Childhood-Onset Multifocal Motor Neuropathy with IgM Antibodies to Gangliosides GM1: A Case Report with Poor Outcome.

BACKGROUND: Multifocal motor neuropathy (MMN) is a slowly progressive motor neuropathy characterized by asymmetric muscle weakness without sensory involvement. Typically, MMN respond completely to treatment with intravenous immunoglobulin (IVIg). MMN is even rarer in the pediatric population, where only five patients have been reported up to now. CASE REPORT: We discuss the 3-year follow-up of a 13-year-old girl with MMN who was positive for IgM antibodies to gangliosides GM1. She was diagnosed with MMN in accordance with the European Federation of Neurological Societies/Peripheral Nerve Society (EFNS/PNS) criteria. Serological studies revealed that she tested positive for IgM antibodies to GM1. She underwent intravenous methylprednisolone followed by an oral prednisone taper, intravenous immunoglobulin (IVIg), plasma exchange followed by IVIG and prednisone and Rituximab. No improvement was referred. At the present, she shows flaccid tetraplegia, facial diplegia, and bulbar cranial nerve palsy. CONCLUSION: Although childhood onset MMN is rare, most patients reported in literature respond to IVIg treatment. In a few cases, however, IVIg can be ineffective. In our patient, IVIg as well as treatment with prednisolone, plasma exchange and rituximab have failed.

Mutations in the Heme Exporter FLVCR1 Cause Sensory Neurodegeneration with Loss of Pain Perception.

Pain is necessary to alert us to actual or potential tissue damage. Specialized nerve cells in the body periphery, so called nociceptors, are fundamental to mediate pain perception and humans without pain perception are at permanent risk for injuries, burns and mutilations. Pain insensitivity can be caused by sensory neurodegeneration which is a hallmark of hereditary sensory and autonomic neuropathies (HSANs). Although mutations in several genes were previously associated with sensory neurodegeneration, the etiology of many cases remains unknown. Using next generation sequencing in patients with congenital loss of pain perception, we here identify bi-allelic mutations in the FLVCR1 (Feline Leukemia Virus subgroup C Receptor 1) gene, which encodes a broadly expressed heme exporter. Different FLVCR1 isoforms control the size of the cytosolic heme pool required to sustain metabolic activity of different cell types. Mutations in FLVCR1 have previously been linked to vision impairment and posterior column ataxia in humans, but not to HSAN. Using fibroblasts and lymphoblastoid cell lines from patients with sensory neurodegeneration, we here show that the FLVCR1-mutations reduce heme export activity, enhance oxidative stress and increase sensitivity to programmed cell death. Our data link heme metabolism to sensory neuron maintenance and suggest that intracellular heme overload causes early-onset degeneration of pain-sensing neurons in humans.

A Novel Mutation in RPL10 (Ribosomal Protein L10) Causes X-Linked Intellectual Disability, Cerebellar Hypoplasia, and Spondylo-Epiphyseal Dysplasia.

RPL10 encodes ribosomal protein L10 (uL16), a highly conserved multifunctional component of the large ribosomal subunit, involved in ribosome biogenesis and function. Using X-exome resequencing, we identified a novel missense mutation (c.191C>T; p.(A64V)) in the N-terminal domain of the protein, in a family with two affected cousins presenting with X-linked intellectual disability, cerebellar hypoplasia, and spondylo-epiphyseal dysplasia (SED). We assessed the impact of the mutation on the translational capacity of the cell using yeast as model system. The mutation generates a functional ribosomal protein, able to complement the translational defects of a conditional lethal mutation of yeast rpl10. However, unlike previously reported mutations, this novel RPL10 missense mutation results in an increase in the actively translating ribosome population. Our results expand the mutational and clinical spectrum of RPL10 identifying a new genetic cause of SED and highlight the emerging role of ribosomal proteins in the pathogenesis of neurodevelopmental disorders.

Longitudinal myelitis in systemic lupus erythematosus: a paediatric case.

Acute transverse myelitis (ATM) is a very rare manifestation of the central nervous system in systemic lupus erythematosus (SLE), especially in case of involvement of continuous segments (longitudinal myelitis). We describe a 12-year-old female with lupus correlated with transverse myelitis with a longitudinal involvement of the spinal cord (D2 to D10) at the onset of the disease. Despite the administration of an early aggressive therapy, the outcome proved to be unfavourable. After 2 years of follow-up, the child still complains of paraplegia, sphincter incontinency and ipo-paresthesias of both legs.

Neonatal Cerebral Venous Thrombosis following Maternal SARS-CoV-2 Infection in Pregnancy.

A possible consequence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is the development of an exacerbated thrombophilic status, and cerebral venous thrombosis (CVT) is a rare but possible complication of SARS-CoV-2 infection reported both in adults and in children. The present case report describes the clinical course of a term neonate showing extended CVT of unclear origin, whose mother had developed SARS-CoV-2 infection during the third trimester of pregnancy. We speculate that the prothrombotic status induced by maternal SARS-CoV-2 infection may have played a pathophysiological role in the development of such severe neonatal complication. Further investigations are required to confirm such hypothesis.

Brain auditory evoked potentials in pediatric intensive care unit: diagnostic role on encephalopathy and central respiratory failure on infants.

Encephalopathy of different etiologies in infants is often the reason for central respiratory insufficiency which eventually leads patients to the paediatric intensive care unit. Magnetic resonance imaging (MRI) and brainstem auditory evoked potentials (BAEPs) may be useful to identify brainstem alterations among patients with respiratory insufficiency of central origin. MRI is a compulsory technique to identify brain abnormalities, but may fail to detect brainstem lesions of small dimensions. BAEPs play a highly sensitive role on brainstem dysfunction identification because of the generators of different peaks which are related to specific brainstem structures. The early identification of brainstem lesions in mechanically ventilated infants with encephalopathy may reduce the weaning off mechanical ventilation's attempt numbers and provide early informative discussions with families and clinical caregivers about treatment options, such as tracheostomy, long term ventilation and the reduction of their lenght of PICU stay. Furthermore, this would support the evaluation process concerning the affected children, their families and the needs of other social groups, including health systems.

Consensus protocol for EEG and amplitude-integrated EEG assessment and monitoring in neonates.

The aim of this work is to establish inclusive guidelines on electroencephalography (EEG) applicable to all neonatal intensive care units (NICUs). Guidelines on ideal EEG monitoring for neonates are available, but there are significant barriers to their implementation in many centres around the world. These include barriers due to limited resources regarding the availability of equipment and technical and interpretive round-the-clock personnel. On the other hand, despite its limitations, amplitude-integrated EEG (aEEG) (previously called Cerebral Function Monitor [CFM]) is a common alternative used in NICUs. The Italian Neonatal Seizure Collaborative Network (INNESCO), working with all national scientific societies interested in the field of neonatal clinical neurophysiology, performed a systematic literature review and promoted interdisciplinary discussions among experts (neonatologists, paediatric neurologists, neurophysiologists, technicians) between 2017 and 2020 with the aim of elaborating shared recommendations. A consensus statement on videoEEG (vEEG) and aEEG for the principal neonatal indications was established. The authors propose a flexible frame of recommendations based on the complementary use of vEEG and aEEG applicable to the various neonatal units with different levels of complexity according to local resources and specific patient features. Suggestions for promoting cooperation between neonatologists, paediatric neurologists, and neurophysiologists, organisational restructuring, and teleneurophysiology implementation are provided.

A reappraisal of the value of video-EEG recording in the emergency department.

Introduction: Some neurologic conditions that can quickly and with low costs be recognized, classified and treated thanks to the availability of an EEG recording in an emergency setting. However, although considered a cheap, not invasive, highly accurate diagnostic investigation, still today, an EEG recording in emergency, in real time during the event paroxysmal ictal phase, is not yet been become a routine.Areas covered: This review will cover the role and utility of EEG recording in the emergency setting, both in emergency department and intensive care unit, in adult and pediatric age, in people admitted for status epilepticus (convulsive or non-convulsive), paroxysmal non-epileptic events, or other conditions/diseases presenting with mental status changes.Expert opinion: The prompt recognition of some specific EEG-patterns can permit an immediate and appropriate therapeutic choice with the resolution of dramatic clinical pictures, which, if not recognized, sometimes could result in severe prognostic events with high mortality or neuropsychiatric disability. It is important in the next future, to improve the availability of these EEG digital continuous monitoring, which should be widely used in emergency settings, developing moreover tools and techniques permitting also review, analysis and EEG-reporting by experts who can work away from the hospital.

Corticospinal tract damage in HHH syndrome: a metabolic cause of hereditary spastic paraplegia.

BACKGROUND: Hyperornithinemia-hyperammonemia-homocitrullinuria (HHH) syndrome is a rare disorder of urea cycle characterized by progressive pyramidal and cerebellar dysfunction, whose pathophysiology is not yet fully understood. Here we describe the spectrum of the long fibers involvement in HHH syndrome, attempting a correlation between clinical, electrophysiological and neuro-radiological data. METHODS: Nine HHH patients were longitudinally evaluated by clinical examination, neurophysiological assessment including motor (MEPs), somato-sensory evoked potentials (PESS) and nerve conduction velocity (NCV), brain and spinal cord MRI RESULTS: All patients had pyramidal dysfunction and 3/9 an overt spastic paraplegia. Mild to moderate cerebellar signs were found in 7/9, intellectual disability in 8/9. At lower limbs, MEPs resulted abnormal in 7/8 patients and PESS in 2/8; peripheral sensory-motor neuropathy was found in 1/9. MRI documented atrophic changes in supra-tentorial brain regions in 6/9 patients, cerebellum in 6/9, spinal cord in 3/7. CONCLUSIONS: A predominant corticospinal dysfunction is evident in HHH syndrome, along with milder cerebellar signs, intellectual disability of variable degree and rare peripheral neuropathy. Phenotypical similarities with other disorders affecting the urea cycle (argininemia and pyrroline-5-carboxylate synthetase deficiency) suggest possible common mechanisms contributing in the maintenance of the corticospinal tract integrity. HHH syndrome phenotype largely overlaps with complex Hereditary Spastic Paraplegias (HSPs), in the list of which it should be included, emphasizing the importance to screen all the unsolved cases of HSPs for metabolic biomarkers.

Influence of etiology on treatment choices for neonatal seizures: A survey among pediatric neurologists.

BACKGROUND: A targeted treatment approach is increasingly promoted in epilepsy management. AIM: To investigate if etiology (both established or initially presumed) influences antiepileptic drug choice of experts in neonatal seizures. METHODS: An invitation to participate to a web-based questionnaire was sent to Italian pediatric neurologists affiliated to the Italian Society of Pediatric Neurology (SINP). RESULTS: 19 pediatric neurologists from different centers, all consultants of third level Neonatal Intensive Care Units (NICUs) answered. As first-line drug phenobarbital was the most common choice, it was used in 79% of cases of acute symptomatic seizures, in 63% of structural epilepsy, in 42% of genetic epilepsies. As second-line drug phenytoin was used by 58% in acute symptomatic seizures, 37% in structural epilepsy, 5% in genetic epilepsy. Pyridoxine/pyridoxalphosphate was much more used in genetic epilepsy (as first-line in 26%, as second-line in 37%) than in the other two conditions. Long-term conventional EEG monitoring was suggested as important to verify efficacy of drugs in controlling seizures by 84% of interviewed neurologists, but EEG was available around the clock in only 53% of their centers. 1 to 3-channel aEEG/EEG (commonly named CFM) was often used instead of conventional EEG monitoring. CONCLUSION: This is the first survey looking at a targeted approach in treatment of neonatal seizures by pediatric neurologists consulted by NICUs. The treatment approach is similar to previous surveys in case of acute symptomatic seizures, but in case of other etiologies the choices are different, especially for the second-line option. Larger studies should address this topic.

Bilateral loss of cortical SEPs predict severe MRI lesions in neonatal hypoxic ischemic encephalopathy treated with hypothermia.

OBJECTIVE: The introduction of therapeutic hypothermia for neonatal hypoxic-ischemic encephalopathy calls for reevaluation of the prognostic role of somatosensory evoked potentials (SEPs). METHODS: Among 80 consecutive neonates undergoing hypothermia for hypoxic-ischemic encephalopathy, 58 performed SEPs and MRI at 4-14 days of life and were recruited in this multicenter study. SEPs were scored as: 0 (bilaterally/unilaterally recorded N20) or 1 (bilaterally absent N20). The severity of brain injury was scored using MRI. RESULTS: Bilaterally absent N20 was observed in 10/58 neonates (17%); all had moderate/severe MRI abnormalities; 36/48 neonates (75%) with score 0 at SEPs had normal MRI. The positive predictive value of SEPs on MRI outcome was of 1.00, while the negative predictive value 0.72, sensitivity 0.48, specificity 1.00, with an accuracy of 0.78 (p < .001). CONCLUSIONS: Bilateral absence of cortical SEPs predicts moderate/severe MRI pattern of injury. SIGNIFICANCE: Therapeutic hypothermia does not seem to significantly affect prognostic reliability of SEPs.

Biochemical and molecular characterization of 18 patients with pyridoxine-dependent epilepsy and mutations of the antiquitin (ALDH7A1) gene.

Patients with pyridoxine dependent epilepsy (PDE) present with early-onset seizures resistant to common anticonvulsants. According to the benefit of pyridoxine (vitamin B(6)) and recurrence of seizures on pyridoxine withdrawal, patients so far have been classified as having definite, probable, or possible PDE. Recently, PDE has been shown to be caused by a defect of alpha-amino adipic semialdehyde (AASA) dehydrogenase (antiquitin) in the cerebral lysine degradation pathway. The accumulating compound piperideine-6-carboxylic acid (P6C) was shown to inactivate pyridoxalphosphate (PLP) by a Knoevenagel condensation. Pipecolic acid (PA) and AASA are markedly elevated in urine, plasma, and cerebrospinal fluid (CSF) and thus can be used as biomarkers of the disease. We have investigated 18 patients with neonatal seizure onset, who have been classified as having definite (11), probable (four), or possible (three) PDE. All patients had elevated PA and AASA in plasma (and urine) while on treatment with individual dosages of pyridoxine. Within this cohort, molecular analysis identified 10 novel mutations (six missense mutations, one nonsense mutation, two splice site mutations) within highly conserved regions of the antiquitin gene. Seven mutations were located in exonic sequences and two in introns 7 and 17. Furthermore, a novel deletion of exon 7 was identified. Two of the 36 alleles investigated require further investigation. A known mutation (p.Glu399Gln) was found with marked prevalence, accounting for 12 out of 36 alleles (33%) within our cohort. Pyridoxine withdrawal is no longer needed to establish the diagnosis of "definite" PDE. Administration of pyridoxine in PDE may not only correct secondary PLP deficiency, but may also lead to a reduction of AASA (and P6C) as presumably toxic compounds.

Missense mutations of CACNA1A are a frequent cause of autosomal dominant nonprogressive congenital ataxia.

BACKGROUND: Mutations in the CACNA1A gene, encoding the pore-forming CaV2.1 (P/Q-type) channel α1A subunit, localized at presynaptic terminals of brain and cerebellar neurons, result in clinically variable neurological disorders including hemiplegic migraine (HM) and episodic or progressive adult-onset ataxia (EA2, SCA6). Most recently, CACNA1A mutations have been identified in patients with nonprogressive congenital ataxia (NPCA). METHODS: We performed targeted resequencing of known genes involved in cerebellar dysfunction, in 48 patients with congenital or early onset ataxia associated with cerebellar and/or vermis atrophy. RESULTS: De novo missense mutations of CACNA1A were found in four patients (4/48, ∼8.3%). Three of them developed migraine before or after the onset of ataxia. Seizures were present in half of the cases. CONCLUSION: Our results expand the clinical and mutational spectrum of CACNA1A-related phenotype in childhood and suggest that CACNA1A screening should be implemented in this subgroup of ataxias.

Intravenous levetiracetam terminates refractory status epilepticus in two patients with migrating partial seizures in infancy.

OBJECTIVE: To evaluate the efficacy and tolerability of intravenous (IV) levetiracetam in refractory status epilepticus of migrating partial seizures in infancy (MPSI). METHODS: IV levetiracetam was infused in two infants, first as a loading dose of 60mg/kg in 30min, then at 30mg/kg twice a day. Both infants were continuously monitored with video-EEG before, during and after the drug trial. Blood count, liver enzymes, serum creatinine, ammonia and lactate blood levels were performed repeatedly before and after the IV levetiracetam administration. Follow-up was of 16 and 10 months. RESULTS: EEG monitoring allowed the diagnosis of MPSI, showing the typical seizures pattern in both patients. IV levetiracetam was effective in stopping status epilepticus in both infants. Levetiracetam also prevented the recurrence of status epilepticus during follow-up. No adverse reactions were observed during the infusion phase or during follow-up. CONCLUSIONS: MPSI is a newly recognized epileptic syndrome characterized by early onset of intractable partial seizures arisingly independently and sequentially from both hemispheres, migrating from one region of the brain to another and from one hemisphere to another. We report the efficacy of intravenous levetiracetam in resolving refractory status epilepticus in two infants with this new epilepsy syndrome.

A Multicentre Database for Normative Brainstem Auditory Evoked Potentials (BAEPs) in Children: Methodology for Data Collection and Evaluation.

BACKGROUND: The influence of physiological and methodological factors on recordings of brainstem auditory evoked potentials (BAEPs) is greater in children than in adults. OBJECTIVE: To collect and evaluate BAEP data in normal children, and measure intra- and inter-laboratory variability. METHODS: Seven hundred and fifty unselected BAEP recordings were collected and evaluated from children ranging from neonates to 14-year-olds by eight laboratories in Italy. RESULTS: In newborns, three laboratories showed satisfactory concordance; wave I was more broadly distributed than wave V and IPL I-V. The evaluation of pooled BAEP data from the older children showed that laboratories with age-matched data gave overlapping results; those with unmatched-age data differed significantly. The sound intensities of the laboratories did not significantly affect absolute BAEP latencies or IPLs. Females had shorter latencies than males; the difference was not significant. A single exponential regression model was an adequate but not the best predictor of normal data. CONCLUSIONS: The pooled data were consistent with the physiological maturation of the brainstem acoustic pathway. The BAEPs was reliably normalised using the natural logarithm of age. The differences between Centres were related to sample size, measurement accuracy, and inclusion and selection criteria. SIGNIFICANCE: The creation of multicentre common database from an unmatched data collection is feasible and reliable enough for clinical diagnosis and multicentre clinical research.

Subdural fluid collections in patients with infantile neuronal ceroid lipofuscinosis.

OBJECTIVE: To describe subdural fluid collections on magnetic resonance imaging as part of the natural history of infantile neuronal ceroid lipofuscinosis. DESIGN: Case series. SETTING: Program on Developmental Endocrinology and Genetics, The Clinical Center, National Institutes of Health, Bethesda, Maryland. PATIENTS: Patients with infantile neuronal ceroid lipofuscinosis with subdural fluid collections. MAIN OUTCOME MEASURE: Neurodegeneration on magnetic resonance imaging. RESULTS: During an ongoing bench-to-bedside clinical investigation, magnetic resonance imaging examinations led to the incidental discovery of subdural fluid collections in 4 of 9 patients with infantile neuronal ceroid lipofuscinosis. No particular event (such as trauma) or change in symptoms was linked to this finding, which was already in the chronic phase when discovered. Of the 4 patients, 1 was followed up for 7 years, 2 for 4 years, and 1 for 2.5 years. Over time, these collections remained stable or decreased in size. CONCLUSION: Recognition that subdural fluid collections are part of the infantile neuronal ceroid lipofuscinosis disease process may obviate the necessity of additional workup as well as therapeutic interventions in these chronically sick children.

Infantile-onset ascending hereditary spastic paralysis is associated with mutations in the alsin gene.

We studied 15 patients, from 10 families, who presented with severe spastic paralysis with an infantile onset and an ascending progression. Spastic paraplegia began during the first 2 years of life and extended to upper limbs within the next few years. During the first decade of life, the disease progressed to tetraplegia, anarthria, dysphagia, and slow eye movements. Overall, the disease was compatible with long survival. Signs of lower motor-neuron involvement were never observed, whereas motor-evoked potentials and magnetic resonance imaging demonstrated a primitive, pure degeneration of the upper motor neurons. Genotyping and linkage analyses demonstrated that this infantile-onset ascending hereditary spastic paralysis (IAHSP) is allelic to the condition previously reported as juvenile amyotrophic lateral sclerosis at the ALS2 locus on chromosome 2q33-35 (LOD score 6.66 at recombination fraction 0). We analyzed ALS2, recently found mutated in consanguineous Arabic families presenting either an ALS2 phenotype or juvenile-onset primary lateral sclerosis (JPLS), as a candidate gene. In 4 of the 10 families, we found abnormalities: three deletions and one splice-site mutation. All the mutations lead to a truncated alsin protein. In one case, the mutation affected both the short and the long alsin transcript. In the six remaining families, absence of cDNA ALS2 mutations suggests either mutations in regulatory ALS2 regions or genetic heterogeneity, as already reported in JPLS. Alsin mutations are responsible for a primitive, retrograde degeneration of the upper motor neurons of the pyramidal tracts, leading to a clinical continuum from infantile (IAHSP) to juvenile forms with (ALS2) or without (JPLS) lower motor-neuron involvement. Further analyses will determine whether other hereditary disorders with primitive involvement of the central motor pathways, as pure forms of spastic paraplegia, could be due to alsin dysfunction.