[Effects of Long-Term Treatment with Levetiracetam as an Adjunctive Therapy in Japanese Children with Uncontrolled Partial-Onset Seizures: A Multicenter, Open-Label Study]

Following the first period of the multicenter, open-label, single-armed N01223 trial, the second period of the N01223 trial was conducted to evaluate long-term safety, along with the efficacy of adjunctive levetiracetam treatment (individualized dose range, 20-60 mg/kg/day or 1,000-3,000 mg/day) in Japanese pediatric patients with uncontrolled partial-onset seizures (POS). Of the 62 children who completed the first period, 55 children [age: 10.4 ± 3.4 years (mean ± standard deviation)] were elected to enter the second period for a maximum of 39 months. Twenty children were withdrawn during this second period. Frequencies of treatment-emergent adverse events (TEAEs) and adverse drug reactions (ADRs) were 98.2% (54/55 cases) and 27.3% (15/55 cases), respectively. The most common TEAEs were nasopharyngitis (76.4%), influenza (36.4%) and pyrexia (25.5%). The only frequent ADR (>2%) was somnolence (3.6%). Although serious TEAEs and death were reported in 8 cases and 1 case (drowning), respectively, a serious ADR was only reported in 1 case (vomiting). The median percentage reduction and 50% response rate for POS were 43.32% and 41.8%, respectively. One child showed a maximum seizure-free period of 163 days. In conclusion, levetiracetam demonstrated long-term safety and good tolerance with beneficial efficacy as an adjunctive therapy in Japanese children with uncontrolled POS. (Received June 30, 2015; Accepted July 14, 2015: Published November 1, 2015).

Ketogenic diet therapy can improve ACTH-resistant West syndrome in Japan

PURPOSE

Ketogenic diet therapy (KD) has been used to treat children with refractory generalized epilepsy. We herein reported the efficacy of KD for West syndrome (WS) resistant to ACTH therapy.

SUBJECTS

SUBJECTS, consisting of 6 patients (3 boys, 3 girls) with WS who continued to have epileptic spasms (ES) and hypsarrhythmia, received KD because other treatments including ACTH therapy failed to control WS.

METHODS

We retrospectively studied the clinical details of these patients and the efficacy of KD.

RESULTS

The mean age at the onset of epilepsy was 4 months (0-15 months). The underlying etiology consisted of lissencephaly, Down's syndrome, and focal cortical dysplasia. Hypsarrhythmia disappeared 1 month after the introduction of KD in 5 patients. The disappearance of ES was achieved in 2 patients, the frequency of ES episodes was 80% less in 3, and no change was observed in 1. Psychomotor development was promoted in 5 patients, along with improvements in ES and EEG. Gastrointestinal complications and lethargy, presumably caused by rapid ketosis, were reported as side effects in 3 patients during the first week of KD. Side effects including lethargy, anorexia, and unfavorable weight gain continued thereafter in these patients in spite of tolerance to KD.

CONCLUSION

KD was effective for WS resistant to ACTH therapy, although gastrointestinal side effects should be considered when introducing KD to milk-fed infants.

Study of epileptic drop attacks in symptomatic epilepsy of early childhood - differences from those in myoclonic-astatic epilepsy

OBJECTIVES

We studied epileptic drop attacks (EDA) in symptomatic epilepsy of early childhood by means of video-polygraphic recordings and compared clinico-electrical differences in EDA among patients with idiopathic myoclonic-astatic epilepsy (MAE).

SUBJECTS AND METHODS

Subjects consisted of 21 children with symptomatic epilepsy and 20 with idiopathic MAE whose EDA were documented at an age between 7 months and 6 years. The seizure types causing EDA as well as other demographic data were compared between the two epilepsy types.

RESULTS

A video-polygraphic study captured a total of 188 EDA (median: 8) in patients with symptomatic epilepsy and 182 EDA (median: 7) in those with idiopathic MAE. In the former, EDA were caused by epileptic spasms (ES) corresponding to generalized biphasic slow discharges, sharp-and-slow wave complexes, or the flattening of ongoing background activity in 15 patients, atonic seizures associated with runs of generalized spike-and-wave complexes in four patients, and myoclonic-atonic seizures in the remaining two patients. The mode of occurrence of EDA in ES was periodic clustering in eight of 15 patients. Interictal EEG revealed generalized irregular multiple spikes-and-waves with focal or multifocal accentuations. Sixteen idiopathic MAE patients had myoclonic-atonic seizures while the remaining four had myoclonic-flexor seizures, all corresponding to generalized high amplitude spikes or polyspike-and-wave complexes and occurring singly.

CONCLUSION

EDA often seen in young children with symptomatic epilepsy were most frequently caused by flexor type ES and rarely by myoclonic-atonic seizures, a hallmark seizure type of MAE. In a clinical setting, the occurrence of periodic clusters and independent focal or multifocal accentuations of generalized spike-and-wave complexes in interictal EEG may indicate EDA caused by ES.

The muscular dystrophies associated with central nervous system lesions: a brief review from a standpoint of the localization and function of causative genes

The muscular dystrophies have been traditionally classified based mainly on clinical manifestation and mode of inheritance. Owing to the discoveries of causative genes, new terminologies derived from each gene, such as dystrophinopathy, α-dystroglycanopathy, sarcoglycanopathy and fukutinopathy, have also become common. Mutations of each gene may cause several clinical phenotypes. Some muscular dystrophies accompany central nervous system (CNS) lesions, especially in the congenital muscular dystrophies. Cobblestone lissencephaly (type II lissencephaly) is a well-known CNS malformation observed in severe forms of α-dystroglycanopathy. Moreover, CNS involvement has been reported in other muscular dystrophies, such as Duchenne muscular dystrophy. In this review, genes related to the muscular dystrophies associated with CNS lesions are briefly described along with the molecular characteristics of each gene and the pathomechanism of the CNS lesions. Understanding of both the clinicopathological characteristics of these CNS lesions and their molecular mechanisms is important for the diagnosis, care of patients, and development of new therapeutic strategies.

Mild developmental delay and obesity in two patients with mosaic 1p36 deletion syndrome

We identified mosaic 1p36 deletions in two patients with developmental delay, distinctive features, and obesity, who can walk alone and communicate with others. Thus, their neurological defects are milder than those in typical patients with 1p36 deletion syndrome because most patients with 1p36 deletion cannot acquire expressive language. Chromosomal microarray testing revealed 3.0 and 4.5 Mb aberrations in the subtelomeric region of the short arm of chromosome 1. Mean signal ratios of the identified aberrations were -0.4 and -0.5, indicating mosaicism, which was confirmed by fluorescence in situ hybridization analysis with a mosaic ratio of 70% and 77%, respectively. Previous studies demonstrated that deletion of the distal 2-3 Mb region would be responsible for hyperphagia and obesity seen in patients. On the other hand, the severity of the neurological defect often correlates with the size of the terminal deletion of 1p36, and patients with larger deletions of 1p36 would usually show severely impaired developmental milestones and be immobile and aphasic. In such cases, hyperphagia and obesity could be clinically masked. In this study, two patients with mosaic deletions of 1p36 showed obesity as a consequence of hyperphagia. This study suggests that patients with 1p36 deletion would be at risk for hyperphagia and obesity when they have both risk factors, that is, (1) deletions including the 2-3 Mb critical region and (2) milder phenotypes that allow them to reach food on their own and to overeat.

[Efficacy and safety of levetiracetam as adjunctive therapy in Japanese children with uncontrolled partial-onset seizures: multicenter and open-label study (N01223), short term evaluation]

A multicenter, open-label, single-armed study (N01223) was conducted to evaluate efficacy and safety of levetiracetam (LEV) as an add-on therapy in Japanese pediatric patients with uncontrolled partial-onset seizures (POS). A total of 73 children aged 4-15 years (mean±SD=10.1±3.4 years) were enrolled in the study, which consisted of an 8-week baseline period and a 14-week treatment period, including a 4-week titration period. A historical placebo control from a pivotal overseas pediatric study in POS add-on therapy was used. A 16.3% median percent reduction from the baseline in POS was observed in this placebo control. Therefore, in the present study, this value (16.3%) was chosen as the predefined threshold for the lower limit of the 95% confident interval (95% CI) of the median percent reduction from the baseline for LEV. In the present study, the percentage reduction (95% CI) in POS during the treatment period was 43.21% (26.19-52.14%), indicating a beneficial impact of LEV. The incidences of treatment-emergent adverse events (TEAEs) and adverse drug reactions (ADRs) were 82.2% (60/73 cases) and 56.2% (41/73 cases), respectively. The most common TEAEs were somnolence, nasopharyngitis, upper respiratory tract infection, and pyrexia. Frequent ADRs (more than 3%) were somnolence and feeling jittery. No serious TEAE or death was reported during the study. Our results suggested that adjunctive therapy with LEV is clinically efficacious and well tolerated in Japanese children with uncontrolled POS.

Microdeletions of 5.5 Mb (4q13.2-q13.3) and 4.1 Mb (7p15.3-p21.1) associated with a saethre-chotzen-like phenotype, severe intellectual disability, and autism

We observed a patient with a Saethre-Chotzen-like phenotype with severe neurological features. Saethre-Chotzen syndrome (acrocephalosyndactyly type III; SCS; OMIM #101400) is an autosomal dominant craniosynostosis syndrome characterized by craniofacial and mild limb abnormalities. The phenotypic features of chromosomal microdeletions involving the 7p21.1, where the twist homolog 1 gene (TWIST1) responsible for SCS is located, are recognized as a contiguous gene deletion syndrome with SCS and other phenotypic manifestations. In this study, we identified microdeletions in 4q13.2 and 7p21.1 in a patient with SCS and severe neurological features including developmental delay and autistic behavior. In comparison to other SCS patients with intragenic mutations or small deletions in 7p21.1, neurological features seen in this patient were extremely severe, likely modified by a concurrent deletion of 4q13.2. Both microdeletions were de novo and paternal in origin. Further information on such concurrent chromosomal deletions should be accumulated for better understanding of the mechanism.

[Pre-evening meal administration of tacrolimus improved refractory ocular symptoms in two young children with latent general myasthenia gravis]

We report two patients with latent general myasthenia gravis (MG) with refractory ocular symptoms who were successfully treated with pre-evening meal administration of tacrolimus. Patient 1 was a 4-year-old girl with persistent ocular symptoms despite high-dose steroid therapy and thymectomy. Oral tacrolimus was initiated at the age of 3 years, which was resulted in complete resolution of symptoms. After one year, hemilateral ptosis recurred. The plasma consentration of tacrolimus was very low, probably due to sudden weight gain. Increasing the dose and a change from post- to pre-evening meal administration of tacrolimus enabled maintenance of its concentration and complete control of ocular symptoms. Patient 2 was a 2-year-old boy whose symptoms were refractory to steroid therapy after his first relapse. Since post-meal administration of tacrolimus provided partial benefit, the closing schedule was changed to pre-evening meal administration, with good results. Neither patient had adverse effects of tacrolimus. It is difficult to maintain an effective tacrolimus concentration in children due to marked growth and rapid metabolic rates. Pre-evening meal administration of tacrolimus is an easy, safe and useful method of treatment in MG young children.

Extensive morphological and immunohistochemical characterization in myotubular myopathy

The X-linked myotubular myopathy (XLMTM) also called X-linked centronuclear myopathy is a rare congenital myopathy due to mutations in the MTM 1 gene encoding myotubularin. The disease gives rise to a severe muscle weakness in males at birth. The main muscle morphological characteristics (significant number of small muscle fibers with centralized nuclei and type 1 fiber predominance) are usually documented, but the sequence of formation and maintenance of this particular morphological pattern has not been extensively characterized in humans. In this study, we perform a reevaluation of morphological changes in skeletal muscle biopsies in severe XLMTM. We correlate the pathologic features observed in the muscle biopsies of 15 newborns with MTM 1-mutations according to the "adjusted-age" at the time of muscle biopsy, focusing on sequential analysis in the early period of the life (from 34 weeks of gestation to 3 months of age). We found a similar morphological pattern throughout the period analyzed; the proportion of myofibers with central nuclei was high in all muscle biopsies, independently of the muscle type, the age of the newborns at time of biopsy and the specific MTM 1 mutation. We did not observe a period free of morphological abnormalities in human skeletal muscle as observed in myotubularin-deficient mouse models. In addition, this study demonstrated some features of delayed maturation of the muscle fibers without any increase in the number of satellite cells, associated with a marked disorganization of the muscle T-tubules and cytoskeletal network in the skeletal muscle fibers.

MECP2 duplication syndrome in both genders

BACKGROUND

Duplications involving the methyl-CpG-binding protein 2 gene (MECP2) locus at Xq28 have been frequently identified in male patients who exhibit a phenotype unique from that of Rett syndrome, which is mainly characterized by severe mental retardation, recurrent infections, and epilepsy. This combination of features is recognized as MECP2 duplication syndrome.

METHODS

Genomic copy number was investigated for patients with unexplained mental retardation, and phenotypic features of the patients having interstitial duplications including MECP2 were analyzed.

RESULTS

Three male and one female patients with MECP2 duplication were identified. The phenotypic features of all the four patients were compatible with MECP2 duplication syndrome. The X-chromosome inactivation (XCI) pattern was analyzed in the female patient, identifying a skewed XCI that activated the X-chromosome containing the MECP2 duplication. Her mother possessed the same MECP2 duplication and a random XCI pattern but exhibited no phenotypic features, indicating a nonsymptomatic carrier. The brain magnetic resonance imaging revealed periventricular cystic lesions in all four patients, including the female patient.

CONCLUSION

This study suggested clinical implications of the MECP2 duplication syndrome not only in the male but also in female patients with unexplained mental retardation.

A long-term, clinical study on symptomatic infantile spasms with focal features

BACKGROUND

We studied the clinical, neuroradiological and EEG characteristics of patients with infantile spasms (IS) who showed focal features to reveal their long-term prognoses and treatment responses.

SUBJECTS AND METHODS

Subjects included 69 patients with IS who consecutively visited our hospital. We tentatively classified the subjects into focal IS (fIS) and diffuse WS (dIS) groups based on the presence and absence of more than two of the following findings, respectively: (1) epileptic spasms (ES) that were asymmetric, (2) a focal epileptic EEG abnormality, (3) a lateralized neurological abnormality, (4) a focal brain MRI and (5) a focal SPECT abnormality.

RESULTS

We found 23 cases with fIS and 46 cases with dIS. ES responded more frequently in fIS than dIS group (100% vs. 80%; P=0.02) to the initial ACTH trial although the subsequent seizure relapse occurred more frequently in fIS than dIS group (74% vs. 38%; P=0.0006). The second course of ACTH trial brought a short as well as long-term remission in both groups (6/8 cases vs. 5/6 cases). Later in the clinical course, the fIS patients tended to display a focal epileptic EEG abnormality and to develop focal seizures. In our series, approximately one-third of patients with fIS later showed either only a focal epileptic EEG abnormality, a focal epileptic EEG abnormality with focal seizures, or bilateral asymmetric EEG foci with disabling seizures, respectively.

CONCLUSION

It is useful to classify patients with IS into fIS and dIS groups based on various lateralizing signs because the classification provides practical information regarding the long-term outcome and treatment strategy.

A cryptic microdeletion including MBD5 occurring within the breakpoint of a reciprocal translocation between chromosomes 2 and 5 in a patient with developmental delay and obesity

The 2q23.1 deletion syndrome has been recently recognized as a neurodevelopmental disorder associated with intellectual disability, epilepsy, and autism spectrum disorder. Recently, methyl-CpG-binding domain 5 gene (MBD5), located in the 2q23.1 region, has been considered as a single causative gene of this syndrome. We report on a female patient with a de novo reciprocal translocation between chromosomes 2 and 5. Chromosomal microarray testing revealed a cryptic 896 kb deletion that included MBD5. Although clinical manifestations of this patient are compatible with those of patients with 2q23.1 deletion syndrome, a focal pachygyria revealed by brain magnetic resonance imaging has never been observed in the previously reported cases. Obesity caused by hyperphagia was observed in our patient and 28% of the previously reported patients with the 2q23.1 deletion syndrome. For better medical management, appropriate dietary guidance against hyperphagia should be given to the patients' family.