Sex differences in tactile defensiveness in children with ADHD and their siblings

Tactile defensiveness (TD) is a disturbance in sensory processing and is observed in some children with attention-deficit-hyperactivity disorder (ADHD). TD has been examined in male children with ADHD and in children with ADHD without differentiating by sex. As males and females with ADHD may differ in the clinical expression of the disorder and associated deficits, the aim of this study was to examine sex differences in TD in males and females with ADHD. Non-affected siblings were also examined to investigate familiality of TD. The Touch Inventory for Elementary-School-Aged Children was administered to 47 children with ADHD (35 males, 12 females; mean age 9y 8mo [SD 1y 11mo]), 36 non-affected siblings (21 males, 15 females; mean age 8y 10mo [SD 2y 4mo]), and 35 control children (16 males, 19 females; mean age 9y 5mo [SD 6mo]). Results indicated that females with ADHD displayed higher levels of TD than males with ADHD (who did not differ from control males). This suggests that TD is sex specific and may contribute to the identification of ADHD in females, thus improving diagnostic and therapeutic strength in this under-referred group. Non-affected siblings were unimpaired, regardless of sex, which suggests that TD is specific to the disorder and not part of a familial risk for ADHD.     

Co-occurrence of developmental delays among preschool children with attention-deficit-hyperactivity disorder

The aim of this study was to provide a comprehensive profile of the sensory, motor, language, and intellectual functioning of a non-referred community sample of 49 preschool children with attention-deficit-hyperactivity disorder (ADHD; 39 males, 10 females; mean age 4y 7mo [SD 7mo]; range 3y 10mo-6y) and 48 typically developing children (38 males, 10 females; mean age 4y 8mo [SD 6mo]; range 3y 11mo-6y) matched by age, sex, and maternal education who underwent a broad battery of neurodevelopmental tests. The results showed that the scores of the ADHD group were significantly lower than the comparison group on all measures. In addition, 23 (47%) of the children with ADHD had clinically significant co-occurring deficits in two or more areas. Logistic regression indicated that the only significant predictors of group classification were scores of verbal intelligence and motor and sensory functioning, accounting for 44.1% of the variance. These findings suggest that preschool children with ADHD have multiple developmental deficits over and above the core symptoms of ADHD and emphasize the importance of evaluating the sensorimotor functioning of preschool children with ADHD symptoms.     

The impact of sex and subtypes on cognitive and psychosocial aspects of ADHD

We compared the effect of sex and attention-deficit-hyperactivity disorder (ADHD) subtyping in groups of females and males. One hundred and one females with ADHD (mean age 10y 4mo [SD 2y 8mo]; range 5y-18y) were classified according to subtype by Diagnostic and Statistical Manual of Mental Disorders (4th edn) criteria (inattentive [ADHD-I]; combined [ADHD-C]) and balanced by subtype to 101 males (mean age 10y 5mo [SD 2y 9mo]; range 5y 4mo-17y 6mo). All children underwent IQ and reading assessment, and 109 underwent the continuous performance task (Test Of Variables of Attention [TOVA]). Parents completed the Conners' Abbreviated Rating Scale (ABRS), the Child Behavior Checklist (CBCL), learning disability questionnaires, and reported use and efficacy of methylphenidate. Teachers completed the Swanson, Kotkin, Agler, M-Flynn, and Pelham (SKAMP) rating scale. Sex differences were found only on the CBCL; females were more impaired on the attention (p<0.001) and somatization (p=0.028) subscales but not for IQ, other questionnaires, TOVA scores, methylphenidate treatment, or demographics. Females with ADHD-C, but not males, had significantly higher T-scores than females with ADHD-I on social, attention, delinquent, and aggressive behaviours. Regardless of sex, children with ADHD-C had higher scores on all CBCL subscales (p=0.047), ABRS (p<0.001), and SKAMP (p=0.03) than children with ADHD-I. The results support the supposition that ADHD in females is the same disorder as in males. ADHD subtyping was the important determinant of ADHD core symptoms; females with ADHD were found to have significant risk of psychopathology.     

Motor skill deficits in children with partial hearing

Aim We examined the effect of partial hearing, including cochlear implantation, on the development of motor skills in children (aged 6–12y). Method Three independent groups of children were selected: a partial hearing group (n=25 [14 males, 11 females]; mean age 8y 8mo, SD 1y 10mo), a nonverbal IQ‐matched group (n=27 [15 males, 12 females]; mean age 9y, SD 1y 6mo), and an age‐matched group (n=26 [8 males, 18 females]; mean age 8y 8mo, SD 1y 7mo) from three schools with special units for children with partial hearing. All children with partial hearing had a bilateral hearing loss >60 decibels. Motor and balance skills were assessed using the Movement Assessment Battery for Children (MABC) and two protocols from the NeuroCom Balance Master clinical procedures. Results The mean standardized total MABC score of the children with partial hearing (95% confidence interval [CI] 71.8–88.7) was significantly lower than both the age‐matched (95% CI 95.8–111.4; p<0.01) and the IQ‐matched (95% CI 87.6–103.0; p=0.03) comparison groups. The children with partial hearing had particular difficulties with balance, most notably during tests of intersensory demand. However, subgroup analyses revealed that the effect of cochlear implantation was clearly dependent on the nature of the task. Interpretation Children with partial hearing are at high risk of clinical levels of motor deficit, with balance difficulties providing support for conventional vestibular deficit theory. However, the effect of cochlear implantation suggests that other sensory systems may be involved. A broader ecological perspective, which takes into account factors external to the child, may prove a useful framework for future research.     

Differentiating attention deficits in children with fetal alcohol spectrum disorder or attention‐deficit–hyperactivity disorder

Aim The attention and inhibition problems found in children with attention‐deficit–hyperactivity disorder (ADHD) are also common in children with fetal alcohol spectrum disorders (FASDs). Attempts to distinguish ADHD from FASDs in terms of these deficits are rare and were pursued in this study. Method A total of 116 children (47 with ADHD, 31 males, 16 females; 30 with FASDs, 17 males, 13 females; and 39 comparison children, 20 males, 19 females) participated. The mean age was 9 years 4 months (SD 1y 8mo) in the ADHD groups, 8 years 10 months (SD 1y 2mo) in the FASD group, and 9 years 1 month (SD 1y 1mo) in the comparison group. Sustained attention was tested with a slow event rate continuous performance task (CPT). Inhibitory control was tested with both a slow and fast event rate Go/No‐Go task. Results On the CPT task, children with ADHD, combined type (ADHD‐C), ADHD, primarily inattentive type (ADHD‐PI), and FASDs showed greater declines in task performance as a function of time than comparison children, suggesting sustained attention problems in all clinical groups. Children’s Go/No‐Go performance was event‐rate dependent, with the ADHD‐C group being affected in the slow condition and the ADHD‐PI and FASD groups having problems with the fast condition. Interpretation Children with ADHD‐C are typically impaired in handling understimulation, while children with FASDs may have problems with overstimulation. The dissociation in responsivity to event rate between groups may have significant differential diagnostic value.     

Does attention‐deficit–hyperactivity disorder exacerbate executive dysfunction in children with neurofibromatosis type 1?

Aim Although approximately 40% of children with neurofibromatosis type 1 (NF1) meet diagnostic criteria for attention‐deficit–hyperactivity disorder (ADHD), the impact of ADHD on the executive functioning of children with NF1 is not understood. We investigated whether spatial working memory and response inhibition are impaired in children with NF1 without a diagnosis of ADHD and whether executive deficits are exacerbated in children with a comorbid diagnosis. Method Forty‐nine children aged 7 to 15 years with NF1 only (31 males, 18 females; mean age 11y, SD 2y 4mo) or 35 with NF1 and ADHD (18 males, 17 females; mean age 10y 8mo, SD 2y 4mo) and 30 typically developing comparison children (16 males, 14 females; mean age 10y, SD 2y 8mo) were compared on measures of spatial working memory and response inhibition. Group differences in IQ and visuospatial ability were controlled for as required. Results Compared with typically developing children, children with NF1 with or without comorbid ADHD demonstrated significant impairment of both spatial working memory (both p<0.004) and inhibitory control (both p<0.010). There were, however, no differences between the two NF1 groups in spatial working memory (p=0.91) or response inhibition (p=0.78). Interpretation Executive dysfunction occurs with the same severity in children with NF1, whether or not they have a comorbid diagnosis of ADHD, suggesting that executive impairments are not unique contributors to ADHD symptomatology in NF1. The findings are discussed within the context of recent evidence in Nf1 optic glioma (OPG) mice, in which a mechanistic connection between NF1 gene expression, executive system failure, and dopaminergic pathway integrity has been established.     

Gross motor development in children adopted from orphanage settings

Aim This study sought to examine the effect of environmental enrichment on the motor skills of children adopted from orphanage settings. We investigated balance and bilateral coordination skills in 33 internationally adopted postinstitutionalized children (16 males, 17 females; age range 8y 5mo–15y 10mo; mean age 10y 9mo; SD 2y 2mo) and compared them with 34 non‐institutionalized children (21 males, 13 females; age range 8y 3mo–14y 10mo; mean age 11y 2mo; SD 2y 1mo) being raised in their birth families. Method The children were individually administered the balance and bilateral coordination subtests of the Bruininks–Oseretsky Test of Motor Proficiency in a research laboratory. Parents completed questionnaires about developmental history, family environment, and orphanage care. Results Postinstitutionalized children showed motor system delays compared with the non‐institutionalized comparison children (postinstitutionalized balance mean 9.44, SD 5.92, comparison children balance mean 14.12, SD 4.39; postinstitutionalized bilateral coordination mean 11.97, SD 5.43, comparison children mean 19.97, SD 3.97). The length of time that children remained institutionalized before adoption predicted balance delays (b=?1.57, t=?2.33, p=0.027) and the severity of caregiving deprivation the children experienced correlated with bilateral coordination (r=?0.44, p=0.013). Interpretation These findings suggest that institutionalized settings do not provide the early life experiences needed for the development of age‐level motor skills later in childhood and that simple environmental enrichment following adoption is not enough to remediate skills. Children who have experienced early institutional care may benefit from early identification and targeted intervention.     

No association between the 2D:4D fetal testosterone marker and multidimensional attentional abilities in children with ADHD

Aim It has been suggested that high levels of prenatal testosterone exposure are implied in the aetiology of attention‐deficit–hyperactivity disorder (ADHD). This study examined the association between the ratio of the length of the second and fourth digits (2D:4D ratio), a marker of fetal testosterone exposure, and the presence of ADHD‐related cognitive and behavioural problems in children with ADHD and in typically developing comparison individuals. Method A clinically referred group of 64 children who fulfilled DSM‐IV‐TR criteria for ADHD (47 males, 17 females; mean age 8y 8mo, SD 1y 8mo, range 7–12y) and 46 comparison children (25 males, 21 females; mean age 9y 2mo; SD 1y 10mo, range 7–12y) were included in the study. The length of the second and fourth digits was measured by two independent raters. The Child Behaviour Checklist (CBCL) and the Test of Everyday Attention for Children (TEA‐Ch) were used to assess behavioural problems and different aspects of attention. Results No group differences in 2D:4D ratio were observed between children with (combined, inattentive, or hyperactive‐impulsive subtype of) ADHD and comparison children. The ratio did not show the postulated relation with cognitive and behavioural aspects of ADHD. Interpretation These findings challenge the hypothesis that fetal testosterone exposure plays a prominent role in the aetiology of ADHD.     

Working memory, processing speed, and set-shifting in children with developmental coordination disorder and attention-deficit-hyperactivity disorder

It has been suggested that the high levels of comorbidity between attention-deficit-hyperactivity disorder (ADHD) and developmental coordination disorder (DCD) may be attributed to a common underlying neurocognitive mechanism. This study assessed whether children with DCD and ADHD share deficits on tasks measuring working memory, set-shifting, and processing speed. A total of 195 children aged between 6 years 6 months and 14 years 1 month (mean 10y 4mo [SD 2y 2mo]) were included in this study. A control group (59 males, 79 females), a DCD group (12 males, six females), an ADHD-predominantly inattentive group (16 males, four females), and an ADHD-combined group (15 males, four females), were tested on three executive functioning tasks. Children with DCD were significantly slower on all tasks, supporting past evidence of a timing deficit in these children. With few exceptions, children with ADHD did not perform more poorly than control children. These findings demonstrate the importance of identifying children with motor deficits when examining tasks involving a timing component.     

Efficacy of a hand-arm bimanual intensive therapy (HABIT) in children with hemiplegic cerebral palsy: a randomized control trial

Children with hemiplegic cerebral palsy (CP) have impairments in bimanual coordination above and beyond their unilateral impairments. Recently we developed hand-arm bimanual intensive therapy (HABIT), using the principles of motor learning, and neuroplasticity, to address these bimanual impairments. A single-blinded randomized control study of HABIT was performed to examine its efficacy in children with hemiplegic CP with mild to moderate hand involvement. Twenty children (age range 3 y 6 mo-15 y 6 mo) were randomized to either an intervention (n=10: seven males, three females; mean age 8 y 7 mo, SD 4 y) or a delayed treatment control group (n=10: seven males, three females; mean age 6 y 10 mo, SD 2 y 4 mo). Children were engaged in play and functional activities that provided structured bimanual practice 6 hours per day for 10 days. Each child was evaluated immediately before and after the intervention, and again at 1-month post-intervention. Children in the intervention group demonstrated improved scores on the Assisting Hand Assessment, increased involved extremity use measured using accelerometry and a caregiver survey, bimanual items of the Bruininks-Oseretsky Test of Motor Proficiency, and the simultaneity of completing a draw-opening task with two hands (p<0.05 in all cases). The results suggest that for this carefully selected subgroup of children with hemiplegic CP, HABIT appears to be efficacious in improving bimanual hand use.     

Motor coordination, empathy, and social behaviour in school-aged children

Children with motor coordination problems are known to have emotional difficulties and poor social skills. The current study investigated whether children with poor motor ability have poor emotion recognition skills, and whether these could be linked to problems in social behaviour. It was hypothesized that difficulties in empathic ability might be related to the poor visuo-spatial processing ability identified in children with developmental coordination disorder (as defined by the American Psychiatric Association). The relationship between motor coordination, emotion recognition, and social behaviour was examined in a sample of 234 children (113 males, 121 females; mean age 9y 7mo, [SD 1y 8mo] age range 6y 8mo to 12y 11mo). From this sample two groups of 39 children each (17 females, 22 males), one group with motor difficulties (mean age 9y 11mo [SD 2y], range 6y 11mo to 12y 11mo) and the other of control children (mean age 10y [SD ly 11mo], range 6y 11mo to 12y 11mo), matched for age and sex, were compared using a set of six emotion recognition scales that measured both verbal and perceptual aspects of empathic ability. Children with motor difficulties were found to perform more poorly on scales measuring the ability to recognize static and changing facial expressions of emotion. This difference remained even when visuo-spatial processing was controlled. When controlling for emotion recognition and visuo-spatial organization, a child's motor ability remained a significant predictor of social behaviour.     

Refractive errors in infancy predict reduced performance on the movement assessment battery for children at 3 1/2 and 5 1/2 years

We have previously reported that significant hyperopia at 9 months predicts mild deficits on visuocognitive and visuomotor measures between 2 years and 5 years 6 months. Here we compare the motor skills of children who had been hyperopic in infancy (hyperopic group) with those who had been emmetropic (control group), using the Movement Assessment Battery for Children (Movement ABC). Children were tested at 3 years 6 months (hyperopic group: 47 males, 63 females, mean age 3 y 7 mo, SD 1.6 mo; control group: 61 males, 70 females, mean age 3 y 7 mo, SD 1.2 mo) and at 5 years 6 months (hyperopic group: 43 males, 56 females, mean age 5 y 4 mo, SD 1.7 mo; control group: 51 males, 62 females, mean age 5 y 3 mo, SD 1.6 mo). The hyperopic group performed significantly worse at both ages, overall and on at least one test from each category of motor skill (manual dexterity, balance, and ball skills). Distributions of scores showed that these differences were not due to poor performance by a minority but to a widespread mild deficit in the hyperopic group. This study also provides the first normative data on the Movement ABC for children below 4 years of age, and shows that it provides a useful measure of motor development at this young age.     

Verbal and academic skills in children with early‐onset type 1 diabetes

Aim Basic verbal and academic skills can be adversely affected by early‐onset diabetes, although these skills have been studied less than other cognitive functions. This study aimed to explore the mechanism of learning deficits in children with diabetes by assessing basic verbal and academic skills in children with early‐onset diabetes and in comparison children. In addition, the incidence of dyslexia (≤10th centile in reading speed or reading–spelling accuracy) was studied. Method The performance of 51 children with early‐onset diabetes (25 females, 26 males; mean age 9y 11mo, SD 4mo; range 9–10y) was compared with that of 92 children without diabetes (40 females, 52 males; mean age 9y 10mo, SD 3mo; range 9–10y) in the tasks of phonological processing, short‐term memory, rapid automatized naming, reading, spelling, and mathematics. Results The performance of children with diabetes was poorer than that of the comparison children in phonological processing (p=0.001), spelling accuracy (p<0.001), and mathematics (p=0.024). They learned to read later (p=0.013), but reading performance and the incidence of dyslexia in the third grade (aged 9–10y) were similar in the two groups. Interpretation Children with early‐onset diabetes are prone to minor learning difficulties in their early school years as a result of deficits in phonological processing.     

Developmental coordination disorder in children with attention-deficit-hyperactivity disorder and physical therapy intervention

Although physical therapy (PT) is effective in improving motor function in children with developmental coordination disorder (DCD), insufficient data are available on the impact of this intervention in children with combined attention-deficit-hyperactivity disorder (ADHD) and DCD. This prospective study aimed to establish the prevalence of DCD among a cohort of patients with ADHD, characterize the motor impairment, identify additional comorbidities, and determine the role of PT intervention on these patients. DCD was detected in 55.2% of 96 consecutive children with ADHD (81 males, 15 females), mostly among patients with the inattentive type (64.3% compared with 11% of those with the hyperactive/impulsive type, p<0.05). Mean age was 8 years 4 months (SD 2 y). Individuals with both ADHD and DCD more often had specific learning disabilities (p=0.05) and expressive language deficits (p=0.03) than children with ADHD only. Twenty-eight patients with ADHD and DCD randomly received either intensive group PT (group A, mean age 9 y 3 mo, SD 2 y 3 mo) or no intervention (group B, mean age 9 y 3 mo, SD 2 y 2 mo). PT significantly improved motor performance (assessed by the Movement Assessment Battery for Children; p=0.001). In conclusion, DCD is common in children with ADHD, particularly of the inattentive type. Patients with both ADHD and DCD are more likely to exhibit specific learning disabilities and phonological (pronunciation) deficits. Intensive PT intervention has a marked impact on the motor performance of these children.     

Motor skill performance of school-age children with visual impairments

The aim of this study was to examine the performance of children with visual impairments (VI) aged 7 to 10 years on different types of motor skills. Furthermore, the association between the degree of the VI and motor performance was examined. The motor performance of 48 children with VI (32 males, 16 females; mean age 8y 10mo [SD 1y 1mo]) was assessed using the Movement Assessment Battery for Children (MABC). Their performance was compared with 48 children without VI (33 males, 15 females; mean age 8y 9mo [SD 1y 1mo]). Children with VI showed the poorest performance compared with peers without VI on unimanual speed, eye-hand coordination, catching, static balance, and dynamic balance while moving slowly. There was no significant difference between children with moderate and severe VI, except for bimanual coordination in 7- to 8-year-olds and eye-hand coordination in both the 7- to 8-year-olds and 9- to 10-year-olds, favouring the children with moderate VI. The poor performance compared with children without VI is related to vision, but the degree of the VI does not appear to relate to motor performance, except when associated with bimanual and eye-hand coordination. For children with VI, it seems very important to adjust the environmental context and task to enhance motor performance.     

Neuromotor development in nocturnal enuresis

In children with nocturnal enuresis, a higher rate of minor neurological dysfunction has been found. The aim of this study was to assess timed performance (a measure of motor performance speed) and associated movements using a standardized and reliable instrument. The motor function of 37 children with nocturnal enuresis (27 males, 10 females; mean age 10y 7mo [SD 1y 10mo]; age range 8y-14y 8mo) and 40 comparison children without enuresis (17 males, 23 females; mean age 10y 7mo [SD 1y 6mo]; age range 8y-14y 8mo) was assessed using the Zurich Neuromotor Assessment. Children with nocturnal enuresis showed a slower motor performance than comparison children, particularly for repetitive hand and finger movements. This study provides evidence for a maturational deficit in motor performance in children with nocturnal enuresis. In addition to a maturational deficit of the brainstem, it is proposed that there is a possible maturational deficit of the motor cortex circuitry and related cortical areas in children with nocturnal enuresis.     

Stability of motor problems in young children with or at risk of autism spectrum disorders,ADHD, and or developmental coordination disorder

Aim The aim of this study was to investigate the stability of motor problems in a clinically referred sample of children with, or at risk of, autism spectrum disorders (ASDs), attention‐deficit–hyperactivity disorder (ADHD), and/or developmental coordination disorder (DCD). Method Participants were 49 children (39 males, 10 females; mean age 5y 6mo, SD 10mo) with various developmental problems, a Movement Assessment Battery for Children (M‐ABC) score on or below the 15th centile, and an IQ of 70 or more. Sixteen children were at risk of developing ADHD, 15 children had a diagnosis of, or were at risk of developing ASD, and 18 children had neither diagnosis. Children were reassessed 2 to 3 years later. Results At follow‐up (mean age 7y 11mo; SD 1y), the mean M‐ABC score was significantly increased, and in 22 children was no longer below the 15th centile. A general linear model to compare the difference in M‐ABC scores in the three groups of children demonstrated a significant difference between groups (p=0.013), with the age at the initial assessment as a significant covariate (p=0.052). The group of children with or at risk of ASD showed less improvement in motor performance. Interpretation Motor problems among preschool age children are not always stable, but appear to be so in most children with ASDs.     

Effects of methylphenidate on quality of life in children with both developmental coordination disorder and ADHD

Measurement of health-related quality of life (HRQOL) in attention-deficit-hyperactivity disorder (ADHD) gives a more complete picture of day-to-day functioning and treatment effects than behavioural rating alone. The aim of this pilot study was to investigate the impact of the combined diagnoses of developmental coordination disorder (DCD) and ADHD on HRQOL, and the effectiveness of methylphenidate (MPH) on HRQOL. HRQOL was established using the Dutch-Child-AZL-TNO-Quality-of-Life (DUX-25) and the TNO-AZL-Child-Quality-of-Life (TACQOL) questionnaires, completed by children and parents. HRQOL of these children was compared with that of 23 age- and sex-matched healthy controls. Twenty-three children (21 males, two females; mean age 8 y 6 mo, [SD 3 mo] range 7 y-10 y 8 mo) with ADHD/DCD entered a 4-week, open-label MPH study, after MPH-sensitivity was established, in a double-blind, placebo-controlled trial. In these children's self- and proxy reports, impact of both DCD and ADHD was reflected in lower general well-being (self and proxy report p=0.001) due to lower functioning in motor (selfp=0.026; proxy 0.001), autonomic (self p<0.001; proxy p=0.047), cognitive (self p=0.001; proxy p=0.01), and social (self and proxy p<0.001) domains. HRQOL scores improved in 18 children receiving MPH (p=0.001) versus controls. The ADHD /DCD group also demonstrated a significant improvement in ADHD symptoms (p<0.001) and motor functioning (p<0.001). Additional motor therapy will still be needed in about half of the children with ADHD/DCD receiving MPH, within multimodal treatment including educational and psychosocial assistance.     

Academic skills in children with early-onset type 1 diabetes: the effects of diabetes-related risk factors

Aim The study aimed to assess the effects of diabetes‐related risk factors, especially severe hypoglycaemia, on the academic skills of children with early‐onset type 1 diabetes mellitus (T1DM). Method The study comprised 63 children with T1DM (31 females, 32 males; mean age 9y 11mo, SD 4mo) and 92 comparison children without diabetes (40 females, 52 males; mean age 9y 9mo, SD 3mo). Children were included if T1DM had been diagnosed before the age of 5 years and if they were aged between 9 and 10 years at the time of study. Children were not included if their native language was not Finnish and if they had a diagnosed neurological disorder that affected their cognitive development. Among the T1DM group, 37 had and 26 had not experienced severe hypoglycaemia and 26 had avoided severe hypoglycaemia. Severe hypoglycaemia, diabetic ketoacidosis (DKA), and glycaemic control were used as T1DM‐related factors. Task performance in reading, spelling, and mathematics was compared among the three groups, and the effects of the T1DM‐related factors were analysed with general linear models. Results The groups with (p<0.001) and without (p=0.001) severe hypoglycaemia demonstrated a poorer performance than the comparison group in spelling, and the group without severe hypoglycaemia showed a poorer performance than the comparison group in mathematics (p=0.003). Severe hypoglycaemia, DKA, and recent glycaemic control were not associated with poorer skills, but poorer first‐year glycaemic control was associated with poorer spelling (p=0.013). Interpretation An early onset of T1DM can increase the risk of learning problems, independently of the history of severe hypoglycaemia or DKA. Poorer glycaemic control after the first year of T1DM is associated with a poorer acquisition of academic skills indicating the effect of the timing of metabolic aberrations on cognitive development.     

Head–torso–hand coordination in children with and without developmental coordination disorder

Aim This study investigated the nature of coordination and control problems in children with developmental coordination disorder (DCD). Method Seven adults (two males, five females, age range 20–28y; mean 23y, SD 2y 8mo) and eight children with DCD (six males, two females, age range 7–9y; mean 8y, SD 8mo), and 10 without DCD (seven males, three females, age range 7–9y; mean 8y, SD 7mo) sat in a swivel chair and looked at or pointed to targets. Optoelectronic apparatus recorded head, torso, and hand movements, and the spatial and temporal characteristics of the movements were computed. Results Head movement times were longer (p<0.05) in children with DCD than in the comparison group, even in the looking task, suggesting that these children experience problems at the lowest level of coordination (the coupling of synergistic muscle groups within a single degree of freedom). Increasing the task demands with the pointing condition affected the performance of children with DCD to a much greater extent than the other groups, most noticeably in key feedforward kinematic landmarks. Temporal coordination data indicated that all three groups attempted to produce similar movement patterns to each other, but that the children with DCD were much less successful than age‐matched children in the comparison group. Interpretation Children with DCD have difficulty coordinating and controlling single degree‐of‐freedom movements; this problem makes more complex tasks disproportionately difficult for them. Quantitative analysis of kinematics provides key insights into the nature of the problems faced by children with DCD.