Induced neural phase precession through exogeneous electric fields.

The gradual shifting of preferred neural spiking relative to local field potentials (LFPs), known as phase precession, plays a prominent role in neural coding. Correlations between the phase precession and behavior have been observed throughout various brain regions. As such, phase precession is suggested to be a global neural mechanism that promotes local neuroplasticity. However, causal evidence and neuroplastic mechanisms of phase precession are lacking so far. Here we show a causal link between LFP dynamics and phase precession. In three experiments, we modulated LFPs in humans, a non-human primate, and computational models using alternating current stimulation. We show that continuous stimulation of motor cortex oscillations in humans lead to a gradual phase shift of maximal corticospinal excitability by ~90°. Further, exogenous alternating current stimulation induced phase precession in a subset of entrained neurons (~30%) in the non-human primate. Multiscale modeling of realistic neural circuits suggests that alternating current stimulation-induced phase precession is driven by NMDA-mediated synaptic plasticity. Altogether, the three experiments provide mechanistic and causal evidence for phase precession as a global neocortical process. Alternating current-induced phase precession and consequently synaptic plasticity is crucial for the development of novel therapeutic neuromodulation methods.

Distress and post-traumatic stress in parents of patients with congenital gastrointestinal malformations: a cross-sectional cohort study.

BACKGROUND: Congenital gastrointestinal malformation (CGIM) require neonatal surgical treatment and may lead to disease-specific sequelae, which have a potential psychological impact on parents. The aim of this study is to assess distress and symptoms of post-traumatic stress disorder (PTSD) in parents of patients with CGIM. In this cross-sectional study, seventy-nine parents (47 mothers and 32 fathers) of 53 patients with CGIM completed the Distress Thermometer for Parents (DT-P) and the Self Rating Scale for Posttraumatic Stress Disorders (SRS-PTSD) as part of the multidisciplinary follow-up of their children (aged 5-35 months). Group differences were tested between parents and representative Dutch reference groups with regard to rates of (clinical) distress and PTSD, and severity of overall distress and PTSD, for mothers and fathers separately. Mixed model regression models were used to study factors associated with the risk of (clinical) distress, PTSD and with severity of symptoms of PTSD (intrusion, avoidance and hyperarousal). RESULTS: Prevalence of clinical distress was comparable to reference groups for mothers (46%) and fathers (34%). There was no difference in severity of overall distress between both mothers as well as fathers and reference groups. Prevalence of PTSD was significantly higher in mothers (23%) compared to the reference group (5.3%) (OR = 5.51, p < 0.001), not in fathers (6.3% vs 2.2.%). Symptoms of intrusion were commonly reported by all the parents (75%). Longer total length of child's hospital stay was associated with more severe symptoms of intrusion, avoidance and hyperarousal. Child's length of follow-up was negatively associated with severity of intrusion. CONCLUSIONS: Having a child with CGIM has a huge impact on parents, demonstrated by a higher prevalence of PTSD in mothers, but not fathers, compared to parents in the general population. Monitoring of symptoms of PTSD of parents in follow-up is necessary.

Bone mineral density in children and adolescents with Prader-Willi syndrome: a longitudinal study during puberty and 9 years of growth hormone treatment.

CONTEXT: Longitudinal data on bone mineral density (BMD) in children and adolescents with Prader-Willi Syndrome (PWS) during long-term GH treatment are not available. OBJECTIVE: This study aimed to determine effects of long-term GH treatment and puberty on BMD of total body (BMDTB), lumbar spine (BMDLS), and bone mineral apparent density of the lumbar spine (BMADLS) in children with PWS. DESIGN AND SETTING: This was a prospective longitudinal study of a Dutch PWS cohort. PARTICIPANTS: Seventy-seven children with PWS who remained prepubertal during GH treatment for 4 years and 64 children with PWS who received GH treatment for 9 years participated in the study. INTERVENTION: The children received GH treatment, 1 mg/m(2)/day (≅ 0.035 mg/kg/d). MAIN OUTCOME MEASURES: BMDTB, BMDLS, and BMADLS was measured by using the same dual-energy x-ray absorptiometry machine for all annual measurements. RESULTS: In the prepubertal group, BMDTB standard deviation score (SDS) and BMDLSSDS significantly increased during 4 years of GH treatment whereas BMADLSSDS remained stable. During adolescence, BMDTBSDS and BMADLSSDS decreased significantly, in girls from the age of 11 years and in boys from the ages of 14 and 16 years, respectively, but all BMD parameters remained within the normal range. Higher Tanner stages tended to be associated with lower BMDTBSDS (P = .083) and a significantly lower BMADLSSDS (P = .016). After 9 years of GH treatment, lean body mass SDS was the most powerful predictor of BMDTBSDS and BMDLSSDS in adolescents with PWS. CONCLUSIONS: This long-term GH study demonstrates that BMDTB, BMDLS, and BMADLS remain stable in prepubertal children with PWS but decreases during adolescence, parallel to incomplete pubertal development. Based on our findings, clinicians should start sex hormone therapy from the age of 11 years in girls and 14 years in boys unless there is a normal progression of puberty.

New insights into factors influencing adult height in short SGA children: Results of a large multicentre growth hormone trial.

BACKGROUND: Growth hormone (GH) treatment is effective in improving adult height (AH) in short children born SGA. However, there is a wide variation in height gain, even after adjustment for predictive variables. It is therefore important to investigate new factors which can influence the response to GH. OBJECTIVE: To investigate the efficacy of GH treatment (1 mg/m(2/) day) in short SGA children on AH. To assess the relation between spontaneous catch-up growth after birth and growth during puberty on the total height gain SDS to AH. PATIENTS: Longitudinal GH trial in 170 children. RESULTS: Median age at start of GH was 7·1 years and height -3·0 SDS. AH was -1·8 SDS (TH-corrected AH -1·1 SDS) in boys and -1·9 SDS (TH-corrected AH -1·3 SDS) in girls. Spontaneous catch-up growth after birth was ≥0·5 SDS in 42% of children. In contrast to expectation, spontaneous catch-up growth was negatively correlated with total height gain SDS during GH (P = 0·009). During puberty, height SDS declined (-0·4 SDS in boys and -0·5 SDS in girls) resulting in a lower total height gain SDS than expected. Pubertal height gain was 25·5 cm in boys and 15·3 cm in girls, significantly lower compared to AGA children (P < 0·001). At onset of puberty, BA for boys and girls was moderately advanced (P = 0·02 and P < 0·001, respectively). Growth velocity was comparable to AGA children during the first two years of puberty, but thereafter significantly lower until reaching AH (P < 0·001). CONCLUSION: In contrast to our hypothesis, children with greater spontaneous catch-up growth after birth show a lower total height gain SDS during GH. Height SDS declines from mid-puberty, due to a marked early deceleration of growth velocity.

Lean mass and fat mass accretion between term age and 6 months post-term in growth-restricted preterm infants.

Early growth restriction followed by nutritional intakes that permit accelerated growth may result in adiposity and metabolic disease in later life. This study compared growth, body composition and nutritional intake between term age and 6 months post-term in 83 appropriate-for-gestational-age preterm infants with growth restriction at term age (AGA GR+), 15 AGA without growth restriction at term age (AGA GR-) and 33 small-for-gestational-age (SGA) preterm infants. AGA GR+ and SGA preterm infants had higher protein intake, higher energy intake and higher gain in weight SDS between term age and 6 months post-term, with similar lean mass (LM) and lower fat mass (FM) at 6 months post-term compared with AGA GR- preterm infants. In conclusion, despite higher energy and protein intake compared with AGA GR- preterm infants during the first 6 months post-term, AGA GR+ and SGA preterm infants restore their LM without excessive FM.

Eight years of growth hormone treatment in children with Prader-Willi syndrome: maintaining the positive effects.

BACKGROUND: The most important reason for treating children with Prader-Willi syndrome (PWS) with GH is to optimize their body composition. OBJECTIVES: The aim of this ongoing study was to determine whether long-term GH treatment can counteract the clinical course of increasing obesity in PWS by maintaining the improved body composition brought during early treatment. SETTING: This was a multicenter prospective cohort study. METHODS: We have been following 60 prepubertal children for 8 years of continuous GH treatment (1 mg/m(2)/d ≈ 0.035 mg/kg/d) and used the same dual-energy x-ray absorptiometry machine for annual measurements of lean body mass and percent fat. RESULTS: After a significant increase during the first year of GH treatment (P < .0001), lean body mass remained stable for 7 years at a level above baseline (P < .0001). After a significant decrease in the first year, percent fat SD score (SDS) and body mass index SDS remained stable at a level not significantly higher than at baseline (P = .06, P = .14, resp.). However, body mass index SDSPWS was significantly lower after 8 years of GH treatment than at baseline (P < .0001). After 8 years of treatment, height SDS and head circumference SDS had completely normalized. IGF-1 SDS increased to +2.36 SDS during the first year of treatment (P < .0001) and remained stable since then. GH treatment did not adversely affect glucose homeostasis, serum lipids, blood pressure, and bone maturation. CONCLUSION: This 8-year study demonstrates that GH treatment is a potent force for counteracting the clinical course of obesity in children with PWS.

Slipped capital femoral epiphysis and its association with endocrine, metabolic and chronic diseases: a systematic review of the literature.

PURPOSE: Puberty, obesity, endocrine and chronic systemic diseases are known to be associated with slipped capital femoral epiphysis (SCFE). The mechanical insufficiency of the physis in SCFE is thought to be the result of an abnormal weakening of the physis. However, the mechanism at the cellular level has not been unravelled up to now. METHODS: To understand the pathophysiology of endocrine and metabolic factors acting on the physis, we performed a systematic review focussing on published studies reporting on hormonal, morphological and cellular abnormalities of the physis in children with SCFE. In addition, we looked for studies of the effects of endocrinopathies on the human physis which can lead to cause SCFE and focussed in detail on hormonal signalling, hormone receptor expression and extracellular matrix (ECM) composition of the physis. We searched in the PubMed, EMBASE.com and The Cochrane Library (via Wiley) databases from inception to 11th September 2012. The search generated a total of 689 references: 382 in PubMed, 232 in EMBASE.com and 75 in The Cochrane Library. After removing duplicate papers, 525 papers remained. Of these, 119 were selected based on titles and abstracts. After excluding 63 papers not related to the human physis, 56 papers were included in this review. RESULTS: Activation of the gonadal axis and the subsequent augmentation of the activity of the growth hormone-insulin-like growth factor 1 (GH-IGF-1) axis are important for the pubertal growth spurt, as well as for cessation of the physis at the end of puberty. The effects of leptin, thyroid hormone and corticosteroids on linear growth and on the physis are also discussed. Children with chronic diseases suffer from inflammation, acidosis and malnutrition. These consequences of chronic diseases affect the GH-IGF-1 axis, thereby, increasing the risk of the development of SCFE. The risk of SCFE and avascular necrosis in children with chronic renal insufficiency, growth hormone treatment and renal osteodystrophy remains equivocal. CONCLUSIONS: SCFE is most likely the result of a multi-factorial event during adolescence when height and weight increase dramatically and the delicate balance between the various hormonal equilibria can be disturbed. Up to now, there are no screening or diagnostic tests available to predict patients at risk.

Urine gonadotropin and testosterone levels in male very-low-birthweight infants.

BACKGROUND/AIMS: The postnatal activation of the hypothalamic-pituitary-gonadal axis is more exaggerated in preterm than in full-term-born infants, and may be important for reproductive function. Our objective was to investigate this activation of the hypothalamic-pituitary-gonadal axis in male very-low-birthweight (VLBW) infants. METHODS: Twenty-one VLBW boys (gestational age 26.0-30.0 weeks), participating in the NIRTURE trial, were included. Gonadotropin and testosterone levels were measured in serial urine samples collected at 1 and 4 weeks' postnatal age, at 32 weeks' postmenstrual age, at expected date of delivery and at the corrected age of 3 and 6 months. RESULTS: Longitudinal analysis shows that after birth LH and FSH levels peak at a mean postnatal age of 1-4 weeks (mean postmenstrual age of 30-32 weeks) and decrease until 38 weeks' postnatal age (corrected age of 6 months). Testosterone levels decrease with increasing age, and this decrease is faster in infants receiving early insulin therapy. CONCLUSIONS: Serial urine sampling for measurement of gonadotropin and testosterone levels provides accurate information about the postnatal activation of the hypothalamic-pituitary-gonadal axis in VLBW boys. FSH and LH levels peak at 1-4 weeks of age. Insulin treatment causes faster decrease in testosterone levels.

Early infantile electroencephalography in patients with spina bifida*.

OBJECTIVE: The aim of this prospective study was to assess the prognostic value of electroencephalography in infants born with spina bifida.31 infants with spina bifida born between 2002 and 2007 at the Radboud Nijmegen University Medical Centre were evaluated and followed for 2½ years. Electroencephalography (EEG) was performed during the first 8 weeks after birth. RESULTS: EEG recordings were all within normal limits and showed no abnormalities. 3 of the 31 children showed mild mental disability and major physical disabilities at the age of 30 months. CONCLUSION: Single Infantile EEG recordings are of limited prognostic value for infants born with spina bifida. Serial EEG recordings in combination with other clinical or neurophysiological investigations might ameliorate the contributing predictive value of neonatal EEG.

Insulin resistance and the metabolic syndrome in obese children referred to an obesity center.

OBJECTIVE: The aim of this study was to describe insulin resistance and the metabolic syndrome in obese children and adolescents. SUBJECTS: The cohort consisted of 518 patients, 250 boys, 268 girls, age +/- sd: 11.8 +/- 3.2 years, BMIsds +/- sd: 2.94 +/- 0.5. A standard OGTT was performed. RESULTS: Impaired glucose tolerance was found in 9.4% of the boys and 5.5% of the girls. Impaired fasting glucose was found in 12.4% of the boys and 11.6% of the girls. The metabolic syndrome was present in 13.9% of children of 10 years or older. The proportion in which the metabolic syndrome was diagnosed was essentially not altered when pubertal groups were used instead of age groups. CONCLUSION: Both impaired fasting glucose and impaired glucose tolerance as well as the metabolic syndrome are highly prevalent among obese children and adolescents.

Treatment for neonatal neuralgic amyotrophy.

We report a 15-day-old neonate with a brachial plexus neuropathy diagnosed as neuralgic amyotrophy concomitant with an osteomyelitis of the ipsilateral humerus. She was treated with intravenous antibiotics and oral dexamethasone and improved dramatically within days.

Self-management treatment of drooling: a case series.

Behavioral treatment of drooling is advocated widely, but evidence of its effectiveness is lacking. In a center-based case-series study, 10 participants with severe drooling were taught self-management skills to reduce drooling. Following treatment, all participants remained dry for intervals of 30-60 min, while being engaged in daily activities. Generalization to the classroom occurred in each participant. For three participants, maintenance of treatment effect was established at 6 and 24 weeks. Seven participants failed to maintain self-management skills at follow-up. Although the self-management procedure showed promising results, further adaptations are required to improve efficacy, generalization, and maintenance.

Prognostic factors after a first attack of inflammatory CNS demyelination in children.

OBJECTIVE: To identify clinical, radiologic, or CSF factors that predict conversion to multiple sclerosis (MS) after a first attack of inflammatory demyelination in children. METHODS: In this nationwide retrospective multicenter study in the Netherlands, 117 children below age 16 were included. Fifty-four children presented with a monofocal clinically isolated syndrome (CIS) and 63 children with a polyfocal CIS (PCIS). RESULTS: A second MS-defining attack occurred in 43% of the CIS cases, compared to 21% of the patients with PCIS onset (p < 0.006). Basal ganglia and thalamic lesions and lesions larger than 2 cm on MRI (considered typical of ADEM) were observed during PCIS, irrespective of the presence of encephalopathy. No significant difference in developing MS was found in children with PCIS with or without encephalopathy. Elevated IgG index and presence of oligoclonal CSF bands were more often observed in children who developed MS. Both Barkhof and KIDMUS MRI criteria shared a high specificity and had a high positive predictive value for conversion to MS. In children under the age of 10, the Barkhof criteria had a higher sensitivity than the KIDMUS criteria, but still lower than in older children. CONCLUSIONS: Barkhof and KIDMUS MRI criteria share a high specificity and positive prognostic value for conversion to multiple sclerosis (MS). Sensitivity of these criteria is poor, especially in children below 10 years of age. Basal ganglia lesions can occur in patients who later develop MS. A substantial number of patients presenting with polyfocal onset and no encephalopathy remained monophasic.

Abnormal lipid profile and hyperinsulinaemia after a mixed meal: additional cardiovascular risk factors in young adults born preterm.

AIMS/HYPOTHESIS: Low birthweight in infants born at term is related to the presence of the metabolic syndrome as an adult. Individuals born preterm invariably have low birthweights and may develop the metabolic syndrome as well. Although high BP, glucose intolerance and insulin resistance have been documented, dyslipidaemia has never been reported in individuals born preterm. METHODS: In three groups of young adults [29 participants from the POPS (Project On Premature and Small for Gestational Age Infants) cohort born preterm appropriate for gestational age (POPS-AGA), 28 participants from the POPS cohort born preterm small for gestational age (POPS-SGA) and 30 individuals born at term with normal birthweight (CON)] we investigated fasting lipids as well as postprandial responses during a mixed meal test. The relationship between fasting and postprandial measurements and insulin sensitivity, measured by the hyperinsulinaemic clamp, was investigated. RESULTS: Preterm participants had higher BP than CON individuals. Postprandial triacylglycerol levels were increased in POPS-SGA men. POPS-SGA individuals were hyperinsulinaemic during the mixed meal test. CONCLUSIONS/INTERPRETATION: The mixed meal test provides additional information on cardiovascular risk factors. Postprandial triacylglycerol levels are increased in POPS-SGA men. Postprandial hyperinsulinaemia is found in POPS-SGA individuals.

Decreased insulin sensitivity in small for gestational age males treated with GH and preterm untreated males: a study in young adults.

BACKGROUND: Low birth weight and preterm birth are associated with growth delay as well as the development of insulin resistance. Insulin resistance is especially seen in subjects with catch-up growth. GH therapy induces growth in short subjects with low birth weight at term, but little is known about the long-term effects on insulin sensitivity. GH therapy is now also proposed for preterms that remain short. METHODS: We investigated insulin sensitivity using the gold standard hyperinsulinemic-euglycemic clamp technique in 10 young adult males born small for gestational age (SGA) who had been treated with GH during childhood (GH) in comparison with 15 males born preterm AGA (premAGA), 13 males born preterm SGA (premSGA), and 15 males born at term with normal birth weight (CON). Furthermore, we investigated the presence of the metabolic syndrome. RESULTS: Insulin sensitivity was decreased in premAGA, premSGA, and GH subjects compared with CON males. The metabolic syndrome was not present in any of the groups. CONCLUSION: Insulin sensitivity is decreased in GH-treated SGA born males as well as in preterm born males. With respect to the SGA subjects, whether the difference results from perinatal-, postnatal-, or GH therapy-related factors are not known. With respect to the preterm born subjects, close surveillance is needed when commencing GH therapy.

Metabolic implications of GH treatment in small for gestational age.

Fetal growth retardation is associated with decreased postnatal growth, resulting in a lower adult height. In addition, a low birth weight is associated with an increased risk of developing diseases during adulthood, such as insulin resistance, type 2 diabetes mellitus, hypertension, dyslipidemia, and cardiovascular diseases. Children with persistent postnatal growth retardation, i.e., incomplete catch-up growth, can be treated with human GH. The GH/IGF-I axis is involved in the regulation of carbohydrate and lipid metabolism. The question of whether treatment with GH in children born small for gestational age (SGA) has long-term implications with respect to glucose/insulin and lipid metabolism has not been answered yet. In this article, the available data are reviewed.

Movement disorders induced by gastrointestinal drugs: two paediatric cases.

A number of frequently prescribed gastrointestinal drugs can cause movement disorders in children, as well as in adults. In our centre for paediatric neurology, we saw a 3-year-old girl with abnormal movements mostly of the legs with an inner restlessness (akathisia) while using cisapride. Another patient, a 17-year-old male, developed a hemiballism (a fierce movement of one arm and shoulder with a hurling appearance) while using ranitidine for gastric distress. In both children, the movement disorder disappeared after discontinuing the drug. The pathophysiological mechanisms of these drug-induced movement disorders might be related to the central function of histamine in the developing brain. These cases illustrate the importance of being alert for possible drug-induced events early in the process of diagnosing abnormal movement disorders.

Arnold-Chiari-II malformation and cognitive functioning in spina bifida.

Spina bifida is a multifaceted neurological condition with complex neuropsychological sequelae. The cognitive outcome in spina bifida has frequently been attributed to the severity of the hydrocephalus. However, because of complex neuropathology, the influence of hydrocephalus alone does not sufficiently explain the deficits in the cognitive profile in spina bifida. To date, little is known of the role of Arnold-Chiari-II malformation (ACM) in the cognitive profile of these patients. Aim of the current study is to delineate the specific contribution of the ACM in spina bifida by comparing children with ACM and those without ACM. 46 children between 6 and 15 years of age underwent a neuropsychological assessment covering intelligence and a wide range of cognitive functions, such as visuo-motor processing, attention, memory, word fluency and speed of information processing. Comparisons were made between patients with ACM (ACM+) and those without ACM (ACM-); all children with ACM+ also had hydrocephalus. Confounding effects of global cognitive impairment were excluded, such that groups were matched on verbal IQ. Because of complex neuropathology, which is inherent to spina bifida, the method applied was based on a comparison of cognitive profiles of the study group with profiles of patients with cerebellar damage and hydrocephalus found in the literature. Impaired visual analysis and synthesis, verbal memory, and verbal fluency, even after correction for global cognitive impairment, were observed in children with ACM. The hypothesis that in addition to impairment in visual analysis and synthesis, which are related to both hydrocephalus and ACM, specific deficiencies in verbal memory and fluency may be attributed to ACM is supported.

Clinical findings and a therapeutic trial in the first patient with beta-ureidopropionase deficiency.

The clinical, neurophysiological and neuroradiological work-up as well as the results of a specific treatment trial are presented of the first patient diagnosed with beta-ureidopropionase deficiency (E.C. 3.5.1.6, McKusick 606673). The patient presented with an early-onset dystonic movement disorder, severe developmental delay with marked impairment of visual responsiveness in combination with severely delayed myelination in magnetic resonance imaging studies. In addition, there were partial optic atrophy, pigmentary retinopathy and mild cerebellar hypoplasia. The enzyme defect was expected to lead to intracerebral deficiency of beta-alanine which seems to be a neuromodulator at inhibitory synapses. Therefore, a therapeutic trial with supplementation of beta-alanine was undertaken over 1.5 years with no convincing clinical improvement.

[Questionable basis for 'hopeless and unbearable suffering' as the criterion for the active termination of life in newborns with spina bifida]. / Problematische basis voor 'uitzichtloos en ondraaglijk lijden' als criterium voor actieve levensbeëindiging bij pasgeborenen met spina bifida.

Is 'hopeless and unbearable suffering' a just criterion for the deliberate termination of life of newborns with spina bifida? Hopeless suffering, with no means of alleviation, is not applicable in the acute phase of spina bifida in newborns, but to the chronic suffering that comes later on as the result of pain and discomfort experienced by the patient. There is a need for a nationwide discussion on (a) how can we determine when acute or chronic suffering become hopeless and unbearable, and on what basis should a given situation be regarded as an 'emergency situation'?; (b) what qualifies as a very severe form of spina bifida?; (c) what kind of care should be provided after the decision to withhold active care?