Risk factors for asthma after infant bronchiolitis.

BACKGROUND: Five studies carried out after bronchiolitis at less than 24 months of age, with a follow-up of more than 10 years, reported that atopic dermatitis, family asthma, early-life exposure to tobacco smoke and rhinovirus aetiology were early-life risk factors for later asthma. This study evaluated the long-term outcome at 11-13 years of age of children who were hospitalized for bronchiolitis in early infancy. METHODS: We previously prospectively followed 166 children hospitalized for bronchiolitis at less than 6 months of age until 5-7 years of age. The current study included a structured questionnaire, parental interviews, clinical examinations and bronchodilation test of 138 of those children at 11-13 years of age. RESULTS: Respiratory syncytial virus caused 66% of the bronchiolitis cases, and nearly half of the patients were exposed to tobacco smoke in early life. Doctor-diagnosed asthma was present in 13% of the former bronchiolitis patients at 11-13 years of age. Maternal asthma was the only independently significant risk factor in early life (adjusted OR 3.45, 95% CI 1.07-11.74), as was allergic rhinitis at 5-7 years of age (adjusted OR 4.06, 95% CI 1.35-12.25). CONCLUSIONS: After bronchiolitis at less than 6 months of age, the risk of doctor-diagnosed asthma at 11-13 years was about twice that of the general Finnish population. Maternal asthma was the only independently significant early-life risk factor for current asthma at 11-13 years of age.

Effects of fluoxetine treatment on striatal dopamine transporter binding and cerebrospinal fluid insulin-like growth factor-1 in children with autism.

A positive effect of fluoxetine has been shown in some children with autism. The present study was undertaken to correlate striatal dopamine transporter (DAT) binding and cerebrospinal fluid insulin-like growth factor-1 (CSF-IGF-1) with clinical response in autistic children (n=13, age 5-16 years) after a 6-month fluoxetine treatment. Good clinical responders (n=6) had a decrease (p=0.031) in DAT binding as assessed using single-photon emission computed tomography with [123I]-nor-ß-CIT, whereas poor responders had a trend to an increase. An increase in CSF-IGF-1 (p=0.003) was detected after the treatment period, but no correlation between the clinical response and CSF-IGF-1 was found. In conclusion, fluoxetine decreases DAT binding indicating alleviation of the hyperdopaminergic state and increases CSF-IGF-1 concentration, which may also have a neuroprotective effect against dopamine-induced neurotoxicity in autistic children.

Long-term outcome in pyridoxine-responsive infantile epilepsy.

BACKGROUND: Dose regimens of pyridoxine (vitamin B6) for treatment of infantile spasms have varied from 200 mg/d to 300 mg/kg/d. Only two long-term outcome studies of the treated patients are available. METHODS: We asked all pediatric neurologists treating pediatric epilepsy in Finland if they had seen patients with pyridoxine-responsive infantile epilepsy. Five children with infantile spasms and hypsarrhythmia and one with focal epilepsy were reported as pyridoxine responders. Data on clinical presentation and outcome were collected from patient charts. RESULTS: All B6 responders had un-known aetiology. Two patients were studied for pyridoxal 5'-phosphate oxidase (PNPO) deficiency and showed negative results. Ages at seizure onset ranged from 4 to 7 months. The maintenance dose of oral pyridoxine was 150 mg/day. Response occurred within 1-to 14 days (mean 5 days). Two patients were treated with concomitant antiepileptic drugs. Duration of pyridoxine therapy varied from 6 weeks to 4 years (mean 26 months). Four patients had later seizure recurrence: one at 15 months with motor seizures (stopped by valproate), another two in adolescence with focal epilepsy and one at 20 years with unclassified epilepsy. Intelligence was normal in five patients and one had a mild mental deficiency. Follow-up ranged from 8.5 to 24 years. CONCLUSIONS: Rare patients with infantile epilepsy but not pyridoxine dependency may respond to smaller doses of pyridoxine than reported before. Long-term cognitive outcome appears to be good but late seizure recurrence (in adolescence or in adulthood) occur. So far it is unknown if the response was determined by genetic traits or disease-related factors.

CSF insulin-like growth factor-1 in infantile neuronal ceroid lipofuscinosis.

BACKGROUND: Infantile neuronal ceroid lipofuscinosis (INCL) is a progressive encephalopathy in which the patients are severely disabled by the age of 3 years. It is characterized by cerebral atrophy, selective loss of cortical neurons, and secondary loss of axons and myelin sheaths of the white matter. INCL has been shown to result from a palmitoyl protein thioesterase deficiency. The authors suggested that insulin-like growth hormones and apoptosis might play a role in the pathogenesis of INCL. METHODS: The authors measured insulin-like growth factor-1 (IGF-1) and IGF binding protein 3 (IGFBP-3) in the CSF of patients with INCL by radioimmunoassay at an early stage when myelin was starting to diminish. RESULTS: The authors found low CSF IGF-1 but normal IGFBP-3 in patients with INCL compared with control subjects. Also, they observed apoptotic cell death in biopsies of INCL patients. CONCLUSIONS: Because the IGF system seems to be important for early brain development, myelination, and neuroprotection, the authors suggest that the pathology in INCL may be associated with low CSF IGF-1.

MECP2 gene analysis in classical Rett syndrome and in patients with Rett-like features.

OBJECTIVE: To discuss the diagnostic criteria for Rett syndrome based on mutational screening of the methyl-CpG-binding protein 2 gene ( MECP2 ) in patients with classic Rett syndrome and patients with Rett-like features. METHODS: Thirty-nine patients with classical Rett syndrome, one with preserved speech variant (PSV), and 12 patients with developmental delay and some features of Rett syndrome were recruited for sequence analysis of the MECP2 gene coding region. The phenotype of the patients was correlated with the presence and type of the mutation as well as the X-chromosome inactivation (XCI) pattern. RESULTS: found in 100% of the patients with classical Rett syndrome originating from Finland. One novel mutation, P127L, was detected in a patient with PSV. No mutations were found in other cases. The XCI status was found to be random in 72% of the patients with classical Rett syndrome, including the patient with PSV and all patients with developmental delay informative for the analysis. CONCLUSIONS: An MECP2 mutation can be found in almost every patient with classical Rett syndrome. More patients need to be analyzed in order to clarify the mutation prevalence in patients with atypical Rett syndrome and in patients with mental retardation.

Brain derived neurotrophic factor is increased in cerebrospinal fluid of children suffering from asphyxia.

Brain derived neurotrophic factor (BDNF) is a neurotrophic factor that is relatively highly expressed in developing and adult brain. Whereas clinical determinations of nerve growth factor (NGF) in human serum and cerebrospinal fluid (CSF) in different conditions have been undertaken there are no reports on levels of BDNF in human CSF. Here we show that BDNF is increased in CSF of neonatal children suffering from asphyxia which is characterised by periods of brain hypoxic-ischemia. In contrast to BDNF, levels of CSF NGF were largely decreased in these children. The present results show that BDNF can be detected in human CSF and that the levels increase following hypoxic-ischemic brain injury. As suggested by animal studies the increased BDNF might counteract neuronal damage observed in these patients following asphyxia.

Nitric oxide metabolites, nitrates and nitrites in the cerebrospinal fluid in children with west syndrome.

Nitric oxide (NO) has been implicated in the mediation of the neuronal excitotoxic cascade. In order to estimate brain NO production, cerebrospinal fluid (CSF) levels of NO metabolites, nitrates and nitrites (NN(x)) were measured in 31 children with west syndrome (WS) and in 12 controls. There was no age-related change in the NN(x) levels during the first year of life. The mean of the NN(x) levels was significantly higher in patients with WS than in controls (8.43 vs. 5.27 microM; P=0.01). Analysis of the etiological subgroups showed that the patients with a symptomatic etiology of WS had significantly higher NN(x) levels than controls (P<0.005) or than the patients with a cryptogenic etiology. The cryptogenic cases, in turn, did not differ from the controls (P=0.48). Levels of NN(x) were also significantly higher in children with focal brain abnormalities (infarction, atrophy or previous infection) than in those with other abnormalities or with normal neuroradiological findings (P<0.005). No correlation was found between the NN(x) levels and the duration of the symptoms, while paired samples obtained from eight children with WS showed that the NN(x) levels rose significantly (P=0.02) within the first 40 days of symptoms. The levels of NN(x) did not correlate with the CSF levels of neuronal growth factor or with the later decline in mental performance. This study demonstrates that the production of NO can be measured in human epileptic conditions and supports the idea gained from experimental studies that NO is involved in the pathophysiology of epilepsy. However, normal levels of NN(x) in patients with cryptogenic infantile spasms suggest that an increase in NO production be due to the concomitant neuronal damage rather than seizure activity per se. The findings suggest that there are no age-related changes in the NN(x) levels during the first year of life, and that children with symptomatic WS have elevated levels of NN(x), which rise during the first 40 days of symptoms. Although the NN(x) levels cannot be used to estimate the duration of symptoms or to predict the prognosis of mental development, they may support the differentiation of symptomatic from cryptogenic etiologies of WS.

How do cryptogenic and symptomatic infantile spasms differ? Review of biochemical studies in Finnish patients.

Infants with cryptogenic infantile spasms seem to differ from those with symptomatic spasms in having a higher cerebrospinal fluid corticotropin content, different levels of corticotropin release after exogenous vasopressin, higher serum levels of progesterone, higher dehydroepiandrosterone: androstenedione ratio (during corticotropin therapy), a higher cerebrospinal fluid gamma-aminobutyric acid content, and higher cerebrospinal fluid nerve growth factor concentrations. It remains to be seen whether the biochemical differences between the two groups are specific or only happen to correlate with the early brain damage. However, these differences would explain many pathophysiologic features of infantile spasms.

Low levels of nerve growth factor in cerebrospinal fluid of children with Rett syndrome.

A role of neurotrophic factors has been postulated in some human neurodegenerative disorders such as Alzheimer's and Parkinson's disease. The known developmental effects of these substances suggested that, in some neurologic diseases affecting children, neurotrophic factors might be inadequate. Using a sensitive, two-site enzyme-linked immunoassay, we examined the content of nerve growth factor in the cerebrospinal fluid of 11 children with Rett syndrome and of 24 control patients with various neurologic diagnoses or suffering from other diseases. Nerve growth factor levels were significantly lower in the cerebrospinal fluid of the patients with Rett syndrome than in control patients. The lower level of cerebrospinal fluid nerve growth factor in Rett syndrome suggests that lack of nerve growth may be involved in the pathogenesis of this disease or reflect the underlying brain damage present.

Neurotrophic factors in cerebrospinal fluid and serum of patients with Rett syndrome.

Rett syndrome is now considered to be a neurodevelopmental disease. Its cause is unknown, but it has been suggested that neuronal growth factors and neurotransmitters play important roles. We measured levels of brain-derived neurotrophic factor and glial cell line-derived neurotrophic factor in cerebrospinal fluid, and nerve growth factor and brain-derived neurotrophic factor in serum in child and adolescent patients with Rett syndrome. Levels of brain-derived neurotrophic factor and glial cell line-derived neurotrophic factor in cerebrospinal fluid were below the limit of sensitivity of the methods used. Serum levels of nerve growth factor and brain-derived neurotrophic factor did not differ from control values. In Rett syndrome, the normal serum levels of nerve growth factor together and previously reported low levels of the factor in cerebrospinal fluid indicate that the latter may reflect low levels of nerve growth factor in the central nervous system.

Advances in therapy of infantile spasms. Current knowledge of actions of ACTH and corticosteroids.

The anticonvulsant actions of ACTH and corticosteroids in the treatment of infantile spasms have been well documented during the past 29 years. In the past decade neuropeptides have been studied intensively and an understanding of their actions has been gained. Most of the actions of ACTH are well documented in animal experiments and cytochemical studies. Some proceedings of modern steroid research are here reviewed. In the treatment of infantile spasms, the principal mechanism of the therapeutic action of ACTH and corticosteroids is unknown. Clinical data concerning their effects, site and mode of action, on brain and CSF neurochemical activity are still scant and controversial. Some mechanisms probably involved in the therapeutic effects are reviewed. It seems that a disturbance of the central neural transmitter regulation at a specific phase of brain development may be the underlying cause for infantile spasms.

Epidemiological data of West syndrome in Finland.

The present study examined whether changes in the incidence of West syndrome (WS) could be used to evaluate changes in the quality of prenatal care over time. The incidence of WS in Finland did not change (1960-1991) in spite of increased survival of low-birth-weight infants. Small-for-gestational age (SGA) infants were more apt to develop infantile spasms than preterm average-for-gestational age infants. The number of SGA infants with neonatal hypoglycemia and infantile spasms decreased significantly. The number of cases of brain malformation and tuberous sclerosis increased; this probably reflects the development of more refined neuroradiological screening methods. Early prenatal factors seem to play a major role in the genesis of infantile spasms. Little can be done to reduce the incidence of WS, but every effort should be made to reduce the number of SGA infants by good prenatal care and treating neonatal hypoglycemia carefully.

ACTH therapy of West syndrome: Finnish views.

To provide up-to-date information on adrenocorticotropic hormone (ACTH) therapy in the treatment of West syndrome, a review of the Finnish studies was made in answer to the questions: what are (1) its efficacy: doses and comparison with vigabatrin (VGB), (2) its tolerability, (3) its mechanism of action? Why do some patients respond, but others do not? No other drugs have been shown to be more effective than ACTH. High doses were not more effective than low doses. Synthetic derivatives were associated with more frequent side effects. Individualized therapy was developed on the basis of etiology and response. With therapy consisting of ACTH 3-6IU/kg/day, all the cryptogenic and half of the symptomatic spasms could be controlled within over 2-3 weeks therapy and with minimal risk of side effects. In a Finnish study, 26% of the patients responded to VGB as the first-line drug. Some of the non-responders responded to ACTH. In tuberous sclerosis, the initial response rate to ACTH was high (73%) and did not differ from the response rate to VGB in other series. Both drugs have severe side effects. The visual field defects caused by VGB occur even in children (in 18/91 Finnish children). The patients with cryptogenic spasms, who responded well to ACTH, differed in their biochemical parameters from the patients with symptomatic spasms. The therapeutic action of ACTH may be mediated by potentiation of nerve growth promoting activity. Neurodegeneration may be due to imbalance between nerve growth factors and nitrate/nitrite in the brain. ACTH should be used as the first choice for treatment of West syndrome (at the minimal effective dose and for shortest effective time). The side effects of steroids, unlike VGB, are well known, treatable, and reversible.

Long-term outcome of patients with West syndrome.

The long-term outcome of Finnish children with West syndrome was evaluated. Two hundred and fourteen patients were followed up for 20-35 years or until death. A third of the patients died before the age of 3 years. The most common cause of death was infection. Autopsy revealed brain anomalies in 25 of 38 (66%) autopsied patients. Intellectual outcome was normal or slightly impaired in a quarter of the patients. All of them completed their education at a normal school or in a school for the educationally impaired children. Another fourth were taught in special training schools. Specific cognitive deficits were seen in some patients with normal intelligence. Nine attended secondary schools and seven of them had a professional occupation. Ten were married and five had children. One third of the patients were seizure-free, another third had seizures daily or monthly, and the remaining patients had seizures less frequently. Factors associated with a good prognosis were cryptogenic etiology, normal development before the onset of the spasms, a short treatment lag, and a good response to adrenocorticotropic hormone; this was seen in both the symptomatic and the cryptogenic group, and there were no relapses. In this study, the late appearance of focal abnormalities in electroencephalography was not associated with an unfavorable outcome. Focal abnormalities in temporal region were often seen in patients with autism. The location of an abnormality may be of importance for the prognosis. In this study, all the patients (100%) could be followed, which may be due to the special circumstances characteristic of Finland. The outcome in children with West syndrome seems to be better than is generally believed.

The PEHO syndrome.

The progressive encephalopathy with edema, hypsarrhythmia, and optic atrophy (PEHO) syndrome is a pediatric disorder of unknown origin, characterized by a combination of postnatally progressive encephalopathy, hypsarrhythmia, and optic atrophy. The pathological findings are early progressive atrophy of the cerebellum, brainstem, and optic nerves. Nitric acid (NO) has recently been implicated in the mechanisms of seizure activity and neurodegeneration, which are both very active in the PEHO syndrome. However, recent studies have provided evidence that insulin-like growth factor 1 (IGF-1) may prevent the NO-mediated neuronal damage and is essential for the survival of the cerebellar granule cells. These cells will degenerate in the PEHO syndrome. In this study, we set out to test the hypothesis that NO production is activated in the PEHO syndrome and that NO production may be correlated with the reduced production of IGF-1 in the brain. Cerebrospinal fluid IGF-1 was determined with an RIA kit and NO metabolites by the Griess calorimetric method. In patients with the PEHO syndrome, as compared with controls, the levels of IGF-1 were reduced and the levels of nitrite/nitrate were markedly elevated. Defective production of IGF-1 probably reflects the underlying neurodegeneration and the increase in NO production probably reflects the seizure activity and/or neurodegeneration. These are the first biochemical abnormalities found in the PEHO syndrome and their study may lead to a better understanding of this devasting disease.

Elevated CSF lactate in the Rett syndrome: cause or consequence?

We report values for CSF and blood lactate and acid-base balance in 8 girls with the Rett syndrome and correlate the findings with respiratory dysfunction. Three patients had elevated CSF lactate values; their hyperventilation (HV) was so intensive that the acid-base balance showed respiratory alkalosis with an abnormally low base excess. One of these three patients had normal CSF lactate and acid-base balance before she developed HV. Two patients were so young that they had not yet developed HV and their CSF lactate values were normal. One patient had elevated CSF lactate when she was younger and her HV was more intensive, but now her CSF and blood lactate were normal; her acid-base balance showed mild hypocapnia but was otherwise normal. Thus, in the Rett syndrome, CSF lactate elevation seems to be a secondary phenomenon connected with the intensive HV and alkalosis rather than a sign of any mitochondrial disorder.

The concentrations of GABA, 5-HIAA and HVA in the cerebrospinal fluid of children with infantile spasms and the effects of ACTH treatment.

Children with infantile spasms (IS) are generally treated with ACTH although little is known of the biochemical basis of the symptoms and the mechanism of this therapy. We have measured the concentrations of gamma-aminobutyric acid (GABA), homovanillic acid (HVA) and 5-hydroxyindoleacetic acid (5-HIAA) in the CSF of IS children, followed the effect of ACTH treatment on these parameters and correlated CSF GABA values with the cause of IS, cranial CT findings and antiepileptic treatment. While significant differences in GABA concentrations were found between the children with IS and those with febrile seizures or nonconvulsive symptoms, these could be accounted for by age, not the disease present. The CSF GABA level was highest in the IS children with normal CT, cryptogenic cause and no antiepileptic treatment, and lowest in those with abnormal CT, symptomatic cause and antiepileptic treatment. The basal level of CSF 5-HIAA in the IS children was higher than that in the nonconvulsive children, but HVA levels did not differ. ACTH therapy did not change the CSF levels of GABA, 5-HIAA and HVA significantly.

West syndrome: individualized ACTH therapy.

Individualized ACTH treatment of the West syndrome (WS) was assessed in a prospective multicenter study, in which each patient's dosage was increased stepwise according to response. Our series included six patients with cryptogenic and 24 with symptomatic infantile spasms. During the treatment period the total ACTH dose ranged from 58 to 373 i.u./kg. In the cryptogenic group one patient responded to pre-ACTH pyridoxine and four to the lowest dosage of ACTH (3 i.u./kg daily) with cessation of spasms and good outcome; one patient needed the highest dosage (12 i.u./kg daily) for cessation of seizures and became developmentally retarded. In the symptomatic group, 21 of the 24 patients needed 6-12 i.u./kg daily; 12 became seizure-free or having infrequent non-IS fits. Complications such as arterial hypertension, cerebral ventricle dilatation, cardiac hypertrophy, and prolonged adrenocortical hyporesponsiveness were related to the dose. The individualization provides all the benefits of ACTH treatment with minimal side effects and cost.

Can barbiturate anaesthesia cure infantile spasms?

Five patients with infantile spasms and hypsarrhythmia and one with Lennox-Gastaut syndrome were treated with brief thiopentone anaesthesia as the primary treatment of infantile spasms. Thiopentone (30 mg/kg) was given intravenously and burst suppression was reached in EEG in three patients by this dose. The results were disappointing. In three patients a transient beneficial effect on spasms and hypsarrhythmia was seen, but all patients relapsed. Three other patients had anaesthesia for surgery. The spasms ceased and hypsarrhythmia disappeared dramatically, and the effect was permanent. The possible mechanisms of the therapeutic effect are discussed. It seems advisable to give anaesthesia and surgery prior to steroid treatment in any case where the both are needed.

Difference in susceptibility to teratogenic effects of alcohol in discordant twins exposed to alcohol during the second half of gestation.

A pair of discordant twins exposed to heavy maternal alcohol consumption only during the second half of pregnancy is reported. Apparently, differences in susceptibility to the dysmorphogenic influence of ethanol caused 1 twin to be more severely affected than the other. One twin had prenatal growth retardation, neonatal withdrawal symptoms, delay in both motor and cognitive function during the first year of life, slowing of background activity on electroencephalography, and cortical and central brain atrophy on computed tomography. Catch-up growth occurred during the postnatal period for the affected twin. The other twin was normal at the end of the follow-up at age 17 months. It seems that exposure to alcohol during the second half of pregnancy greatly increases the risk for brain damage but not lasting postnatal growth retardation. Minor abnormalities can also be caused during the second half of pregnancy. Genetic factors may have been important in determining the differences in fetal susceptibility to alcohol exposure.