The attention network test: a characteristic pattern of deficits in children with ADHD.

Background: The Attention Network test (ANT) gives measures of different aspects of the complex process of attention. We ask if children with Attention Deficit Hyperactivity Disorder (ADHD) will show a characteristic pattern of deficits on this test.

Methods: The sample included 157 children (M = 10 years) who performed the child version of ANT as participants of the Bergen Child Study.

Noise removal using fourth-order partial differential equation with applications to medical magnetic resonance images in space and time.

In this paper, we introduce a new method for image smoothing based on a fourth-order PDE model. The method is tested on a broad range of real medical magnetic resonance images, both in space and time, as well as on nonmedical synthesized test images. Our algorithm demonstrates good noise suppression without destruction of important anatomical or functional detail, even at poor signal-to-noise ratio.

Factor analysis of the Autism Spectrum Screening Questionnaire.

The present study investigated the factor structure of parent and teacher Autism Spectrum Screening Questionnaire (ASSQ) in a population of 7-9 years old children. For validation purposes, factors derived were correlated with results on the Strengths and Difficulties Questionnaire (SDQ). A three-factor solution was identified on both parent and teacher ASSQ.

Predicting nonresponse bias from teacher ratings of mental health problems in primary school children.

The impact of nonresponse on estimates of mental health problems was examined in a prospective teacher screen in a community survey of 9,155 7-9 year olds. For 6,611 of the children, parents consented to participation in the actual study (Responders), while for 2,544 children parental consent was not obtained (Nonresponders). The teacher screen involved assessment of a broad set of symptoms of mental health problems and functional impairment.

Genetic analyses of dopamine related genes in adult ADHD patients suggest an association with the DRD5-microsatellite repeat, but not with DRD4 or SLC6A3 VNTRs.

Attention deficit hyperactivity disorder (ADHD) is a common and highly heritable psychiatric disorder in children and adults. Recent meta-analyses have indicated an association between genes involved in dopaminergic signaling and childhood ADHD, but little is known about their possible role in adult ADHD. In this study of adults with ADHD, we evaluated the three most commonly studied ADHD candidate genetic polymorphisms; the dopamine receptor D4 (DRD4) exon 3 VNTR repeat, a microsatellite repeat 18.

Shape-adaptive DCT for denoising of 3D scalar and tensor valued images.

During the last ten years or so, diffusion tensor imaging has been used in both research and clinical medical applications. To construct the diffusion tensor images, a large set of direction sensitive magnetic resonance image (MRI) acquisitions are required. These acquisitions in general have a lower signal-to-noise ratio than conventional MRI acquisitions.

Fractal dimension analysis of MR images reveals grey matter structure irregularities in schizophrenia.

The fractal dimension (FD) was used to reveal brain structure irregularities in patients with schizophrenia. FD provides a unique way of quantifying the shape complexity of cortical folding of the human brain. MR images were obtained from seven patients with schizophrenia that were compared with six healthy control subjects.

The effect of a REM sleep deprivation procedure on different aspects of memory function in humans.

Previous studies have suggested that memory is dependent on the occurrence of REM sleep. Research has mainly focused on two distinct types of memory function, declarative and procedural, and it seems that the latter may more directly depend on REM sleep. Memory consolidation has been more investigated than acquisition, maintenance, and recall, despite the fact that sleep may affect flow of information into/from storage.

APOE status and its association to learning and memory performance in middle aged and older Norwegians seeking assessment for memory deficits.

Background: We examined the hypothesis that deficits in learning, memory, and other cognitive functions are associated with the epsilon4 allele of the Apolipoprotein E (APOE) gene in a non-demented sample with memory complaints recruited from a population with a high prevalence of this allele.

Methods: The study group comprised 70 consecutively referred patients aged 50-75 seeking assessment due to memory complaints. They were screened for dementia, for neurological and psychiatric disease, and for cerebral infarction using Magnet Resonance Imaging (MRI).

Emotional symptoms in inattentive primary school children: a population-based study.

Objective: The present study investigates teacher and parent reports of inattention and emotional symptoms in 6,229 primary school children.

Method: The assessment included the Emotional Symptoms subscale and the Impact scale from the Strengths and Difficulties Questionnaire and the inattention items from the Swanson, Nolan, and Pelham IV Questionnaire.

Results: Children defined as inattentive showed a high risk of being defined as high scorers on the Emotional Symptoms subscale.

Chronic physical illness and mental health in children. Results from a large-scale population study.

Background: The aim of the present study was to evaluate the sensitivity and specificity of the Strengths and Difficulties Questionnaire (SDQ) in detecting emotional and behavioural problems among children with chronic illness (CI).

Methods: Parents and teachers of a population of primary school children in Norway (n = 9430) completed a questionnaire including the SDQ, and a question about chronic illness. A total of 74% (n = 7007) of the parents participated.

Psychiatric disorders in Norwegian 8- to 10-year-olds: an epidemiological survey of prevalence, risk factors, and service use.

Objective: The Bergen Child Study is a longitudinal study of child mental health from the city of Bergen, Norway. We present methods and results from the first wave of the study, focusing on prevalence of disorders, associations with risk factors, and the use of services.

Method: The target population included all 9,430 children attending grades 2 to 4 in Bergen schools during the academic year 2002/2003.

Diffusion k-tensor estimation from Q-ball imaging using discretized principal axes.

A reoccurring theme in the diffusion tensor imaging literature is the per-voxel estimation of a symmetric 3 x 3 tensor describing the measured diffusion. In this work we attempt to generalize this approach by calculating 2 or 3 or up to k diffusion tensors for each voxel. We show that our procedure can more accurately describe the diffusion particularly when crossing fibers or fiber-bundles are present in the datasets.

Reduced white matter connectivity in the corpus callosum of children with Tourette syndrome.

Background: Brain imaging studies have revealed anatomical anomalies in the brains of individuals with Tourette syndrome (TS). Prefrontal regions have been found to be larger and the corpus callosum (CC) area smaller in children and young adults with TS compared with healthy control subjects, and these anatomical features have been understood to reflect neural plasticity that helps to attenuate the severity of tics.

Method: CC white matter connectivity, as measured by the Fractional Anisotropy (FA) index from diffusion tensor images, was assessed in 20 clinically well-defined boys with Tourette syndrome and 20 age- and gender-matched controls.

Functional brain asymmetry, attentional modulation, and interhemispheric transfer in boys with Tourette syndrome.

We tested the hypothesis that children with Tourette syndrome (TS) would exhibit aberrant brain lateralization compared to a healthy control (HC) group in an attention-modulation version of a verbal dichotic listening task using consonant-vowel syllables. The modulation of attention to focus on the right ear stimulus in the dichotic listening situation is thought to involve the same prefrontal attentional and executive functions that are involved in the suppression of tics, whereas, performance when focusing attention on the left ear stimulus additionally involves a callosal transfer of information. In light of presumed disturbances in transfer of information across the corpus callosum, we hypothesized that children with TS would, however, have difficulty modulating the functional lateralization that ensues through a shift of attention to the left side.

Automated detection of tunneling nanotubes in 3D images.

Background: This paper presents an automated method for the identification of thin membrane tubes in 3D fluorescence images. These tubes, referred to as tunneling nanotubes (TNTs), are newly discovered intercellular structures that connect living cells through a membrane continuity. TNTs are 50-200 nm in diameter, crossing from one cell to another at their nearest distance.

Interactive effects of APOE and CHRNA4 on attention and white matter volume in healthy middle-aged and older adults.

In the present study, we investigated age-related changes in interactions between efficiency of neuronal repair mechanisms and efficiency of cholinergic neurotransmission in the context of attentional orienting. In addition, we explored white matter volume changes as possible neuronal underpinnings. A sample of 230 healthy middle-aged (53-64 years) and older (65-75 years) adults was genotyped for polymorphisms of APOE and CHRNA4, a nicotinic receptor subunit gene.

Frontoparietal activation during delayed visuospatial recall in patients with epilepsy due to hippocampal sclerosis.

We hypothesized that brain activation during encoding and retrieval of visual material differed between epilepsy patients with hippocampal sclerosis (HS) and healthy controls. Eleven patients with epilepsy and HS and nine age- and education-matched control subjects were tested during functional MRI recording. A three-block design for visuospatial memory encoding and retrieval and an interference interval longer than 1 minute without memory tasks were used.

Co-existing symptoms and risk factors among African school children with hyperactivity-inattention symptoms in Kinshasa, Congo.

Unlabelled: The aims of the study were to explore hyperactivity-inattention (HI) symptoms and co-existing symptoms of emotional and behavioural problems among African school children and their relationship with health status, socio-demographic factors, and school performance.

Method: A case-control approach was used. The Strengths and Difficulties Questionnaire (SDQ) was used to explore the co-existing emotional and behavioural symptoms and a semi-structured interview with parents to explore the socio-demographic variables.

The functional and structural significance of the frontal shift in the old/new ERP effect.

There is a lack of studies mapping electrophysiological event-related potentials (ERPs) to structural neuroanatomical characteristics. The aim of the present study was to integrate electrophysiological memory-related activity with cortical and hippocampal volume, as well as psychometric memory performance, in a life-span sample. More specifically, we wanted to investigate the functional significance of the often-observed frontal shift of ERP amplitude with increasing age and whether neuroanatomical characteristics can explain this shift.

Autistic features in a total population of 7-9-year-old children assessed by the ASSQ (Autism Spectrum Screening Questionnaire).

Background: The prevalence of autism is reported to be on the rise worldwide. Change of diagnostic criteria and a broadening of the concept of autism have been mentioned as contributing factors. Further studies of general populations are needed.

NG2 expression regulates vascular morphology and function in human brain tumours.

Tumour angiogenesis is a tightly regulated process involving cross-talk between tumour cells and the host tissue. The underlying mechanisms that regulate such interactions remain largely unknown. NG2 is a transmembrane proteoglycan whose presence on transformed cells has been demonstrated to increase proliferation in vitro and angiogenesis in vivo.

Cognition in African children with attention-deficit hyperactivity disorder.

The aims of the study were: (1) to describe the performance of African children with symptoms of attention-deficit hyperactivity disorder on selected neuropsychologic tests and compare it with performance among peers of the same age without symptoms; (2) to explore through a factor analysis if the selected tests cover the same functions as known from studies in Europe and North America. A nested case-control approach was used to select the two groups of children. The tests were selected to measure aspects of executive functions, attention and memory functions as well as motor skills.

Selective increase of cortical thickness in high-performing elderly--structural indices of optimal cognitive aging.

The aim of this study was to identify cortical areas important for optimal cognitive aging. 74 participants (20-88 years) went through neuropsychological tests and two MR sessions. The sample was split into two age groups.

Frequency and characteristics of recurrent major depressed patients with unimpaired executive functions.

Major depression is associated with impairment of cognitive functions, and especially higher-order cognitive processes referred to as executive functions (EF). Whether this is a general finding is unclear. Patients without EF impairment may have different treatment needs than patients with EF impairment, and will probably have a better everyday functioning.