Delayed cortical processing of auditory stimuli in children with autism spectrum disorder: A meta-analysis of electrophysiological studies.

Several researchers have hypothesised that individuals with Autism Spectrum Disorder (ASD) show encoding delays in their obligatory event-related potentials (ERPs)/ event-related fields (ERFs) for low-level auditory information compared to neurotypical (NT) samples. However, empirical research has yielded varied findings, such as low-level auditory processing in ASD samples being unimpaired, superior, or impaired compared to NT samples. Diverse outcomes have also been reported for studies investigating ASD-NT differences in functional lateralisation of delays. The lack of consistency across studies has prevented a comprehensive understanding of the overall effects in the autistic population. Therefore, this meta-analysis compared long-latency ERPs and ERFs produced by autistic and NT individuals to non-linguistic auditory stimuli to test, firstly, the robustness of auditory processing differences and, secondly, whether these differences are observed in one or both hemispheres. Nine articles meeting the inclusion criteria were included in the meta-analysis. Meta-analytic results indicated that autistic individuals demonstrate bilaterally delayed P1/ M50 peaks and lateralised delays in the right but not left hemisphere N1/ M100 peak. These results further inform our understanding of auditory processing and lateralisation across the autism spectrum.

Vitamin D in fetal development: findings from a birth cohort study.

Birth cohort studies provide an invaluable resource for studies of the influence of the fetal environment on health in later life. It is uncertain to what extent maternal vitamin D status influences fetal development. Using an unselected community-based cohort of 901 mother-offspring pairs (the Western Australian Pregnancy Cohort [Raine] Study), we examined the relationship between maternal vitamin D deficiency at 18 weeks' pregnancy and long-term health outcomes of offspring who were born in Perth, Western Australia (32° South), in 1989-1991. Vitamin D deficiency (serum 25-hydroxyvitamin D [25(OH)D] <50 nmol/L) was present in 36% (323 of 901) of the pregnant women. After adjusting for relevant covariates, maternal vitamin D deficiency during pregnancy was associated with impaired lung development in 6-year-old offspring, neurocognitive difficulties at age 10, increased risk of eating disorders in adolescence, and lower peak bone mass at 20 years. In summary, vitamin D may have an important, multifaceted role in the development of fetal lungs, brain, and bone. Experimental animal studies support an active contribution of vitamin D to organ development. Randomized controlled trials of vitamin D supplementation in pregnant women with long-term follow-up of offspring are urgently required to examine whether the correction of vitamin D deficiency in pregnant women is beneficial for their offspring and to determine the optimal level of maternal serum 25(OH)D for fetal development.

Complementary and alternative medicine for autism spectrum disorders: rationale, safety and efficacy.

Complementary and alternative medicine is widely used for children with autism spectrum disorder, despite uncertainty regarding efficacy. This review describes complementary and alternative practices commonly used among this population, the rationale for the use of each practice, as well as the side-effect profile and evidence for efficacy. The existing evidence base indicates that melatonin can be recommended as a treatment for sleeping disturbances associated with autism spectrum disorder, while secretin can be rejected as an efficacious treatment for broader autistic symptoms. There is insufficient evidence to draw conclusions on the efficacy of modified diets, hyperbaric oxygen therapy, immune therapy, and vitamin and fatty acid supplementation. There is a clear need for methodologically rigorous studies to provide evidence-based guidance to families and clinicians regarding complementary and alternative practices for individuals with autism spectrum disorders.

Maternal serum vitamin D levels during pregnancy and offspring neurocognitive development.

OBJECTIVES: To determine the association between maternal serum 25(OH)-vitamin D concentrations during a critical window of fetal neurodevelopment and behavioral, emotional, and language outcomes of offspring. METHODS: Serum 25(OH)-vitamin D concentrations of 743 Caucasian women in Perth, Western Australia (32°S) were measured at 18 weeks pregnancy and grouped into quartiles. Offspring behavior was measured with the Child Behavior Checklist at 2, 5, 8, 10, 14, and 17 years of age (n range = 412-652). Receptive language was assessed with the Peabody Picture Vocabulary Test-Revised at ages 5 (n = 534) and 10 (n = 474) years. Raw scores were converted to standardized scores, incorporating cutoffs for clinically significant levels of difficulty. RESULTS: χ(2) analyses revealed no significant associations between maternal 25(OH)-vitamin D serum quartiles and offspring behavioral/emotional problems at any age. In contrast, there were significant linear trends between quartiles of maternal vitamin D levels and language impairment at 5 and 10 years of age. Multivariate regression analyses, incorporating a range of confounding variables, found that the risk of women with vitamin D insufficiency (≤46 nmol/L) during pregnancy having a child with clinically significant language difficulties was increased close to twofold compared with women with vitamin D levels >70 nmol/L. CONCLUSIONS: Maternal vitamin D insufficiency during pregnancy is significantly associated with offspring language impairment. Maternal vitamin D supplementation during pregnancy may reduce the risk of developmental language difficulties among their children.