s)
- Nathalie Boddaert
- INSERM-CEA U 797, Service Hospitalier Frédéric Joliot, CEA, Orsay, France.
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Abstract
AbstractAutism is a neurodevelopmental disorder characterized by social and communication deficits, and repetitive behavior. Studies investigating the integrity of brain systems in autism suggest a wide range of gray and white matter abnormalities that are present early in life and change with development. These abnormalities predominantly affect association areas and undermine functional integration. Executive function, which has a protracted development into adolescence and reflects the integration of complex widely distributed brain function, is also affected in autism. Evidence from studies probing response inhibition and working memory indicate impairments in these core components of executive function, as well as compensatory mechanisms that permit normative function in autism. Studies also demonstrate age-related improvements in executive function from childhood to adolescence in autism, indicating the presence of plasticity and suggesting a prolonged window for effective treatment. Despite developmental gains, mature executive functioning is limited in autism, reflecting abnormalities in wide-spread brain networks that may lead to impaired processing of complex information across all domains.
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Degirmenci B, Miral S, Kaya GC, Iyilikçi L, Arslan G, Baykara A, Evren I, Durak H. Technetium-99m HMPAO brain SPECT in autistic children and their families. Psychiatry Res 2008; 162:236-43. [PMID: 18302983 DOI: 10.1016/j.pscychresns.2004.12.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2004] [Revised: 11/24/2004] [Accepted: 12/20/2004] [Indexed: 11/17/2022]
Abstract
The purpose of the study was to investigate perfusion patterns in autistic children (AC) and their families. Ten AC (9 boys, 1 girl; mean age: 6.9+/-1.7 years) with autistic disorder defined by DSM-III-R criteria, five age-matched children (3 boys, 2 girls) as a control group, and the immediate family members of eight AC (8 mothers, 8 fathers, 7 siblings; mean ages: 39+/-4 years, 36+/-5 years and 13+/-5 years, respectively) were included in the study. Age- and sex-matched control groups for both the parents and the siblings were also included in the study. Brain perfusion images were obtained 1 h after the intravenous injection of an adjusted dose of Tc-99m HMPAO to children and the adults. Visual and semiquantitative evaluations were performed. Hypoperfusion was seen in the right posterior parietal cortex in three AC, in bilateral parietal cortex in one AC, bilateral frontal cortex in two AC, left parietal and temporal cortex in one AC, and right parietal and temporal cortex in one AC. Asymmetric perfusion was observed in the caudate nucleus in four AC. In semiquantitative analyses, statistically significant hypoperfusion was found in the right inferior and superior frontal, left superior frontal, right parietal, right mesial temporal and right caudate nucleus. In parents of AC, significant hypoperfusion was noted in the right parietal and bilateral inferior frontal cortex. In siblings of AC, perfusion in the right frontal cortex, right nucleus caudate and left parietal cortex was significantly decreased. This preliminary study suggests the existence of regional brain perfusion alterations in frontal, temporal, and parietal cortex and in caudate nucleus in AC and in their first-degree family members.
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Affiliation(s)
- Berna Degirmenci
- Department of Nuclear Medicine, Dokuz Eylul University Medical School, 35340, Inciralti, Izmir, Turkey.
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Abstract
AIM To establish a link between rCBF assessed with Tc-ECD SPET and the clinical manifestation of the disease. METHODS We performed the study on 11 patients (five girls and six boys; mean age 11.2 years) displaying autistic behaviour and we compared their data with that of an age-matched reference group of eight normal children. A quantitative analysis of rCBF was performed calculating a perfusion index (PI) and an asymmetry index (AI) in each lobe. Images were analysed with statistical parametric mapping software, following the spatial normalization of SPET images for a standard brain. RESULTS A statistically significant (P=0.003) global reduction of CBF was found in the group of autistic children (PI=1.07+/-0.07) when compared with the reference group (PI=1.25+/-0.12). Moreover, a significant difference was also observed for the right-to-left asymmetry of hemispheric perfusion between the control group and autistic patients (P=0.0085) with a right prevalence greater in autistic (2.90+/-1.68) with respect to normal children (1.12+/-0.49). Our data show a significant decrease of global cerebral perfusion in autistic children in comparison with their normal counterparts and the existence of left-hemispheric dysfunction, especially in the temporo-parietal areas devoted to language and the comprehension of music and sounds. CONCLUSION We suggest that these abnormal areas are related to the cognitive impairment observed in autistic children, such as language deficits, impairment of cognitive development and object representation, and abnormal perception and responses to sensory stimuli. Tc-ECD SPET seems to be sensitive in revealing brain blood flow alterations and left-to-right asymmetries, when neuroradiological patterns are normal.
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Chugani HT, Juhász C, Behen ME, Ondersma R, Muzik O. Autism with facial port-wine stain: a new syndrome? Pediatr Neurol 2007; 37:192-9. [PMID: 17765807 DOI: 10.1016/j.pediatrneurol.2007.05.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2007] [Revised: 04/17/2007] [Accepted: 05/14/2007] [Indexed: 10/22/2022]
Abstract
The hallmark of Sturge-Weber syndrome is leptomeningeal angiomatosis. Over 15 years, four children were identified (2 boys, age 2.9-6 years) with unilateral facial port-wine stain, referred for presumable Sturge-Weber syndrome but who were also autistic. Computed tomography and magnetic resonance imaging scans failed to show evidence of leptomeningeal angioma in all four children. Three of the children had a history of seizures. Detailed neuropsychologic testing of three children revealed a similar presentation, characterized by developmental disturbance, particularly involving delayed onset of language, and early-emerging social atypicality. Positron emission tomography scanning of cerebral glucose metabolism revealed hypometabolism in the bilateral medial temporal regions, anterior cingulate gyrus, frontal cortex, right temporal cortex, and cerebellum. The pattern of glucose hypometabolism differed from that of 12 children with infantile autism (age 2.7-7.9 years) who had mild left medial temporal but more severe right temporal cortical hypometabolism and showed a reversal of normal frontotemporal asymmetry of glucose metabolism. Unilateral facial port-wine stain and autism with no intracranial angioma on conventional imaging may represent a rare clinical entity distinct from both infantile autism and previously described variants of Sturge-Weber syndrome.
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Affiliation(s)
- Harry T Chugani
- Carman and Ann Adams Department of Pediatrics, Children's Hospital of Michigan, Wayne State University School of Medicine, Detroit, Michigan 48201, USA.
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Zeegers M, Van Der Grond J, Durston S, Nievelstein RJ, Witkamp T, Van Daalen E, Buitelaar J, Engeland HV. Radiological findings in autistic and developmentally delayed children. Brain Dev 2006; 28:495-9. [PMID: 16616445 DOI: 10.1016/j.braindev.2006.02.006] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2005] [Revised: 01/23/2006] [Accepted: 02/12/2006] [Indexed: 10/24/2022]
Abstract
PURPOSE The aim of this study was to evaluate the prevalence of brain abnormalities in a group of young children with developmental disorders, specifically including children that came to the attention of a child psychiatrist before the age of 3 years. METHODS Forty-five children participated in an MR study (mean age 43 months, SD=12, four females). The study design was approved by the local Medical Ethical Review Board. All parents gave written informed consent. Scans were independently assessed by two board-certified radiologists for malformations of gray and white matter. RESULTS Cohen's kappa for the consensus between the two raters was 0.79. In 22 children (49%) abnormalities were reported. Four patients (8.5%) had an arachnoid cyst. One female was diagnosed with a Chiari I malformation. Three children show enlarged Virchow-Robin spaces, an increased occurrence when compared to the normal population. CONCLUSIONS A high rate of intracranial abnormalities was found in this study. Radiological findings do not contribute to the diagnosis of developmental disorders. However, young children with developmental disorders may not be able to express discomfort associated with brain abnormalities, such as a Chiari I malformation. Given the high prevalence of abnormalities in this sample neuroimaging may be a useful tool in clinically assessing children with developmental disorders.
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Affiliation(s)
- Mijke Zeegers
- Rudolf Magnus Institute of Neuroscience, Department of Child and Adolescent Psychiatry, University Medical Center Utrecht, The Netherlands.
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Kashyap N. Autism-Recent Advances. APOLLO MEDICINE 2005. [DOI: 10.1016/s0976-0016(11)60513-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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20
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Tecchio F, Benassi F, Zappasodi F, Gialloreti LE, Palermo M, Seri S, Rossini PM. Auditory sensory processing in autism: a magnetoencephalographic study. Biol Psychiatry 2003; 54:647-54. [PMID: 13129660 DOI: 10.1016/s0006-3223(03)00295-6] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Patients with autism show clinical features suggestive of abnormal processing of auditory and other sensory information. We hypothesized that low-functioning autistic subjects present abnormalities in discriminating simple auditory stimuli at sensory system preconscious stages of cortical processing. METHODS To verify our hypothesis, we used magnetoencephalographic measurements of mismatch field (MMF), which reflects the detection of a change in the physical characteristics of a repetitive sound. Fourteen patients (aged 8-32 years) who met DSM-IV diagnostic criteria for autistic disorder participated in an auditory oddball experiment. Ten healthy participants matched for age and gender acted as control subjects. RESULTS Significant differences in cerebral responses between patients and control subjects were recorded. Whereas control subjects showed a clearly identifiable MMF, with distinct generators in the M100 brain wave with regard to latency, position, and strength, no identifiable MMF was present in the autistic group. CONCLUSIONS Our findings suggest that low-functioning autistic subjects present a dysfunction at preconscious stages of cortical auditory discrimination, playing a role in the abnormal processing of auditory sensory afferences. The attention independence of the MMF allows for exclusion of an effect related to impaired attention or task-related responses.
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Affiliation(s)
- Franca Tecchio
- Instituto di Sciente e Tecnologie della Cognitione-Cousiglio Nationale delle Ricerche, Rome, Italy
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Villemagne PM, Naidu S, Villemagne VL, Yaster M, Wagner HN, Harris JC, Moser HW, Johnston MV, Dannals RF, Wong DF. Brain glucose metabolism in Rett Syndrome. Pediatr Neurol 2002; 27:117-22. [PMID: 12213612 DOI: 10.1016/s0887-8994(02)00399-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Rett syndrome is a progressive neurologic disorder affecting girls in early childhood with loss of achieved psychomotor abilities and mental retardation. Six sedated female patients (4 to 15 years of age) with a diagnosis of Rett syndrome were studied with [(18)F]fluorodeoxyglucose (FDG) and underwent positron emission tomography scanning of the brain. Relative tracer concentrations between different areas of the brain were assessed, and results were compared with 18 age-matched control subjects. Patients were divided into two age groups: 3 to 8 years of age and 9 to 15 years of age. A relative decrease in [(18)F]FDG uptake in the lateral occipital areas in relation with the whole brain and a relative increase in the cerebellum was evident in both age groups (P < 0.001, unpaired Student t test). A relative increase in frontal tracer uptake was observed in the younger group. Sensorimotor areas and relations between cortical and subcortical structures were preserved in all patients. Changes in glucose cerebral metabolism resemble the regional distribution of normal children less than 1 year of age, likely reflecting a maturational arrest. Changes in frontal areas parallel those in postmortem N-methyl-D-aspartate receptor densities and could correlate with different clinical stages of the disease. This pattern differs from those described in Down syndrome, autism, and Alzheimer's disease.
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Affiliation(s)
- Patricia M Villemagne
- Department of Radiology, Johns Hopkins Medical Institutions;, Baltimore, Maryland 21287-0807, USA
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22
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De Volder AG. Functional brain imaging of childhood clinical disorders with PET and SPECT. Dev Sci 2002. [DOI: 10.1111/1467-7687.00374] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Abstract
Neuroimaging studies of neurobehavioral disorders are using new imaging modalities. In dyslexia, anatomic imaging studies demonstrate an abnormal symmetry of the planum temporale. Functional imaging supports the hypothesis that developmental dyslexia is frequently the result of deficits in phonologic processing and that normal reading requires a patent network organization of a number of anterior and posterior brain areas. In autism, anatomic imaging studies are conflicting. Functional imaging demonstrates temporal lobe abnormalities and abnormal interaction between frontal and parietal brain areas. In attention-deficit-hyperactivity disorder, imaging studies suggest an abnormality in the prefrontal and striatal regions. Neuroimaging studies are often contradictory, but trends, especially with functional imaging analysis, are evolving. Because neurobehavioral disorders seem to be a result of a dysfunction in brain circuits, no one region will be abnormal in all patients studied. Further studies with well-defined patient populations and appropriate activation paradigms will better elucidate the pathophysiology of these conditions.
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Affiliation(s)
- Y Frank
- Child Study Center, Bronx Lebanon Hospital Center, Bronx, New York 10457, USA
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24
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Abstract
Immune panels of many autism-spectrum children reveal signs of atypical infections and shifted cell counts. In conjunction with trait-related cerebral hypometabolism and hypoperfusion, these findings suggest a hypothesis: Several autism-spectrum subgroups derive from intra-monocyte pathogens such as measles virus, cytomegalovirus, human herpesvirus 6, and Yersinia enterocolitica. Furthermore, with much inter-child variation, their effects manifest as diminished hematopoiesis, impaired peripheral immunity, and altered blood-brain barrier function often accompanied by demyelination. In some such children, one or more of these pathogens persists as a chronic-active, seemingly subclinical infection etiologically significant to the child's autistic traits. Within these subgroups, immune impairments and atypical infections may be treatable.
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Affiliation(s)
- T Binstock
- Institute for Molecular Introspections, Estes Park, Colorado, USA.
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Hashimoto T, Sasaki M, Fukumizu M, Hanaoka S, Sugai K, Matsuda H. Single-photon emission computed tomography of the brain in autism: effect of the developmental level. Pediatr Neurol 2000; 23:416-20. [PMID: 11118797 DOI: 10.1016/s0887-8994(00)00224-1] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Brain single-photon emission computed tomography was performed in 22 autistic and 10 nonautistic disabled patients. The regional cerebral blood flow in both laterotemporal and dorso-medio-lateral frontal areas decreased significantly in the autistic group compared with in nonautistic group. In the autistic group, the regional cerebral blood flow was significantly higher in the right temporal and right parietal lobes than that in the left ones. Inversely, the regional cerebral blood flow in the frontal and occipital lobes was significantly higher on the left side than on the right side. In the nonautistic group, except for in the dorso-medio-lateral frontal lobes (left > right), there was no difference in the regional cerebral blood flow in either cerebrum or cerebellum. A positive correlationship between regional cerebral flow and development quotient (intelligence quotient) was observed in the left laterotemporal and both dorso-medio-lateral frontal areas, and a negative one was observed in the cerebellar vermis area. These results suggest that the regional cerebral blood flow decrease in the temporal and frontal areas relates to not only the brain mechanism of autism reported previously but also intelligence levels.
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Affiliation(s)
- T Hashimoto
- Department of Education for Handicapped Children, Naruto University of Education, 748, Nakashima, Takashima, Naruto-cho, Naruto-city, Tokushima, Japan
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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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27
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Abstract
Autism is a developmental disorder characterized by disturbance in language, perception and socialization. A variety of biochemical, anatomical and neuroradiographical studies imply a disturbance of brain energy metabolism in autistic patients. The underlying etiology of a disturbed bioenergetic metabolism in autism is unknown. A likely etiological possibility may involve mitochondrial dysfunction with concomitant defects in neuronal oxidative phosphorylation within the central nervous system. This hypothesis is supported by a frequent association of lactic acidosis and carnitine deficiency in autistic patients. Mitochondria are vulnerable to a wide array of endogenous and exogenous factors which appear to be linked by excessive nitric oxide production. Strategies to augment mitochondrial function, either by decreasing production of endogenous toxic metabolites, reducing nitric oxide production, or stimulating mitochondrial enzyme activity may be beneficial in the treatment of autism.
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Affiliation(s)
- J Lombard
- Westchester Square Medical Center, New York, NY 10461, USA
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28
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Abstract
In this paper the results of an extensive medical investigation of 25 children with childhood autism are presented and compared with those found in a group of non-autistic individuals matched for sex, age and intellectual level, all referred for developmental deviancy of unknown etiology. The examination included a psychiatric assessment and a neurological examination in addition to neurophysiological, chromosomal, metabolic and neuroimaging evaluation. In the clinical examination macrocephaly was found only among the autistic individuals, while the frequency of pathological cerebral CT and clinical parameters such as tendon reflexes and mobility problems was significantly greater in the control group. All the other pathological findings were found to occur with the same frequency in the two groups. Except for research purposes this study did not lend support to those who argue for extensive medical examinations for all children with autism. Based on the present findings, ordinary procedures for assessment of developmentally delayed children should be followed. This should include a systematic clinical neuropaediatric examination, an assessment of vision and hearing and a chromosome study, including that for fragile X.
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Affiliation(s)
- O H Skjeldal
- Department of Pediatrics, Rikshospitalet, University of Oslo, Norway.
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Mottron L, Mineau S, Décarie JC, Jambaqué I, Labrecque R, Pépin JP, Aroichane M. Visual agnosia with bilateral temporo-occipital brain lesions in a child with autistic disorder: a case study. Dev Med Child Neurol 1997; 39:699-705. [PMID: 9352734 DOI: 10.1111/j.1469-8749.1997.tb07367.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
A 2-year-old boy meeting the criteria for autistic disorder was diagnosed 2 years later with a visual agnosia characterised by a combination of certain aspects of associative and apperceptive agnosia. MRI then revealed a severe encephalomalacia of the right temporal lobe and bilateral temporo-occipital areas. This association is discussed in terms of a clinical and aetiological relation between autistic disorder and visual agnosia.
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Affiliation(s)
- L Mottron
- Service de Recherche, Hôpital Rivière-des-Prairies, Montréal, Québec, Canada
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31
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Abstract
Language development is delayed in most children on the autistic spectrum. The children are dysphasic as well as autistic. Comprehension and pragmatics are invariably affected. Lower level mixed receptive/expressive disorders involve phonological and syntactical processing, whereas higher level processing disorders involve semantics and formulation of discourse. In some children, lower level disorders may be so severe as to preclude speech, whereas in others phonology may be deficient in spontaneous production but not in repetition. Abnormal features of autistic language include aberrant prosody, immediate and delayed echolalia (scripts), and perseveration. Electrophysiological studies indicate that brainstem-evoked potentials are normal. Even in fully verbal individuals with autism, early and late cortical components of auditory, but not visual, event-related potentials are abnormal. Appropriate intervention must address language and behavioral issues. In children with severely defective auditory language, provision of visual language to supplement speech is essential.
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Affiliation(s)
- I Rapin
- Saul R. Korey Department of Neurology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
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Hashimoto T, Tayama M, Miyazaki M, Yoneda Y, Yoshimoto T, Harada M, Miyoshi H, Tanouchi M, Kuroda Y. Differences in brain metabolites between patients with autism and mental retardation as detected by in vivo localized proton magnetic resonance spectroscopy. J Child Neurol 1997; 12:91-6. [PMID: 9075017 DOI: 10.1177/088307389701200204] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
We performed volume-selective proton magnetic resonance spectroscopy (1H-MRS) of the brain with a 1.5 T magnet in 28 patients with autism, and compared the results with those from 28 age-matched patients with unclassified mental retardation and 25 age-matched healthy children. Peaks for N-acetylaspartate, choline and creatine, but not lactate, were observed in each group on 1H-MRS. The N-acetylaspartate/choline ratio was lower in patients with mental retardation than in patients with autism and controls (P = .05, respectively). However, there were no differences in the N-acetylaspartate/ choline ratios between patients with autism and controls, and the N-acetylaspartate/creatine and choline/creatine ratios did not differ among the three groups. These results suggest that N-acetylaspartate is decreased in patients with mental retardation and that a disorder or dysfunction of neurons in the brain exists. There also appear to be differences in the brain lesions or dysfunctions found in patients with autism and mental retardation.
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Affiliation(s)
- T Hashimoto
- Department of Pediatrics, University of Tokushima School of Medicine, Tokyo, Japan
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Chugani HT, Da Silva E, Chugani DC. Infantile spasms: III. Prognostic implications of bitemporal hypometabolism on positron emission tomography. Ann Neurol 1996; 39:643-9. [PMID: 8619550 DOI: 10.1002/ana.410390514] [Citation(s) in RCA: 112] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Positron emission tomography (PET) of brain glucose utilization is highly sensitive in detecting focal cortical abnormalities in patients with infantile spasms even when the computed tomographic (CT) and magnetic resonance imaging (MRI) scans are normal. Of 110 infants with spasms evaluated for potential surgical intervention during an 8-year period, we encountered 18 infants (7 males, 11 females; age range, 10 mo to 5 yr) with a common metabolic pattern on positron emission tomography (PET) consisting of bilateral hypometabolism in the temporal lobes. CT and MRI scans did not reveal any focal abnormalities in the 18 infants. Video-electroencephalographic monitoring indicated either bilateral or multifocal epileptogenicity, or failed to show any epileptic focus, so that none of the 18 infants were considered candidates for resective surgery. These patients were then enrolled in a prospective study aimed at determining long-term outcome in the presence of bilateral temporal PET hypometabolism. Analysis of outcome in 14 of the 18 subjects (follow-up period, 10 mo to 10 yr 5 mo; mean, 3 yr 11 mo +/- 2 yr 4 mo [SD]) revealed the following: (1) all had severe developmental delay and had failed to gain significant milestones; (2) language development had been minimal or absent; (3) 10 of the 14 met the DSM-IV criteria for autistic disorder. Our findings indicate that patients with infantile spasms and bitemporal glucose hypometabolism on PET comprise a relatively homogeneous group and are typically not candidates for cortical resection. The long-term outcome of these infants is particularly poor and the majority are autistic.
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Affiliation(s)
- H T Chugani
- Department of Pediatrics, Children's Hospital of Michigan, Detroit 48201, USA
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Bailey A, Phillips W, Rutter M. Autism: towards an integration of clinical, genetic, neuropsychological, and neurobiological perspectives. J Child Psychol Psychiatry 1996; 37:89-126. [PMID: 8655659 DOI: 10.1111/j.1469-7610.1996.tb01381.x] [Citation(s) in RCA: 369] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Autism constitutes one of the best validated child psychiatric disorders. Empirical research has succeeded in delineating the key clinical phenomena, in demonstrating strong genetic influences on the underlying liability, and in identifying basic cognitive deficits. A range of neurobiological abnormalities has also been found, although the replicability of specific findings has not been high. An understanding of the causal processes leading to autism, and accounting for the marked variability in its manifestations, requires an integration across these different levels of enquiry. Although this is not yet possible, a partial integration provides a useful strategy for identifying key research questions, the limitations of existing hypotheses, and future research directions that are likely to prove fruitful. The research findings for each research level are critically reviewed in order to consider how to move towards an integration across levels.
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Affiliation(s)
- A Bailey
- MRC Child Psychiatry Unit, Institute of Psychiatry, London, U.K
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Abstract
OBJECTIVE To review the major findings and pathophysiological implications of imaging studies of neuropsychiatric disorders that onset in childhood or adolescence. METHOD More than 200 neuroimaging studies were selected for review from Medline searches if the studies concerned developmental neuropsychiatric disorders such as autism, fragile X syndrome, Down syndrome, schizophrenia, obsessive-compulsive disorder, Tourette's syndrome, attention-deficit hyperactivity disorder, and dyslexia. RESULTS Disordered central nervous system development may produce evidence of cortical neuronal migration abnormalities in autism, smaller cortical structures in Down syndrome, frontal lobe deficits and larger basal ganglia in schizophrenia, hypoplastic basal ganglia in Tourette's syndrome, aberrancies of the planum temporale in dyslexia, and hypoplastic cerebellar structures in numerous developmental disorders. Normal cerebral asymmetries appear to be disrupted in a number of disorders, including schizophrenia, Tourette's syndrome, attention deficit disorder, and dyslexia. CONCLUSIONS Neuroimaging data regarding pathological central nervous system development in childhood are still sparse, and many of the findings in developmental disorders of childhood onset concern the study of adult subjects with those disorders. Nevertheless, imaging modalities previously used only in adults are with increasing frequency being applied to the study of children, which will likely continue to contribute to the understanding of pathological brain structure and function throughout childhood and to the improved treatment of these disorders.
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Affiliation(s)
- B S Peterson
- Yale Child Study Center, Yale University School of Medicine, New Haven, CT 06520, USA
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