The neurology of learning and behavioural problems in pre-adolescent children

Theoretical-Methodological Foundations for the Global Integration Method (Método de Integração Global-MIG) in the Treatment of Autism Spectrum Disorder

Currently, there is no intervention model for autism spectrum disorder (ASD) that addresses all levels and factors of the International Classification of Functioning, Disability and Health (ICF, WHO). The most researched programs focus on naturalistic, developmental and behavioral approaches to socio-communication. Less attention has been paid to motor and environmental reactivity aspects (behavior/interest restriction and sensory reactivity). The evidence rationale for the Global Integration Method (MIG, "Método de Integração Global"), a model addressing sensorimotor reactivity in addition to socio-communication, is presented. MIG is an integrative, interdisciplinary, family-oriented intervention and naturalistic program that addresses all levels and moderating factors of ASD's impact. MIG's theoretical rationale is based on the predictive coding impairment and embodied cognition hypotheses. MIG incorporates both bottom-up (flexible therapeutic suit, social-motor synchronization) and top-down (schematic social information processing, narratives, imagery) strategies to promote the building and use of accurate, flexible and context-sensitive internal predictive models. MIG is based on the premises that predictive coding improves both socio-communication and environmental reactivity, and that the postural stabilization provided by the flexible therapeutic suit frees information processing resources for socio-cognitive learning. MIG builds on interdisciplinary, professionally and parentally mediated work based on behavioral principles of intensive training in a situated environment.

The Mini-Mental Examination for Children (MMC): Evidence of validity for children with learning difficulties

The Mini-Mental Examination for Children (MMC) is a widely used tool for assessing global cognitive deficits, however,is still unknown whether MMC is sensitive for investigating cognitive profiles associated with learning difficulties (LD).

IVF procedures are not, but subfertility is associated with neurological condition of 9-year-old offspring

In vitro fertilization (IVF) is not associated with neurological abnormalities in offspring's early childhood. Yet, it is unclear whether this is also true for school age. Neither do we know the role of parental subfertility in offspring's neurological development. The present study examined neurological condition at 9 years of 57 singletons born after controlled ovarian hyperstimulation IVF (COH-IVF), 46 singletons born after modified natural cycle IVF (MNC-IVF) and 66 singletons born to subfertile parents after natural conception (Sub-NC). To assess the effect of subfertility, the groups were pooled to form a subfertile group, and compared with a prospectively followed fertile reference group (n = 282). The sensitive Minor Neurological Dysfunction (MND) examination was used, resulting in the detailed Neurological Optimality Score (NOS) and the prevalence of the clinically relevant complex MND. Neurological condition of the three subfertile groups did not differ significantly: median NOS was 53 in each subfertile group and the prevalence of complex MND in the three subfertile groups was 30%, 37% and 36%, respectively. However, the NOS was lower and the prevalence of complex MND higher in children born to subfertile couples than in children of fertile couples (adjusted mean difference [95% CI]: -4.48 [-5.53 to -3.42]) and adjusted OR [95% CI]: 5.13 [2.60-10.16], respectively). We conclude that ovarian hyperstimulation, in vitro procedures, and the combination of both were not associated with a less favourable neurological outcome of 9-year-old singletons. However, the presence of parental subfertility was associated with less favourable neurological outcome of offspring at 9 years follow up.

Developmental outcome of 9-year-old children born after PGS: follow-up of a randomized trial

STUDY QUESTION

Does Day-3 cleavage-stage PGS affect neurodevelopment of 9-year-old IVF offspring?

SUMMARY ANSWER

We did not find evidence of adverse consequences of Day-3 cleavage-stage PGS on neurodevelopment of 9-year-old IVF offspring, although children born after IVF with or without PGS often had a non-optimal neurological condition.

WHAT IS KNOWN ALREADY

Knowledge on long-term sequelae for development and health of children born following PGS is lacking. This is striking as evidence accumulates that IVF itself is associated with increased risk for impaired health and development in the offspring.

STUDY DESIGN SIZE, DURATION

This prospective, assessor-blinded, multicentre, follow-up study evaluated development and health of 9-year-old IVF children born to women who were randomly assigned to IVF with PGS (PGS group) or without PGS (control group). The follow-up examination at 9 years took place between March 2014 and May 2016.

PARTICIPANTS/MATERIALS, SETTING, METHODS

In total, 408 women were included and randomly assigned to IVF with or without Day-3 cleavage-stage PGS. This resulted in 52 ongoing pregnancies in the PGS group and 74 in the control group. In the PGS group, 59 children were born alive; in the control group, 85 children were born alive. At the age of 9 years, 43 children born after PGS and 56 control children participated in the study. Our primary outcome was the neurological optimality score, a sensitive measure of neurological condition assessed with a standardized, age-specific test (Touwen test). Secondary outcomes were adverse neurological condition (neurologically abnormal and the complex form of minor neurological dysfunction), cognitive development (intelligence quotient and specific domains), behaviour (parental and teacher's questionnaires), blood pressure and anthropometrics.

MAIN RESULTS AND THE ROLE OF CHANCE

Neurodevelopmental outcome of PGS children did not differ from that of controls; the neurological optimality scores (mean values [(95% CI]: PGS children 51.5 [49.3; 53.7], control children 53.1 [50.5; 55.7]) were not significantly different. The prevalences of adverse neurological outcome (in all but one child implying the presence of the complex form of minor neurological dysfunction) did not differ between the groups (PGS group 17/43 [40%], control group 19/56 [34%]), although the prevalence of complex minor neurological dysfunction in both groups was rather high. Also intelligence quotient scores of the two groups were not significantly different (PGS group 114 [108; 120]); control group 117 [109; 125]), and the behaviour, blood pressure and anthropometrics of both groups did not differ. Mean blood pressures of both groups were above the 60th percentile.

LIMITATIONS REASONS FOR CAUTION

The power analysis of the study was not based on the number of children needed for the follow-up study, but on the number of women who were needed to detect an increase in ongoing pregnancy rates after PGS. In addition, our study evaluated embryo biopsy in the form of PGS at cleavage stage (Day-3 embryo biopsy), while currently PGS at blastocyst stage (Day-5 embryo biopsy) is recommended and increasingly being used.

WIDER IMPLICATIONS OF THE FINDINGS

Our findings indicate that PGS in cleavage stage embryos is not associated with adverse effects on neurological, cognitive and behavioural development, blood pressure and anthropometrics of offspring at 9 years. This is a reassuring finding as embryo biopsy in the forms of PGS and PGD is increasingly applied. However, both groups of IVF offspring showed high prevalences of the clinically relevant form of minor neurological dysfunction, which is a point of concern for the IVF community. In addition, our study confirms findings of others that IVF offspring may be at risk of an unfavourable cardiovascular outcome. These findings are alarming and highlight the importance of research on the underlying mechanisms of unfavourable neurodevelopmental and cardiovascular outcomes in IVF offspring.

STUDY FUNDING/COMPETING INTEREST(S)

The randomized controlled trial was financially supported by the Organization for Health Research and Development (ZonMw), The Netherlands (Grant number 945-03-013). The follow-up was financially supported by the University Medical Center Groningen (Grant number: 754510), the Cornelia Foundation, and the graduate schools BCN and Share, Groningen, The Netherlands. The sponsors of the study had no role in study design, data collection, data analysis, data interpretation or writing of the report. There are no conflicts of interest.

TRIAL REGISTRATION NUMBER

ISRCTN76355836.

Numerical Processing Impairment in 22q11.2 (LCR22-4 to LCR22-5) Microdeletion: A Cognitive-Neuropsychological Case Study

Although progress has been made, the cognitive, biological and, particularly, the genetic underpinnings of math learning difficulties (MD) remain largely unknown. This difficulty stems from the heterogeneity of MD and from the large contribution of environmental factors to its etiology. Understanding endophenotypes, e.g., the role of the Approximate Number System (ANS), may help understanding the nature of MD. MD associated with ANS impairments has been described in some genetic conditions, e.g., 22q11.2 deletion syndrome (22q11.2DS or Velocardiofacial syndrome, VCFS). Recently, a girl with MD was identified in a school population screening. She has a new syndrome resulting from a microdeletion in 22q11.2 (LCR22-4 to LCR22-5), a region adjacent to but not overlapping with region 22q11.2 (LCR22-2 to LCR22-4), typically deleted in VCFS. Here, we describe her cognitive-neuropsychological and numerical-cognitive profiles. The girl was assessed twice, at 8 and 11 years. Her numerical-cognitive performance at both times was compared to demographically similar girls with normal intelligence in a single-case, quasi-experimental study. Neuropsychological assessment was normal, except for relatively minor impairments in executive functions. She presented severe and persistent difficulties in the simplest single-digit calculations. Difficulties in commutative operations improved from the first to the second assessment. Difficulties in subtraction persisted and were severe. No difficulties were observed in Arabic number writing. Difficulties in single-digit calculation co-occurred with basic numerical processing impairments in symbolic and non-symbolic (single-digit comparison, dot sets size comparison and estimation) tasks. Her difficulties suggest ANS impairment. No difficulties were detected in visuospatial/visuoconstructional and in phonological processing tasks. The main contributions of the present study are: (a) this is the first characterization of the neuropsychological phenotype in 22q11.2DS (LCR22-4 to LCR22.5) with normal intelligence; (b) mild forms of specific genetic conditions contribute to persistent MD in otherwise typical persons; (c) heterogeneity of neurogenetic underpinnings of MD is suggested by poor performance in non-symbolic numerical processing, dissociated from visuospatial/visuoconstructional and phonological impairments; (d) similar to what happens in 22q11.2DS (LCR22-2 to LCR22-4), ANS impairments may also characterize 22q11.2DS (LCR22-4 to LCR22-5).

Minor neurological dysfunction and associations with motor function, general cognitive abilities, and behaviour in children born extremely preterm

AIM

To study the prevalence of minor neurological dysfunction (MND) at 6 years of age in a cohort of children born extremely preterm without cerebral palsy (CP) and to investigate associations with motor function, cognitive abilities, and behaviour.

METHOD

This study assessed 80 children born at less than 27 weeks of gestation and 90 children born at term age between 2004 and 2007 at a mean age of 6 years 6 months. The assessments included a simplified version of the Touwen Infant Neurological Examination, the Movement Assessment Battery for Children, Second Edition (MABC-2), Wechsler Intelligence Scale for Children, Fourth Edition (WISC-IV), the Strengths and Difficulties Questionnaire (SDQ), and the parent version of the Five to Fifteen questionnaire.

RESULTS

Fifty-one of the children born preterm had normal neurology, 23 had simple MND, and six had complex MND compared with 88 who had normal neurology and two simple MND in the term-born group (p<0.001). There were significant differences between the children with normal neurology and MND in the preterm group in MABC-2-assessed motor function (p<0.001), general cognitive abilities with WISC-IV (p=0.005), and SDQ overall behavioural problems and peer problems reported by the parents (p=0.021 and p=0.003 respectively). SDQ teacher-reported overall behavioural and hyperactivity problems were significantly different between children with normal and simple MND (p=0.036 and p=0.019).

INTERPRETATION

Children born extremely preterm, in the absence of CP, are at risk of MND and this is associated with motor function, cognitive ability, and behaviour.

WHAT THIS PAPER ADDS

Extremely preterm birth carries a risk of minor neurological dysfunction (MND). MND in children born extremely preterm is associated with impaired motor function and cognitive abilities, and behavioural problems. Male sex is associated with MND in children born extremely preterm.

Neurological condition assessed with the Hempel examination and cognition and behaviour at 4years

AIM

To investigate associations between neurological condition, assessed with the Hempel examination, in terms of minor neurological dysfunction (MND) and neurological optimality, and cognition and behaviour at 4years.

STUDY DESIGN

Cross-sectional analyses within a prospective, assessor-blinded follow-up study.

SUBJECTS

Four-year-old singletons born to subfertile parents (n=235; 120 boys).

OUTCOME MEASURES

Outcome parameters were complex minor neurological dysfunction (complex MND) and the neurological optimality score (NOS). Cognitive outcome was evaluated with the Kaufman Assessment Battery for Children, resulting in a total intelligence quotient (IQ). Behavioural outcome was evaluated with the Child Behavior Checklist, resulting in a total problem T-score.

RESULTS

Fifty-seven (24.3%) children had complex MND. None of the children showed fine motor dysfunction, suggesting a ceiling effect of the Hempel assessment. Complex MND was not correlated with IQ or total problem T-score. Nevertheless, a higher NOS was correlated with a higher IQ and a lower total problem T-score (adjusted mean estimate [95% confidence interval]: cognition: 0.445 [0.026; 0.865], p=0.038; behaviour: -0.458 [-0.830; -0.087], p=0.016).

INTERPRETATION

At age 4, complex MND assessed with the Hempel assessment was not associated with cognition and behaviour, presumably due to a ceiling effect in the Hempel domain of fine motor function. A more optimal neurological condition was associated with higher IQ and better behaviour.

Examining pitch and numerical magnitude processing in congenital amusia: A quasi-experimental pilot study

INTRODUCTION

Congenital amusia is a developmental disorder associated with deficits in pitch height discrimination or in integrating pitch sequences into melodies. This quasi-experimental pilot study investigated whether there is an association between pitch and numerical processing deficits in congenital amusia. Since pitch height discrimination is considered a form of magnitude processing, we investigated whether individuals with amusia present an impairment in numerical magnitude processing, which would reflect damage to a generalized magnitude system. Alternatively, we investigated whether the numerical processing deficit would reflect a disconnection between nonsymbolic and symbolic number representations.

METHOD

This study was conducted with 11 adult individuals with congenital amusia and a control comparison group of 6 typically developing individuals. Participants performed nonsymbolic and symbolic magnitude comparisons and number line tasks. Results were available from previous testing using the Montreal Battery of Evaluation of Amusia (MBEA) and a pitch change detection task (PCD).

RESULTS

Compared to the controls, individuals with amusia exhibited no significant differences in their performance on both the number line and the nonsymbolic magnitude tasks. Nevertheless, they showed significantly worse performance on the symbolic magnitude task. Moreover, individuals with congenital amusia, who presented worse performance in the Meter subtest, also presented less precise nonsymbolic numerical representation.

CONCLUSIONS

The relationship between meter and nonsymbolic numerical discrimination could indicate a general ratio processing deficit. The finding of preserved nonsymbolic numerical magnitude discrimination and mental number line representations, with impaired symbolic number processing, in individuals with congenital amusia indicates that (a) pitch height and numerical magnitude processing may not share common neural representations, and (b) in addition to pitch processing, individuals with amusia may present a deficit in accessing nonsymbolic numerical representations from symbolic representations. The symbolic access deficit could reflect a widespread impairment in the establishment of cortico-cortical connections between association areas.

Contributions from specific and general factors to unique deficits: two cases of mathematics learning difficulties

Mathematics learning difficulties are a highly comorbid and heterogeneous set of disorders linked to several dissociable mechanisms and endophenotypes. Two of these endophenotypes consist of primary deficits in number sense and verbal numerical representations. However, currently acknowledged endophenotypes are underspecified regarding the role of automatic vs. controlled information processing, and their description should be complemented. Two children with specific deficits in number sense and verbal numerical representations and normal or above-normal intelligence and preserved visuospatial cognition illustrate this point. Child H.V. exhibited deficits in number sense and fact retrieval. Child G.A. presented severe deficits in orally presented problems and transcoding tasks. A partial confirmation of the two endophenotypes that relate to the number sense and verbal processing was obtained, but a much more clear differentiation between the deficits presented by H.V. and G.A. can be reached by looking at differential impairments in modes of processing. H.V. is notably competent in the use of controlled processing but has problems with more automatic processes, such as nonsymbolic magnitude processing, speeded counting and fact retrieval. In contrast, G.A. can retrieve facts and process nonsymbolic magnitudes but exhibits severe impairment in recruiting executive functions and the concentration that is necessary to accomplish transcoding tasks and word problem solving. These results indicate that typical endophenotypes might be insufficient to describe accurately the deficits that are observed in children with mathematics learning abilities. However, by incorporating domain-specificity and modes of processing into the assessment of the endophenotypes, individual deficit profiles can be much more accurately described. This process calls for further specification of the endophenotypes in mathematics learning difficulties.

Minor neurological dysfunction and behaviour in 9-year-old children born at term: evidence for sex dimorphism

AIM

The aim of the study was to assess associations between minor neurological dysfunction (MND) and behaviour, with specific attention to sex differences.

METHOD

This was an observational cohort study in which 341 9-year-old children (177 male, 164 female) without perinatal risk were neurologically assessed, with attention to severity and type of MND. Eight domains of dysfunction were distinguished, including posture and muscle tone, fine manipulative ability and coordination. Severity of MND was based on the number of dysfunctional domains. Behaviour was assessed by parents and teachers using the Child Behavior Checklist and Teacher's Report Form (TRF); outcomes were internalizing and externalizing behaviour and total score of behavioural problems.

RESULTS

Females with complex MND or dysfunctional posture and muscle tone had increased risk for externalizing behavioural problems (OR 4.52, 95% CI 1.01-20.2, and OR 4.05, 95% CI 1.06-15.5, respectively). In males, these associations were absent. However, males with simple MND had an increased risk for behavioural problems indicated by the total TRF-score (OR 7.52, 95% CI 1.36-41.4).

INTERPRETATION

In children without perinatal risk, associations between MND and behaviour are sex-specific. In females, dysfunction of complex neural networks, including the cerebellum, is associated with externalizing behaviour. In males, neurobehavioural relationships are limited, suggesting a larger role of psychosocial factors in the genesis of behavioural problems.

Minor neurological dysfunction and cognition in 9-year-olds born at term

BACKGROUND

In children with developmental disorders, motor problems often co-occur with cognitive difficulties. Associations between specific cognitive deficits underlying learning problems and minor neurological dysfunction (MND) are still unknown.

AIMS

To assess associations between specific types of MND as clinical markers of non-optimal brain function and performance in specific cognitive domains.

STUDY DESIGN

Part of a randomized controlled trial.

SUBJECTS

Three hundred and forty one 9-year-old children born at term (177 boys, 164 girls).

OUTCOME MEASURES

Children were neurologically assessed to detect eight types of MND: mild dysfunction in posture and muscle tone, reflexes, coordination, fine manipulative ability, sensory function, cranial nerve function, choreiform dyskinesia and excessive associated movements. Cognitive function in the domains of attention, memory and language was evaluated using the Test of Everyday Attention for Children (TEA-Ch), a developmental neuropsychological assessment (NEPSY) and the Children's Memory Scale.

RESULTS

Fine manipulative disability and coordination problems were associated with lower scores on attention, memory and learning and language, other types of MND were not. Girls with coordination problems performed significantly worse on attention/executive function than those without this dysfunction; however, in boys, such association was absent.

CONCLUSION

Particularly, fine manipulative disability and coordination problems were associated with worse cognitive function in the domains of attention, learning and memory and language. Previous and present data suggest a minor sex difference in neurocognitive associations: in girls dysfunction of the cerebello-thalamo-cortical pathways may be associated with cognitive deficits, while in boys cognitive impairment may be associated with dysfunction of cortico-striato-thalamo-cortical pathways.

Neurodevelopment after moderate hyperbilirubinemia at term

BACKGROUND

The aim of this work was to investigate in a prospective study whether moderate hyperbilirubinemia in healthy term neonates is associated with an increase of minor neurological dysfunction (MND) and behavioral problems up to 18 mo.

METHOD

We enrolled 43 healthy term infants with a bilirubin level ≥ 220 µmol/l (BILI group) at 72-96 h postnatally at the University Medical Center Groningen (UMCG), including eight referrals for hyperbilirubinemia. Seventy healthy term infants born at the UMCG with bilirubin level <220 µmol/l served as comparisons (COMP group). We evaluated the neurologic condition neonatally and at 3 and 18 mo; behavior was evaluated at birth and 18 mo.

RESULTS

Rates of MND in BILI and COMP groups were similar at all ages. However, bilirubin levels of ≥ 300 µmol/l (n = 10) were associated with an increased risk of complex MND (odds ratio: 4.21; 95% confidence interval: 1.02-17.37). Neonatally, BILI infants were more often lethargic than COMP infants (odds ratio: 3.54; 95% confidence interval: 1.32-9.51); at 18 mo, they had higher hyperactivity scores (effect: 0.32; 95% confidence interval: 0.08-0.56).

CONCLUSION

Occurrence of complex MND at 18 mo in infants with moderate hyperbilirubinemia was not different from that in comparison infants, but bilirubin level ≥ 300 was associated with an increased risk of complex MND. This study also suggests that minor behavioral effects of moderate hyperbilirubinemia cannot be excluded.

The effect of preimplantation genetic screening on neurological, cognitive and behavioural development in 4-year-old children: follow-up of a RCT

STUDY QUESTION

Does embryo biopsy inherent to preimplantation genetic screening (PGS) affect neurological, cognitive and behavioural development of 4-year-old children?

SUMMARY ANSWER

PGS does not seem to affect neurological, cognitive and behavioural development of 4-year-old singletons; however, our data suggest that it may be associated with altered neurodevelopment in twins.

WHAT IS KNOWN ALREADY

Evidence concerning the safety of PGS on neurodevelopmental outcome in offspring is scarce. The present study provides information on neurodevelopmental, cognitive and behavioural outcome of 4-year-old PGS offspring.

STUDY DESIGN, SIZE, DURATION

A prospective, assessor-blinded follow-up study of children born to women who participated in a multi-centre RCT on the effect of IVF with or without PGS.

PARTICIPANTS/MATERIALS, SETTING, METHODS

At 4 years, 49 children (31 singletons, 9 sets of twins) born following IVF with PGS and 64 children (42 singletons, 11 sets of twins) born following IVF without PGS (controls) were assessed (post-natal attrition 18%). Neurological development was evaluated with the standardized, age-specific and sensitive neurological examination according to Hempel, resulting in a neurological optimality score (NOS), a fluency score and the rate of adverse neurological outcome. Primary outcome was the fluency score, as fluency of movements is easily reduced by subtle dysfunction of the brain. Cognitive development was evaluated with the Kaufman Assessment Battery for Children; behavioural development was evaluated with the Child Behavior Checklist. The effect of PGS was analysed with a mixed effects model.

MAIN RESULTS AND THE ROLE OF CHANCE

Based on the intention to treat analysis, neurodevelopmental outcome of PGS children was similar to that of controls. However, additional analyses indicated that PGS affected neurodevelopmental outcome of twins in a different way than that of singletons. The fluency score of singletons born following PGS was similar to that of control singletons [mean values, 95% confidence intervals (CIs): 12.2 (11.5;12.8) and 12.2 (11.6;12.8)], respectively, P = 0.977) that was also true for the other neurodevelopmental parameters. The fluency score of PGS twins was significantly lower than that of control twins [mean values, 95% CIs: 10.6 (9.8;11.3) and 12.3 (11.5;13.1)], respectively, P = 0.001); the same was true for the NOS. In addition, PGS in twins was associated with a higher sequential intelligence quotient score. On the other hand, other neurodevelopmental parameters were similar for PGS twins and control twins. Post hoc sample size calculation for the primary outcome parameter, the fluency score, indicated that the study groups, including the subgroups of singletons and twins, were adequately powered.

LIMITATIONS, REASONS FOR CAUTION

We assessed singletons and twins who contributed to the generalizability of the study. A limitation of our study is the relative small size of our study groups and the selective dropout in both groups (dropouts PGS group: higher gestational age; control group: less well-educated parents). These preclude the conclusion that PGS per se is not associated with neurodevelopmental, cognitive and behavioural problems in singletons and the conclusion that PGS is associated with altered neurodevelopmental outcome in twins.

WIDER IMPLICATIONS OF THE FINDINGS

The need for careful long-term monitoring of children born following embryo biopsy remains, as it is still applied in the form of PGD and it is still unknown whether embryo biopsy affects long-term neurodevelopmental outcome.

Minor neurological dysfunction and IQ in 9-year-old children born at term

AIM

The aim of this study was to examine the relationship between the severity and type of minor neurological dysfunction (MND) and IQ in 9-year-old children born at term.

METHOD

Three hundred and forty-one children (177 males, 164 females; mean age 9y, SD 3mo, range 8y 10mo-9y 7mo) who were born at term were neurologically assessed according to Touwen. Children with perinatal risk or with a congenital disorder were excluded. Special attention was paid to the severity and type of MND. Eight domains of dysfunction were distinguished, including fine manipulative ability and coordination. On the basis of the number of dysfunctional domains, the severity of dysfunction was expressed as simple MND (sMND) or complex MND (cMND). Verbal, Performance, and Full-scale IQ (FSIQ) were assessed with the Wechsler Abbreviated Scale of Intelligence. Univariate and multivariate statistical analyses were performed.

RESULTS

Neurologically normal children had higher IQ scores than those with sMND and cMND (mean FSIQ 104 [95% confidence interval (CI) 102-106] to 100 [95% CI 97-102] and 95 [95% CI 91-98] respectively). Multivariate statistics confirmed that the IQ scores of children with sMND and cMND did not differ. Fine manipulative disability and coordination problems were associated with lower IQ scores but other dysfunctions were not.

INTERPRETATION

The type of MND rather than the severity is associated with lower IQ in children born at term.

Limited motor performance and minor neurological dysfunction at school age

AIM

To investigate the relationship between motor performance and minor neurological dysfunction (MND) at school age.

METHODS

Two hundred and fifty-three children (158 boys, 95 girls; mean age 8 years and 7 months) of whom 167 children received mainstream education and 86 children special education were neurologically examined according to Touwen. Special attention was paid to the severity of MND (simple or complex form) and type of dysfunction. Motor performance was assessed with the Movement Assessment Battery for Children (MABC), a parental questionnaire (Developmental Coordination Disorder Questionnaire; DCD-Q) and a teacher's questionnaire (Motor Observation Questionnaire for Teachers; MOQ-T).

RESULTS

Total scores of MABC, DCD-Q and MOQ-T were strongly related to the severity of MND and to dysfunctional coordination and fine manipulation. Mild dysfunction in posture and muscle tone was only weakly related to limited motor performance. Children with a MABC score < 5th percentile showed significantly more often complex MND than children with scores between the 5th and 15th percentile or >15th percentile (54% vs 17% and 10%).

CONCLUSION

Limited motor performance is related to the severity and type of MND. Coordination problems and fine manipulative disability are strongly related to poor motor performance, mild dysfunctions of posture and muscle tone to a lesser extent.

ADHD: volumetry, motor, and oculomotor functions

The use of quantitative neuroimaging (volumetry), motor, and oculomotor assessments for studying children with attention-deficit/hyperactivity disorder (ADHD) has grown dramatically in the past 20 years. Most evidence to date suggests that anomalous basal ganglia development plays an important role in early manifestation of ADHD; however, widespread cerebellar and cortical delays are also observed and are associated with the behavioral (cognitive, motor, oculomotor) phenotype in children with ADHD. These motor and "executive" control systems appear to develop in parallel, such that both systems display a similar protracted developmental trajectory, with periods of rapid growth in elementary years and continued maturation into young adulthood. Development of each system is dependent on the functional integrity and maturation of related brain regions, suggesting a shared neural circuitry that includes frontostriatal systems and the cerebellum (i.e., those identified as anomalous in studies of volumetry in ADHD). Motor and oculomotor paradigms provide unique opportunities to examine executive control processes that exist at the interface between movement and cognition in children with ADHD, also linking cognition and neurological development. The observed pattern of volumetric differences, together with the known parallel development of motor and executive control systems, appears to predict motor and oculomotor anomalies in ADHD, which are highly relevant, yet commonly overlooked in clinical settings.

Minor neurological dysfunction in children with dyslexia

AIM

to improve understanding of brain function in children with severe dyslexia in terms of minor neurological dysfunctions (MNDs).

METHOD

one hundred and four children (81 males, 23 females; age range 7-12y; mean age 9y 7mo, SD 1y 2mo;) with severe dyslexia (the presence of a Full-scale IQ score of ≥ 85, retardation in single-word or text reading of ≥2y), assessed in a department of dyslexia of a third-level regional psychiatric centre, underwent a neurological examination according to Touwen and a multidisciplinary child psychiatric assessment. Special attention was paid to severity and type of MND. Data were compared with neurological morbidity data of children in the general population.

RESULTS

most children had MND (87%): 43% had simple MND, 44% complex MND. The incidence of MND was significantly higher (p<0.001) in the children with dyslexia than in the general population (simple MND 15%, complex MND 6%). Children with dyslexia showed especially fine manipulative disability and - to a lesser extent - mild dysfunction in muscle tone regulation and excessive presence of associated movements. A comorbid psychiatric syndrome was diagnosed in 66 children (63%): emotional disturbances (27%), adjustment disorder (42%), hyperkinetic disorder (15%), autism spectrum disorder (3%), specific disturbances of childhood not otherwise specified (13%). The neurological findings of children with dyslexia with and without psychiatric comorbidity were similar.

INTERPRETATION

our results demonstrate the importance of neurological and child psychiatric assessment in children with severe dyslexia. Our findings suggest that dysfunction of cortical structures plays a dominant role in dyslexia.

Early childhood stunting and later fine motor abilities

AIM

The aim of this study was to determine the effects of early childhood stunting (height for age 2SD or more below reference values) and interventions on fine motor abilities at 11 to 12 years, and the relationship between fine motor abilities and school achievement and intelligence.

METHOD

A cohort of stunted children who had participated in a randomized trial of psychosocial stimulation and/or nutritional supplementation in early childhood was compared with a group of non-stunted children. Fine motor abilities were assessed in 116 stunted (67 males, 49 females) and 80 non-stunted children (43 males, 37 females) at a mean age of 11 years 8 months (SD 4.3 mo) and 11 years 9 months (SD 3.8 mo) respectively. Testers were blind to the children's group assignment.

RESULTS

Two fine motor factors were derived: rapid sequential continuous movements (RSCM) and dexterity. No effect of the early intervention was found. RSCM scores were lower in the stunted group than in the non-stunted group (p=0.01), but differences in dexterity were not significant (p=0.18) after adjusting for social background. Among stunted children, the RSCM score was significantly associated with IQ (p=0.04) and school achievement (all p<0.05).

INTERPRETATION

Stunting in early childhood is associated with poor scores on tests of rapid sequential continuous hand movements in later childhood. Children with poorer scores are at greater risk for low IQs and low levels of school achievement.

Neurological condition of infants born after in vitro fertilization with preimplantation genetic screening

Aim of this study was to evaluate the effect of preimplantation genetic screening (PGS) on neurodevelopmental outcome in children. We conducted a prospective follow-up study of children born to women randomly assigned to in vitro fertilization with or without PGS. Primary outcome was adverse neurologic outcome at 18 mo; secondary outcomes were types of minor neurologic dysfunction (MND), neurologic outcome before 18 mo, neonatal intensive care admission, and congenital malformations. Twenty women in the PGS group participated with 25 children and 26 women in the control group participated with 31 children. Five PGS pregnancies (25%) and four control pregnancies (15%) resulted in birth of at least one child with an adverse neurologic outcome (adjusted odds ratio: 2.3 [0.4-12.0]). Dysfunction in fine motor abilities and posture and muscle tone dysregulation tended to be present more frequently after PGS. Neurologic outcome before 18 mo, neonatal intensive care admission, and prevalence of congenital malformations were similar in study and control pregnancies. Nevertheless, at child level, rates of adverse outcome were higher after PGS. In conclusion, outcome in pregnancies after in vitro fertilization (IVF) with and without PGS was similar. The small sample size precludes the conclusion that PGS is not associated with less favorable neurologic outcome. Safety of new assisted reproductive techniques should be evaluated before large-scale implementation.

The Groningen ART cohort study: ovarian hyperstimulation and the in vitro procedure do not affect neurological outcome in infancy

BACKGROUND

Due to the growing number of children born following assisted reproduction technology, even subtle changes in the children's health and development are of importance to society at large. The aim of the present study was to evaluate the specific effects of ovarian hyperstimulation and the in vitro procedure on neurological outcome in 4-18-month-old children.

METHODS

In this prospective assessor-blinded cohort study, we included singletons born following controlled ovarian hyperstimulation in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) (COH-IVF; n = 68) or modified natural cycle-IVF/ICSI (MNC-IVF; n = 57) or naturally conceived singletons of subfertile couples (NC; n = 90). Children were assessed with standardized, age-specific and sensitive neurological assessments (TINE and Hempel assessment) at 4, 10 and 18 months. Neurological examination resulted in a neurological optimality score (NOS), a fluency score and a clinical neurological classification. Fluency of movements is easily affected by neurological dysfunction and is therefore a sensitive measure for minimal changes in neuromotor development.

RESULTS

The NOS and the fluency score were similar in COH-IVF, MNC-IVF and NC children. None of the children showed major neurological dysfunction and rates of minor neurological dysfunction at the three ages were not different between the three conception groups.

CONCLUSIONS

We found no effects of ovarian hyperstimulation or the in vitro procedure itself on neurological outcome in children aged 4-18 months. The findings of our study are reassuring, nevertheless it should be kept in mind that subtle neurodevelopmental disorders may emerge when children grow older. Continuation of follow-up in older and larger groups of children is therefore still needed.

Test-retest, inter-assessor and intra-assessor reliability of the modified Touwen examination

Interest in the Touwen examination (1979) for the assessment of minor neurological dysfunction (MND) is growing. However, information on psychometric properties of this assessment is scarce. Therefore the present study aimed at assessing the test's test-retest, inter- and intra-assessor reliability. Eleven boys and 14 girls, visiting a mainstream school, aged 4-12 years, were tested neurologically by 3 investigators. Inter- and intra-assessor reliability were based on videotapes of the assessments. To determine test-retest reliability children were re-assessed after about 1 month. The various forms of reliability were calculated for neurological classification (normal, simple MND, complex MND), clusters of dysfunction and single items. Twelve girls and 7 boys showed a normal neurological condition; 2 girls and 1 boy were classified as having simple MND and 3 boys as having complex MND. The 3 forms of reliability for neurological classification were good (kappa=0.71-0.83). Reliability for the majority of cluster scores was good. Test-retest agreement was moderate for the clusters reflexes and coordination and poor for fine manipulation; inter-assessor agreement was moderate for the clusters coordination and fine manipulation; intra-assessor agreement moderate for fine manipulation. Reliability for the majority of items was good. In conclusion, the Touwen examination has a moderate to good reliability when applied in a relatively healthy population. Whether reliability is similarly good in populations of children with minor developmental disorders has to be determined.

Outcomes of infants with idiopathic hypotonia

PURPOSE

To describe the outcomes of children diagnosed before the age of two with idiopathic hypotonia.

METHODS

A total of 105 parents of children who were diagnosed with hypotonia returned a questionnaire. Medical records were reviewed.

RESULTS

A transient impairment group (10.5%) reported no problems. A minimal impairment group (32.4%) had mild problems such as learning disability or language delay but no major developmental diagnosis. A globally impaired group (40.9%) had mental retardation or a recognizable genetic/developmental diagnosis. More than 50% of the minimal impairment group had poor coordination, language delay, and learning difficulties. The mean walking age (minimal group) was 22 months. Initial fine motor and cognitive, but not gross motor, developmental quotients were significantly greater in the minimal compared with global impairment group.

CONCLUSION

Deficits in motor coordination, language, and learning difficulties were common problems that persisted in the minimal and global impairment groups.

Psychiatric morbidity is related to a chain of prenatal and perinatal adversities

BACKGROUND

Most studies on the effects of early risk factors on future mental health focus on specific obstetric complications as risk factors for specific disorders. However, obstetric complications rarely occur in isolation, and the same holds for psychiatric problems.

AIMS

To study prenatal and perinatal risk factors for psychiatric multimorbidity in early adulthood and to determine whether these differ from risk factors for monomorbidity.

STUDY DESIGN

Monomorbidity and multimorbidity of six types of psychiatric disorders were determined by a standardised psychiatric interview. Using univariate and multivariate logistic and ordinal logistic regression, associations of mono- and multimorbidity with prospectively collected early risk factors were examined.

SUBJECTS

Two hundred and eighty-five young adults selected from a prospective birth cohort on the basis of their Obstetric Optimality Scores.

OUTCOME MEASURES

Six types of psychiatric disorder and their co-occurrence.

RESULTS

Monomorbidity was related to isolated early risk factors such as low birth weight or a low Apgar score, and to an accumulation of unfavourable pre- and perinatal events. Multimorbidity on the other hand, was only related to a chain of pre- and perinatal adversities.

CONCLUSION

Research and prevention strategies should not focus solely on isolated early risk factors, but also on the entire pre- and perinatal situation.

The neuromotor examination of the preschool child and its prognostic significance

The present paper reviews the methods available for neurological or neuromotor evaluation at preschool age. General textbooks on pediatric neurology describe the neurological examination at preschool age in terms of the assessment of the evaluation of cranial nerves, muscle tone, muscle power, reflexes, and the presence of abnormal movements. They stress the fact that assessment at preschool age is difficult because of the time needed to achieve the child's cooperation. Noncooperation at the preschool neurological exam is associated with an increased risk for learning and behavioral problems at school age. At present three age-specific and standardized test for neurological or neuromotor evaluation at preschool age are available. The method of Amiel-Tison and Gosselin, of which information can be accessed easily, has the drawback that it focuses on muscle tone and reflexes. It pays little attention to the quality of spontaneous motor behavior. The other two methods, i.e., the neuromotor behavioral inventory (NBI) and the Hempel assessment, are probably more promising in terms of assessment of minor neurological dysfunction as these methods pay ample attention to the child's quality of motor behavior. All methods have in common that information in terms of concurrent validity is scarce, with no information on predictive validity. This means that further research on applicability and validity of preschool neuromotor assessment is urgently needed.

Obstetric optimality and emotional problems and substance use in young adulthood

BACKGROUND

Pregnancy and delivery are complex processes, and isolated obstetric complications rare and often accompanied or followed by a number of others.

AIMS

To study the relationship between the overall obstetric situation (as opposed to single obstetric risk factors) and emotional and substance use disorders in young adulthood, and to analyse whether these links are mediated by temperaments in childhood.

STUDY DESIGN

In a prospective birth cohort (n=3162), questionnaires were sent to mothers and teachers when the child was 7-10 years old, and to the children when they were 20-25 years old.

SUBJECTS

Six hundred and eighty-two cohort members with complete data sets at three ages (perinatal, childhood, and young adulthood).

OUTCOME MEASURES

Emotional problems and substance use in young adulthood.

MAIN RESULTS

Substance use in young adulthood was predicted better by the overall obstetrical optimality score than emotional problems were. Links studied were stronger for men than for women.

CONCLUSIONS

This study demonstrated the use of an aggregated obstetrical optimality score in analysing the associations between early risk factors and emotional problems and substance use in young adulthood.

Impaired spatial working memory in adults with attention-deficit/hyperactivity disorder: comparisons with performance in adults with borderline personality disorder and in control subjects

OBJECTIVE

This study investigated a previous claim that working memory may be 'particularly impaired' in adult attention-deficit/hyperactivity disorder (ADHD), compared with other psychiatric disorders which affect frontal lobe-mediated executive functions.

METHOD

Performance on spatial working memory (SWM) and two additional tasks were investigated for adult patients selected on the basis of DSM-IV ADHD (n = 19), adult patients selected on the basis of borderline personality disorder (BPD) (n = 19), and non-clinical control subjects (n = 19). Groups were matched for age, verbal IQ and gender.

RESULTS

Analysis of variance showed that the ADHD group had significant impairment of SWM performance relative to the non-clinical controls. Although there was a trend towards impairment in the BPD group relative to non-clinical controls, this did not reach significance.

CONCLUSION

The results are consistent with the claim that aspects of working memory are 'particularly impaired' in adult ADHD. Also, the BPD group had a longer deliberation time for one of the additional tasks, compared with the ADHD group, which indicated that the patient groups may have different patterns of neuropsychological impairments.