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

Single-photon emission computed tomography (SPECT) of the brain has been used to define functional abnormalities in two groups of childhood behavior disorders: (1) a "primary" category in which there is exclusive or predominant presentation with cognitive and/or behavioral dysfunction and (2) encephalopathies, often defined etiologically at the biochemical or molecular level, in which clinical expression includes, but is not confined to, neural dysfunction. Radiopharmaceuticals available for such studies are manifold, but those used to date have been predominantly perfusion agents, eg, Xenon-133 (133Xe) and technetium-99m (99mTc) hexamethylpropylene amine oxime, and studies with [99mTc]bicisate are eagerly awaited. Xenon-133 studies require that the patient be in the field of view of the detector while the tracer is administered. This renders it difficult for a subject to perform cognitive and other exercises while being imaged, because the environment is quite foreign. On the other hand, the 99mTc-labeled perfusion agents permit a scintigraphic "snapshot" of regional cerebral blood flow during a behavioral event without having to have the patient under the imaging instrument. Thus, one can separate the administration of the radiotracer, which can be done under more controlled and physiological conditions, from the actual imaging. In addition, greater spatial resolution is achieved with the technetium-based agents. Currently, multidetector or dedicated annular crystal-type cameras are the preferred brain SPECT devices, and they are essential to applications such as cortical "activation mapping" or tomographic detection of receptor systems. Close attention to technical detail and standardization of the child's behavioral environment during the investigation are critical to a successful study. The relative advantages and disadvantages of qualitative versus semiquantitative analysis of imaging date are reviewed. Among primary behavioral disorders, 133Xe SPECT studies in attention deficit disorder-hyperactivity (ADHD) have suggested a pattern of hypoperfusion of striatal and periventricular structures with sensorimotor cortical hyperperfusion. This pattern is consistent with some neurophysiological models of the disorder. In cerebral palsy, perfusional abnormalities have paralleled clinical deficits and may offer information to help predict outcome. The important field of childhood affective disorders (schizophrenia, juvenile autism, depression, etc) remains largely unstudied with SPECT. Finally, representative examples of the use of SPECT to study perfusion in encephalopathies with behavioral expression (phenylketonuria, MELAS (mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes) syndrome, Wilson's disease, etc) are given.
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PMID:Brain single-photon emission computed tomography for behavior disorders in children. 837 98

High-functioning children with autistic-spectrum disorder show the typical pattern of lower Comprehension relative to their own scores on Block Design. This profile is shared, almost exactly, by age- and IQ-matched children with poorer control PKU. Quite distinct profiles are shown by children with better control PKU, who show no difference between Block Design and Comprehension, and by children with head injury involving frontal lobe contusion, who show slightly better Comprehension that Block Design. The data bear on several questions: the relation between Comprehension deficits and language functions measured by Vocabulary; the limits of the advantages conveyed by higher IQ to autistic individuals; whether impaired Comprehension in autism indexes persisting symptoms and/or impairments on theory of mind tasks; the possibility that dopamine deficiency is common to autism and poorer control PKU; and the need for future research aimed at understanding the relations among neurodevelopmental disorders.
J Autism Dev Disord 1999 Feb
PMID:Intelligence patterns among children with high-functioning autism, phenylketonuria, and childhood head injury. 1009 91

Fibers of the global projection system ramify tremendously and distribute in the diverse region of the brain. Biogenic amines in the global projection system have been shown to facilitate formation and maintenance of synapses in the developing and adult brain. In terms of serotonin 5-HT2A receptor was shown to mediate the function of serotonin. We raised specific antibodies against 5-HT2A receptor protein. Virtually all the neurons in the cerebral cortex expressed 5-HT2A receptor. By using the function of biogenic amines to facilitate synapse formation and maintenance a novel approach can be developed in the neuroscience. That is to perturb biogenic amines, to change synaptic density, and to examine changes in the ability of learning and memory. Removing serotonin and acetylcholine for a week, at the maximum 58% of synapses are decreased in the hippocampus. The animals losing synapses spent a longer latency compared to intact animals in Morris water maze. The level of biogenic amines in the developing brain has been known to decrease tremendously by genetic diseases such as phenylketonuria, Down syndrome and autism as well as environmental factors such as nutrition and stress. In those situations synapses in the brain are suggested to be decreased. Synaptic mechanism for mental retardation and developmental disability by the cascade appears to contribute for understanding pathophysiology and a new therapy.
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PMID:[Mechanisms for formation and maintenance of synapses mediated by biogenic amines: pathogenesis and therapy of mental retardation and developmental disabilities by genetic and epigenetic factors]. 1057 64

Although the exact prevalence of metabolic abnormalities in autism spectrum disorders is unknown, several metabolic defects have been associated with autistic symptoms. These include phenylketonuria, histidinemia, adenylosuccinate lyase deficiency, dihydropyrimidine dehydrogenase deficiency, 5'-nucleotidase superactivity, and phosphoribosylpyrophosphate synthetase deficiency. When the metabolic consequences of an enzyme defect are well defined (e.g., phenylketonuria, 5'-nucleotidase superactivity), treatment with diet, drugs, or nutritional supplements may bring about a dramatic reduction in autistic symptoms. This review evaluates evidence for metabolic etiologies in autism spectrum disorders, as well as for the efficacy of dietary and vitamin treatments. The relationship between gastrointestinal abnormalities and autism spectrum disorders is also considered.
J Autism Dev Disord 2000 Oct
PMID:Metabolic approaches to the treatment of autism spectrum disorders. 1109 86

This article provides a targeted review of the scientific literature on the effects of experience on early brain and behavioral development and later outcome as it pertains to risk for some forms of child psychopathology. It is argued that ample evidence exists indicating that the prenatal and early postnatal years likely represent a sensitive period with respect to the effects of stress on the developing nervous system and behavioral outcome, and with respect to the long-term beneficial effects of early interventions on brain and behavioral development for some genetically based disorders, such as phenylketonuria and autism. Moreover, evidence suggests that parental mental health during the first years of life has a significant influence on early brain activity and behavior, and long-term behavioral outcome. It is concluded that, although prevention and early intervention efforts should not exclusively focus on the earliest years of development, such efforts should begin during this period. By directing such efforts toward promoting optimal prenatal and infant-toddler development, the long-term negative consequences of factors that have their greatest influences during early development and which set the stage for future development can be minimized or avoided entirely. Several recommendations for public policy and future research pertaining to the effects of early experience on child outcome are offered.
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PMID:The role of early experience in shaping behavioral and brain development and its implications for social policy. 1120 40

The paper provides clinical and catamnestic descriptions of 240 children with infantile autism; 160 with atypical autism (of them 100 had schizophrenic attacks, 60 presented with mental retardation concurrent with atypical autism (in phenylketonuria, tuberose sclerosis, Down syndrome, Martin-Bell syndrome), 20 with Asperger's syndrome, 60 with Rett's syndrome, 20 with psychogenic paraautism according the Nissen classification. The similarity of autism-like disorders and atypical autism was considered. Syndromal verifications in accordance with ICD-10 (1994) and ICD-10 (1999) in Russian versions and clinical nosological verifications adopted in Russia were studied in all the examinees. New approaches to treating patients with autistic disorders were developed.
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PMID:[Current approaches to the problem of autism in childhood]. 1152 31

Phenylketonuria (PKU) has been also reported in children with infantile autism (IA); however, the frequency of this association is variably reported. Patients with various forms of hyperphenylalaninemia (HPA) were evaluated applying two methods: the Autism Diagnostic Interview-Revised (ADI-R) and the Childhood Autism Rating Scale (CARS). A total of 243 patients were investigated, 97 with classical PKU, 62 identified by neonatal screening, and 35 late diagnosed. None out of 62 patients with classic PKU diagnosed early met criteria for autism. In the group of 35 patients diagnosed late, two boys (5.71%) ages 16 and 13 years fulfilled the diagnostic criteria for autism. The present study confirms that classical PKU is one of the causes of autism, but the prevalence seems to be very low.
J Autism Dev Disord 2003 Apr
PMID:Autism and phenylketonuria. 1275 60

Autism is a heterogeneous disorder that can reveal a specific genetic disease. This paper describes several genetic diseases consistently associated with autism (fragile X, tuberous sclerosis, Angelman syndrome, duplication of 15q11-q13, Down syndrome, San Filippo syndrome, MECP2 related disorders, phenylketonuria, Smith-Magenis syndrome, 22q13 deletion, adenylosuccinate lyase deficiency, Cohen syndrome, and Smith-Lemli-Opitz syndrome) and proposes a consensual and economic diagnostic strategy to help practitioners to identify them. A rigorous initial clinical screening is presented to avoid unnecessary laboratory and imaging studies. Regarding psychiatric nosography, the concept of "syndromal autism"--autism associated with other clinical signs should be promoted because it may help to distinguish patients who warrant a multidisciplinary approach and further investigation.
J Autism Dev Disord 2005 Feb
PMID:Specific genetic disorders and autism: clinical contribution towards their identification. 1579 26

Whereas a growing interest in the development of attentional flexibility (AF) and in perseverative behavior, being one marker of this component, exists in neuropsychological studies and in the domain of developmental psychopathology (e.g., PKU, infantile schizophrenia, autism and Parkinson's disease) (Pennington & Ozonoff, 1996; Stahl & Pry, 2002), only a few studies have concerned themselves with this subject in normal children. It is thus of interest to add more empirical data to the existing literature in this domain. Therefore, the aim of our study was to explore the development of AF and of perseverative errors in young preschool children with normal development, aged 1.5 to 6 years. Using set-shifting tasks of increasing difficulty level, three age groups were compared with respect to their AF skills. Results show a developmental factor underlying AF, with different levels of this form becoming more and more complex with age, ranging from a rudimentary visual form to a complex representational form of flexibility. Overall, few perseverative errors occurred and they decreased with age. Results are discussed from a developmental and neuropsychological perspective.
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PMID:Attentional flexibility and perseveration: developmental aspects in young children. 1603 43

Mental retardation (MR) is a common disorder frequently of unknown origin. Because there are few studies regarding MR and inborn errors of metabolism (IEM), we aimed to identify patients with IEM from a cohort of 944 patients with unexplained MR. Biochemical examinations such as determination of creatine (Cr) metabolites, acylcarnitines, purine, and pyrimidines in urine were applied. We found seven patients with IEM [three with cerebral Cr deficiency syndromes (CCDS)], one with adenylosuccinate lyase (ADSL) deficiency, and three, born before the neonatal metabolic screening program in Catalonia, with phenylketonuria (PKU). All told, they represent 0.8% of the whole cohort. All of them had additional symptoms such as epilepsy, movement disorders, autism, and other psychiatric disturbances. In conclusion, in patients with MR, it is essential to perform a thorough appraisal of the associated signs and symptoms, and in most disorders, it is necessary to apply specific analyses. In some cases, it is important to achieve an early diagnosis and therapy, which may reduce the morbimortality, and to offer genetic counselling.
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PMID:Study of inborn errors of metabolism in urine from patients with unexplained mental retardation. 2004 33


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