Superior performance on the Embedded Figures Task (EFT) has been attributed to weak central coherence in perceptual processing in Autism Spectrum Disorders (ASD). The present study used functional magnetic resonance imaging to examine the neural basis of EFT performance in 7-12 year old ASD children and age and IQ matched controls. ASD children activated only a subset of the distributed network of regions activated in controls. In frontal cortex, control children activated left dorsolateral, medial and dorsal premotor regions whereas ASD children only activated the dorsal premotor region. In parietal and occipital cortices, activation was bilateral in control children but unilateral (left superior parietal and right occipital) in ASD children. Further, extensive bilateral ventral temporal activation was observed in control, but not ASD children. ASD children performed the EFT at the same level as controls but with reduced cortical involvement, suggesting that disembedded visual processing is accomplished parsimoniously by ASD relative to typically developing brains.Despite deficits in multiple functional domains including social interaction, language, and executive functioning, individuals with Autism Spectrum Disorders (ASD) exhibit a notable strength, namely, superior ability to identify local features of complex visual stimuli (Happe & Frith, 2006). This perceptual superiority is most consistently reflected in faster and/or more accurate performance on the Embedded Figures Task (EFT), which requires identification of a simple shape embedded within a complex figure (Jolliffe & Baron-Cohen, 1997;Shah & Frith, 1983). An influential theoretical interpretation of this and similar findings on other visual-spatial tasks has been the proposal that individuals with ASD have a perceptual processing style that facilitates visual processing of local rather than global information, termed weak central coherence (Happe & Frith, 2006). Such an information processing style is consistent with symptoms of preoccupation with object parts and difficulty perceiving whole objects following changes in constituent parts (Happe & Frith, 2006). Regarding the EFT, the Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. NIH Public Access Author ManuscriptNeuroimage. Author manuscript; available in PMC 2008 October 15. NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author Manuscript task draws upon the natural bias towards local visual processing in ASD, thereby yielding better performance in ASD than controls. In contrast, typically developing individuals are slower and/or less accu...

Unmasking the neural basis of neurodevelopmental disorders, such as autism spectrum disorders (ASD), requires studying functional connectivity during childhood when cognitive skills develop. A functional connectivity magnetic resonance imaging (fcMRI) analysis was performed on data collected during Go/NoGo task performance from 24 children ages 8-12 years (12 with ASD; 12 controls matched on age and intellectual functioning). We investigated the connectivity of the left and right inferior frontal cortex (IFC; BA 47), key regions for response inhibition, with other active regions in frontal, striatal, and parietal cortex. Groups did not differ on behavioral measures or functional connectivity of either IFC region. A trend for reduced connectivity in the right IFC for the ASD group was revealed when controlling for age. In the ASD group, there was a significant negative correlation between age and 2 right IFC correlation pairs: right IFC-bilateral presupplementary motor area (BA 6) and right IFC-right caudate. Compared with typical controls, children with ASD may not have gross differences in IFC functional connectivity during response inhibition, which contrasts with an adult study of ASD that reported reduced functional connectivity. This discrepancy suggests an atypical developmental trajectory in ASD for right IFC connectivity with other neural regions supporting response inhibition.

A default mode network of brain regions is known to demonstrate coordinated activity during the resting state. While the default mode network is well characterized in adults, few investigations have focused upon its development. We scanned 9-13 year old children with diffusion tensor imaging and resting-state functional magnetic resonance imaging. We identified resting state networks using Independent Component Analysis and tested whether the functional connectivity between the medial prefrontal cortex (mPFC) and posterior cingulate cortex (PCC) depends upon the maturation of the underlying cingulum white matter tract. To determine the generalizability of this relationship, we also tested whether functional connectivity depends on white matter maturity between bilateral lateral prefrontal cortex (lateral PFC) within the executive control network. We found a positive relationship between mPFC-PCC connectivity and fractional anisotropy of the cingulum bundle; this positive relationship was moderated by the age of the subjects such that it was stronger in older children. By contrast, no such structure-function relationship emerged between right and left lateral PFC. However, functional and structural connectivity of this tract related positively with cognitive speed, fluency, and set-switching neuropsychological measures.

In deep brain stimulation (DBS) of the subthalamic nucleus (STN) for Parkinson’s disease (PD), there is debate concerning the use of neuroimaging alone to confirm correct anatomic placement of the DBS lead into the STN, versus the use of microelectrode recording (MER) to confirm functional placement. We performed a retrospective study of a contemporaneous cohort of 45 consecutive patients who underwent either interventional-MRI (iMRI) or MER-guided DBS lead implantation. We compared radial lead error, motor and sensory side effect, and clinical benefit programming thresholds, and pre- and post-operative unified PD rating scale scores, and levodopa equivalent dosages. MER-guided surgery was associated with greater radial error compared to the intended target. In general, side effect thresholds during initial programming were slightly lower in the MER group, but clinical benefit thresholds were similar. No significant difference in the reduction of clinical symptoms or medication dosage was observed. In summary, iMRI lead implantation occurred with greater anatomic accuracy, in locations demonstrated to be the appropriate functional region of the STN, based on the observation of similar programming side effect and benefit thresholds obtained with MER. The production of equivalent clinical outcomes suggests that surgeon and patient preference can be used to guide the decision of whether to recommend iMRI or MER-guided DBS lead implantation to appropriate patients with PD.

Background Polymorphism of the dopamine transporter genotype (DAT1) confers a small but significant susceptibility to Attention Deficit Hyperactivity Disorder (ADHD). We examined whether the volume of the head of caudate, a striatal structure with high DAT expression that is important for inhibitory function, differs by DAT1 in a children diagnosed with the disorder relative to age and IQ matched controls. Method Volume of the head of caudate was delineated in the right and left hemisphere and compared between 7–13 year old children with and without ADHD (Combined type) who were carriers of two (10/10) or one (9/10) copy of the 10-repeat DAT1 allele. Results Caudate volumes were overall smaller 10/10 than 9/10 children, particularly in the left than right hemisphere. While DAT1 effects did not vary by ADHD diagnosis, overall caudate volumes were smaller in ADHD relative to control children. Conclusions Altered caudate development associated with 10-repeat homozygosity of DAT1 may contribute susceptibility to ADHD.

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Abusive head trauma (AHT) is a unique form of pediatric TBI with increased mortality and neurologic sequelae. Hemispheric hypodensity (HH) in association with subdural blood after AHT has been described. Though risk factors for HH are not understood, we hypothesized that risk factors could be identified. We retrospectively enrolled children under 5 years with TBI secondary to AHT (child advocacy diagnosis) who had undergone initial and interval brain imaging. Records were interrogated for prearrival and in-hospital physiologic and radiographic findings. HH was determined by a blinded observer. Twenty-four children were enrolled and 13 developed HH. HH was not significantly associated with age, initial Glascow Coma Scale, or mortality. Pediatric Intensity Level of Therapy (PILOT) scores ( p = 0.01) and daily maximal intracranial pressure (ICP max ; p = 0.037) were higher in HH. Hypoxia, hypotension, cardiopulmonary arrest, need for blood transfusion, and daily blood glucoses tended to be greater in HH. Whereas all children with HH had acute subdural hematoma (SBH), many children without HH also had subdural blood; the presence of skull fracture was more likely in the children who did not develop HH ( p = 0.04), but no other intracranial radiographic pattern of injury was associated with HH. Surgical intervention did not appear to protect against development of HH. A variety of insults associated with ischemia, including intracranial hypertension, ICP-directed therapies, hypoxia, hypotension, and cardiac arrest, occurred in the children who developed HH. Given the morbidity and mortality of this condition, larger studies to identify mechanisms leading to the development of HH and mitigating clinical approaches are warranted.

Current knowledge of the functional anatomy of the subthalamic nucleus and globus pallidus, discovered through microelectrode recording and postoperative imaging, justifies purely anatomic targeting for deep brain stimulation (DBS). Interventional MRI (iMRI)-DBS is more anatomically accurate than traditional awake procedures and has similar clinical outcomes without increased risk or increased operative times. iMRI lead implantation allows patients to receive DBS therapy who cannot tolerate or do not agree to undergo an awake procedure. This article describes considerations for iMRI-DBS implantation in the subthalamic nucleus and globus pallidus, including patient selection, technique of electrode placement, expected outcomes, and potential complications.