Neuropsychiatric disorders

Aggressive symptoms in children with tic disorders

Episodes of explosive anger and aggression are reported in patients with tic disorders and probably contribute to psychosocial stress and low quality of life. The source of these symptoms is controversial. The objective of the study was to study the relationship between tic disorders, their associated comorbidities, and aggressive behavior. The cohort included 47 children and adolescents (age 7-17 years) with Tourette syndrome or other chronic tic disorders attending a tertiary pediatric Tourette clinic. Associated psychopathology was assessed with the Yale Global Tic Severity Scale, Yale Brown Obsessive Compulsive Scale, Conners ADHD Rating Scale, Screen for Child Anxiety-Related Emotional Disorders, and Child Depression Inventory. Aggression was assessed with the Overt Aggression Scale and scores were compared with a group of 32 healthy age- and sex-matched children. There were no significant differences in aggression scores between the children with tic disorders and controls. Verbal aggression was the most prevalent type of aggression, found in 70% of the patients with tic disorders. The level of aggression was not correlated to tic severity. Comorbid attention-deficit hyperactivity disorder and obsessive-compulsive disorder increased the probability of aggressive behavior in patients with tic disorders. On regression analysis, the only significant predictor of aggression was the severity of attention-deficit hyperactivity disorder. This study suggests that there is no difference in aggressive behavior between children with tics without comorbidities and healthy children. It is possible that aggressive behavior in children with tic disorders is predominantly associated with comorbid attention-deficit hyperactivity disorder.

Movement-related potentials in high-functioning autism and Asperger's disorder

Autism and Asperger's disorder (AD) are neurodevelopmental conditions that affect cognitive and social-communicative function. Using a movement-related potential (MRP) paradigm, we investigated the clinical and neurobiological issue of 'disorder separateness' versus 'disorder variance' in autism and AD. This paradigm has been used to assess basal ganglia/supplementary motor functioning in Parkinson's disease. Three groups (high functioning autism [HFA]: 16 males, 1 female; mean age 12y 5mo [SD 4y 4mo]; AD: 11 males, 2 females; mean age 13y 5mo [SD 3y 8mo]; comparison group: 13 males, 8 females; mean age 13y 10mo [SD 3y 11mo]) completed a cued motor task during electroencephalogram recording of MRPs. The HFA group showed reduced peak amplitude at Cz, indicating less activity over the supplementary motor area during movement preparation. Although an overall significant between-group effect was found for early slope and peak amplitude, sub-analysis revealed that the group with AD did not differ significantly from either group. However, it is suggested that autism and AD may be dissociated on the basis of brain-behaviour correlations of IQ with specific neurobiological measures. The overlap between MRP traces for autism and Parkinson's disease suggests that the neurobiological wiring of motor functioning in autism may bypass the supplementary motor area/primary motor cortex pathway.

Constipation with acquired megarectum in children with autism

OBJECTIVE

Recent evidence suggests that autistic children may have significant gastrointestinal symptoms. Although constipation occurs in 2% to 5% of healthy children, its clinical diagnosis is often difficult in children with behavioral disorders. We thus aimed to assess the prevalence of fecal loading in autistic children with gastrointestinal symptoms and to identify possible predictors of constipation.

METHODS

We studied abdominal radiographs of 103 autistic children (87 boys) who were referred for gastroenterological assessment, in comparison with 29 control radiographs from children who were referred to the emergency department, most with abdominal pain. Radiographs were scored independently, in blinded manner, by 4 pediatric gastroenterologists and a radiologist. The severity of constipation was determined using a validated index. Details of stool habit, abdominal pain, dietary history, and laxative use were obtained from case notes.

RESULTS

The incidence of constipation in the control subjects with abdominal pain was higher than reported for normal children. Despite this, moderate or severe constipation was more frequent in the autistic group than in the control subjects (36% vs 10%). Analysis of rectosigmoid loading showed more striking differences (54.4% of autistic children had moderate/severe loading or acquired megarectum compared with 24.1% of control subjects). Multivariate regression analysis showed consumption of milk to be the strongest predictor of constipation in the autistic group, whereas stool frequency, gluten consumption, soiling, and abdominal pain were not predictive of constipation.

CONCLUSIONS

Constipation is a frequent finding in children with gastrointestinal symptoms and autism, particularly in the rectosigmoid colon, often with acquired megarectum. The absence of any correlation between the clinical history and the degree of fecal impaction in autistic children confirms the importance of an abdominal radiograph in the assessment of their degree of constipation.

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

OBJECTIVE

The aim of the study was to evaluate whether in pre-adolescent children specific types of minor neurological dysfunction (MND) are related to specific types of learning and behavioural problems, and whether it is the type or the severity of neurological dysfunction that matters most.

METHOD

A total of 1186, 5.5-11-year-old, children were examined for the presence of clusters of signs of MND. Parents and teachers completed brief behaviour rating scales. In school-aged children (n = 580) cognitive achievement was assessed using standardized Dutch tests. Least-squares regression was used to examine neurobehavioural and neurocognitive links.

RESULTS

Children with more MND clusters performed worse scholastically and had more signs of attention deficit than others. Externalizing and internalizing behaviour were only linked to specific forms of MND.

CONCLUSION

Evaluation of the neurological condition of the child with learning and behavioural problems offers insight into the aetiology and pathogenesis of these problems.

Autism and the pervasive developmental disorders

Our understanding of childhood autism and the related pervasive developmental disorders continues to advance in many areas. Nevertheless, the heterogeneity of phenotypic expression presents many challenges, not least to efforts to ascertain the prevalence of the disorders. There is now wide agreement on, and reliable application of, the diagnostic criteria for childhood autism, but there is less agreement on and less reliable application of the criteria for the related disorders atypical autism, pervasive developmental disorder-unspecified and Asperger's syndrome. Evidence about genetic associations indicates that several genes are involved in creating susceptibility to the disorder, and the first steps to identify susceptibility loci have begun. Neuroanatomical models have yet to receive consistent support but early signs of promising advances have been made in pharmacological interventions, and adequate evaluation of behavioural intervention programmes is now underway.