Elisabeth Fernell

Computerized Training of Working Memory in Children With ADHD-A Randomized, Controlled Trial

OBJECTIVE Deficits in executive functioning, including working memory (WM) deficits, have been suggested to be important in attention-deficit/hyperactivity disorder (ADHD). During 2002 to 2003, the authors conducted a multicenter, randomized, controlled, double-blind trial to investigate the effect of improving WM by computerized, systematic practice of WM tasks. METHOD Included in the trial were 53 children with ADHD (9 girls; 15 of 53 inattentive subtype), aged 7 to 12 years, without stimulant medication. The compliance criterion (>20 days of training) was met by 44 subjects, 42 of whom were also evaluated at follow-up 3 months later. Participants were randomly assigned to use either the treatment computer program for training WM or a comparison program. The main outcome measure was the span-board task, a visuospatial WM task that was not part of the training program. RESULTS For the span-board task, there was a significant treatment effect both post-intervention and at follow-up. In addition, there were significant effects for secondary outcome tasks measuring verbal WM, response inhibition, and complex reasoning. Parent ratings showed significant reduction in symptoms of inattention and hyperactivity/impulsivity, both post-intervention and at follow-up. CONCLUSIONS This study shows that WM can be improved by training in children with ADHD. This training also improved response inhibition and reasoning and resulted in a reduction of the parent-rated inattentive symptoms of ADHD.

Reduced midbrain dopamine transporter binding in male adolescents with attention-deficit/hyperactivity disorder: Association between striatal dopamine markers and motor hyperactivity

BACKGROUND The hypothesis that altered dopamine transmission underlies hyperactive-inattentive behavior in children with attention-deficit/hyperactivity disorder (ADHD) is based on genetic studies and the efficacy of psychostimulants. Most of previous positron emission tomography (PET) and single photon emission tomography (SPET) studies have shown altered binding of dopamine markers in the basal ganglia. Yet, the functional role of the neurochemical disturbances are poorly understood. The purpose of our study was to examine dopamine transporter (DAT) and dopamine D2 receptor (D2R) binding in adolescents with ADHD and to search for its relationship with cognitive functions as well as locomotor hyperactivity. METHODS Twelve adolescents with ADHD and 10 young adults were examined with PET using the selective radioligands [11C]PE2I and [11C]raclopride, indexing DAT and D2R density. The simplified reference tissue model was used to calculate binding potential (BP) values. Attention and motor behavior were investigated with a continuous performance task (CPT) and motion measurements. RESULTS The BP value for [11C]PE2I and [11C]raclopride in the striatum of children with ADHD did not differ from that of the young adult control subjects. In the midbrain, however, the BP values for DAT were significantly lower (16%; p = .03) in children with ADHD. Dopamine D2 receptor binding in the right caudate nucleus correlated significantly with increased motor activity (r = .70, p = .01). CONCLUSIONS The lower BP values for DAT in the midbrain suggest that dopamine signaling in subjects with ADHD is altered. Altered dopamine signaling might have a causal relationship to motor hyperactivity and might be considered as a potential endophenotype of ADHD.

Preterm Children Have Disturbances of White Matter at 11 Years of Age as Shown by Diffusion Tensor Imaging

Preterm birth frequently involves white matter injury and affects long-term neurologic and cognitive outcomes. Diffusion tensor imaging has been used to show that the white matter microstructure of newborn, preterm children is compromised in a regionally specific manner. However, until now it was not clear whether these lesions would persist and be detectible on long-term follow-up. Hence, we collected diffusion tensor imaging data on a 1.5-T scanner, and computed fractional anisotropy and coherence measures to compare the white matter integrity of children born preterm to that of control subjects. The subjects for the preterm group (10.9 ± 0.29 y; n = 9; birth weight ≤ 1500 g; mean gestational age, 28.6 ± 1.05 wk) possessed attention deficits, a common problem in preterms. They were compared with age- and sex-matched control children (10.8 ± 0.33 y; n = 10; birth weight ≥ 2500; gestational age, ≥ 37 wk). We found that the preterm group had lower fractional anisotropy values in the posterior corpus callosum and bilaterally in the internal capsules. In the posterior corpus callosum this difference in fractional anisotropy values may partially be related to a difference in white matter volume between the groups. An analysis of the coherence measure failed to indicate a group difference in the axonal organization. These results are in agreement with previous diffusion tensor imaging findings in newborn preterm children, and indicate that ex-preterm children with attention deficits have white matter disturbances that are not compensated for or repaired before 11 y of age.

Autism spectrum disorders in children with normal intellectual levels: associated impairments and subgroups

In order to define potential subgroups pertaining to the spectrum of‘high‐functioning’pervasive developmental disorders (PDDs) the medical and psychiatric records of 101 children with PDD were reviewed. Ninety‐one children had a diagnosis of Asperger syndrome, nine had a PDD not otherwise specified, and one had‘high‐functioning’autism. Mean age of the children (71 males, 30 females) was 9 years 8 months (age range 5 to 12 years). Apart from the core dysfunctions of the PDD, i.e. deficient social interaction, communication and repertoires, and restricted interests, 95% had attentional problems, 75% had motor difficulties, 86% had problems with regulation of activity level, and 50% had impulsiveness. About three‐quarters had symptoms compatible with mild or severe attention‐deficit‐hyperactivity disorder (ADHD) or had deficits in attention, motor control, and perception (DAMP), indicating a considerable overlap between these disorders and high‐functioning PDD in children of normal or near‐normal intelligence. A combination of affective dysregulation, thought disturbance, and severely restricted social interaction, referred to as a multiple complex developmental disorder (MCDD; a condition possibly related to schizoaffective disorder), was recorded in about 8% of the children. Seventeen percent had another major medical diagnosis or medical syndrome, which highlights the importance of completing a neurological assessment of all children with PDDs.

Visual impairment in preterm children with periventricular leukomalacia--visual, cognitive and neuropaediatric characteristics related to cerebral imaging.

Thirteen preterm children, aged 4 to 14 years, with visual impairment due to periventricular leukomalacia (PVL) were evaluated for visual function, intellectual level, cognitive profile and motor function. Their visual impairment was characterized by low acuity, crowding, visual field defects and ocular motility disturbances. Their cognitive profile was uneven, often with considerably higher scores on verbal than on visual‐spatial tasks. Nine children had normal intelligence, three had mild mental retardation and one had severe mental retardation. In all the children, visual impairment was complicated by visual perceptual difficulties, accounting for their greater visual handicap than would be expected from their visual acuities and strabismus alone. Though CT or MRI revealed bilateral PVL in all the children, six had no motor impairment consistent with cerebral palsy, which is an unexpected finding.

Autism spectrum disorder diagnoses in Stockholm preschoolers.

The aims of this study were to estimate prevalence rates of children with autism spectrum disorder (ASD) diagnoses in a cohort of 6-year-old children with birth year 2002, referred to the Autism Centre for Young Children, serving the whole of Stockholm county and on the basis of the available data discuss clinical aspects of assessment, habilitation and follow-up. Records of 142 of a total of 147 (123 boys and 24 girls) identified children with ASD diagnoses were scrutinised with respect to type of diagnosis, cognitive level, other developmental disorders and medical/neurological disorders. The overall prevalence of such disorders was 6.2/1000 (95% confidence interval 5.2-7.2/1000). The rates of learning disability/mental retardation, developmental delay without a specified cognitive level and normal intelligence constituted about one third, respectively. AS and atypical autism tended to be diagnosed more often at age 5-6 years while AD with learning disability/mental retardation was more often diagnosed at age 3-4 years. The awareness of ASDs has resulted in increasing numbers of children being diagnosed at young ages. We conclude that it is important to take into account these childrens broader developmental profiles, need for repeated assessment of cognitive functions and follow-up over time and also the requirement for medical/neurological consideration and work-up.

Vitamin D and autism: Clinical review

BACKGROUND Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder with multiple genetic and environmental risk factors. The interplay between genetic and environmental factors has become the subject of intensified research in the last several years. Vitamin D deficiency has recently been proposed as a possible environmental risk factor for ASD. OBJECTIVE The aim of the current paper is to systematically review the research regarding the possible connection between ASD and vitamin D, and to provide a narrative review of the literature regarding the role of vitamin D in various biological processes in order to generate hypotheses for future research. RESULTS Systematic data obtained by different research groups provide some, albeit very limited, support for the possible role of vitamin D deficiency in the pathogenesis of ASD. There are two main areas of involvement of vitamin D in the human body that could potentially have direct impact on the development of ASD: (1) the brain (its homeostasis, immune system and neurodevelopment) and (2) gene regulation. CONCLUSION Vitamin D deficiency--either during pregnancy or early childhood--may be an environmental trigger for ASD in individuals genetically predisposed for the broad phenotype of autism. On the basis of the results of the present review, we argue for the recognition of this possibly important role of vitamin D in ASD, and for urgent research in the field.

Prevalence of autism in children born to Somali parents living in Sweden : a brief report

In a geographical area of Stockholm, with a relatively large Somali immigrant population, parents as well as teachers in special schools and staff at habilitation centres have raised concerns over whether children with a Somali background are over‐represented in the total group of children with autism. The aim of the study was, therefore, to investigate the prevalence of autism in children with parents from Somalia, living in Stockholm county, and to compare the prevalence in children of Somali background with that in the non‐Somali group. We reviewed the records of 17 children (13 males, four females), born between 1988 and 1998 (age range 7–17y) and with a Somali background, who had a diagnosis of autistic disorder or pervasive developmental disorder not otherwise specified (PDDNOS) and were registered at either of the two autism habilitation centres for school‐aged children. The prevalence of autistic disorder or PDDNOS was found to be three to four times higher than in the non‐Somali group (0.7% vs 0.19%). All children also had learning disability. * Our findings warrant further investigations of possible aetiological factors behind the increased prevalence of autistic disorders in children of Somali origin found in this area in Sweden.

Autistic spectrum disorders in Möbius sequence: a comprehensive study of 25 individuals

The prevalence of autistic disorder was analysed in 25 individuals with Möbius sequence, a disorder with brain-stem dysfunction. The sample consisted of 18 males and seven females (20 participants were aged 2 to 22 years, and five were aged 1, 19 and 23 months, and 55 years old). Participants were recruited after a nationwide call and were part of a multidisciplinary study of individuals with Möbius sequence. They were given a meticulous neuropsychiatric examination including standardized autism diagnostic interviews. Ten individuals had an autistic spectrum disorder. Six of these met all diagnostic criteria for autism. In 23 individuals cognitive development could be assessed. Eight of those 23 patients had clear learning disability and six individuals were functioning in the normal but subaverage range. Autistic spectrum disorder and learning disability occurred in more than a third of the examined patients. Considering the hospital-based nature of the sample, these findings may be overestimates. Nevertheless, awareness of this coexistence is important in the diagnosis and habilitation care of children with Möbius sequence. Moreover, the results provide further support for the notion of a subgroup of autistic spectrum disorders being caused by first trimester brain-stem damage.

Infantile hydrocephalus epidemiology: an indicator of enhanced survival.

The epidemiology of infantile hydrocephalus in the birth years 1973-90 was investigated in west Sweden. The study revealed a significant increase in prevalence from 1973-8 and 1979-82 considered due to the enhanced survival of very and extremely preterm infants. The increase did not continue from 1983-90. This could indicate an improved outcome in preterm survivors as the neonatal survival rate continued to increase. The striking predominance of a perinatal/neonatal aetiology in very preterm hydrocephalic infants could be confirmed: 89% born from 1983-90 had suffered a confirmed postpartum intraventricular haemorrhage. In infants born at term, prenatal origins, mainly maldevelopments, dominated. The outcome in very preterm surviving infants with infantile hydrocephalus was poor: 73% had cerebral palsy, 52% epilepsy, 22% severe visual disability, and 55% were mentally retarded. Despite the increased survival resulting in a majority of healthy infants, there is an accumulating cohort of hydrocephalic children.