Biomedical subjects

Johan S H Vles

Publications and source records attributed to Johan S H Vles.

18 recordsLinked to original sources

PubMed2006

Methylphenidate improves reading performance in children with attention deficit hyperactivity disorder and comorbid dyslexia: an unblinded clinical trial.

Attention Deficit Hyperactivity Disorder (ADHD) and dyslexia are frequently co-occurring disorders. Although methylphenidate (MPH) is the primary treatment for ADHD, the effect on reading in children with these comorbid problems is not yet known. This study was an unblinded clinical trial to evaluate the reading performance before and after treatment with MPH. Reading performance was compared with General Linear Model repeated measures between three groups: (1) an experimental group of children with both ADHD and dyslexia (N = 24), (2) a control group of children with ADHD (N = 9) and (3) a control group of children with dyslexia (N = 10). MPH improved reading performance significantly stronger in the experimental group than in the control groups; the number of correctly read words increased to a larger extent. In conclusion, MPH proved to be an aid in the reading process of children with ADHD and comorbid dyslexia by improving the learning conditions, but MPH cannot cure the reading disorder. Future research should study the effect of MPH on reading in a double-blind clinical trial.

Adolescent↗

PubMed2006

Isolated spinal accessory neuropathy in an adolescent: a case study.

We describe a case of dynamic scapular winging due to trapezius muscle paresis following a sport-related injury of the accessory nerve. The typical clinical findings related to the peripheral nerve involved, the importance of neurophysiologic work-up, and possibilities for treatment are discussed.

Accessory Nerve Injuries↗

PubMed2006

Folinic acid-responsive seizures initially responsive to pyridoxine.

This report presents a male who developed clonic seizures on the day he was born. The next day, the diagnosis of pyridoxine-dependent seizures was made. However, contradictory to this diagnosis, seizures reappeared despite treatment with pyridoxine. Seizures ceased after folinic acid was initiated. The clinical and biochemical characteristics of folinic acid-responsive seizures are reviewed. Treatment with folinic acid should be considered in neonatal seizures of unknown origin that do not respond to pyridoxine, or manifest a transient response to pyridoxine.

Epilepsy↗

PubMed2006

Are males with Duchenne muscular dystrophy at risk for reading disabilities?

Males with Duchenne muscular dystrophy have sub-average cognitive capacities and may manifest more specifically language-related deficits. In the current study, the information-processing capacity, reading performance, and behavioral functioning of 25 Dutch males with Duchenne muscular dystrophy (mean age 10.1 years) were systematically assessed. This study relied on the use of a new battery of tests to explore more precisely reading disabilities in males with Duchenne muscular dystrophy. Five of the males had serious reading problems and another five had moderate reading problems, which indicates that reading problems are significantly more common in males with Duchenne muscular dystrophy than in males from a normal population. These reading problems were independent of the level of information processing and behavioral functioning. Implications of these findings and possible directions for future research are discussed, especially with regard to the early detection and treatment of reading problems in males with Duchenne muscular dystrophy.

Aptitude↗

PubMed2005

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.

Anticonvulsants↗

PubMed2005

Acid-base status at birth, spontaneous motor behaviour at term and 3 months and neurodevelopmental outcome at age 4 years in full-term infants.

OBJECTIVE: The aim of the study was to assess the relationship between acid-base status and quality and quantity of General Movements (GMs) at birth and quality of GMs at age 3 months and motor, cognitive and behavioural functioning at the age of 4 years. METHODS: From a cohort of 84 term children with different umbilical artery pH without severe neonatal neurological abnormalities, GMs were assessed at term and at 3 months. At the age of 4 years, 44 children were assessed by means of the Movement Assessment Battery for Children (Movement-ABC), Neurological Examination for Toddlers of Hempel, Kaufman Assessment Battery for Children information processing (Kaufman ABC), Visuomotor Integration (VMI), the Child Behaviour Checklist (CBCL) and Precursors ADHD Questionnaire (PAQ). RESULTS: We found no relationship between pH or GM-quality and quantity at term or GM-quality at 3 months and scores on most of the items of the Movement-ABC, cognitive and behavioural outcome. However, neonatal pH value and GM-quality at 3 months were related to some extent to the presence of subtle signs of neuromotor dysfunction as measured by the Hempel test. CONCLUSIONS: In a sample of infants with a large variation in umbilical artery pH and without severe neonatal neurological abnormalities, acid-base status at birth and quality of GMs at 3 months of age is not predictive for motor milestone achievement, cognitive and behavioural functioning at 4 years, but these parameters are related to a less optimal condition of the nervous system. The latter finding has, however, limited clinical significance.

Acid-Base Equilibrium↗

PubMed2005

Dopamine transporter in attention-deficit hyperactivity disorder normalizes after cessation of methylphenidate.

Attention-deficit hyperactivity disorder (ADHD) is a common neurodevelopmental disorder of childhood, which is frequently treated with methylphenidate. The short-term response to treatment with methylphenidate is a substantial decrease in dopamine transporter density, with improvement in neuropsychological tests. In this study, single-photon emission computed tomography was used to investigate possible long-term alterations in the cerebral dopamine system after cessation of treatment with methylphenidate in five children with ADHD. Three months after initiation of treatment with methylphenidate, a reduction of the dopamine transporter in the striatal system was observed. Methylphenidate was administered for a period of 9 to 20 months. Follow-up with single-photon emission computed tomography after withdrawal of methylphenidate medication disclosed an increase of dopamine transporter activity comparable with pretreatment values. The observed upregulation of dopamine transporter activity might support the assumption that methylphenidate does not lead to permanent damage of the nigrostriatal dopaminergic pathways.

Attention Deficit Disorder with Hyperactivity↗

PubMed2005

Speed, speed variability, and accuracy of information processing in 5 to 6-year-old children at risk of ADHD.

The early assessment of Attention-Deficit/Hyperactivity Disorder (ADHD) children has mainly focused on the behavioral, social, and pre-academic impairments. This study examined whether 5 to 6-year-old children at risk of ADHD are characterized by information-processing deficits. By screening 1317 children in Southern Limburg (the Netherlands) with the Child Behavior Checklist, 363 were selected and underwent a computerized examination. Eighteen months later, standardized psychiatric information was obtained. Thirty-three ADHD children were compared with 75 borderline ADHD children, 122 pathological controls, and 133 healthy controls. ADHD and borderline ADHD children were slower and more variable in their processing speed on all tasks than children with no or other pathology. These differences were most pronounced for the divided and focused attention tasks. Furthermore, one measure of a state regulation deficit discriminated between groups. With regard to accuracy, only the proportion of misses on a go-no-go task was higher in the ADHD group than in the other groups. Evidence was found that ADHD is better seen as a continuum rather than a discrete category. Already at a young age, children at risk of ADHD show specific information-processing deficits. Deficits in time perception and/or energetic state control in children with ADHD may possibly account for subnormal task performance.

Attention↗

PubMed2005

Pulsed and continuous 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.

Animals↗

PubMed2004

Reliability and validity of a qualitative and quantitative motor test for 5- to 6-year-old children.

Clumsiness in preschool children may be a precursor to impaired academic performance and psychological and developmental problems. It is assumed that in this age group especially the qualitative aspects (=pattern) of a movement reflect variations in motor development. Currently available motor tests for this age group, however, mostly objectify quantitative aspects of a movement alone and do not objectify qualitative aspects. The aim of this study was to develop a new, valid, and reliable tool (Maastricht's Motor Test (MMT)) to objectify qualitative and quantitative aspects of movement in 5- to 6-year-old children. The test covers Static Balance (14 items), Dynamic Balance (20 items), Ball Skills (eight items), and Diadochokinesis and Manual Dexterity (28 items). About 50% of the items measure qualitative aspects and 50% quantitative aspects of movements. In total 487 subjects were recruited from the first year of primary school. To validate the test, one school doctor's global judgment was used as a form of expert validity. Sensitivity and specificity were calculated for different cut-off points. Intra-class correlation coefficients (ICC) of inter-rater (N = 42), intra-rater (N = 24), and test-retest (N = 43) agreement were determined. ICCs of the qualitative total score ranged from 0.61 to 0.95 and were comparable with those of the total quantitative score. The MMT can be used to objectify both qualitative and quantitative aspects of movements. The additional value of the qualitative observations has to be determined in children with various developmental problems.

Age Factors↗

PubMed2004

Neonatal loss of motor function in human spina bifida aperta.

OBJECTIVE: In neonates with spina bifida aperta (SBA), leg movements innervated by spinal segments located caudal to the meningomyelocele are transiently present. This study in neonates with SBA aimed to determine whether the presence of leg movements indicates functional integrity of neuronal innervation and whether these leg movements disappear as a result of dysfunction of upper motor neurons (axons originating cranial to the meningomyelocele) and/or of lower motor neurons (located caudal to the meningomyelocele). METHODS: Leg movements were investigated in neonates with SBA at postnatal day 1 (n = 18) and day 7 (n = 10). Upper and lower motor neuron dysfunction was assessed by neurologic examination (n = 18; disinhibition or inhibition of reflexes, respectively) and by electromyography (n = 12; absence or presence of denervation potentials, respectively). RESULTS: Movements, related to spinal segments caudal to the meningomyelocele, were present in all neonates at postnatal day 1. At day 1, leg movements were associated with signs of both upper (10 of 18) and lower (17 of 18) motor neuron dysfunction caudal to the meningomyelocele. In 7 of 10 neonates restudied after the first postnatal week, leg movements had disappeared. The absence of leg movements coincided with loss of relevant reflexes, which had been present at day 1, indicating progression of lower motor neuron dysfunction. CONCLUSIONS: We conclude that the presence of neonatal leg movements does not indicate integrity of functional lower motor neuron innervation by spinal segments caudal to the meningomyelocele. Present observations could explain why fetal surgery at the level of the meningomyelocele does not prevent loss of leg movements.

Electromyography↗

PubMed2003

A new leukoencephalopathy with brainstem and spinal cord involvement and high lactate.

We identified eight patients with a distinct magnetic resonance imaging pattern of inhomogeneous cerebral white matter abnormalities and selective involvement of brainstem and spinal tracts. Proton magnetic resonance imaging showed increased lactate in the abnormal white matter. Clinically, the patients had slowly progressive pyramidal, cerebellar, and dorsal column dysfunction. The uniform, highly characteristic magnetic resonance imaging pattern and the similarities in clinical and magnetic resonance spectroscopy findings provide evidence for a new disease entity. Autosomal recessive inheritance is likely.

Adolescent↗

PubMed2003

Low- and high-level controlled processing in executive motor control tasks in 5-6-year-old children at risk of ADHD.

BACKGROUND: The scant research on the characteristics of Attention-Deficit/Hyperactivity Disorder (ADHD) in kindergarten years curtails progress on early assessment of ADHD. METHOD: By screening a general population sample of 1317 five- to six-year-old children, four groups of children were selected. The performance of 30 children later diagnosed with ADHD was compared with 74 children later diagnosed with 'borderline ADHD' (children exhibiting all ADHD symptoms but without disruptions on two situations), 113 children later diagnosed with other psychopathology, and 126 healthy controls on computerised motor control tasks involving low- and high-level controlled processing. In addition, motor control was compared with movement speed. RESULTS: The children at risk of ADHD were in general less accurate and more variable in their movements than the children with other psychopathology and healthy controls. Under conditions of high-level controlled processing, the children at risk of ADHD were disproportionately more inaccurate and had a more unstable performance with their preferred hand than the other children. In addition, linear effects were found, with the children at risk of ADHD having the worst performance, followed by the children with 'borderline ADHD', and then both groups of control children. No significant group differences were found in movement speed. CONCLUSIONS: The main findings are interpreted as evidence for a specific deficit in high-level controlled processing in young children at risk of ADHD, now found in a motor task, rather than a response task. Furthermore, the results support the notion that ADHD represents a dimensional trait. In addition, problems in movement control (the need to allocate attentional capacity) rather than problems in movement speed distinguish children at risk of ADHD from other children. The findings are interpreted as evidence that higher-order executive processes, such as self-control and self-regulation, are already affected early in the development of ADHD.

Attention↗

PubMed2002

Quality of movement as predictor of ADHD: results from a prospective population study in 5- and 6-year-old children.

The aims of this prospective study were (1) to examine whether quantitative and/or qualitative aspects of motor performance in 5- to 6-year-old children can predict attention-deficit-hyperactivity disorder (ADHD) 18 months later; (2) to investigate whether this relation is also present in oppositional defiant disorder and conduct disorder (ODD/CD). Quantitative and qualitative aspects of motor performance were tested in a selected community sample (n=401; 232 males, 169 females; mean age 6 years 4 months, SD 6 months, range 5 years 4 months to 7 years 11 months) using the Maastricht Motor Test. Eighteen months later, standardized psychiatric information was obtained with the Amsterdam Diagnostic Interview for Children and Adolescents: 35 children were classified as having ADHD, and 92 children as having ODD/CD. Weighted analyses were used in logistic regression analyses to investigate predictive values. Unlike quantitative aspects of motor performance, qualitative aspects were predictive of ADHD. Motor performance was not predictive of ODD/CD.

Attention Deficit Disorder with Hyperactivity↗

PubMed2002

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.

Attention Deficit Disorder with Hyperactivity↗

PubMed2002

A longitudinal community study: do psychosocial risk factors and child behavior checklist scores at 5 years of age predict psychiatric diagnoses at a later age?

OBJECTIVE: To examine the extent to which certain risk factors in 5- to 6-year-old children predict later psychopathology in a population-based sample of children from the province of Limburg in the south of the Netherlands. METHOD: Of the 2,290 children of interest, 1,317 children were screened with the Child Behavior Checklist (CBCL) and psychosocial risk factors for these children were collected. On the basis of the CBCL ratings, 403 children participated in the second stage in which, 1.5 years later, standardized child psychiatric information was obtained. Weighted logistic regression analyses were used to investigate predictors of psychopathology. RESULTS: In separate analyses of specific types of child psychopathology, different risk factors emerged as significant. Low-level parental occupation and having foreign-born parents were predictive of conduct disorders, and living in a single-parent family and a having a life event were the most important predictors of mood and anxiety disorders. Furthermore, CBCL-based ratings at 5 to 6 years of age corresponded well with interview-defined diagnoses 1.5 years later. CONCLUSIONS: Investigation of psychosocial risk factors and CBCL scores at the age of 5 to 6 years could be helpful in predicting child psychopathology and could help identify children at risk, in order to provide them with timely attention.

Adolescent↗

PubMed2002

Acute distortion of the anatomy of the third ventricle during third ventriculostomy. Report of four cases.

The authors report on four third ventriculostomy procedures in which upward ballooning of the third ventricular floor occurred immediately after perforation of the floor and withdrawal of a Fogarty catheter. The floor herniated into the third ventricle, hindering the endoscopic view. Preoperative magnetic resonance imaging demonstrated a similar anatomy in all four cases, consisting of hydrocephalus, extreme dilation of the third ventricle, and disappearance of the interpeduncular cistern due to a very thin, membranous floor of the third ventricle, which herniated downward, draping over the basilar artery. The authors suggest that excessive rinsing in combination with this anatomical configuration provoked the phenomenon of upward ballooning of the third ventricular floor, which is described in this report.

Adult↗

PubMedDate not supplied

Relation between cognitive and motor performance in 5- to 6-year-old children: results from a large-scale cross-sectional study.

The relation between cognitive and motor performance was studied in a sample of 378 children aged 5-6. Half of these children had no behavior problems; the others were selected for externalizing (38%) or internalizing problems (12%). Quantitative and qualitative aspects of motor performance were related to several aspects of cognition, after controlling for the influence of attention. No relation between global aspects of cognitive and motor performance was found. Specific positive relations were found between both aspects of motor performance, visual motor integration and working memory, and between quantitative aspects of motor performance and fluency. These findings reveal interesting parallels between normal cognitive and motor development in 5- to 6-year-old children that cannot be ascribed to attention processes.

Attention↗