Johan S.H. Vles

Pulsed and continous radiofrequency current adjacent to the cervical dorsal root ganglion of the rat induces late cellular activity in the dorsal horn

Background: Pulsed radiofrequency treatment has recently been described as a non-neurodestructive or minimally neurodestructive alternative to radiofrequency heat lesions. In clinical practice long-lasting results of pulsed radiofrequency treatment adjacent to the cervical dorsal root ganglion for the management of chronic radicular spinal pain have been reported without neurologic complications. However, the mode of action is unclear. An early (3 h) effect of pulsed radiofrequency as measured by an increase of c-Fos in the pain-processing neurons of the dorsal horn of rats has been described in the literature. This effect was not mediated by tissue heating. The authors investigated a possible late or long-term effect of three different radiofrequency modalities. Methods: Cervical laminectomy was performed in 19 male Wistar rats. The cervical dorsal root ganglion was randomly exposed to one of the four interventions: sham, continuous radiofrequency current at 67 centigrades, or pulsed radiofrequency current for 120 s or 8 min. The animals were sacrificed and the spinal cord was prepared for c-Fos labeling 7 days after the intervention. Results: The number of c-Fos immunoreactive cells in the dorsal horn was significantly increased in the three different radiofrequency modalities as compared with sham. No significant difference was demonstrated between the three active intervention groups. Conclusions: The authors demonstrated a late neuronal activity in the dorsal horn after exposure of the cervical dorsal root ganglion to different radiofrequency modalities, which was not temperature dependent.

Neuropsychiatric Disorders in Males With Duchenne Muscular Dystrophy: Frequency Rate of Attention-Deficit Hyperactivity Disorder (ADHD), Autism Spectrum Disorder, and Obsessive—Compulsive Disorder:

Using a questionnaire-based study, we assessed the parent-reported prevalence of attention-deficit hyperactivity disorders (ADHDs), autism spectrum disorders, and obsessive—compulsive disorders in a group of 351 males with Duchenne muscular dystrophy. Of the 351 males with Duchenne muscular dystrophy, 11.7% were reported to have a comorbid diagnosis of ADHD, 3.1% had autism spectrum disorder, and 4.8% had obsessive—compulsive disorder. It can be concluded that the incidence of these neuropsychiatric disorders is higher in Duchenne males than in the normal population. This finding, together with recent reports on the higher prevalence of cognitive and learning problems in Duchenne, supports the view that Duchenne muscular dystrophy is not only a muscular disorder but also a disorder affecting the brain. It is important for clinical practice to take in account this heightened association. More research is needed to examine this association and its consequences.

Neighbourhood level and individual level SES effects on child problem behaviour: a multilevel analysis

OBJECTIVE This study examined whether neighbourhood level socioeconomic variables have an independent effect on reported child behaviour problems over and above the effect of individual level measures of socioeconomic status. DESIGN AND SETTING Multilevel analysis of cross sectional survey data relating individual level child behavioural problems and parental measures of socioeconomic status with neighbourhood level measures of socioeconomic deprivation in the city of Maastricht, the Netherlands. PARTICIPANTS Children born in the years 1990–1991 attending the second grade of normal kindergarten schools in the city of Maastricht, the Netherlands. Out of 1417 eligible 5–7 year olds, the parents of 734 children (51.8%) agreed to participate. MAIN RESULTS Child behaviour problems were more frequent in families of low parental occupation and education (F=14.51, df 3, 721, p<0.001; F=12.20, df 3, 721, p<0.001, respectively) and in families living in deprived neighbourhoods (F=13.26, df 2, 722, p<0.001). Multilevel random effects regression analysis showed that the effect of neighbourhood level deprivation remained after adjustment for individual level socioeconomic status (B over three levels of deprivation: 1.36; 95%CI=0.28, 2.45). CONCLUSIONS Living in a more deprived neighbourhood is associated with higher levels of child problem behaviour, irrespective of individual level socioeconomic status. The additional effect of the neighbourhood may be attributable to contextual variables such as the level of social cohesion among residents.

Cognitive and behavioral effects of nocturnal epileptiform discharges in children with benign childhood epilepsy with centrotemporal spikes

This review addresses the effects of subclinical localized epileptiform discharges during sleep in children with benign childhood epilepsy with centrotemporal spikes (BCECTS) on cognition and behavior. A diversity of educational deficits, behavioral impairments, language delay, and neuropsychological test results have been reported in children with BCECTS. The occurrence of atypical seizure characteristics seems to be related to language delay, and several atypical EEG characteristics are related to cognitive or behavioral problems. It remains to be shown whether treatment of nocturnal discharges in children with BCECTS is indicated to improve cognitive and behavioral problems.

Verbal fluency over time as a measure of automatic and controlled processing in children with ADHD

The performance of ADHD children on semantic category fluency (SCF) versus initial letter fluency (ILF) tasks was examined. For each participant, word production was recorded for each 15-s time slice on each task. Performance on both fluency tasks was compared to test the hypothesis that children with ADHD are characterized by a performance deficit on the ILF task because performance on this task is less automated than performance on the SCF. Children classified with ADHD (N = 20) were compared to children with other psychopathology (N = 118) and healthy controls (N = 130). Results indicated that the groups could not be differentiated by the total number of words produced in 60 s in either fluency task. As hypothesized, a significant interaction of group by productivity over time by type of fluency task was found: ADHD children had more problems finding words in the first 15 s of the IFL than did children in the other two groups, and as compared with their performance on the SCF. Results were taken to indicate that children with ADHD symptoms show a delay in the development of automating skills for processing abstract verbal information.

Botulinum toxin A and upper limb functional skills in hemiparetic cerebral palsy: a randomized trial in children receiving intensive therapy

The objective of this study was to determine whether the use of intramuscular botulinum toxin A (BTX‐A) increases upper limb function and skills in the context of a specific therapy programme in children with hemiparetic cerebral palsy. Twenty children (nine females, 11 males) aged 4 to 16 years who were thought likely to benefit from BTX‐A treatment were included. After matched pairs were made, on the basis of Zancolli grade and age, randomization took place. All patients were given structured rehabilitation (physiotherapy and occupational therapy three times a week for 6 months), and half of the patients received intramuscular BTX‐A. No placebo injections were given in the control group. Participants were assessed at baseline, at 2 and 6 weeks, and at 3, 6, and 9 months after injection. The Ash worth scale, active range of motion of arm joints, the Melbourne assessment of upper limb function, the Pediatric Evaluation of Disability Inventory, and the nine‐hole peg test were used for outcome measurement. Observers were blinded for treatment allocation only for scoring the Melbourne test. The children in the treatment group showed a clinically relevant increase in active dorsal flexion, and tone reduction of the wrist. For the functional outcome measures, no statistically significant differences between the groups could be demonstrated. Intramuscular BTX‐A added to an intensive therapy programme reduces impairment for at least 9 months; the effect on activity level is still uncertain.

Child Psychiatric Diagnoses in a Population of Dutch Schoolchildren Aged 6 to 8 Years

OBJECTIVE To determine the prevalence rates of child psychiatric diagnoses in a school-based population of children aged 6 to 8 years in the south of the province of Limburg (The Netherlands). METHOD In a two-stage design 1,317 children were screened with the Child Behavior Checklist. From 403 of these children, child psychiatric information was obtained with the Amsterdam Diagnostic Interview for Children and Adolescents (ADIKA, DSM-III-R/IV). Data were generalized to the responder group (n = 1,317) and to the entire cohort (N = 2,290). For the latter procedure, a prediction model was used to generalize ADIKA results to the nonresponders (n = 973). RESULTS Estimates of the prevalence of different ADIKA diagnoses in the responder group were quite comparable with those for the entire cohort. Twenty-four percent of the entire cohort met criteria for a single disorder, and 21.0% met criteria for two or more disorders. However, in only 5.7% of the cases parents did report a need for help. CONCLUSIONS Where other studies generalize psychiatric diagnoses to the responder group only, this report adds new information by generalizing the prevalence to a school-based cohort of children aged 6 to 8 years. These prevalence estimates are of importance with regard to the demand for care for child psychopathology.

Semantic category fluency versus initial letter fluency over 60 seconds as a measure of automatic and controlled processing in healthy school-aged children

Verbal fluency was operationalized as the number of words produced in a restricted category (i.e., semantic category [SCF] and words beginning with a given letter [ILF]) in 60 seconds. Word production in the first 15 seconds of either type of fluency task was defined as a measure of automatic information processing, whereas word production in the remaining 45 seconds (in 15-second periods) was taken as a measure of controlled information processing. Data revealed that over 60 seconds healthy children aged 8.4–9.7 years (n = 91) produced significantly more words and less incorrect responses on the SCF task than on the ILF task. Although word production was a function of both type of task and time, it was highest in the initial time slice of either type of fluency and decreased as time on task increased. Finally, no sex differences were found for any measure of performance on either type of fluency task. In contrast, the level of occupational achievement of the caregiver (LOA) appeared to be a determinant of the child’s performance on either type of fluency task, indicating that LOA affects higher-order processes, such as the automation of newly learned verbal skills and effortful processing.

EEG characteristics related to educational impairments in children with benign childhood epilepsy with centrotemporal spikes.

Purpose: Learning and behavioral difficulties often occur in benign childhood epilepsy with centrotemporal spikes (BCECTS). In recent years, several electroencephalogram (EEG) characteristics have been related to the occurrence of learning and behavioral problems.

Neurocognitive performance of 5- and 6-year-old children who met criteria for attention deficit/hyperactivity disorder at 18 months follow-up: results from a prospective population study.

The aim of this prospective study was to examine whether neurocognitive performance of children aged 5–6 years distinguished children who were later diagnosed with attention deficit/hyperactivity disorder (ADHD) or “borderline ADHD” from children without ADHD after adjustment for behavioral measures and to examine the influence of comorbid psychopathology. Out of a general population of 1,317 children, 366 children were selected on the basis of their scores on the Child Behavior Checklist (CBCL). Eighteen months later, the parents were interviewed using a standardized child psychiatric interview: 33 children were classified as ADHD and 75 children as borderline ADHD, and there were 258 children without ADHD. Children with rated ADHD were significantly impaired on measures of visuomotor ability and working memory compared to children without ADHD after adjustment for CBCL results. The performance of borderline ADHD children was in between that of children with and without ADHD. In addition, 4 groups of children were analyzed: 9 ADHD, 24 ADHD with comorbid oppositional defiant disorder/conduct disorder (ODD/CD), 59 ODD/CD, and 274 controls. Children with rated comorbid ADHD and ODD/CD performed significantly worse on these tasks compared to children with rated ODD/CD and control children while they did not differ from ADHD children. Our results imply that neurocognitive measures can contribute to the early identification of ADHD with and without comorbid ODD/CD.