Maternal Serotonin Levels Are Associated With Cognitive Ability and Core Symptoms in Autism Spectrum Disorder.

OBJECTIVE: The serotonin (5-hydroxytryptamine [HT]) system has long been implicated in autism spectrum disorder (ASD). Whole-blood 5-HT level (WB5-HT) is a stable, heritable biomarker that is elevated in more than 25% of children with ASD. Recent findings indicate that the maternal 5-HT system may influence embryonic neurodevelopment, but maternal WB5-HT has not been examined in relation to ASD phenotypes. METHOD: WB5-HT levels were obtained from 181 individuals (3-27 years of age) diagnosed with ASD, 99 of their fathers, and 119 of their mothers. Standardized assessments were used to evaluate cognitive, behavioral, and language phenotypes. RESULTS: Exploratory regression analyses found relationships between maternal WB5-HT and nonverbal IQ (NVIQ), Autism Diagnostic Interview-Revised (ADI-R) Nonverbal Communication Algorithm scores, and overall adaptive function on the Vineland Adaptive Behavior Scales-II. Latent class analysis identified a three-class structure in the assessment data, describing children with low, intermediate, and high severity across measures of behavior, cognition, and adaptive function. Mean maternal WB5-HT differed across classes, with the lowest maternal WB5-HT levels seen in the highest-severity group (Welch F2,46.048 = 17.394, p < .001). Paternal and proband WB5-HT did not differ between classes. CONCLUSION: Maternal WB5-HT is associated with neurodevelopmental outcomes in offspring with ASD. Prospective, longitudinal studies will be needed to better understand the relationship between the function of the maternal serotonin system during pregnancy and brain development. Further studies in animal models may be able to reveal the mechanisms underlying these findings.

Visually Evoked Response Differences to Contrast and Motion in Children with Autism Spectrum Disorder.

High-density electroencephalography (EEG) was used to examine the utility of the P1 event-related potential (ERP) as a marker of visual motion sensitivity to luminance defined low-spatial frequency drifting gratings in 16 children with autism and 16 neurotypical children. Children with autism displayed enhanced sensitivity to large, high-contrast low-spatial frequency stimuli as indexed by significantly shorter P1 response latencies to large vs. small gratings. The current study also found that children with autism had larger amplitude responses to large gratings irrespective of contrast. A linear regression established that P1 adaptive mean amplitude for large, high-contrast sinusoidal gratings significantly predicted hyperresponsiveness item mean scores on the Sensory Experiences Questionnaire for children with autism, but not for neurotypical children. We conclude that children with autism have differences in the mechanisms that underlie low-level visual processing potentially related to altered visual spatial suppression or contrast gain control.

Decompressive craniectomy in childhood posterior circulation stroke: a case series and review of the literature.

Few reports address the role of decompressive craniectomy in children with space-occupying cerebral edema attributable to severe ischemic infarction of the posterior cerebral arterial circulation. We describe four children with posterior circulation arterial ischemic stroke who required decompressive craniectomy. These children accounted for 11% of all cases of posterior circulation ischemic stroke at our institution from 2002-2010. Three manifested large, cerebellar hemispheric infarcts, and one manifested a large, temporo-occipital posterior cerebral artery infarct. Deterioration occurred within 72 hours of stroke onset. Two patients demonstrated minimal functional deficits at follow-up, and two demonstrated moderate deficits with functional limitations. Because decompressive craniectomy can be lifesaving in children with severe posterior circulation arterial ischemic stroke, early neurosurgical referral should be considered.