Inadequate intake of nutrients essential for neurodevelopment in children with fetal alcohol spectrum disorders (FASD)

This study evaluated dietary intake in children with fetal alcohol spectrum disorders (FASD). Pre-clinical research suggests that nutrient supplementation may attenuate cognitive and behavioral deficits in FASD. Currently, the dietary adequacy of essential nutrients in children with FASD is unknown. Dietary data were collected as part of a randomized, double-blind controlled trial of choline supplementation in FASD. Participants included 31 children with FASD, ages 2.5-4.9 years at enrollment. Dietary intake data was collected three times during the nine-month study via interview-administered 24-hour recalls with the Automated Self-Administered 24-hour Recall. Dietary intake of macronutrients and 17 vitamins/minerals from food was averaged across three data collection points. Observed nutrient intakes were compared to national dietary intake data of children ages 2-5 years (What we Eat in America, NHANES 2007-2008) and to the Dietary Reference Intakes. Compared to the dietary intakes of children in the NHANES sample, children with FASD had lower intakes of saturated fat, vitamin D, and calcium. The majority (>50%) of children with FASD did not meet the Recommended Dietary Allowance (RDA) or Adequate Intake (AI) for fiber, n-3 fatty acids, vitamin D, vitamin E, vitamin K, choline, and calcium. This pattern of dietary intake in children with FASD suggests that there may be opportunities to benefit from nutritional intervention. Supplementation with several nutrients, including choline, vitamin D, and n-3 fatty acids, has been shown in animal models to attenuate the cognitive deficits of FASD. These results highlight the potential of nutritional clinical trials in FASD.

Context-processing abilities in chronic cocaine users

Cocaine dependence is a particularly severe problem in the United States, resulting in broad economic and personal costs. Significant evidence of generalized cognitive deficits associated with cocaine dependence has been reported. Two studies evaluated whether context processing, the processes involved in representing and maintaining information regarding the context of one's environment, might be seen as a process-specific deficit that may explain some aspects of the broader cognitive deficits associated with cocaine dependence. Study 1 used the expectancy variant of the AX task to assess this ability; Study 2 employed the Dot Pattern Expectancy task. Significant between-groups differences were found in each study for d'-context, a comparison of AX hits and BX misses; these results indicated significant between-groups differences in context-processing ability. In Study 1, significant between-groups a priori contrasts of AY versus BX trials indicated the likelihood of a specific deficit in context processing in the cocaine group; however, this contrast was not significant in Study 2. Overall, the results of these studies support the theory of impaired context-processing ability associated with cocaine misuse. However, these results do not allow for the interpretation of a process-specific deficit in context-processing ability. Future research targeted at investigating aspects of this context-processing impairment associated with cocaine misuse can shed light on the specificity of this deficit.

Global functional connectivity abnormalities in children with fetal alcohol spectrum disorders

BACKGROUND

Previous studies, including those employing diffusion tensor imaging (DTI), have revealed significant disturbances in the white matter of individuals with fetal alcohol spectrum disorders (FASD). Both macrostructural and microstructural abnormalities have been observed across levels of FASD severity. Emerging evidence suggests that these white matter abnormalities are associated with functional deficits. This study used resting-state functional MRI (fMRI) to evaluate the status of network functional connectivity in children with FASD compared with control subjects.

METHODS

Participants included 24 children with FASD, ages 10 to 17, and 31 matched controls. Neurocognitive tests were administered including Wechsler Intelligence Scales, California Verbal Learning Test (CVLT), and Behavior Rating Inventory of Executive Functioning. High-resolution anatomical MRI data and 6-minute resting-state fMRI data were collected. The resting-state fMRI data were subjected to a graph theory analysis, and 4 global measures of cortical network connectivity were computed: characteristic path length, mean clustering coefficient, local efficiency, and global efficiency.

RESULTS

Results revealed significantly altered network connectivity in those with FASD. The characteristic path length was 3.1% higher (p = 0.04, Cohen's d = 0.47), and global efficiency was 1.9% lower (p = 0.04, d = 0.63) in children with FASD compared with controls, suggesting decreased network capacity that may have implications for integrative cognitive functioning. Global efficiency was significantly positively correlated with cortical thickness in frontal (r = 0.38, p = 0.005), temporal (r = 0.28, p = 0.043), and parietal (r = 0.36, p = 0.008) regions. No relationship between facial dysmorphology and functional connectivity was observed. Exploratory correlations suggested that global efficiency and characteristic path length are associated with capacity for immediate verbal memory on the CVLT (r = 0.41, p = 0.05 and r = 0.41, p = 0.01, respectively) among those with FASD.

CONCLUSIONS

Resting-state functional connectivity measures provide new insight into the integrity of brain networks in clinical populations such as FASD. Results demonstrate that children with FASD have alterations in core components of network function and that these aspects of brain integrity are related to measures of structure and cognitive functioning.

Cerebral and muscle MRI abnormalities in myotonic dystrophy

Pathophysiological mechanisms underlying the clinically devastating CNS features of myotonic dystrophy (DM) remain more enigmatic and controversial than do the muscle abnormalities of this common form of muscular dystrophy. To better define CNS and cranial muscle changes in DM, we used quantitative volumetric and diffusion tensor MRI methods to measure cerebral and masticatory muscle differences between controls (n=5) and adults with either congenital (n=5) or adult onset (n=5) myotonic dystrophy type 1 and myotonic dystrophy type 2 (n=5). Muscle volumes were diminished in DM1 and strongly correlated with reduced white matter integrity and gray matter volume. Moreover, correlation of reduced fractional anisotropy (white matter integrity) and gray matter volume in both DM1 and DM2 suggests that these abnormalities may share a common underlying pathophysiological mechanism. Further quantitative temporal and spatial characterization of these features will help delineate developmental and progressive neurological components of DM, and help determine the causative molecular and cellular mechanisms.

Inter-hemispheric functional connectivity disruption in children with prenatal alcohol exposure

BACKGROUND

MRI studies, including recent diffusion tensor imaging (DTI) studies, have shown corpus callosum abnormalities in children prenatally exposed to alcohol, especially in the posterior regions. These abnormalities appear across the range of fetal alcohol spectrum disorders (FASD). Several studies have demonstrated cognitive correlates of callosal abnormalities in FASD including deficits in visual-motor skill, verbal learning, and executive functioning. The goal of this study was to determine whether inter-hemispheric structural connectivity abnormalities in FASD are associated with disrupted inter-hemispheric functional connectivity and disrupted cognition.

METHODS

Twenty-one children with FASD and 23 matched controls underwent a 6-minute resting-state functional MRI scan as well as anatomical imaging and DTI. Using a semi-automated method, we parsed the corpus callosum and delineated 7 inter-hemispheric white matter tracts with DTI tractography. Cortical regions of interest (ROIs) at the distal ends of these tracts were identified. Right-left correlations in resting fMRI signal were computed for these sets of ROIs, and group comparisons were made. Correlations with facial dysmorphology, cognition, and DTI measures were computed.

RESULTS

A significant group difference in inter-hemispheric functional connectivity was seen in a posterior set of ROIs, the para-central region. Children with FASD had functional connectivity that was 12% lower than in controls in this region. Subgroup analyses were not possible owing to small sample size, but the data suggest that there were effects across the FASD spectrum. No significant association with facial dysmorphology was found. Para-central functional connectivity was significantly correlated with DTI mean diffusivity, a measure of microstructural integrity, in posterior callosal tracts in controls but not in FASD. Significant correlations were seen between these structural and functional measures, and Wechsler perceptual reasoning ability.

CONCLUSIONS

Inter-hemispheric functional connectivity disturbances were observed in children with FASD relative to controls. The disruption was measured in medial parietal regions (para-central) that are connected by posterior callosal fiber projections. We have previously shown microstructural abnormalities in these same posterior callosal regions, and the current study suggests a possible relationship between the two. These measures have clinical relevance as they are associated with cognitive functioning.

White matter abnormalities and neurocognitive correlates in children and adolescents with myotonic dystrophy type 1: a diffusion tensor imaging study

Diffusion tensor imaging was used to evaluate cerebral white matter in eight patients (ages 10-17), with myotonic dystrophy type 1 (3 congenital-onset, 5 juvenile-onset) compared to eight controls matched for age and sex. Four regions of interest were examined: inferior frontal, superior frontal, supracallosal, and occipital. The myotonic dystrophy group showed white matter abnormalities compared to controls in all regions. All indices of white matter integrity were abnormal: fractional anisotropy, mean diffusivity, axial diffusivity, and radial diffusivity. With no evidence of regional variation, correlations between whole cerebrum white matter fractional anisotropy and neurocognitive functioning were examined in the patients. Strong correlations were observed between whole cerebrum fractional anisotropy and full-scale intelligence and a measure of executive functioning. Results indicate that significant white matter abnormality is characteristic of young patients with myotonic dystrophy type 1 and that the white matter abnormality seen with neuroimaging has implications for cognitive functioning.

Microstructural corpus callosum anomalies in children with prenatal alcohol exposure: an extension of previous diffusion tensor imaging findings

BACKGROUND

Several studies have now shown corpus callosum abnormalities using diffusion tensor imaging (DTI) in children with fetal alcohol spectrum disorders (FASD) in comparison with nonexposed controls. The data suggest that posterior regions of the callosum may be disproportionately affected. The current study builds on previous efforts, including our own work, and moves beyond midline corpus callosum to probe major inter-hemispheric white matter pathways with an improved DTI tractographic method. This study also expands on our prior work by evaluating a larger sample and by incorporating children with a broader range of clinical effects including full-criteria fetal alcohol syndrome (FAS).

METHODS

Participants included 33 children with FASD (8 FAS, 23 partial FAS, 2 static encephalopathy) and 19 nonexposed controls between the ages of 10 and 17 years. Participants underwent DTI scans and intelligence testing. Groups (FASD vs. controls) were compared on fractional anisotropy (FA) and mean diffusivity (MD) in 6 white matter tracts projected through the corpus callosum. Exploratory analyses were also conducted examining the relationships between DTI measures in the corpus callosum and measures of intellectual functioning and facial dysmorphology.

RESULTS

In comparison with the control group, the FASD group had significantly lower FA in 3 posterior tracts of the corpus callosum: the posterior mid-body, the isthmus, and the splenium. A trend-level finding also suggested lower FA in the genu. Measures of white matter integrity and cognition were correlated and suggest some regional specificity, in that only posterior regions of the corpus callosum were associated with visual-perceptual skills. Correlations between measures of facial dysmorphology and posterior regions of the corpus callosum were nonsignificant.

CONCLUSIONS

Consistent with previous DTI studies, these results suggest that microstructural posterior corpus callosum abnormalities are present in children with prenatal alcohol exposure and cognitive impairment. These abnormalities are clinically relevant because they are associated with cognitive deficits and appear to provide evidence of abnormalities associated with prenatal alcohol exposure independent of dysmorphic features. As such, they may yield important diagnostic and prognostic information not provided by the traditional facial characteristics.

Clinical and neurocognitive course in early-onset psychosis: a longitudinal study of adolescents with schizophrenia-spectrum disorders

AIM

Adolescents with psychotic disorders show deficits in IQ, attention, learning and memory, executive functioning, and processing speed that are related to important clinical variables including negative symptoms, adaptive functioning and academics. Previous studies have reported relatively consistent deficits with varying relationships to illness status and symptoms. The goals of this study were to examine these relationships in a larger sample at baseline, and also to examine the longitudinal course of these deficits in a smaller subset of adolescents.

METHOD

Thirty-six subjects, aged 10 to 17 years, were included at baseline. All had Diagnostic and Statistical Manual-Fourth Edition diagnoses of schizophrenia, schizoaffective disorder, schizophreniform disorder and psychosis - not otherwise specified, as determined by Kiddie-Schedule for Affective Disorders and Schizophrenia for School-Age Children structured interviews. Patients were administered a neuropsychological battery, and Positive and Negative Syndrome Scale ratings were completed at baseline and again at 1 year (n = 14). Most participants were inpatients at baseline, and 13 of 14 were on atypical antipsychotic medication during both sessions.

RESULTS

At baseline, the patients demonstrated impairments in working memory, processing speed, executive function and verbal learning. No significant cognitive change was detected at 1-year follow-up. In contrast, clinical symptoms were variable across 1 year, with an improvement in positive symptoms at 1 year. No relationships between clinical and cognitive symptoms were observed, with the exception of baseline IQ predicting negative symptoms at 1 year.

CONCLUSIONS

Young patients with schizophrenia-spectrum disorders displayed neurocognitive impairments at baseline. Despite measurable fluctuations in clinical symptoms over the year, no significant changes were measured in cognition. Lower IQ at baseline was predictive of more negative symptoms at 1 year.

Brain macrostructural and microstructural abnormalities in cocaine dependence

RATIONALE

Two previous studies have utilized diffusion tensor imaging (DTI) to examine microstructural integrity in cocaine abuse and found evidence of brain abnormalities in white matter.

OBJECTIVE

Using anatomical magnetic resonance imaging (MRI), DTI, and clinical evaluation, the macrostructural and microstructural correlates of cocaine abuse were investigated.

METHODS

Twenty-one men and women (mean age 42.5 and mean 18.9 years of cocaine use) and 21 age/gender-matched controls were included. Fractional anisotropy (FA) was measured in frontal white matter ROIs. Gray and white matter volumes in superior and inferior frontal regions were compared.

RESULTS

DTI data revealed that cocaine users had lower FA than controls, specifically in inferior frontal white matter. FA differences were not seen in other areas. Significant volumetric differences were not seen, but both gray and white matter inferior frontal volumes trended toward smaller in the cocaine group. The data suggested that duration of use was associated with decreased gray and white matter volumes. FA and gray matter volume were correlated in cocaine users.

CONCLUSIONS

Both macrostructural and microstructural abnormalities were seen in a group of cocaine abusers. Length of cocaine use was associated with severity of the brain abnormalities. Future studies of white matter tissue integrity are warranted including examination of the relationship between DTI measures and traditional volumetric measures.

Neuropsychological functioning in kleptomania

Kleptomania is characterized by the failure to resist impulses to steal objects not needed for personal use or their monetary value. The objective of this study was to examine cognitive and executive functioning in subjects with kleptomania. Fifteen women with a primary DSM-IV diagnosis of kleptomania underwent a detailed psychiatric examination, including measures of kleptomania severity, and a battery of neuropsychological tests that emphasized executive functions. Correlational analyses were computed between measures of kleptomania severity and tests of executive functioning. Kleptomania subjects reported a mean duration of illness of 17.9 years and shoplifting a mean of 1.7 times per week. All subjects reported an inability to resist urges to shoplift. Neuropsychological testing revealed group mean test scores within 0.5 standard deviations of normative standards for age. Five subjects (33.3%), however, had below-average performance on at least one measure of executive functioning, and 4 (26.7%) had below-average scores on two executive measures. Correlational analyses revealed a statistically significant correlation between kleptomania severity and Wisconsin Card Sorting Test performance (r=-0.693, p=0.004). As a group, subjects with kleptomania did not demonstrate deficits on neuropsychological testing. Greater kleptomania symptom severity, however, was correlated with impairment in executive functioning.

Neurocognitive and neuroimaging correlates of pediatric traumatic brain injury: a diffusion tensor imaging (DTI) study

This study examined the sensitivity of diffusion tensor imaging (DTI) to microstructural white matter (WM) damage in mild and moderate pediatric traumatic brain injury (TBI). Fourteen children with TBI and 14 controls ages 10-18 had DTI scans and neurocognitive evaluations at 6-12 months post-injury. Groups did not differ in intelligence, but children with TBI showed slower processing speed, working memory and executive deficits, and greater behavioral dysregulation. The TBI group had lower fractional anisotropy (FA) in three WM regions: inferior frontal, superior frontal, and supracallosal. There were no group differences in corpus callosum. FA in the frontal and supracallosal regions was correlated with executive functioning. Supracallosal FA was also correlated with motor speed. Behavior ratings showed correlations with supracallosal FA. Parent-reported executive deficits were inversely correlated with FA. Results suggest that DTI measures are sensitive to long-term WM changes and associated with cognitive functioning following pediatric TBI.

Diffusion tensor imaging in children with fetal alcohol spectrum disorders

BACKGROUND

Prenatal alcohol exposure, which is associated with macrostructural brain abnormalities, neurocognitive deficits, and behavioral disturbances, is characterized as fetal alcohol syndrome (FAS) in severe cases. The only published study thus far using diffusion tensor imaging (DTI) showed microstructural abnormalities in patients with FAS. The current study investigated whether similar abnormalities are present in less severely affected, prenatally exposed patients who did not display all of the typical FAS physical stigmata.

METHODS

Subjects included 14 children, ages 10 to 13, with fetal alcohol spectrum disorders (FASD) and 13 matched controls. Cases with full-criteria FAS, mental retardation, or microcephaly were excluded. Subjects underwent MRI scans including DTI.

RESULTS

Although cases with microcephaly were excluded, there was a trend toward smaller total cerebral volume in the FASD group (p=0.057, Cohen's d effect size =0.73). Subjects with FASD had greater mean diffusivity (MD) in the isthmus of the corpus callosum than controls (p=0.013, effect size =1.05), suggesting microstructural abnormalities in this region. There were no group differences in 5 other regions of the corpus callosum. Correlations between MD in the isthmus and facial dysmorphology were nonsignificant.

CONCLUSIONS

These results suggest that even relatively mild forms of fetal alcohol exposure may be associated with microstructural abnormalities in the posterior corpus callosum that are detectable with DTI.

Advances in white matter imaging: a review of in vivo magnetic resonance methodologies and their applicability to the study of development and aging

Several newer magnetic resonance imaging (MRI) techniques are increasingly being applied to the study of white matter development and pathology across the lifespan. These techniques go beyond traditional macrostructural volumetric methods and provide valuable information about underlying tissue integrity and organization at the microstructural and biochemical levels. We first provide an overview of white matter development and discuss the role of white matter and myelin in cognitive function. We also review available studies of development that have employed traditional volumetric measures. Then, we discuss the contributions of four newer imaging paradigms to our understanding of brain development and aging. These paradigms are Diffusion Tensor Imaging (DTI), Magnetization Transfer Imaging (MTI), T2-Relaxography, and Magnetic Resonance Spectroscopy (MRS). Studies examining brain development during childhood and adulthood as well as studies of the effects of aging are discussed.

Clonidine for sleep disturbances associated with attention-deficit hyperactivity disorder: a systematic chart review of 62 cases

OBJECTIVE

Children and adolescents with attention-deficit hyperactivity disorder (ADHD), with or without psychostimulant treatment, frequently suffer from sleep disturbances. This report evaluates the use of clonidine in the treatment of sleep disturbances associated with ADHD.

METHOD

A systematic search of a computerized database in an outpatient pediatric psychopharmacology unit of patients treated with clonidine for ADHD-associated sleep disturbances (N = 62; 42 children and 20 adolescents) was performed. Patients were rated retrospectively about the type and severity of sleep disturbances at baseline and after treatment with clonidine.

RESULTS

A majority of patients (85%) treated with clonidine for ADHD-associated sleep disturbances were considered to be much to very much improved by the National Institute of Mental Health global assessment of improvement (sleep). Nighttime clonidine doses ranged from 50 to 800 micrograms (mean +/- SEM; 157 +/- 14 micrograms), and subjects received clonidine for 35.5 +/- 3.5 months. There was no association between response and age group, gender, comorbidity, or concurrent pharmacotherapy. Children and adolescents with ADHD with baseline, medicine-induced, or medicine-exacerbated sleep disturbances responded equally well to clonidine treatment. Mild adverse effects were reported in 19 subjects (31%).

CONCLUSIONS

These findings suggest that clonidine may be an effective agent for sleep disturbances associated with ADHD, or its treatment, and warrant further controlled investigations.