Pubmed du 19/11/11

Pubmed du jour

2011-11-19 12:03:50

1. Anderson JS, Nielsen JA, Froehlich AL, Dubray MB, Druzgal TJ, Cariello AN, Cooperrider JR, Zielinski BA, Ravichandran C, Fletcher PT, Alexander AL, Bigler ED, Lange N, Lainhart JE. {{Functional connectivity magnetic resonance imaging classification of autism}}. {Brain};2011 (Oct 17)

Group differences in resting state functional magnetic resonance imaging connectivity between individuals with autism and typically developing controls have been widely replicated for a small number of discrete brain regions, yet the whole-brain distribution of connectivity abnormalities in autism is not well characterized. It is also unclear whether functional connectivity is sufficiently robust to be used as a diagnostic or prognostic metric in individual patients with autism. We obtained pairwise functional connectivity measurements from a lattice of 7266 regions of interest covering the entire grey matter (26.4 million connections) in a well-characterized set of 40 male adolescents and young adults with autism and 40 age-, sex- and IQ-matched typically developing subjects. A single resting state blood oxygen level-dependent scan of 8 min was used for the classification in each subject. A leave-one-out classifier successfully distinguished autism from control subjects with 83% sensitivity and 75% specificity for a total accuracy of 79% (P = 1.1 x 10(-7)). In subjects <20 years of age, the classifier performed at 89% accuracy (P = 5.4 x 10(-7)). In a replication dataset consisting of 21 individuals from six families with both affected and unaffected siblings, the classifier performed at 71% accuracy (91% accuracy for subjects <20 years of age). Classification scores in subjects with autism were significantly correlated with the Social Responsiveness Scale (P = 0.05), verbal IQ (P = 0.02) and the Autism Diagnostic Observation Schedule-Generic’s combined social and communication subscores (P = 0.05). An analysis of informative connections demonstrated that region of interest pairs with strongest correlation values were most abnormal in autism. Negatively correlated region of interest pairs showed higher correlation in autism (less anticorrelation), possibly representing weaker inhibitory connections, particularly for long connections (Euclidean distance >10 cm). Brain regions showing greatest differences included regions of the default mode network, superior parietal lobule, fusiform gyrus and anterior insula. Overall, classification accuracy was better for younger subjects, with differences between autism and control subjects diminishing after 19 years of age. Classification scores of unaffected siblings of individuals with autism were more similar to those of the control subjects than to those of the subjects with autism. These findings indicate feasibility of a functional connectivity magnetic resonance imaging diagnostic assay for autism.

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2. Channon S, Collins R, Swain E, Young MB, Fitzpatrick S. {{The Use of Skilled Strategies in Social Interactions by Groups High and Low in Self-Reported Social Skill}}. {J Autism Dev Disord};2011 (Oct 19)

Individuals high or low in self-reported social skill were recruited opportunistically. When presented with everyday social scenarios ending with an awkward request or offer, the high social skill participants more often used sophisticated strategies that showed greater consideration for all parties. By contrast, the low skill participants were more reliant on simple strategies including acquiescence or refusal, and the emotional tone of their responses was less positive. Greater reliance on sophisticated rather than simple strategies may be linked to more successful social interactions. The potential implications are considered for understanding everyday performance in skilled individuals and populations with limited social skills, such as those with autistic spectrum disorders.

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3. Damodaran LP, Arumugam G. {{Urinary oxidative stress markers in children with autism}}. {Redox Rep};2011;16(5):216-222.

Oxidative stress caused by increased production of free radicals and impaired functions of antioxidants remains as the major factor associated with the pathophysiology of many neuropsychiatric diseases. OBJECTIVE: The objective of the present study was to analyze the oxidative stress markers in urine sample since the collection of blood from these children is highly meticulous and also to evaluate whether these urinary markers can be correlated with the severity of autism. METHODS: The subjects of the study were 45 autistic children with different grades of severity (low functioning autism (LFA), medium functioning autism (MFA), and high functioning autism (HFA) according to Childhood Autism Rating Scale (CARS), n=15 children in each group and 50 healthy children (age and sex matched). The boys and girls ratio involved in this study was 4:1, and they were of age 4-12 years. We determined the urinary levels of oxidative stress markers like thiobarbituric acid-reacting substances, lipid hydroperoxides, 4-hydroxy nonenal, protein carbonyls, sulfhydryl groups, total antioxidant capacity, total peroxide content, oxidative stress index, and also UA/Cr ratio in autistic children. RESULTS: The study observed a significant elevation in the level of oxidative stress markers in autistic children when compared with normal children. The level of antioxidants excreted in urine was found to be significantly low in autistic children. These findings when correlated with the degrees of severity, oxidative stress markers showed positive correlation with increasing order of severity (LFA>MFA>HFA), whereas antioxidants showed negative correlation. DISCUSSION: The study reveals that the urinary levels of oxidative stress markers can be considered as the measure of oxidative stress index in autistic children. The significant correlation between the severity of autism with urinary lipid peroxidation products also support the use of oxidative stress markers and antioxidants as biomarkers of autism.

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4. Gawronski A, Kuzmanovic B, Georgescu A, Kockler H, Lehnhardt FG, Schilbach L, Volpert K, Vogeley K. {{[Expectations Concerning Psychotherapy of High-Functioning Adults with Autism Spectrum Disorders.]}}. {Fortschr Neurol Psychiatr};2011 (Oct 17)

BACKGROUND:In recent years there has been a strong increase in psychiatric diagnoses belonging to the autism spectrum in adulthood. For this diagnostic group of patients, often characterised by normal or above-average intelligence, i.e, high-functioning autism or Asperger syndrome, only few adequate psychotherapeutic treatment options exist. In order to develop a disorder-specific psychotherapeutic group training in a demand-oriented manner, we surveyed adults with autism spectrum disorders (ASD) concerning their needs and expectations relating to psychotherapy. METHODS:A two-step analysis of needs was carried out: First, after a set of open questions written descriptions of 33 individuals with ASD were analysed using the qualitative content analysis according to Mayring. The resulting category system provided the basis for the closed questionnaire EPAS (« Expectations Psychotherapy Autism Spectrum »). In a second step, 64 individuals with ASD were assessed by EPAS to confirm the relevance of the qualitatively derived dimensions. RESULTS:Both the results of the qualitative and the quantitative analysis confirmed the initial hypothesis that adults with ASD expressed problems associated with disorder-specific core symptoms. Moreover, the quantitative analysis demonstrated that in addition to deficits in social competence and identity formation, the lack of stress management skills represents a crucial load factor. Also, the therapist-associated variables were reported to play an important role for the patients. DISCUSSION:The analysis of needs indicates that psychotherapy for adults with ASD should focus on the training and development of social-communicative skills. Furthermore, dealing with stress in everyday situations and identity formation after diagnosis should also be considered. Psychotherapists can refer to well-established techniques from cognitive behavioural therapy, which are known to be effective in the identified fields and should have sufficient disorder-specific knowledge, not least in order to prevent misunderstandings within the therapeutic working relationship.

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5. Pascual JM. {{Animal models of the human mind: Is there anything it is like to be autistic?}}. {Neurosci Lett};2011 (Oct 10)

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6. Pinto-Martin JA, Levy SE, Feldman JF, Lorenz JM, Paneth N, Whitaker AH. {{Prevalence of Autism Spectrum Disorder in Adolescents Born Weighing <2000 Grams}}. {Pediatrics};2011 (Oct 17)

Objective:To estimate the diagnostic prevalence of autism spectrum disorders (ASDs) in a low birth weight (LBW) cohort.Methods:Participants belonged to a regional birth cohort of infants (N = 1105) born weighing <2000 g between October 1, 1984, and July 3, 1989, and followed up by periodic assessments to 21 years of age. At 16 years (n = 623), adolescents were screened for ASD using a wide net (previous professional diagnosis of an ASD or a score above a liberal cutoff on the Social Communication Questionnaire or the Autism Spectrum Symptoms Questionnaire). At 21 years (n = 189), 60% of screen positives and 24% of screen negatives were assessed for diagnoses of ASD by the Autism Diagnostic Observation Schedule or the Autism Diagnostic Interview-Revised.Results:Samples retained at ages 16 and 21 years were representative of samples assessed at earlier ages except for lower levels of social risk. Of positive screens, 11 of 70 had ASD; of negative screens, 3 of 119 had ASD. The fractions of the 2 screening groups with ASD (14.3% in screen-positives and 2.5% in screen negatives) were weighted by fractions of screen-positives and screen-negatives among the adolescents (18.8% and 81.2%, respectively). This calculation produced an estimated prevalence rate of ASD in the entire cohort of 5% (31 of 623).Conclusions:The diagnostic prevalence of ASD in this LBW preterm cohort was higher than that reported by the Centers for Disease Control and Prevention for 8-year-olds in the general US population in 2006.

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7. Platte P, Jaschke H, Herbert C, Korenke GC. {{Increased Resting Metabolic Rate in Girls with Rett Syndrome Compared to Girls with Developmental Disabilities}}. {Neuropediatrics};2011 (Oct 17)

The aim of this study was to determine the body composition and resting metabolic rate (RMR) of girls with Rett syndrome (RS) (n=15) and to compare them with an equally handicapped group of girls with developmental disabilities (DD) (n=13). Body composition was measured by bioelectrical impedance analysis and RMR – the amount of energy expended while at rest – by indirect calorimetry. Weight, height, body mass index (BMI), BMI percentiles and food intake were all measured and calculated by standardized procedures. Feeding time, ambulatory status and ability to self-feed were also assessed. Due to the sampling, there were no significant differences in age, height, weight, BMI, BMI percentiles and ambulatory status. Significant differences between groups were found for lower percentage lean body mass (LBM) (64.2+/-14.6 vs. 84.4+/-24.6) and higher absolute and relative fat mass (FM) in RS. RMR values adjusted for LBM were significantly higher in the group of girls with RS (approximately 160 kcal/day), indicating that higher energy expenditure is a component of increased risk of severely low body weight.

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8. Roy S, Zhao Y, Allensworth M, Farook MF, Ledoux MS, Reiter LT, Heck DH. {{Comprehensive motor testing in Fmr1-KO mice exposes temporal defects in oromotor coordination}}. {Behav Neurosci};2011 (Oct 17)

Fragile X syndrome (FXS; MIM #300624), a well-recognized form of inherited human mental retardation is caused, in most cases, by a CGG trinucleotide repeat expansion in the 5′-untranslated region of FMR1, resulting in reduced expression of the fragile X mental retardation protein (FMRP). Clinical features include macroorchidism, anxiety, mental retardation, motor coordination, and speech articulation deficits. The Fmr1 knockout (Fmr1-KO) mouse, a mouse model for FXS, has been shown to replicate the macroorchidism, cognitive deficits, and neuroanatomical abnormalities found in human FXS. Here we asked whether Fmr1-KO mice also display appendicular and oromotor deficits comparable to the ataxia and dysarthric speech seen in FXS patients. We employed standard motor tests for balance and appendicular motor coordination, and used a novel long-term fluid-licking assay to investigate oromotor function in Fmr1-KO mice and their wild-type (WT) littermates. Fmr1-KO mice performed equally well as their WT littermates on standard motor tests, with the exception of a raised-beam task. However, Fmr1-KO mice had a significantly slower licking rhythm than their WT littermates. Deficits in rhythmic fluid-licking in Fmr1-KO mice have been linked to cerebellar pathologies. It is believed that balance and motor coordination deficits in FXS patients are caused by cerebellar neurophathologies. The neuronal bases of speech articulation deficits in FXS patients are currently unknown. It is yet to be established whether similar neuronal circuits control rhythmic fluid-licking pattern in mice and speech articulation movement in humans. (PsycINFO Database Record (c) 2011 APA, all rights reserved).

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9. Takei A, Mera K, Sato Y, Haraoka Y. {{High-functioning autistic disorder with Ehlers-Danlos syndrome}}. {Psychiatry Clin Neurosci};2011 (Oct);65(6):605-606.

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10. Tavassoli T, Baron-Cohen S. {{Taste Identification in Adults with Autism Spectrum Conditions}}. {J Autism Dev Disord};2011 (Oct 18)

Sensory issues are widely reported in Autism Spectrum Conditions (ASC). Since taste perception is one of the least studied senses in ASC we explored taste identification in adults with ASC (12 males, 11 females) compared to control participants (14 males, 12 females). ‘Taste strips’ were used to measure taste identification overall, as well as bitter, sour, sweet and salty tastes. Results revealed lower taste scores overall in the ASC group, as well as for bitter, sour and sweet tastes. Salty taste scores did not differ between the groups. Examining error types showed that adults with ASC more often misidentified a taste as salty or as no taste. Future studies should investigate underlying mechanisms of taste identification difficulties in ASC.

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11. Tordjman S. {{Time and its representations: At the crossroads between psychoanalysis and neuroscience}}. {J Physiol Paris};2011 (Oct 8)

Representations of time and time measurements depend on subjective representations that vary according to changes in our concepts, beliefs and technological advances. Similarly, the past, the future and also the present are subjective representations that depend on each individual’s psychic time and biological time. Nonetheless, the construction of these representations is influenced by objective factors (cognitive, physiological and physical) related to neuroscience. Thus, studying representation of time lies at the crossroads between neuroscience and psychoanalysis. Furthermore, these objective factors are supposed to meet criteria of scientific validity, such as reproducibility. However, reproducibility depends on the individual’s state that will not be exactly the same later, due precisely to the passage of time. The criteria of scientific validity are therefore only applicable if we place ourselves at time « t ». This does not take into account lifespan biological changes. In fact, it is not neuroscience that is opposed to psychoanalysis based on this notion of subjectivity, illustrated by the concept of temporality, but rather the use and interpretation of neuroscience centered on taking snapshots. We can assume that focusing on present time, in particular instantaneity rather than infinity, prevents us from facing our own finitude. Individuals with autism provide us a good illustration of this idea. Through their autistic behaviors, they are totally focused on the present moment and create repeated discontinuity out of continuity. The hypothesis is stated here that children with autism need to create stereotyped discontinuity because discontinuity repeated at regular intervals might have been fundamentally lacking in their physiological development, due to circadian rhythm alterations. In conclusion, the question is raised that both the current use of neuroscience and the current representation of time might be a means of managing our fear of death, giving us the illusion of controlling the uncontrollable, in particular the passage of time.

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12. Wang J, Zhou X, Xia W, Sun C, Wu L. {{Autism awareness and attitudes towards treatment in caregivers of children aged 3-6 years in Harbin, China}}. {Soc Psychiatry Psychiatr Epidemiol};2011 (Oct 19)

OBJECTIVE: To (1) estimate the proportion of people in the community who could correctly recognize autism spectrum disorders (ASD); (2) describe the attitudes towards various treatments for ASD; and (3) identify factors associated with ASD recognition. METHODS: A population-based cross-sectional survey was conducted in Harbin, China (n = 4,947). We estimated the proportions of participants who were at different levels of knowledge about ASD and of their attitudes towards mental health service use. Multivariate logistic regression modeling was used to identify factors associated with the recognition of ASD. RESULTS: Overall, 2,786 (57.8%) of the respondents could recognize the ASD. Recognition of autism depended on gender, residing areas, age and educational levels. With respect to the attitudes towards mental health service use for ASD, 4,007 respondents (84.6%) chose to visit a health organization for treatment; 2,470 (68.2%) made the choice of consulting a psychotherapist. CONCLUSIONS: There is a large room for improvement in awareness about ASD and treatment in the Chinese communities. Insufficient knowledge about ASD and inappropriate attitudes towards mental health service use may impede the efforts of early identification and intervention. Health education and promotion are needed to improve people’s knowledge about ASD and available mental health services.

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13. Webb SJ, Jones EJ, Merkle K, Venema K, Greenson J, Murias M, Dawson G. {{Developmental Change in the ERP Responses to Familiar Faces in Toddlers With Autism Spectrum Disorders Versus Typical Development}}. {Child Dev};2011 (Oct 17)

Individuals with autism spectrum disorder (ASD) show differences in face processing abilities from early in development. To examine whether these differences reflect an atypical versus delayed developmental trajectory, neural responses to familiar and unfamiliar faces in twenty-four 18- to 47-month-old children with ASD were compared with responses of thirty-two 12- to 30-month-old typically developing children. Results of 2 experiments revealed that neural responses to faces in children with ASD resembled those observed in younger typically developing children, suggesting delayed development. Electrophysiological responses to faces were also related to parent report of adaptive social behaviors for both children with ASD and typical development. Slower development of the face processing system in ASD may be related to reduced self-directed « expected » experience with faces in early development.

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14. Whittaker CA. {{The speech aversion hypothesis has explanatory power in a Minimal Speech Approach to aloof, non-verbal, severe autism}}. {Med Hypotheses};2011 (Oct 15)

In the search for ‘pure autism’, non-verbal children labeled aloof, Severely Autistic with Developmental Disabilities (ASA/DD), are routinely excluded from psychological research. This exclusion is predicated on the claim that they are indistinguishable from those with SLD/PMLD, which is refuted through a discussion of the extant literature. A novel, falsifiable, speech aversion hypothesis is proposed: « aloof, non-verbal young children (<7years), with severe autism (CARS 37), but without significant dysmorphic features, will show aversive reactions to complex speech (>2-3 words), but not to a silent interlocutor, or one imitating their vocalizations, in proximal encounters. » Implications are examined by deconstructing the presenting symptoms of ASA/DD in response to the hypothesis. Supporting evidence is drawn from: Minimal Speech Approach (MSA) research showing high levels of spontaneous requests for social routines; a reinterpretation of still-face research as a still-(silent)-face paradigm; auditory processing MMN data employing EEG/MEG; and possible links to epileptiform activity and verbal auditory agnosia. Guidelines are established for future research. This hypothesis, if corroborated, would add to the auditory processing anomalies seen in severe autism and lead to synergies of existing and new areas of research, with significant theoretical, therapeutic, and educational implications.

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