Pubmed du 20/04/10

Pubmed du jour

2010-04-20 12:03:50

1. Fournier KA, Kimberg CI, Radonovich KJ, Tillman MD, Chow JW, Lewis MH, Bodfish JW, Hass CJ. {{Decreased static and dynamic postural control in children with autism spectrum disorders}}. {Gait Posture} (Apr 16)

The purpose of this study was to investigate postural control in children with Autism Spectrum Disorders (ASD) during static and dynamic postural challenges. We evaluated postural sway during quiet stance and the center of pressure (COP) shift mechanism during gait initiation for 13 children with ASD and 12 age-matched typically developing (TD) children. Children with ASD produced 438% greater normalized mediolateral sway (p<0.05) and 104% greater normalized anteroposterior sway (p<0.05) than TD children. Consequently, normalized sway area was also significantly greater (p<0.05) in the group with ASD. Similarly, the maximum separation between the COP and center of mass (COM) during quiet stance was 100% greater in the anteroposterior direction (p<0.05) and 146% greater in the resultant direction (p<0.05) for children with ASD. No significant difference was observed in the mediolateral direction, in spite of the 123% greater separation detected in children with ASD. During gait initiation, no group differences were detected in the posterior COP shift mechanism, suggesting the mechanism for generating forward momentum is intact. However, significantly smaller lateral COP shifts (p<0.05) were observed in children with ASD, suggesting instability or an alternative strategy for generating momentum in the mediolateral direction. These results help to clarify some discrepancies in the literature, suggesting an impaired or immature control of posture, even under the most basic conditions when no afferent or sensory information have been removed or modified. Additionally, these findings provide new insight into dynamic balance in children with ASD.

2. Hare DJ. {{Information about autism}}. {Autism} (Mar);14(2):91-92.

3. Hitoglou M, Ververi A, Antoniadis A, Zafeiriou DI. {{Childhood autism and auditory system abnormalities}}. {Pediatr Neurol} (May);42(5):309-314.

Hearing disorders are common among children with autism, ranging from peripheral and sensorineural hearing deficit or loss to auditory hypersensitivity with bizarre reactions to sounds. The auditory abnormalities and consequent sensory deprivation exacerbate the communication deficit of autism, and early auditory assessment holds an important place in the planning of intervention and the overall prognosis of patients. Physiologic, pathologic, imaging, and neurochemical studies have revealed an array of aberrations in the perception and processing of the audiologic stimuli, including (among others) maturational defects, atypical lateralization, and serotonin dysfunction.

4. Malik M, Sheikh AM, Wen G, Spivack W, Brown WT, Li X. {{Expression of inflammatory cytokines, Bcl2 and cathepsin D are altered in lymphoblasts of autistic subjects}}. {Immunobiology} (Mar 12)

To determine whether inflammation and apoptosis are involved in the pathogenesis of autism, we examined cytokines, Bcl2 expression and cathepsin D protease activity in the lymphoblasts of autistic subjects and age-matched controls. We found increased expression levels of pro-inflammatory cytokines TNF-alpha and IL-6, but decreased Bcl2 expression in lymphoblasts of autistic subjects. We also found that cathepsin D mRNA and protein expression were significantly increased in autistic lymphoblasts. Conclusion: Our findings suggest that inflammation and apoptosis may play a significant role in the pathogenesis of autism, and cathepsin D may participate in the regulation of cytokine-induced inflammation and apoptosis in autistic lymphoblasts.

5. Pillion JP, Bibat G, Naidu S. {{Effects of sedation on auditory brainstem response in Rett syndrome}}. {Pediatr Neurol} (May);42(5):331-334.

Prolongation of the I-V interpeak latency intervals have been reported in Rett syndrome and other neurodevelopmental disorders. It has been suggested that the use of sedation may account for differences in the interpeak latency intervals when comparisons are made across diagnostic groups if sedated control groups are not used for the basis of comparison. This study examined the effects of sedation on auditory brainstem response interpeak latency intervals (i.e., I-III, III-V, and I-V) in two groups: (1) a group with Rett syndrome who were positive for mutations in the MECP2 gene and (2) a group negative for mutations in the MECP2 gene but who were severely to profoundly delayed with other causes of mental retardation. To further assess the effects of sedation, a third group of sedated and nonsedated female participants, taken from an in-house normative auditory brainstem response database was also included. An analysis of variance indicated (1) longer I-V interpeak latency intervals in the sedated participants with Rett syndrome; (2) longer III-V interpeak latency intervals in the mutation-positive participants as compared to non-Rett syndrome, mutation-negative participants; and (3) no significant effects of sedation on the I-III, III-V, or I-V interpeak latency intervals among the normative group participants, according to t tests. The findings suggest a possible biological basis for the discrepancy in the literature on auditory brain stem responses in Rett syndrome, and warrant cautious interpretation of auditory brainstem responses findings in sedated subjects with Rett syndrome, as well as in those with mental retardation and seizures.

6. White R, Ho G, Schmidt S, Scheffer IE, Fischer A, Yendle SC, Bienvenu T, Nectoux J, Ellaway CJ, Darmanian A, Tong X, Cloosterman D, Bennetts B, Kalra V, Fullston T, Gecz J, Cox TC, Christodoulou J. {{Cyclin-Dependent Kinase-Like 5 (CDKL5) Mutation Screening in Rett Syndrome and Related Disorders}}. {Twin Res Hum Genet} (Apr);13(2):168-178.

Abstract Rett syndrome (RTT) is a severe neurodevelopmental disorder affecting females almost exclusively and is characterized by a wide spectrum of clinical manifestations. Mutations in the X-linked methyl-CpG-binding protein 2 (MECP2) gene have been found in up to 95% of classical RTT cases and a lesser proportion of atypical cases. Recently, mutations in another X-linked gene, CDKL5 (cyclin-dependent kinase-like 5) have been found to cause atypical RTT, in particular the early onset seizure (Hanefeld variant) and one female with autism. In this study we screened several cohorts of children for CDKL5 mutations, totaling 316 patients, including individuals with a clinical diagnosis of RTT but who were negative for MECP2 mutations (n = 102), males with X-linked mental retardation (n = 9), patients with West syndrome (n = 52), patients with autism (n = 59), patients with epileptic encephalopathy (n = 33), patients with Aicardi syndrome (n = 7) and other patients with intellectual disability with or without seizures (n = 54). In all, seven polymorphic variations and four de novo mutations (c.586C>T [p.S196L]; c.58G>C [p.G20R]; c.2504delC [p.P835fs]; deletion of exons 1 – 3) were identified, and in all instances of the latter the clinical phenotype was that of an epileptic encephalopathy. These results suggest that pathogenic CDKL5 mutations are unlikely to be identified in the absence of severe early-onset seizures and highlight the importance of screening for large intragenic and whole gene deletions.

7. Zhang J. {{A review of autism spectrum disorders (ASD) from A perspective of classical Chinese medicine (CCM)}}. {J Tradit Chin Med} (Mar);30(1):53-59.