Interhemispheric coherence of EEG rhythms in children: Maturation and differentiation in corpus callosum dysgenesis.

OBJECTIVES: To evaluate the evolution of interhemispheric coherences (ICo) in background and spindle frequency bands during childhood and use it to identify individuals with corpus callosum dysgenesis (CCd). METHODS: A monocentric cohort of children aged from 0.25 to 15 years old, consisting of 13 children with CCd and 164 without, was analyzed. The ICo of background activity (ICOBckgrdA), sleep spindles (ICOspindles), and their sum (sICO) were calculated. The impact of age, gender, and CC status on the ICo was evaluated, and the sICO was used to discriminate children with or without CCd. RESULTS: ICOBckgrdA, ICOspindles and sICO increased significantly with age without any effect of gender (p < 10-4), in both groups. The regression equations of the different ICo were stronger, with adjusted R2 values of 0.54, 0.35, and 0.57, respectively. The ICo was lower in children with CCd compared to those without CCd (p < 10-4 for all comparisons). The area under the precision recall curves for predicting CCd using sICO was 0.992 with 98.9 % sensitivity and 87.5 % specificity. DISCUSSION: ICo of spindles and background activity evolve in parallel to brain maturation and depends on the integrity of the corpus callosum. sICO could be an effective diagnostic biomarker for screening children with interhemispheric dysfunction.

Detection of seizure onset in childhood absence epilepsy.

OBJECTIVE: This study aims to detect the seizure onset, in childhood absence epilepsy, as early as possible. Indeed, interfering with absence seizures with sensory simulation has been shown to be possible on the condition that the stimulation occurs soon enough after the seizure onset. METHODS: We present four variations (two supervised, two unsupervised) of an algorithm designed to detect the onset of absence seizures from 4 scalp electrodes, and compare their performance with that of a state-of-the-art algorithm. We exploit the characteristic shape of spike-wave discharges to detect the seizure onset. Their performance is assessed on clinical electroencephalograms from 63 patients with confirmed childhood absence epilepsy. RESULTS: The proposed approaches succeed in early detection of the seizure onset, contrary to the classical detection algorithm. Indeed, the results clearly show the superiority of the proposed methods for small delays of detection, under 750 ms from the onset. CONCLUSION: The performance of the proposed unsupervised methods is equivalent to that of the supervised ones. The use of only four electrodes makes the pipeline suitable to be embedded in a wearable device. SIGNIFICANCE: The proposed pipelines perform early detection of absence seizures, which constitutes a prerequisite for a closed-loop system.

Megalencephaly secondary to a novel germline missense variant p.Asp322Tyr in AKT3 associated with growth hormone deficiency and central hypothyroidism: A case report.

Germline gain of function variations in the AKT3 gene cause brain overgrowth syndrome with megalencephaly and diffuse bilateral cortical malformations. Here we report a child with megalencephaly, who is a carrier of a novel heterozygous missense variant in the AKT3 gene NM_005465.7:c.964G>T,p.Asp322Tyr. The phenotype of this patient is associated with pituitary deficiencies diagnosed at 2 years of age: growth hormone (GH) deficiency responsible for growth delay and central hypothyroidism. After 6 months of GH treatment, intracranial hypertension was noted, confirmed by the observation of papilledema and increased intracranial pressure, requiring the initiation of acetazolamide treatment and the discontinuation of GH treatment. This is the second reported patient described with megalencephaly and AKT3 gene variant associated with GH deficiency . Other endocrine disorders have also been reported in few cases with hypothyroidism and hypoglycemia. Pituitary deficiency may be a part of the of megalencephaly phenotype secondary to germline variant in the AKT3 gene. Special attention should be paid to growth in these patients and search for endocrine deficiency is necessary in case of growth retardation or hypoglycemia.

Overview of therapeutic options for epilepsy.

Tuberous sclerosis (TSC) epilepsy includes infantile spasms and focal seizures before the age of 2 years, whereas focal seizures are predominant over 2 years and generalized seizures may occasionally be part of Lennox-Gastaut syndrome. The better and earlier the seizure control, the better the child's subsequent cognitive and behavioral prognosis. As for epilepsy of other causes, therapeutic options depend on the type of seizure/epilepsy, age and drug resistance, but there are significant specificities for TSC. (1) As first-line treatment, vigabatrin is unanimously recommended for infantile spasms and focal seizures before 2 years and is also widely used for seizures over 2 years, as are levetiracetam and carbamazepine. (2) If seizures persist (about 40% of children and adolescents), cannabidiol and everolimus, an inhibitor of the mTOR pathway, have recently been approved as adjunctive therapy to the arsenal of antiseizure medications authorized for this age group and to the ketogenic diet. (3) Surgery is an essential treatment option in cases of drug resistance and should be discussed as soon as two treatments have failed. Presurgical investigations and operating techniques have recently progressed spectacularly, for example laser thermocoagulation with stereotactic location. A particularity of TSC is the possibility of sequential interventions on several epileptogenic tubers. (4) Finally, the innovative principle of initiating "pre-seizure" treatment with vigabatrin from the first months of life has just proven effective on the subsequent development of epilepsy in TSC. © 2022 French Society of Pediatrics. Published by Elsevier Masson SAS. All rights reserved.

Arterial Spin-Labeling Perfusion Imaging in the Early Stage of Sturge-Weber Syndrome.

BACKGROUND AND PURPOSE: Sturge-Weber syndrome is a rare congenital neuro-oculo-cutaneous disorder. Although the principal mechanism of Sturge-Weber syndrome is characterized by a leptomeningeal vascular malformation, few data regarding perfusion abnormalities of the brain parenchyma are available. Therefore, the aim of this study was to assess the diagnostic performance of arterial spin-labeling perfusion imaging in the early stage of Sturge-Weber syndrome before 1 year of age until 3.5 years of age. We hypothesized that a leptomeningeal vascular malformation has very early hypoperfusion compared with controls with healthy brains. MATERIALS AND METHODS: We compared the CBF using arterial spin-labeling perfusion imaging performed at 3T MR imaging in the brain parenchymal regions juxtaposing the leptomeningeal vascular malformation in patients with Sturge-Weber syndrome (n = 16; 3.5 years of age or younger) with the corresponding areas in age-matched controls with healthy brains (n = 58). The analysis was performed following two complementary methods: a whole-brain voxel-based analysis and a visual ROI analysis focused on brain territory of the leptomeningeal vascular malformation. RESULTS: Whole-brain voxel-based comparison revealed a significant unilateral decrease in CBF localized in the affected cortices of patients with Sturge-Weber syndrome (P < .001). CBF values within the ROIs in patients with Sturge-Weber syndrome were lower than those in controls (in the whole cohort: median, 25 mL/100g/min, versus 44 mL/100g/min; P < .001). This finding was also observed in the group younger than 1 year of age, emphasizing the high sensitivity of arterial spin-labeling in this age window in which the diagnosis is difficult. CONCLUSIONS: Arterial spin-labeling perfusion imaging in the early stage of Sturge-Weber syndrome can help to diagnose the disease by depicting a cortical hypoperfusion juxtaposing the leptomeningeal vascular malformation.

Physician and patient satisfaction with the switch to remote outpatient encounters in epilepsy clinics during the Covid-19 pandemic.

PURPOSE: Analyzing parents' and physicians' opinions regarding phone-based encounters in emergency shifts of a French pediatric epilepsy center compared to traditional face-to-face encounters during the first lockdown of the COVID-19 pandemic METHODS: Prospective monocentric study on remote encounters at Necker rare epilepsy reference center from March 20th, 2020 to April 23rd, 2020 due to lockdown measures. This study was conducted with a survey based on 5-point Likert scales (LS-2/2) designed for both parents and physicians. We compared first versus follow-up encounters as well as physicians' and parents' opinions. RESULTS: We had a total of 224 responses, among which 204 were completed by physicians (91%) and 173 (84,4%) by parents. Twenty five were first encounters (14,2%). Physicians pointed out the need for clinical examination (42.6%), mainly for first encounters (p=0.0004). Physicians rated the quality of communication lower (p=0.003) as their capacity to answer parents' questions (p=0.004). They were significantly less satisfied with remote encounters compared to parents (p<10-4). We identified six urgent (2.9%) and 50 semi-urgent (24%) situations requiring programming face-to-face encounter during or shortly after the lockdown. CONCLUSION: Remote encounters could be a helpful practice for pediatric patients with epilepsy in emergency situations such as pandemics. It allowed the identification and prioritization of emergency situations. Physicians were less positive than parents. We raised the possible use of remote encounters in association to face-to-face encounters for routine follow-up of pediatric patients with epilepsy.

Safety considerations selecting antiseizure medications for the treatment of individuals with Dravet syndrome.

Introduction: Management of individuals with Dravet Syndrome has evolved significantly over the past 10 years. Progress has been made in understanding the pathophysiology, the long-term outcome and possible consequences of inappropriate therapies, new drugs have been approved by the regulatory authorities and patients and families expressed their needs beyond seizures' control.Areas covered: The authors aimed at providing an overview of the main antiseizure medications used in Dravet syndrome with a particular focus on safety considerations. As the highly active phase of seizures takes place before the age of 5 years, the characteristics of antiseizure medications in infancy and childhood have also been considered due to their impact on antiseizure medication safety.Expert opinion: Recent treatments, evaluated via randomized clinical trials, are promising in terms of efficacy and safety in individuals with DS. However, the balance between expected benefits and risks taken must be accurately assessed on an individual basis. There is a lack of data to understand the needs of patients and families, a major point particularly in this population, where the evaluation of efficacy and safety beyond seizures is difficult due to cognitive delay and behavioral disorders and where this evaluation is coming almost exclusively from caregivers.

Multi-feature classifiers for burst detection in single EEG channels from preterm infants.

OBJECTIVE: The study of electroencephalographic (EEG) bursts in preterm infants provides valuable information about maturation or prognostication after perinatal asphyxia. Over the last two decades, a number of works proposed algorithms to automatically detect EEG bursts in preterm infants, but they were designed for populations under 35 weeks of post menstrual age (PMA). However, as the brain activity evolves rapidly during postnatal life, these solutions might be under-performing with increasing PMA. In this work we focused on preterm infants reaching term ages (PMA ⩾36 weeks) using multi-feature classification on a single EEG channel. APPROACH: Five EEG burst detectors relying on different machine learning approaches were compared: logistic regression (LR), linear discriminant analysis (LDA), k-nearest neighbors (kNN), support vector machines (SVM) and thresholding (Th). Classifiers were trained by visually labeled EEG recordings from 14 very preterm infants (born after 28 weeks of gestation) with 36-41 weeks PMA. MAIN RESULTS: The most performing classifiers reached about 95% accuracy (kNN, SVM and LR) whereas Th obtained 84%. Compared to human-automatic agreements, LR provided the highest scores (Cohen's kappa = 0.71) using only three EEG features. Applying this classifier in an unlabeled database of 21 infants ⩾36 weeks PMA, we found that long EEG bursts and short inter-burst periods are characteristic of infants with the highest PMA and weights. SIGNIFICANCE: In view of these results, LR-based burst detection could be a suitable tool to study maturation in monitoring or portable devices using a single EEG channel.

[Peroneal nerve palsy in children: Uncommon diagnosis of a proximal tibiofibular synovial cyst]. / Paralysie du nerf fibulaire commun : diagnostic rare chez l'enfant d'un kyste synovial tibio-fibulaire supérieur.

Compression of the common peroneal nerve by synovial cysts of the tibiofibular joint is a rare disease. Two macroscopic forms may be encountered: extraneural cysts and intraneural cysts. In a review of the literature, we found only three pediatric cases of common peroneal nerve palsy due to extraneural cysts and about 60 cases reported in adults. Taking advantage of the clinical history of two children operated in our department for this disease, we describe this uncommon entity, which must be diagnosed and treated rapidly. Even in the presence of severe clinical and electrophysiological symptoms, a full clinical recovery is possible, as observed in these two children. However, follow-up is needed because recurrence is possible.

Monopolar-probe monitoring during spinal surgery with expandable prosthetic ribs.

BACKGROUND: Intraoperative monitoring (IOM) has been proven to decrease the risk of neurological injury during scoliosis surgery. The vertical expandable prosthetic titanium rib (VEPTR) is a device that allows spinal growth. However, injuries to the spinal cord and brachial plexus have been reported after VEPTR implantation in 2 and 5% of patients, respectively. Simultaneous monitoring of these two structures requires the use of multiple time-consuming and complex methods that are ill-suited to the requirements of paediatric surgery, particularly when repeated VEPTR lengthening procedures are needed. We developed a monopolar stimulation method derived from Owen's monitoring technique. This method is easy to implement, requires only widely available equipment, and allows concomitant monitoring of the spinal cord and brachial plexus. The primary objective of this study was to assess the reliability of our technique for brachial plexus monitoring by comparing the stability of neurogenic mixed evoked potentials (NMEPs) at the upper and lower limbs. HYPOTHESIS: We hypothesised that the coefficients of variation (CVs) of NMEPs were the same at the upper and lower limbs. MATERIAL AND METHODS: Twelve VEPTR procedures performed in 6 patients between 1st January 2012 and 1st September 2014 were monitored using a monopolar stimulating probe. NMEPs were recorded simultaneously at the upper and lower limbs, at intervals of 150 s. The recording sites were the elbow over the ulnar nerve and the popliteal fossa near the sciatic nerve. Wilcoxon's test for paired data was used to compare CVs of the upper and lower limb NMEPs on the same side. RESULTS: Mean CV of NMEP amplitude at the lower limbs was 16.34% on the right and 16.67% on the left; corresponding values for the upper limbs were 18.30 and 19.75%, respectively. Mean CVs of NMEP latencies at the lower limbs were 1.31% on the right and 1.19% on the left; corresponding values for the upper limbs were 1.96 and 1.73%. The risk of type I error for a significant difference between the upper and lower limbs was 0.5843 on the right and 0.7312 on the left for NMEP amplitudes and 0.7618 on the right and 0.4987 on the left for NMEP latencies. CONCLUSION: Using an epidural active electrode and a sternal return electrode allows simultaneous stimulation of the cervical spinal cord and brachial plexus roots. The NMEPs thus obtained are as stable (reliable) at the upper limbs as at the lower limbs. This easy-to-implement method allows simultaneous monitoring of the upper and lower limbs. It seems well suited to VEPTR procedures. LEVEL OF EVIDENCE: IV, retrospective single-centre non-randomised study.