Journal of Child Neurology

Noninvasive nasal ventilation is an effective but underutilized method of chronic respiratory support for patients with respiratory insufficiency due to neuromuscular disease. Noninvasive nasal ventilation corrects nocturnal hypoxia and hypercapnia, resolving symptoms of chronic alveolar hypoventilation. Noninvasive nasal ventilation can allow selected patients with acute respiratory failure to avoid intubation and it can facilitate endotracheal extubation. Practical guidelines and the rationale for pediatric noninvasive nasal ventilation therapy will be discussed in this review. (J Child Neurol 1997;12:231-236).

Neuro-Behçet's disease, which is uncommonly reported in childhood, encompasses a wide variety of clinical features since any part of the neuraxis may be involved. It carries a serious prognosis and represents a leading cause of death or severe disability. Neuro-Behçet's disease may occur in 5%.to 50% of adults with Behçet's disease and is usually subsequent to other systemic manifestations. In this report, we express the possibility of a primary neurologic presentation of Behçet's disease in childhood with pseudotumor cerebri and meningoencephalitis as exclusive initial features. We focus on diagnostic problems when major features of Behçet's disease are missing at the outset. We emphasize the high sensitivity of magnetic resonance imaging to make the diagnosis of cerebral vasculitis or thrombosis with a good reliability to clinical features. (J Child Neurol 1997;12:237—241).

Three unrelated North American cases with slowly progressive forms of G_M1 gangliosidosis were found to have two unique point mutations and a 9 bp insertion in the coding region of the gene encoding β-galactosidase. Case 1 was noted to have a 9 bp insertion {CAGAATTTT} on one allele between nucleotides 730 and 731 with no other mutations identified in the other allele. In case 2, two point mutations were found: a unique G→A transition at nucleotide 602 causing an Arg→His substitution in codon 201 (mutation R201H); and a previously identified G→T transition at nucleotide 1527 causing a Trp→Cys substitution in codon 509 (mutation W509C), which has been noted in adult and chronic forms of G_M1 gangliosidosis. Case 3 had a unique point mutation (A→G transition at nucleotide 797) resulting in a Asn→Ser amino acid substitution in codon 266 (mutation N266S), with no other mutations found in the same or the other allele. Single-strand conformation polymorphism performed on over 100 controls did not demonstrate the presence of the point mutations R201H or N266S. Also, the mutant proteins coded by the two point mutations did not show enzymatic activity in the Cos-1 cell expression system confirming that these mutations are associated with low enzyme activity. ( J Child Neurol 1997;12:242—247).

Children with Williams syndrome frequently present with symptoms of attention deficit hyperactivity disorder (ADHD), but there is little information that stimulant medication is useful in this population. A series of double-blind, placebo-controlled case studies was used to evaluate the cognitive and behavioral effects of methylphenidate on four children with Williams syndrome. Teachers and mothers completed behavioral rating scales and cognitive tests of attention, learning and memory, and academic productivity and accuracy in mathematics in each medication condition. Two of the children responded favorably in terms of decreased impulsivity, decreased irritability, and lower activity level as well as improved ability to pay attention. Methylphenidate is a useful adjunct in the treatment of some children with Williams syndrome. (J Child Neurol 1997;12:248—252).

This review was conducted to evaluate the long-term prognosis of children responding to vigabatrin by examining the incidence of increased seizure frequency, loss of efficacy, and appearance of new seizures in a cohort of 196 children (mean age, 68.2 months; range, 2 months to 19 years) with drug-resistant epilepsy, who had received vigabatrin as add-on treatment in clinical trials. The results indicate that an increase in seizure frequency was uncommon, occurring in only 10% of children with highly drug-resistant epilepsy and that it usually appears shortly after the initiation of treatment. It was clearly not dose-dependent and most often occurred in patients with nonprogressive myoclonic epilepsy. No specific seizure type was specially involved and usually the problem reversed on discontinuing vigabatrin. Loss of efficacy was also uncommon (12% of patients), and again no specific seizure type was found to be associated. Epilepsy syndrome does seem to be a better predictor of loss of efficacy because it occurred most often in symptomatic generalized epilepsies and cryptogenic infantile spasms. A total of 21 patients (11%) developed genuinely new types of seizures. Fifteen of these patients developed new partial seizures that had little impact on the patients' overall clinical improvement. The new partial seizures were better tolerated than the initial seizure type which in most cases had disappeared. Approximately 3% of patients experienced new generalized seizures that aggravated their initial condition. These occurred most often in patients with nonprogressive myoclonic epilepsy; therefore vigabatrin should be used with particular caution in such patients. (J Child Neurol 1997;12:253-259).

In this study we sought to investigate parasympathetic activity among children with severe cyanotic breath-holding spells by examining respiratory sinus arrhythmia. The study sample was composed of two groups of patients, 16 subjects with cyanotic breath-holding spells (5 male, 11 female; mean age, 37.5 mo) and 17 controls (8 male, 9 female; mean age, 37.7 mo). Each subject's electrocardiogram was recorded in a quiet room and digitized by an 80386 personal computer during five 1-minute periods. R—R intervals within each 1-minute period were converted to heart rate in 120 successive 0.5-second intervals. The resultant heartrate time series was converted to its underlying frequency composition by a fast Fourier transform and averaged across minutes. Respiratory sinus arrhythmia was defined as the variability in the time series over a frequency range (0.096-0.48 Hz) corresponding to a range of respiratory rates from 6 to 30 breaths per minute. Analysis revealed after ANCOVA adjustment for age and gender with subject group and frequency bin as dependent measures, that subjects with cyanotic breath-holding spells had similar variability in their heart rates as did controls (group × frequency bin: F = 0.74, P = 0.71). This study supports the hypothesis that autonomic dysregulation in cyanotic breath-holding spells is not due to a primary disturbance in central parasympathetic control over cardiac rate and rhythm. (J Child Neurol 1997;12:260-262).