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Query: UMLS:C0004352 (autism)
 32,579 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

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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PMID:Differences in brain metabolites between patients with autism and mental retardation as detected by in vivo localized proton magnetic resonance spectroscopy. 907 17

Rett syndrome (RS) is a clinically defined disorder characterized by autistic behavior, and cognitive and motor skill loss early in life. We performed 1H-MRS of the brain in 3 cases of RS in comparison with in autism and controls. The older patient with RS demonstrated decreased N-acetylaspartate (NAA)/choline (Cho) and NAA/creatine (Cr) ratios when compared with the autism and control groups, whereas the younger patients did not demonstrate these decreased metabolite ratios. The Cho/Cr ratio did not differ among Rett syndrome, autism and controls. Since the clinical stage did not differ among the 3 cases of RS, it was suggested that NAA was decreased with increasing age and was not related with the clinical stage of RS. The NAA/Cho, NAA/Cr and Cho/Cr ratios did not differ between autism and controls. The present data suggest that there may be a secondary degenerative process of late onset in RS, which pathophysiologically differs from autism.
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PMID:Proton magnetic resonance spectroscopy of the brain in three cases of Rett syndrome: comparison with autism and normal controls. 969 21

To evaluate brain dysfunction in autism, proton magnetic resonance spectroscopy (1H-MRS) was performed for 29 autistic patients (5-15 y.o.) and 19 normal children (6-14 y.o.). We obtained magnetic resonance (MR) spectra of the left and right amygdaloid-hippocampal regions and the left cerebellar hemisphere with a STEAM sequence (TR = 5000 ms, TE = 18 ms). In addition to the evaluation of signal intensity ratios, the absolute concentration of three major metabolites (N-acetylaspartate [NAA], creatine/phosphocreatine [Cr] and choline-containing substances [Cho]) was quantified by an internal reference method using unsuppressed tissue water. Although no abnormal MR images were found in the three regions examined, the signal intensity and the concentration of NAA in the left amygdaloid-hippocampal region and the left cerebellar hemisphere were reduced significantly in autistic patients compared to normal children. We speculated that this decrease in NAA reflected neuronal loss, immaturity or hypofunction in these regions. The results of our study were in agreement with those of previous studies on autism, one by neuropathological methods and the other using a single photon emission computed tomography with 99mTc HMPAO. Disorders of the amygdaloid-hippocampal region and cerebellum are considered to play an important role in the characteristic cognitive and emotional dysfunction in autism. 1H-MRS is a valuable tool to clarify the pathophysiology of autism.
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PMID:[Proton magnetic resonance spectroscopy of the autistic brain]. 1149 76

The performance of two screening instruments for Pervasive Developmental Disorders was studied in the total population of participants with mental retardation between 4 and 18 years (n = 1059) in Friesland, a northern province of the Netherlands. Parents completed the Autism Behavior Checklist (ABC), staff completed the Scale of Pervasive Developmental Disorder in Mentally Retarded Persons (PDD-MRS). The screening instruments were related to the Autism Diagnostic Interview-Revised and Autism Diagnostic Observation Schedule-Generic for 184 participants. The agreement between ABC and PDD-MRS was fair (kappa = .24). The ABC had a better criterion-related validity compared with the Autism Diagnostic Interview-Revised, and the PDD-MRS compared to the Autism Diagnostic Observation Schedule-Generic. However, related to the clinical classification, both instruments performed equally well. Concluding, the ABC and PDD-MRS partially identify the same cases related to external criteria. In addition, each instrument has its own contribution. Both instruments are valuable in detecting children who are at high risk for PDD.
J Autism Dev Disord 2003 Dec
PMID:Measuring pervasive developmental disorders in children and adolescents with mental retardation: a comparison of two screening instruments used in a study of the total mentally retarded population from a designated area. 1471 29

The Scale of Pervasive Developmental Disorder in Mentally Retarded Persons (PDD-MRS) is described. The PDD-MRS is a simple classification and screening instrument devised for identification of autistic disorders (of the entire spectrum) in persons with mental retardation from mild to profound levels, age-range 2-55 years. The norms of the scale are based on the research protocols of 1230 Dutch persons with mental retardation. The scale's sensitivity for the entire normative sample was found to be 92.4%; calculated separately for persons at all levels of mentally retarded functioning, male and female persons, speaking and non-speaking persons and five age categories, the sensitivity figures range between 87.0 and 100.0%. The specificity of the scale is also 92.4%; for the aforementioned subgroups separately, the specificity figures range between 84.6 and 95.5%. Roughly similar values for sensitivity and specificity were found when using the scale with severely visually impaired/blind persons; severely hearing-impaired/deaf persons; persons with Down syndrome; male persons with fragile X syndrome. The original version of the PDD-MRS dates from 1990; since then the scale has been widely used in the Netherlands and Belgium. The PDD-MRS should be regarded as a useful instrument for identifying PDD in persons with mental retardation.
J Autism Dev Disord 2005 Aug
PMID:The PDD-MRS: an instrument for identification of autism spectrum disorders in persons with mental retardation. 1613 35

Thalamic alterations have been reported in autism, but the relationships between these abnormalities and clinical symptoms, specifically sensory features, have not been elucidated. The goal of this investigation is to combine two neuroimaging methods to examine further the pathophysiology of thalamic anomalies in autism and to identify any association with sensory deficits. Structural MRI and multi-voxel, short echo-time proton magnetic resonance spectroscopy ((1)H MRS) measurements were collected from 18 male children with autism and 16 healthy children. Anatomical measurements of thalamic nuclei and absolute concentration levels of key (1)H MRS metabolites were obtained. Sensory abnormalities were assessed using a sensory profile questionnaire. Lower levels of N-acetylaspartate (NAA), phosphocreatine and creatine, and choline-containing metabolites were observed on the left side in the autism group compared with controls. No differences in thalamic volumes were observed between the two groups. Relationships, although limited, were observed between measures of sensory abnormalities and (1)H MRS metabolites. Findings from this study support the role of the thalamus in the pathophysiology of autism and more specifically in the sensory abnormalities observed in this disorder. Further investigations of this structure are warranted, since it plays an important role in information processing as part of the cortico-thalamo-cortical pathways.
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PMID:An MRI and proton spectroscopy study of the thalamus in children with autism. 1850 43

Attentional dysfunction is one of the most consistent findings in individuals with autism spectrum disorders (ASD). However, the significance of such findings for the pathophysiology of autism is unclear. In this study, we investigated cellular neurochemistry with proton magnetic resonance spectroscopy imaging ((1)H-MRS) in brain regions associated with networks subserving alerting, orienting, and executive control of attention in patients with ASD. Concentrations of cerebral N-acetyl-aspartate (NAA), creatinine+phosphocreatinine, choline-containing compounds, myo-inositol (Ins) and glutamate+glutamine (Glx) were determined by 3T (1)H-MRS examinations in 14 high-functioning medication-free adults with a diagnosis of ASD and 14 age- and IQ-matched healthy controls (HC) in the anterior cingulate cortex (ACC), thalamus, temporoparietal junction (TPJ), and areas near or along the intraparietal sulcus (IPS). Compared to HC group, the ASD group showed significantly lower Glx concentration in right ACC and reduced Ins concentration in left TPJ. This study provides evidence of abnormalities in neurotransmission related to networks subserving executive control and alerting of attention, functions which have been previously implicated in ASD pathogenesis.
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PMID:In vivo 1H-magnetic resonance spectroscopy study of the attentional networks in autism. 2118 69

We piloted a suite of approaches aimed to facilitate a successful series of up to four brain and muscle (31)Phosphorus-Magnetic Resonance Spectroscopy ((31)P-MRS) scans performed in one session in 12 awake, non-sedated subjects (ages 6-18), 6 with autism spectrum disorders (ASD) and 6 controls. We targeted advanced preparation, parental input, physical comfort, short scan protocols, allocation of extra time, and subject emotional support. 100% of subjects completed at least one brain scan and one leg muscle scan: 42 of 46 attempted scans were completed (91%), with failures dominated by exercise muscle scans (completed in 6/6 controls but 3/6 cases). One completed scan lacked usable data unrelated to subject/scan procedure (orthodonture affected a frontal brain scan). As a group, these methods provide a foundation for conduct and enhancement of future MR studies in pediatric subjects with ASD.
J Autism Dev Disord 2012 Jun
PMID:Brief report: approaches to 31P-MRS in awake, non-sedated children with and without autism spectrum disorder. 2197 8

Autism spectrum disorders (ASD) represent complex neurodevelopmental disorders characterized by impairments in reciprocal social interactions, abnormal development and use of language, and monotonously repetitive behaviors. With an estimated heritability of more than 90%, it is the most strongly genetically influenced psychiatric disorder of the young age. In spite of the complexity of this disorder, there has recently been much progress in the research on etiology, early diagnosing, and therapy of autism. Besides already advanced neuropathologic research, several new technological innovations, such as sleep functional MRI, diffusion tensor imaging (DTI) and proton magnetic resonance spectroscopy imaging ((1)H-MRS) divulged promising breakthroughs in exploring subtle morphological and neurochemical changes in the autistic brain. This review provides a comprehensive summary of morphological and neurochemical alterations in autism known to date, as well as a short introduction to the functional research that has begun to advance in the last decade. Finally, we mention the progress in establishing new standardized diagnostic measures and its importance in early recognition and treatment of ASD.
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PMID:RECENT DEVELOPMENTS IN NEUROPATHOLOGY OF AUTISM SPECTRUM DISORDERS. 2218 Aug 40

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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PMID:1H-MRS in autism spectrum disorders: a systematic meta-analysis. 2242 3


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