Focal nonconvulsive status epilepticus in children: clinical and electroencephalographic features in 38 patients.

PURPOSE: The aim of this study was to characterize clinically, etiologically, and electroencephalographically focal Nonconvulsive Status Epilepticus (NCSE) in children. Moreover, we tried to identify focal NCSE features distinguishing between different ages, NCSE etiologies, and cases of de novo onset. METHODS: We retrospectively identified patients (aged 1 month to 18 years) who had EEG-documented focal NCSE between January 2001 and December 2019. We analyzed the clinical features, etiology, and EEG features of each event. RESULTS: Thirty-eight patients were included in this study. NCSE had a de novo onset in 26 patients and was the first manifestation of previously undiagnosed epilepsy in 12 patients. NCSE etiology was acute symptomatic in 13 patients. Acute symptomatic NCSE events were mainly observed in hospitalized children, were usually longer, and had a significantly higher frequency of repetitive EEG patterns than other etiologies. In patients with epilepsy, the etiology of NCSE was remote symptomatic in 14, progressive in 6, and cryptogenic in 5; a definite or suspected genetic disorder was observed in 11. EEG localization was frequent in posterior regions (18 children). Eleven patients had refractory NCSE and 4 required admission to the intensive care unit. CONCLUSION: Focal NCSE in children is more frequent in the first years of life, mainly involves posterior regions, and often has de novo onset. In the case of de novo focal NCSE both acute symptomatic NCSE and new-onset epilepsy must be considered and investigated. A higher frequency of repetitive EEG patterns and an inpatient setting are significantly associated with acute symptomatic NCSE.

Pyridoxine-dependent epilepsies: an observational study on clinical, diagnostic, therapeutic and prognostic features in a pediatric cohort.

The aim of our study was to describe the clinical, electroencephalogram, molecular findings and the diagnostic and therapeutic flow-chart of children with pyridoxine-dependent epilepsies (PDEs). We performed a retrospective observational study on children with PDEs, diagnosed and followed-up in Italian Pediatric Departments. In each centre, the authors collected data from a cohort of children admitted for intractable seizures, responsive to pyridoxine administration and resistant to other anticonvulsant therapies. Data were retrospectively analysed from January 2016 to January 2017. Sixteen patients (13 males, and 3 females) were included. We found that 93.75% of patients underwent conventional anticonvulsant therapy before starting pyridoxine administration and 62.5% had ex-juvantibus diagnosis, as specific serum diagnostic tests had been performed in only 37.5% of patients by alpha-AASA and pipecolic acid blood and urine dosage. The most common type of seizure was generalized tonic-clonic in 7 patients and the most common EEG pattern was characterized by a "burst suppression" pattern. Before pyridoxine administration, other anticonvulsant drugs were used in 93.75% of patients, with consequent onset of drug-resistance. Phenobarbital was the most frequently used drug as first-line treatment. The importance of our study relies on the need of a deeper knowledge of PDEs in terms of early diagnosis, avoiding incorrect treatment and related adverse events, clinical and EEG pathognomonic features, and genetic aspects of the disease.

Cytogenetic and molecular characterization of a recombinant X chromosome in a family with a severe neurologic phenotype and macular degeneration.

BACKGROUND: Duplications of MECP2 gene in males cause a syndrome characterized by distinctive clinical features, including severe to profound mental retardation, infantile hypotonia, mild dysmorphic features, poor speech development, autistic features, seizures, progressive spasticity and recurrent infections. Patients with complex chromosome rearrangements, leading to Xq28 duplication, share most of the clinical features of individuals with tandem duplications, in particular neurologic problems, suggesting a major pathogenetic role of MECP2 overexpression. RESULTS: We performed cytogenetic and molecular cytogenetic studies in a previously described family with affected males showing congenital ataxia, late-onset progressive myoclonic encephalopathy and selective macular degeneration. Microsatellite, FISH and array-CGH analyses identified a recombinant X chromosome with a deletion of the PAR1 region, encompassing SHOX, replaced by a duplicated segment of the Xq28 terminal portion, including MECP2. CONCLUSIONS: Our report describes the identification of the actual genetic cause underlying a severe syndrome that previous preliminary analyses erroneously associated to a terminal Xp22.33 region. In the present family as well as in previously reported patients with similar rearrangements, the observed neurologic phenotype is ascribable to MECP2 duplication, with an undefined contribution of the other involved genes. Maculopathy, presented by affected males reported here, could be a novel clinical feature associated to Xq28 disomy due to recombinant X chromosomes, but at present the underlying pathogenetic mechanism is unknown and this potential clinical correlation should be confirmed through the collection of additional patients.

A mutation in PAK3 with a dual molecular effect deregulates the RAS/MAPK pathway and drives an X-linked syndromic phenotype.

Loss-of-function mutations in PAK3 contribute to non-syndromic X-linked intellectual disability (NS-XLID) by affecting dendritic spine density and morphology. Linkage analysis in a three-generation family with affected males showing ID, agenesis of corpus callosum, cerebellar hypoplasia, microcephaly and ichthyosis, revealed a candidate disease locus in Xq21.33q24 encompassing over 280 genes. Subsequent to sequencing all coding exons of the X chromosome, we identified a single novel variant within the linkage region, affecting a conserved codon of PAK3. Biochemical studies showed that, similar to previous NS-XLID-associated lesions, the predicted amino acid substitution (Lys389Asn) abolished the kinase activity of PAK3. In addition, the introduced residue conferred a dominant-negative function to the protein that drives the syndromic phenotype. Using a combination of in vitro and in vivo studies in zebrafish embryos, we show that PAK3(N389) escapes its physiologic degradation and is able to perturb MAPK signaling via an uncontrolled kinase-independent function, which in turn leads to alterations of cerebral and craniofacial structures in vivo. Our data expand the spectrum of phenotypes associated with PAK3 mutations, characterize a novel mechanism resulting in a dual molecular effect of the same mutation with a complex PAK3 functional deregulation and provide evidence for a direct functional impact of aberrant PAK3 function on MAPK signaling.

Case report of pyruvate dehydrogenase deficiency with unusual increase of fats during ketogenic diet treatment.

This article describes a case of pyruvate dehydrogenase deficiency in a 3-year-old boy who presented generalized hypotonia, severe psychomotor development delay, and generalized and partial seizures and was refractory to antiepileptic drugs. After the diagnosis, the patient was put on a ketogenic diet. Six months later, seizure frequency was reduced and psychomotor development had improved. At the same time he presented some side effects, such as 2 episodes of significant increases in cholesterol and triglycerides associated with viral respiratory infections. The latter decreased with a supplementation of ω-3 fatty acids and an increase in caloric intake.

Molecular genetic analysis of the PLP1 gene in 38 families with PLP1-related disorders: identification and functional characterization of 11 novel PLP1 mutations.

BACKGROUND: The breadth of the clinical spectrum underlying Pelizaeus-Merzbacher disease and spastic paraplegia type 2 is due to the extensive allelic heterogeneity in the X-linked PLP1 gene encoding myelin proteolipid protein (PLP). PLP1 mutations range from gene duplications of variable size found in 60-70% of patients to intragenic lesions present in 15-20% of patients. METHODS: Forty-eight male patients from 38 unrelated families with a PLP1-related disorder were studied. All DNA samples were screened for PLP1 gene duplications using real-time PCR. PLP1 gene sequencing analysis was performed on patients negative for the duplication. The mutational status of all 14 potential carrier mothers of the familial PLP1 gene mutation was determined as well as 15/24 potential carrier mothers of the PLP1 duplication. RESULTS AND CONCLUSIONS: PLP1 gene duplications were identified in 24 of the unrelated patients whereas a variety of intragenic PLP1 mutations were found in the remaining 14 patients. Of the 14 different intragenic lesions, 11 were novel; these included one nonsense and 7 missense mutations, a 657-bp deletion, a microdeletion and a microduplication. The functional significance of the novel PLP1 missense mutations, all occurring at evolutionarily conserved residues, was analysed by the MutPred tool whereas their potential effect on splicing was ascertained using the Skippy algorithm and a neural network. Although MutPred predicted that all 7 novel missense mutations would be likely to be deleterious, in silico analysis indicated that four of them (p.Leu146Val, p.Leu159Pro, p.Thr230Ile, p.Ala247Asp) might cause exon skipping by altering exonic splicing elements. These predictions were then investigated in vitro for both p.Leu146Val and p.Thr230Ile by means of RNA or minigene studies and were subsequently confirmed in the case of p.Leu146Val. Peripheral neuropathy was noted in four patients harbouring intragenic mutations that altered RNA processing, but was absent from all PLP1-duplication patients. Unprecedentedly, family studies revealed the de novo occurrence of the PLP1 duplication at a frequency of 20%.

FA2H-related disorders: a novel c.270+3A>T splice-site mutation leads to a complex neurodegenerative phenotype.

Homozygous mutations in the gene for fatty acid 2-hydroxylase (FA2H) have been associated in humans with three neurodegenerative disorders: complicated spastic paraplegia (SPG35), leukodystrophy with spastic paraparesis and dystonia, and neurodegeneration with brain iron accumulation. Here, we describe a novel homozygous c.270+3A>T mutation in an Italian consanguineous family. In two affected brothers (age at molecular diagnosis 22y and 15y; age at last follow-up 24y and 17y), altered FA2H function led to a severe phenotype, with clinical features overlapping those of the three FA2H-associated disorders. Both patients showed childhood onset progressive spastic paraparesis, mild pyramidal and cerebellar upper limb signs, severe cognitive impairment, white-matter disease, and cerebellar, brainstem, and spinal cord atrophy. However, absence of dystonia, drowsiness episodes, and a subtle globus pallidus involvement suggested that FA2H mutations result in a clinical spectrum, rather than causing distinct disorders. Although clinical heterogeneity is apparent, larger numbers of patients are needed to establish more accurate genotype-phenotype correlations.

A new case of idiopathic hemiplegia hemiconvulsion syndrome.

We report a new case of infantile idiopathic hemiconvulsion-hemiplegia syndrome (HH). A prolonged right-sided febrile convulsion was followed 4 days later, by right hemiconvulsive status epilepticus, documented by video-electroencephalogram (EEG) recording. The child developed an ipsilateral hemiplegia, partially improved during the first month of follow-up. Sequential cerebral magnetic resonance imaging (MRI) and proton magnetic resonance spectroscopy (1H-MRS) at 6, 15, 30 days of follow-up showed a cytotoxic edema in the left hemisphere and a subsequent necrosis. At 1-year of follow-up, we performed MRI control because of febrile convulsion lasting few minutes that confirmed a non-progressive left hemisphere atrophy. After 2 years, the patient was seizure-free, with a mild right hemiplegia and language skills deficit. We discuss the unclear pathogenesis of HH through sequential neuroradiological evaluation.

VNS in drug resistant epilepsy: preliminary report on a small group of patients.

BACKGROUND: In 1997 Vagus Nerve Stimulation (VNS) received approval from the US Food and Drug Administration (FDA) as an adjunctive therapy in the treatment of medically intractable partial epilepsy in people aged 12 years and older who are ineligible for resective epilepsy surgery. Although the exact mechanisms of action are unknown, the use of VNS with children has increased, including those younger than 12 years of age, or those with generalized epilepsy. METHODS: We describe the outcome for the first group of nine patients, aged 8-28 years, who had pharmaco-resistant epilepsy and were treated with VNS. During the follow up, we gradually and slowly increased the parameters of the stimulation in order to assess the efficacy of VNS even at parameters which would usually be considered "non-therapeutic", along with possible side effects and changes in quality of life. RESULTS: At the last follow, up 1 patient was "seizures free", 3 were "very good responders", 3 were "good responders" and 2 were "non responders". We obtained an initial seizure reduction with low stimulation parameters, the highest current reached being 2.00 mA. This observation supports the possibility that, for younger patients, lower stimulation intensities than those commonly used in clinical practice for adults can be therapeutic. We also wanted to underline the reduction in seizure frequency (approximately 91.7%) and the reduction in seizure duration (> 50%) in the patients affected by drug-resistant absence epilepsy. Adverse effects were mild, tolerable and, in most of cases, easily resolved by adjusting the stimulation parameters. Hoarseness of voice was the most frequent side effect. The improvements in the quality of life are relevant and seem to be independent of the VNS effect in controlling seizures. CONCLUSIONS: Our small experience seems to confirm the efficacy and safety of VNS in drug resistant partial and generalized epilepsy in developing age groups.

Prospective study on long-term treatment with oxcarbazepine in pediatric epilepsy.

Following a previous preliminary report on a group of children suffering from partial epilepsies, we present the final considerations on the same group in order to evaluate the long-term efficacy, tolerability and safety of oxcarbazepine (OXC). We enrolled 36 patients (mean age 8.5), between January 2003 and December 2004, with new diagnosis of partial epilepsy: 25 patients were affected by idiopathic partial epilepsy, eight by symptomatic epilepsy and three by cryptogenic epilepsy. Each patient was scheduled to attend the center four times after the initial examination: 3 months (T1), 12 months (T2), 24 (T3) months and 36 (T4) months after the beginning of OXC-monotherapy (T0). At the end of our study, 20 patients were seizure free (SF): nine stopped OXC because of SF for at least 2 years, 11 were still on therapy. One patient showed a reduction of seizure frequency >or=50%, three were non responders (but still on therapy), nine stopped OXC due to a non-responder condition during follow-up before T4 and one because of adverse effects. At the end of the study no EEG focal abnormalities became generalized because of treatment. Normalization of EEG was observed in ten patients. Our preliminary findings have been confirmed. OXC can be considered an effective and well tolerated first line drug for long-term monotherapy in children with epilepsy, both for idiopathic and symptomatic/cryptogenic forms.

No kinetic interaction between levetiracetam and cyclosporine: a case report.

Levetiracetam is a new antiepileptic drug reported to be effective and well-tolerated in adults and children affected by epilepsy. Its lack of hepatic cytochrome metabolism is the theoretic basis for the absence of interactions with other drugs that follow this pathway. We present a 14-year-old girl who underwent orthotopic heart transplantation, followed by antirejection therapy including cyclosporine. Symptomatic occipital lobe epilepsy developed that was successfully treated with oxcarbazepine, but cyclosporine plasma levels decreased to below the antirejection threshold. Oxcarbazepine was replaced by levetiracetam. Levetiracetam did not affect the metabolism of cyclosporine, and cyclosporine plasma levels have remained in the therapeutic range up to now. The patient is still seizure-free and does not complain of any side effects after a 1-year follow-up. Further studies are necessary to confirm the lack of interactions between these drugs, which would make levetiracetam a useful therapeutic option in managing seizure control during antirejection therapy with cyclosporine.