Deep Venous Remodeling in Unilateral Sturge-Weber Syndrome: Robust Hemispheric Differences and Clinical Correlates.

BACKGROUND: Enlarged deep medullary veins (EDMVs) in patients with Sturge-Weber syndrome (SWS) may provide compensatory venous drainage for brain regions affected by the leptomeningeal venous malformation (LVM). We evaluated the prevalence, extent, hemispheric differences, and clinical correlates of EDMVs in SWS. METHODS: Fifty children (median age: 4.5 years) with unilateral SWS underwent brain magnetic resonance imaging prospectively including susceptibility-weighted imaging (SWI); children aged 2.5 years or older also had a formal neurocognitive evaluation. The extent of EDMVs was assessed on SWI by using an EDMV hemispheric score, which was compared between patients with right and left SWS and correlated with clinical variables. RESULTS: EDMVs were present in 89% (24 of 27) of right and 78% (18 of 23) of left SWS brains. Extensive EDMVs (score >6) were more frequent in right (33%) than in left SWS (9%; P = 0.046) and commonly occurred in young children with right SWS. Patients with EDMV scores >4 had rare (less than monthly) seizures, whereas 35% (11 of 31) of patients with EDMV scores ≤4 had monthly or more frequent seizures (P = 0.003). In patients with right SWS and at least two LVM-affected lobes, higher EDMV scores were associated with higher intelligence quotient (P < 0.05). CONCLUSIONS: Enlarged deep medullary veins are common in unilateral SWS, but extensive EDMVs appear to develop more commonly and earlier in right hemispheric SWS. Deep venous remodeling may be a compensatory mechanism contributing to better clinical outcomes in some patients with SWS.

Altered efficiency of white matter connections for language function in children with language disorder.

To characterize structural white matter substrates associated with language functions in children with language disorders (LD), a psychometry-driven diffusion tractography network was investigated with canonical correlation analysis (CCA), which can reliably predict expressive and receptive language scores from the nodal efficiency (NE) of the obtained network. The CCA found that the NE values of six regions: left inferior-frontal-opercular, left insular, left angular gyrus, left superior-temporal-gyrus, right hippocampus, and right cerebellar-lobule were highly correlated with language scores (ρexpressive/ρreceptive = 0.609/0.528), yielding significant differentiation of LD from controls using new imaging predictors uexpressive (F = 15.024, p = .0003) and ureceptive (F = 7.421, p = .009). This study demonstrates the utility of intrinsic language network analyses in distinguishing and potentially subtyping the type and severity of language deficit, especially in very young children (≤3 years) with LD. The use of structural imaging to identify children with persisting language disorder could prove useful in understanding the etiology of language disorder.

Evolution of Brain Glucose Metabolic Abnormalities in Children With Epilepsy and SCN1A Gene Variants.

Three children with drug-refractory epilepsy, normal magnetic resonance image (MRI), and a heterozygous SCN1A variant underwent 2-deoxy-2-[18F]fluoro-d-glucose positron emission tomography (FDG-PET) scanning between age 6 months and 1 year and then at age 3 years 6 months to 5 years 5 months. Regional FDG uptake values were compared to those measured in age- and gender-matched pseudo-controls. At baseline, the brain glucose metabolic pattern in the SCN1A group was similar to that of the pseudo-controls. At follow-up, robust decreases of normalized FDG uptake was found in bilateral frontal, parietal and temporal cortex, with milder decreases in occipital cortex. Children with epilepsy and an SCN1A variant have a normal pattern of cerebral glucose metabolism at around 1 year of age but develop bilateral cortical glucose hypometabolism by age 4 years, with maximal decreases in frontal, parietal, and temporal cortex. This metabolic pattern may be characteristic of epilepsy associated with SCN1A variants and may serve as a biomarker to monitor disease progression and response to treatments.

Evolution of lobar abnormalities of cerebral glucose metabolism in 41 children with drug-resistant epilepsy.

OBJECTIVE: We analyzed long-term changes of lobar glucose metabolic abnormalities in relation to clinical seizure variables and development in a large group of children with medically refractory epilepsy. METHODS: Forty-one children (25 males) with drug-resistant epilepsy had a baseline positron emission tomography (PET) scan at a median age of 4.7 years; the scans were repeated after a median of 4.3 years. Children with progressive neurological disorders or space-occupying lesion-related epilepsy and those who had undergone epilepsy surgery were excluded. The number of affected lobes on 2-deoxy-2(18 F)-fluoro-D-glucose-PET at baseline and follow-up was correlated with epilepsy variables and developmental outcome. RESULTS: On the initial PET scan, 24 children had unilateral and 13 had bilateral glucose hypometabolism, whereas 4 children had normal scans. On the follow-up scan, 63% of the children showed an interval expansion of the hypometabolic region, and this progression was associated with persistent seizures. In contrast, 27% showed less extensive glucose hypometabolism at follow-up; most of these subjects manifested a major interval decrease in seizure frequency. Delayed development was observed in 21 children (51%) at baseline and 28 (68%) at follow-up. The extent of glucose hypometabolism at baseline correlated with developmental levels at the time of both baseline (r = .31, P = .05) and follow-up scans (r = .27, P = .09). SIGNIFICANCE: In this PET study of unoperated children with focal epilepsy, the lobar pattern of glucose hypometabolism changed over time in 90% of the cases. The results support the notion of an expansion of metabolic dysfunction in children with persistent frequent seizures and its association with developmental delay, and support that optimized medical treatment to control seizures may contribute to better neurocognitive outcome if no surgery can be offered.

Deep cerebral vein expansion with metabolic and neurocognitive recovery in Sturge-Weber syndrome.

We present longitudinal imaging data of a child with Sturge-Weber syndrome (SWS). At age 8 months, 3 weeks after initial seizures and prolonged motor deficit, MRI showed extensive right hemispheric SWS involvement with severe glucose hypometabolism on PET. She was treated with levetiracetam and aspirin. Follow-up imaging at age 29 months showed a robust interval expansion of enlarged deep medullary veins throughout the affected hemisphere along with a dramatic recovery of hemispheric metabolism and normalized neurocognitive functioning. These findings demonstrate a robust, multilobar hemispheric remodeling of deep venous collaterals that likely contributed to reversal of initial metabolic and neurocognitive deficits.

Cognitive and motor outcomes in children with unilateral Sturge-Weber syndrome: Effect of age at seizure onset and side of brain involvement.

PURPOSE: Most children with Sturge-Weber syndrome (SWS) develop seizures that may contribute to neurocognitive status. In this study, we tested the hypothesis that very early seizure onset has a particularly detrimental effect on the cognitive and/or motor outcomes of children with unilateral SWS. We also tested whether side of SWS brain involvement modulates the effect of seizure variables on the pattern of cognitive abnormalities. METHODS: Thirty-four children (22 girls; mean age 6.1years) with unilateral SWS and history of epilepsy in a longitudinal cohort underwent neurological and cognitive evaluations. Global intelligent quotient (GIQ), verbal intelligent quotient (VIQ), nonverbal intelligent quotient (IQ), and motor function were correlated with epilepsy variables, side and extent of brain involvement on magnetic resonance imaging (MRI). RESULTS: Mean age at seizure onset was 1.3years (0.1-6years) and mean IQ at follow-up was 86 (45-118). Age at seizure onset showed a logarithmic association with IQ, with maximum impact of seizures starting before age 1year, both in uni- and multivariate regression analyses. In the left SWS group (N=20), age at seizure onset was a strong predictor of nonverbal IQ (p=0.001); while early seizure onset in the right-hemispheric group had a more global effect on cognitive functions (p=0.02). High seizure frequency and long epilepsy duration also contributed to poor outcome IQ independently in multivariate correlations. Children with motor involvement started to have seizures at/before 7months of age, while frontal lobe involvement was the strongest predictor of motor deficit in a multivariate analysis (p=0.017). CONCLUSION: These findings suggest that seizure onset prior to age 1year has a profound effect on severity of cognitive and motor dysfunction in children with SWS; however, the effect of seizures on the type of cognitive deficit is influenced by laterality of brain involvement.

Metabolic correlates of cognitive function in children with unilateral Sturge-Weber syndrome: Evidence for regional functional reorganization and crowding.

To evaluate metabolic changes in the ipsi- and contralateral hemisphere in children showing a cognitive profile consistent with early reorganization of cognitive function, we evaluated the regional glucose uptake, interhemispheric metabolic connectivity, and cognitive function in children with unilateral SWS. Interictal 2-deoxy-2[18 F]fluoro-D-glucose (FDG)-PET scans of 27 children with unilateral SWS and mild epilepsy and 27 age-matched control (non-SWS children with epilepsy and normal FDG-PET) were compared using statistical parametric mapping (SPM). Regional FDG-PET abnormalities calculated as SPM(t) scores in the SWS group were correlated with cognitive function (IQ) in left- and right-hemispheric subgroups. Interhemispheric metabolic connectivity between homotopic cortical regions was also calculated. Verbal IQ was substantially (≥10 points difference) higher than non-verbal IQ in 61% of the right- and 71% of the left-hemispheric SWS group. FDG SPM(t) scores in the affected hemisphere showed strong positive correlations with IQ in the left-hemispheric, but not in right-hemispheric SWS group in several frontal, parietal, and temporal cortical regions. Significant positive interhemispheric metabolic connectivity, present in controls, was diminished in the SWS group. In addition, the left-hemispheric SWS group showed inverse metabolic interhemispheric correlations in specific parietal, temporal, and occipital regions. FDG SPM(t) scores in the same regions of the right (unaffected) hemisphere showed inverse correlations with IQ. These findings suggest that left-hemispheric lesions in SWS often result in early reorganization of verbal functions while interfering with ("crowding") their non-verbal cognitive abilities. These cognitive changes are associated with specific metabolic abnormalities in the contralateral hemisphere not directly affected by SWS.

Clinical and metabolic correlates of cerebral calcifications in Sturge-Weber syndrome.

AIM: To evaluate clinical and metabolic correlates of cerebral calcifications in children with Sturge-Weber syndrome (SWS). METHOD: Fifteen children (11 females, four males; age range 7mo-9y, mean 4y 1mo) with unilateral SWS underwent baseline and follow-up magnetic resonance imaging (MRI) with susceptibility weighted imaging (SWI), glucose metabolism positron emission tomography (PET), and neurocognitive assessment (mean follow-up 1y 8mo). Calcified brain volumes measured on SWI were correlated with areas of abnormal glucose metabolism, seizure variables, and cognitive function (IQ). RESULTS: Ten children had brain calcification at baseline and 11 at follow-up. Mean calcified brain volume increased from 1.69 to 2.47cm3 (p=0.003) in these children; the rate of interval calcified volume increase was associated with early onset of epilepsy (Spearman's rho [rs ]=-0.63, p=0.036). Calcified brain regions showed a variable degree of glucose hypometabolism with the metabolic abnormalities often extending to non-calcified cerebral lobes. Larger calcified brain volumes at baseline were associated with longer duration of epilepsy (rs =0.69, p=0.004) and lower outcome IQ (rs =-0.53, p=0.042). INTERPRETATION: Brain calcifications are common and progress faster in children with SWS with early epilepsy onset, and are associated with a variable degree of hypometabolism, which is typically more extensive than the calcified area. Higher calcified brain volumes may indicate a risk for poorer neurocognitive outcome.

Predictors of Cognitive Functions in Children With Sturge-Weber Syndrome: A Longitudinal Study.

BACKGROUND: Sturge-Weber syndrome is often accompanied by seizures and neurocognitive deterioration, although previous studies have suggested that early functional brain reorganization may diminish the cognitive sequelae in some children with unilateral Sturge-Weber syndrome. The "rules" governing these plasticity mechanisms are poorly understood. In this study, we evaluated longitudinal changes of cognitive functioning (intelligence quotient [IQ]) and assessed the performance of clinical, electroencephalography (EEG), and magnetic resonance imaging (MRI) variables for predicting IQ in children with Sturge-Weber syndrome. METHODS: Thirty-three young children (mean age: 3.3 years at baseline) with unilateral Sturge-Weber syndrome underwent MRI, scalp EEG, and neuropsychology evaluation twice, with a median follow-up of 2 years. None of the children had epilepsy surgery. Longitudinal IQ changes were calculated. Seizure variables, interictal EEG abnormalities, and extent and location of MRI brain involvement were correlated with IQ assessed at follow-up. RESULTS: Global IQ showed a highly variable course with both increases and decreases over time. Lower IQ at baseline was associated with interval IQ increase. In univariate analyses, lower outcome IQ was associated with baseline EEG abnormalities (P < 0.001), young age at seizure onset (P = 0.001), high seizure frequency (P = 0.02), and early frontal-lobe involvement on MRI (P = 0.01). In multivariate analysis, EEG abnormalities at baseline remained a robust, independent predictor of outcome IQ. CONCLUSIONS: The early trajectory of cognitive changes in children with unilateral Sturge-Weber syndrome is highly variable; children with improving IQ likely undergo effective unimpeded functional reorganization. Early onset, frequent seizures, and interictal epileptiform abnormalities on EEG likely interfere with this process resulting in poor cognitive functions. Future studies assessing interventions should target this high-risk subgroup to optimize cognitive outcome in Sturge-Weber syndrome.

Postoperative axonal changes in the contralateral hemisphere in children with medically refractory epilepsy: A longitudinal diffusion tensor imaging connectome analysis.

To determine brain plasticity changes due to resective epilepsy surgery in children, we performed a longitudinal connectome analysis on the pattern of axonal connectivity in the contralateral hemisphere. Pre- and postoperative diffusion tensor imaging (DTI) data were acquired from 35 children with intractable focal epilepsy. A total of 54 brain regions of interest (ROIs) were generated in the hemisphere contralateral to the resection. Within a 54 × 54 connectivity matrix, a pairwise connectivity score was calculated for each connection between two ROIs, based on the DTI fiber streamline number in each connection. A permuted Spearman's ρ-rank analysis was used to identify specific inter-regional connections showing a significant association between the postoperative change of connectivity score and clinical variables. Nineteen connections in the contralateral hemisphere showed postoperative increases in the strength of connectivity. Postoperative increase in connectivity between insular-inferior frontal operculum regions as well as that between superior frontal orbital and mid frontal orbital regions were both significantly associated with a larger surgical resection volume (ρ > +0.40) and a younger patient age (ρ > -0.34). These increases were more robust in patients with frontal resection and in those achieving seizure freedom. Neuropsychological evaluation on subsets of patients revealed that such increases in connectivity were associated with preserved or improved cognitive functions such as visual memory and planning. Resective epilepsy surgery may lead to increased contralateral axonal connectivity in children with focal epilepsy. Our data lead to a hypothesis that such increased connectivity may be an imaging marker of postoperative brain plasticity to compensate for cognitive function. Hum Brain Mapp 37:3946-3956, 2016. © 2016 Wiley Periodicals, Inc.

Relationship between genotype and arcuate fasciculus morphology in six young children with global developmental delay: Preliminary DTI stuy.

PURPOSE: To investigate whether different genetic mutations observed in children with global developmental delay (GD) are associated with unique patterns of the arcuate fasciculus dysmorphology. MATERIALS AND METHODS: Six children with GD (age: 36.8 ± 14.1 months, 5 boys) having mutations in MID1, CDK4, SFRP1, EN2, RXRG-GLRB, or MECP2, and five children with typical development (TD, age: 38.5 ± 20.5 months, 4 boys) underwent a 3 Tesla MRI including diffusion weighted imaging (DWI). Five language pathway segments in the left hemisphere, "C1 : Broca's to Wernicke's area," "C2 : Broca's to premotor area," "C3 : premotor to Wernicke's area," "C4 : Wernicke's to inferior parietal area," and "C5 : premotor to inferior parietal area" were objectively identified using the DWI "maximum a posteriori probability" classifier. RESULTS: Affinity propagation clustering analysis found that three arcuate pathway segments, C1,2,4 , of MID1, CDK4, EN2, and MECP2 had a similar pattern of volume ratio while those of SFRP1 and RXRG-GLRB had a heterogeneous pattern of volume ratio (net similarity = -0.01). Using receiver operating characteristic curve analysis, the fiber ratios of C1,2,4 showed a high probability to discriminate between GD and TD, yielding an accuracy of 0.91, 0.91, 1.00, respectively. The fiber volumes of C1 and C4 showed a strong correlation with expressive language (R2 = 0.6019; P-value = 0.033) and receptive language (R2 = 0.6379; P-value = 0.028), respectively. CONCLUSION: The findings of the present study provide preliminary evidence to suggest that different segments of the arcuate fasciculus are formed under the regulation of different genes which, when mutated, may result in developmental delay. J. Magn. Reson. Imaging 2016;44:1504-1512.

Frontal Aslant Tract Abnormality on Diffusion Tensor Imaging in an Aphasic Patient With 49, XXXXY Syndrome.

BACKGROUND: The karyotype 49, XXXXY is one of the most severe forms of chromosome aneuploidy and is characterized clinically by developmental delay and profound language impairment, particularly involving expressive language functions. We describe the neurocognitive profile and structural anatomy of language pathway in a 2-year-old boy with 49, XXXXY syndrome with expressive aphasia. METHODS: Retrospective chart review of the patient was performed. We characterized the language deficits using neuropsychologic testing. We further studied the language pathways using diffusion tensor imaging analytical technique. RESULTS: The neurocognitive profile of the patient showed relative weakness of expressive language skills compared with other domains. Diffusion tensor imaging analysis demonstrated a poorly developed frontal aslant tract, a weak indirect segment of arcuate fasciculus, and normally developed direct segment of arcuate fasciculus. The frontal aslant tract is a novel pathway that connects the Broca's area with the anterior cingulate and presupplementary motor area and plays a role in the "motor stream" of language. CONCLUSION: A poorly developed frontal aslant tract may underlie the expressive language deficits and provide some insight into the role of X chromosome in modulating the development of language tracts.

Imaging cerebral tryptophan metabolism in brain tumor-associated depression.

BACKGROUND: Depression in patients with brain tumors is associated with impaired quality of life and shorter survival. Altered metabolism of tryptophan to serotonin and kynurenine metabolites may play a role in tumor-associated depression. Our recent studies with alpha[(11)C]methyl-L-tryptophan (AMT)-PET in brain tumor patients indicated abnormal tryptophan metabolism not only in the tumor mass but also in normal-appearing contralateral brain. In the present study, we explored if tryptophan metabolism in such brain regions is associated with depression. METHODS: Twenty-one patients (mean age: 57 years) with a brain tumor (10 meningiomas, 8 gliomas, and 3 brain metastases) underwent AMT-PET scanning. MRI and AMT-PET images were co-registered, and AMT kinetic parameters, including volume of distribution (VD', an estimate of net tryptophan transport) and K (unidirectional uptake, related to tryptophan metabolism), were measured in the tumor mass and in unaffected cortical and subcortical regions contralateral to the tumor. Depression scores (based on the Beck Depression Inventory-II [BDI-II]) were correlated with tumor size, grade, type, and AMT-PET variables. RESULTS: The mean BDI-II score was 12 ± 10 (range: 2-33); clinical levels of depression were identified in seven patients (33 %). High BDI-II scores were most strongly associated with high thalamic AMT K values both in the whole group (Spearman's rho = 0.63, p = 0.004) and in the subgroup of 18 primary brain tumors (r = 0.68, p = 0.004). Frontal and striatal VD' values were higher in the depressed subgroup than in non-depressed patients (p < 0.05); the group difference was even more robust when moderately/severely depressed patients were compared to patients with no/mild depression (frontal: p = 0.005; striatal: p < 0.001). Tumor size, grade, and tumor type were not related to depression scores. CONCLUSIONS: Abnormalities of tryptophan transport and metabolism in the thalamus, striatum, and frontal cortex, measured by PET, are associated with depression in patients with brain tumor. These changes may indicate an imbalance between the serotonin and kynurenine pathways and serve as a molecular imaging marker of brain tumor-associated depression. TRIAL REGISTRATION: ClinicalTrials.gov NCT02367469.

In vivo detection of reduced Purkinje cell fibers with diffusion MRI tractography in children with autistic spectrum disorders.

Postmortem neuropathology studies report reduced number and size of Purkinje cells (PC) in a majority of cerebellar specimens from persons diagnosed with autism spectrum disorders (ASD). We used diffusion weighted MRI tractography to investigate whether structural changes associated with reduced number and size of PC, could be detected in vivo by measuring streamlines connecting the posterior-lateral region of the cerebellar cortex to the dentate nucleus using an independent component analysis with a ball and stick model. Seed regions were identified in the cerebellar cortex, and streamlines were identified to two sorting regions, the dorsal dentate nucleus (DDN) and the ventral dentate nucleus (VDN), and probability of connection and measures of directional coherence for these streamlines were calculated. Tractography was performed in 14 typically developing children (TD) and 15 children with diagnoses of ASD. Decreased numbers of streamlines were found in the children with ASD in the pathway connecting cerebellar cortex to the right VDN (p-value = 0.015). Reduced fractional anisotropy (FA) values were observed in pathways connecting the cerebellar cortex to the right DDN (p-value = 0.008), the right VDN (p-value = 0.010) and left VDN (p-value = 0.020) in children with ASD compared to the TD group. In an analysis of single subjects, reduced FA in the pathway connecting cerebellar cortex to the right VDN was found in 73% of the children in the ASD group using a threshold of 3 standard errors of the TD group. The detection of diffusion changes in cerebellum may provide an in vivo biomarker of Purkinje cell pathology in children with ASD.

Patterns of structural reorganization of the corticospinal tract in children with Sturge-Weber syndrome.

BACKGROUND: Reorganization of the corticospinal tract after early damage can limit motor deficit. In this study, we explored patterns of structural corticospinal tract reorganization in children with Sturge-Weber syndrome. METHODS: Five children (age 1.5-7 years) with motor deficit resulting from unilateral Sturge-Weber syndrome were studied prospectively and longitudinally (1-2 years follow-up). Corticospinal tract segments belonging to hand and leg movements were separated and their volume was measured by diffusion tensor imaging tractography using a recently validated method. Corticospinal tract segmental volumes were normalized and compared between the Sturge-Weber syndrome children and age-matched healthy controls. Volume changes during follow-up were also compared with clinical motor symptoms. RESULTS: In the Sturge-Weber syndrome children, hand-related (but not leg-related) corticospinal tract volumes were consistently decreased in the affected cerebral hemisphere at baseline. At follow-up, two distinct patterns of hand corticospinal tract volume changes emerged. (1) Two children with extensive frontal lobe damage showed a corticospinal tract volume decrease in the lesional hemisphere and a concomitant increase in the nonlesional (contralateral) hemisphere. These children developed good hand grasp but no fine motor skills. (2) The three other children, with relative sparing of the frontal lobe, showed an interval increase of the normalized hand corticospinal tract volume in the affected hemisphere; these children showed no gross motor deficit at follow-up. CONCLUSIONS: Diffusion tensor imaging tractography can detect differential abnormalities in the hand corticospinal tract segment both ipsi- and contralateral to the lesion. Interval increase in the corticospinal tract hand segment suggests structural reorganization, whose pattern may determine clinical motor outcome and could guide strategies for early motor intervention.

Microstructural abnormalities in language and limbic pathways in orphanage-reared children: a diffusion tensor imaging study.

This study utilized diffusion tensor imaging fiber tractography to examine the miscrostructural integrity of limbic and paralimbic white matter tracts in 36 children (age M = 124 months) with histories of early deprivation, raised from birth in orphanages and subsequently adopted into the United States, compared to 16 age-matched typically developing children. We found increased mean diffusivity bilaterally in the arcuate fasciculus and increased mean diffusivity and reduced fractional anisotropy bilaterally in the uncinate fasciculus and cingulum in children with early deprivation. Microstructural integrity of the left arcuate fasciculus and right cingulum was related to language and behavioral functioning, respectively. White matter abnormalities were also associated with length of deprivation and time in the adoptive home. Our findings suggest that white matter pathways, connecting limbic and paralimbic brain regions is abnormal in children with histories of early deprivation, with some pathways appearing more susceptible to early deprivation than others.

Quantitative Assessment of Brain Networks in Children With Sturge-Weber Syndrome Using Resting State Functional Magnetic Resonance Imaging (MRI).

In this study, we examined whether topologic network analysis, using resting state functional magnetic resonance imaging (MRI), can detect abnormalities of functional brain connectivity in children with unilateral brain injury due to Sturge-Weber syndrome. Three children with Sturge-Weber syndrome (ages 1, 3, and 10 years) underwent structural and resting state functional MRI, glucose metabolism positron emission tomography (PET), and neurocognitive evaluation. Eight different resting state networks were compared between the affected and unaffected hemispheres by quantitatively accessing communication efficiency measures. Significantly reduced efficiency values were found in all 3 patients. Visual network deficiency was present in both children with a visual field defect; frontal network abnormalities were associated with fine motor impairment. Location of network abnormalities corresponded to and, in some cases, extended beyond structural MRI and glucose PET abnormalities. The presented approach can detect early functional abnormalities of specific brain networks in children with Sturge-Weber syndrome.

Neurocognitive and behavioral correlates of non-right-handedness in internationally adopted children.

The incidence of non-right-handedness was assessed among a sample of international adoptees. Neurocognitive and behavioral correlates to handedness were also examined among participants. A sample of 139 international adoptees (54 males; mean age at testing = 111.4 months ± 32.9 months) underwent a comprehensive neuropsychological evaluation, assessing verbal and visual reasoning, language, memory, attention, impulse control, processing speed, academic functioning, manual dexterity, and behavioral functioning. Over 26% of participants reported non-right-handedness. Non-right- and right-handers did not differ on demographic or orphanage specific variables. The groups were found to significantly differ on behavioral indices of attention and several neurocognitive variables, including visual memory, verbal memory, and manual dexterity of the dominant hand, with non-right-handers having worse performance. Possible mechanisms for these findings are discussed.

Altered white matter structure of the dentatorubrothalamic pathway in children with autistic spectrum disorders.

Neuropathological studies have demonstrated decreased Purkinje cells in cerebellar cortex and changes in the dentate nucleus of the cerebellum, the projection target for the Purkinje cells, in autistic spectrum disorders (ASD). The dentatorubrothalamic tract is formed by efferents from the dentate nucleus projecting toward the red nucleus with axon collaterals to this nucleus and continuing to innervate the ventral lateral and ventral anterior nuclei of the thalamus. In the current study, we assessed whether the dentatorubrothalamic tract is altered in ASD using Q-ball imaging (QBI). The QBI tractography was performed in 13 children with high functioning ASD (HFA), 11 children with low functioning ASD (LFA), and 14 typically developing children (TD). Regions of interest in dentate nucleus and red nucleus in both hemispheres were objectively placed to sort bilateral dorsal-rostral (DR), dorsal-caudal (DC), ventral-rostral (VR), and ventral-caudal (VC) portions of the dentatorubrothalamic pathway. Group differences in fractional anisotropy (FA), axial diffusivity, radial diffusivity, and fiber volume of individual pathways were analyzed. Significantly reduced FA was found in children with LFA and HFA, compared to the TD group in tracts originating in all four subdivisions of the right dentate nucleus. Tract-based morphometry (TBM) analysis demonstrated significant reductions of FA in caudal midbrain (p<0.0001), dorsal-caudal dentate (p=0.0013), and ventral-caudal dentate (p=0.0061) on the right in the LFA group. The FA values in TBM segments of right VR and VC pathways were significantly correlated with communication skills in the combined HFA/LFA group, while there was a significant correlation found between TBM segments of right DR pathway and daily living skills (r=0.76; p=0.004). Decreased white matter integrity in dorsal portions of the dentatorubrothalamic tract may be related to motor features in ASD, while changes in the ventral portions are related more to communication behavior.

Relationship between aberrant brain connectivity and clinical features in Angelman Syndrome: a new method using tract based spatial statistics of DTI color-coded orientation maps.

AIM: In order to relate brain structural abnormalities to clinical features of Angelman Syndrome (AS), we determined the locations of abnormal regional white matter architecture in AS children using a sensitive and objective whole brain approach to analyze diffusion tensor imaging (DTI) color-coded orientation maps. METHODS: Using tract based spatial statistics (TBSS) of DTI color-coded orientation maps, the fraction of fibers oriented in the anteroposterior (AP), mediolateral (ML) and superioinferior (SI) directions were determined in whole brain white matter of 7 children with AS (mean age: 70±25.78 months, 5 males) and 7 children with typical development (TD, mean age: 79.8±17.25 months, 4 males). TBSS of FA map was also performed for comparison. RESULTS: Children with AS had a significantly lower AP component than the TD group in 9 clusters (3 bilateral and 3 unilateral). Bilateral clusters were located in inferior fronto-occipital fasciculus, anterior thalamic radiation and arcuate fasciculus regions. Unilateral clusters involved left brainstem, left cingulum and right uncinate regions. Similarly, children with AS had significantly lower ML component than the TD group in 4 clusters (2 in corpus callosum and 2 unilateral clusters). Unilateral clusters were located in the left cingulum and left anterior thalamic radiation regions. SI component was lower in children with AS in two clusters compared to TD (corticospinal tract and corpus callosum). FA map clusters mostly corresponded with component clusters. INTERPRETATION: Children with AS have a global impairment of white matter integrity including AP, ML and SI components in whole brain suggesting a potential underlying error with axon guidance mechanisms during brain development possibly due to loss of UBE3A gene expression. Some of this aberrant connectivity can be related to the clinical features of AS.