Executive Functioning: A Mediator Between Sensory Processing and Behaviour in Autism Spectrum Disorder.

Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder characterized by impairments in social interaction, executive functioning, sensory-perceptual abilities and behaviour, such as anxious/depressed states, attention problems, aggression, or somatic complains. However, the dynamic relationship between these dimensions remains to be addressed. Therefore, we explored the link between executive functions, sensory processing and behaviour in 79 children and adolescents with ASD. Results showed significant associations between all dimensions-executive functions, sensory processing and behaviour. Furthermore, using structural equation modelling methods, we observed a mediation effect of executive functioning, specifically the domain pertaining to emotion regulation and control, and in the relationship between sensory processing abnormalities and behavioural problems. We discuss the importance of emotion regulation as a mediator between sensory processing and behavioural impairments and its impact in social competence in ASD.

Touch Processing and Social Behavior in ASD.

Abnormal patterns of touch processing have been linked to core symptoms in ASD. This study examined the relation between tactile processing patterns and social problems in 44 children and adolescents with ASD, aged 6-14 (M = 8.39 ± 2.35). Multiple linear regression indicated significant associations between touch processing and social problems. No such relationships were found for social problems and autism severity. Within touch processing, patterns of hyper-responsiveness and hypo-responsiveness best predicted social problems, whereas sensory-seeking did not. These results support that atypical touch processing in individuals with ASD might be contributing to the social problems they present. Moreover, it the need to explore more in depth the contribution of sensory features to the ASD phenotype.

PET and MRI detection of early and progressive neurodegeneration in spinocerebellar ataxia type 36.

BACKGROUND: The spinocerebellar ataxias (SCAs) form a clinically, genetically, and pathological heterogeneous group of autosomal-dominant degenerative diseases. In particular, SCA36 is characterized by a late-onset, slowly progressive cerebellar syndrome typically associated with sensorineural hearing loss. This study was aimed at analyzing the neurodegenerative process underlying SCA36 through fluorodeoxyglucose positron emission tomography (FDG-PET) and MRI scans. METHODS: Twenty SCA36 patients underwent a study consisting of FDG-PET and MRI scans. Clinical motor evaluation was performed through the Scale for the Assessment and Rating of Ataxia (SARA). FDG-PET was carried out using a voxel-by-voxel and region-of-interest analysis. MRI evaluation was based on visual inspection and volumetric analysis. RESULTS: SARA ranged from 0 to 24.5 (4 patients asymptomatic, 3 with unspecific symptoms, and 13 with cerebellar signs). FDG-PET revealed hypometabolism in the asymptomatic stage in the vermis and right cerebellar hemisphere. In the ataxic stage, hypometabolism spread to both cerebellar hemispheres and the brain stem. MRI was normal in asymptomatic and preataxic individuals and showed superior cerebellar vermis atrophy early in the ataxic stage, diffuse cerebellar atrophy some years into the disease course, and a pattern of olivopontocerebellar atrophy in the oldest patients. There was no significant cerebellar atrophy in patients younger than 50 years. CONCLUSIONS: We present the first FDG-PET study of SCA36 and one of the largest neuroimaging study of SCAs. Our results revealed neuronal dysfunctions in the vermis and right cerebellar hemisphere as soon as a decade before the onset of motor symptoms. In the ataxic stage, dysfunctions spread to both hemispheres and the brain stem. © 2016 International Parkinson and Movement Disorder Society.

Interstitial microdeletions including the chromosome band 4q13.2 and the UBA6 gene as possible causes of intellectual disability and behavior disorder.

The few proximal 4q chromosomal aberrations identified in patients with neurodevelopmental phenotypes that have been published to date are variable in type, size and breakpoints and, therefore, encompass different chromosome bands and genes, making the establishment of genotype-phenotype correlations a challenging task. Here, microarray-based copy number analysis allowed us the detection of two novel and partially overlapping deletions in two unrelated families. In Family 1, a 4q13.1-q13.2 deletion of 3.84 Mb was identified in a mother with mild intellectual disability and in her two children, both with mild intellectual disability and attention deficit hyperactivity disorder. In Family 2, a de novo 4q13.2-q13.3 deletion of 6.81 Mb was detected in a female patient, born to unaffected parents, with a diagnosis of mild intellectual disability, behavioral disorder and facial dysmorphism. The shortest region of overlap between these two aberrations is located at chromosome 4q13.2 and includes 17 genes amongst of which we suggest UBA6 (ubiquitin-like modifier-activating enzyme 6) as a strong candidate gene for these phenotypes.

How executive functions are related to intelligence in Williams syndrome.

Williams syndrome is characterized by impairments in executive functions (EFs). However, it remains unknown how distinct types of EFs relate to intelligence in this syndrome. The present study analyzed performance on working memory, inhibiting and shifting, and its links to IQ in a sample of 17 individuals with WS, and compared them with a group of 17 typically developing individuals matched on chronological age and gender. In conclusion, our results suggest that working memory, inhibiting, and shifting relate differently to intelligence in WS as well as in typical development, with working memory being the EF most closely related to intelligence in both groups. Notably, the magnitude of the associations between the three EFs and IQ was substantially higher in the WS group than in the TD group, bringing further confirmation to the notion that frontal lobe impairments may produce a general compromise of several EFs.