Benign myoclonic epilepsy in infancy with preceding afebrile generalized tonic-clonic seizures in Japan

Benign myoclonic epilepsy in infancy (BMEI) is the youngest form of idiopathic generalized epilepsy, characterized by myoclonic seizures (MS) in the first three years of life in otherwise normal infants, and the lack of other seizure types except for rare simple febrile seizures. Although afebrile generalized tonic-clonic seizures (GTCS) have been described to develop later in the clinical course of BMEI, mostly during adolescence, an association with GTCS in the early stage of BMEI has never been recognized. We herein report seven children who satisfied the criteria of BMEI except for the recurrence of GTCS before the onset of MS. The age of onset and ictal video-polygraphic features of MS, as well as the long-term seizure and developmental outcome in these children were similar to those of children with typical BMEI. Furthermore, these GTCS mostly disappeared within several months and were replaced by MS. Our study indicates that these children may constitute a BMEI subgroup, expanding the spectrum of BMEI.

[A case of spinal muscular atrophy type 0 in Japan]

The patient was a 2-month-old female infant born at 41 weeks and 2 days of gestation presenting multiple arthrogryposis, severe muscle hypotonia and respiratory distress with difficulty in feeding. She suffered from repeated complications with aspiration pneumonia. On admission to our hospital, she exhibited fasciculation and absence of deep tendon reflexes. Examination of the motor nerve conduction velocity (MCV) revealed no muscle contraction. Deletions of the SMN and NAIP genes were noted. Based on severe clinical course and disease development in utero, she was given a diagnosis of spinal muscular atrophy (SMA) type 0 (very severe type). Arthrogryposis and disappearance of MCV are exclusion criteria for SMA. However, the clinical course of the infant was very severe and included such exclusion items. Consequently, when an infant presents muscle hypotonia and respiratory distress, SMA must be considered as one of the differential diagnoses, even though arthrogryposis is an exclusion criterion for SMA. We discuss this case in relation to the few extant reports on SMA type 0 in Japanese infants in the literature.

Atomoxetine improves communication in a girl with semantic-pragmatic disorder

This report describes the case of an ADHD girl (hereafter referred to as K) with semantic-pragmatic disorder, she was treated with atomoxetine. K was a 9-year-old girl. She had difficulty understanding words or sentences, finding words, and producing sentences. K also displayed symptoms of severe inattentiveness. K was diagnosed with DSM-IV-defined(1) ADHD, predominantly the inattentive type. Her communication impairment was considered symptomatic of semantic-pragmatic disorder. K was started on atomoxetine, the dose was increased to 50 mg/day (dosage based on weight: 1.8 mg/kg). Her communication activities were improved a few weeks after atomoxetine 50 mg/day was administered. She was unable to organize information pertaining to words, and so could not use words in expressive language. These problems were mitigated through the administration of atomoxetine. Further prospective studies are needed to better understand the therapeutic effects of atomoxetine in patients with semantic-pragmatic disorder.

[A child with paroxysmal exertion-induced dyskinesia]

We experienced a 12-year-old boy with paroxysmal exertion (exercise)-induced dyskinesia (PED). His attacks, characterized by painless paralytic stiffness of the extremities during running or playing, developed at 4 years of age. He was initially diagnosed as having epilepsy based on epileptic discharges on interictal EEG. Although several anti-epileptic drugs were not effective, clorazepate was found to be very useful for complete control of attacks for 3 years. His attacks recurred at 8 years of age and appeared to be aggravated by psychological stress, fatigue and lack of sleep. His attacks were confirmed to be non-epileptic paroxysmal hypokinesia with rigid tetraplegia, by ictal video EEG recording, and he was diagnosed as having PED. They did not respond to various anti-epileptic drugs and L-dopa/carbidopa. His attacks were reduced to some extent by administration of hydroxyzine. PED is a very rare condition and similar to paroxysmal kinesigenic dyskinesia (PKD). There is a strong possibility that patients with PED have been misdiagnosed as PKD.

Post-transcriptional regulation of fukutin in an astrocytoma cell line

Fukutin is the gene responsible for Fukuyama-type congenital muscular dystrophy (FCMD), an autosomal recessive disease associated with central nervous system (CNS) and eye anomalies. Fukutin is involved in basement membrane formation via the glycosylation of α-dystroglycan (α-DG), and hypoglycosylation of α-DG provokes the muscular, CNS and eye lesions of FCMD. Astrocytes play an important role in the pathogenesis of the CNS lesions, but the post-transcriptional regulation of fukutin mRNA has not been elucidated. In this study, we investigated the characteristics of fukutin mRNA using an astrocytoma cell line that expresses fukutin and glycosylated α-DG. The glycosylation of α-DG was considered to be increased by over-expression of fukutin and decreased by knockdown of fukutin. Knockdown of Musashi-1, one of the RNA-binding proteins involved in the regulation of neuronal differentiation, induced a decrease in fukutin mRNA. Immunoprecipitation and ELISA-based RNA-binding assay demonstrated possible binding between fukutin mRNA and Musashi-1 protein. A relationship between fukutin mRNA and vimentin protein was also proposed. In situ hybridization for fukutin mRNA showed a positive cytoplasmic reaction including cytoplasmic processes. From these results, fukutin mRNA is suggested to be a localized mRNA up-regulated by Musashi-1 and to be a component of a mRNA-protein complex which includes Musashi-1 and (presumably) vimentin proteins.

Severe muscle damage following viral infection in patients with Fukuyama congenital muscular dystrophy

Fukuyama congenital muscular dystrophy (FCMD), which is characterized by cortical migration defect and eye abnormalities, is the most common subtype of CMD in Japan. Fukutin (FKTN), the responsible gene for FCMD, encodes a protein involved in the glycosylation of alpha-dystroglycan. We have experienced some patients with FCMD who showed sudden exacerbation of muscle weakness with marked elevation of serum creatine kinase (CK) and urinary myoglobin levels a few days after a febrile episode of viral infection, occasionally leading to death. To describe this peculiar phenomenon, we focused on 12 patients who developed a sudden exacerbation of muscle weakness among 96 genetically defined FCMD patients and hospitalized because of a febrile illness at Tokyo Women's Medical University between 1997 and 2008. All the 12 patients were homozygous for a 3-kb insertion mutation of FKTN. The patients developed exacerbation of muscle weakness ranging from paralysis to loss of head control. The onset was concentrated in summer, and coxsackieviruses and enteroviruses were most often detected, especially in infantile patients. Eight of the 12 patients were treated with corticosteroids and recovered within 2 weeks. Four patients were treated without steroid, and needed 18.5 days on mean for improvement. None developed renal failure. The reason for muscle damage induced by viral infection remains unknown; however, physicians should consider its risk, sometimes leading to death, and draw it to parents' attention, especially in the defervescent stage.

High-density CT of muscle and liver may allow early diagnosis of childhood-onset Pompe disease

Pompe disease is classified into infantile-, childhood- and adult-onset forms based on onset age and the degree of organ involvement. Differing from the infantile-onset form which is characterized by marked organ involvement, the childhood-onset form usually presents with muscle weakness and elevation of serum creatine kinase (CK), mimicking those of progressive muscular dystrophy. We report our successful early diagnosis and initiation of enzyme replacement therapy (ERT) in a young girl with childhood-onset Pompe disease before the development of skeletal muscle symptoms. She was referred to our hospital at the age of 2 years 4 months because of hyperCKemia detected incidentally. She was active and lacked developmental delay and muscle weakness; however, hepatomegaly was noted. The combination of high-density changes in the liver and skeletal muscle on computed tomography (CT) images was suggestive of glycogen storage disorder, especially childhood-onset Pompe disease. Low alpha-glucosidase (GAA) activity on dried blood spots facilitated the diagnostic process, and genetic analysis of GAA allowed a definitive diagnosis, without performing muscle biopsy. We promptly started ERT at the age of 2 years 6 months. After 1 year, she still had not developed any skeletal muscle symptoms, and serum CK level was almost normal. Since the efficacy of ERT is thought to depend on the extent of muscle damage at its commencement, we expect that ERT may have prevented the manifestation of skeletal muscle involvement in this patient.

Close monitoring of initial enzyme replacement therapy in a patient with childhood-onset Pompe disease

Pompe disease is classified into infantile and late-onset (childhood and adult) forms based on onset age and degree of organ involvement. While benefits of enzyme replacement therapy (ERT) for the infantile form have been confirmed, efficacy for late-onset forms reportedly varies. We report close monitoring of initial ERT, focusing especially on the first year, in a 12-year-old boy with childhood-onset Pompe disease. At age 10, he started ERT at 20 mg/kg every other week. Respiratory and motor functions were evaluated at each infusion, and by skeletal muscle computed tomography (CT) and cardiac echography every 4 months. He gained the ability to climb stairs without a rail and % vital capacity improved just 1.5 months after starting ERT. Grip power, manual muscle testing (MMT) and the timed and 6-min walking distance tests (6MWT) improved promptly, paralleling improvements in clinical symptoms. However, this steady improvement stopped around 8 months, with deterioration to the initial level by about 24 months. Antibody against recombinant human alpha-glucosidase was very low at 15 months; therefore, the lack of treatment response did not completely correspond to antibody production. On the other hand, cardiac wall thickening worsened after 4 months, then improved to better than baseline after 8 months, and this improvement was well maintained. Among our set parameters, the timed test results corresponded better to his changing clinical course than did grip power, MMT or 6-min walking test results.

Shared molecular targets in pediatric gliomas and ependymomas

BACKGROUND

Recent advances in multidisciplinary treatment approaches have improved the overall prognosis of pediatric brain tumors, but some patients remain refractory to treatment and do poorly. Several molecularly targeted therapies are under development for the treatment of brain tumors, and high-grade gliomas in adults are a particular area of study.

PROCEDURE

To better understand if these new therapies can be used in pediatric populations, we examined the expression of the following seven marker genes involved in signaling pathways targeted by new therapies: β-catenin, suppressor of fused (SUFU), erythroblastic leukemia viral oncogene homolog (ERBB) 2, platelet-derived growth factor receptorα (PDGFRα), proliferating cell nuclear antigen (PCNA), secreted protein acid and rich in cysteine (SPARC), and granulocyte colony-stimulating factor receptor (G-CSFR). Samples from 27 patients with the primitive neuroectodermal tumor (PNET)/medulloblastomas (MBs) (n = 8), ependymomas (n = 5), or gliomas (n = 14) were assessed by quantitative real-time PCR. [Correction made here after initial online publication]. We assigned an EXP score to compare across samples and determined the levels of gene expression among tumor cell types.

RESULTS

Gene expression varied among the different tumors, but, within a tumor type, clear expression patterns were seen. The expression of SUFU, ERBB2, and PCNA in metastatic MBs were greater than that seen in non-metastatic MBs. Most glioma cases highly expressed PDGFRα and G-CSFR. Additionally, the expression patterns of gliomas and ependymomas were similar (r = 0.77, P = 0.04), but PNET/MBs substantially differed from gliomas (r = -0.37, P = 0.41) or ependymomas (r = 0.23, P = 0.62).

CONCLUSIONS

The development of new drugs targeting up-regulated pathways may be useful for the treatment of pediatric brain tumors. As new drugs are developed, gliomas and ependymomas may be treated with similar compounds.

Newborn screening for Pompe disease in Japan

Pompe disease is caused by a deficiency of acid alpha-glucosidase (GAA) that results in glycogen accumulation, primarily in muscle. Newborn screening (NBS) for Pompe disease has been initiated in Taiwan and is reportedly successful. However, the comparatively high frequency of pseudodeficiency allele makes NBS for Pompe disease complicated in Taiwan. To investigate the feasibility of NBS for Pompe disease in Japan, we obtained dried blood spots (DBSs) from 496 healthy Japanese controls, 29 Japanese patients with Pompe disease, and five obligate carriers, and assayed GAA activity under the following conditions: (1) total GAA measured at pH 3.8, (2) GAA measured at pH 3.8 in the presence of acarbose, and (3) neutral glucosidase activity (NAG) measured at pH 7.0 without acarbose. The % inhibition and NAG/GAA ratio were calculated. For screening, samples with GAA<8% of the normal mean, % inhibition>60%, and NAG/GAA ratio>30 were considered to be positive. Two false positive cases (0.3%) were found, one was a healthy homozygote of pseudodeficiency allele (c.1726G>A). The low false-positive rate suggests that NBS for Pompe disease is feasible in Japan.

[Three children with Rasmussen encephalitis showing marked improvement in daily life activity following the functional hemispherectomy]

We investigated seizure, intelligence quotient (IQ), and neurological outcomes including the process of motor function recovery after functional right hemispherectomy in 3 children with Rasmussen's encephalitis (RE). Before the procedure, they were unable to walk, nor sit without support due to progressive worsening of left hemiplegia and relentless epilepsia partialis continua (EPC) of the left extremities, which were refractory to antiepileptic drug and immunological treatment. After functional right hemispherectomy, EPC completely disappeared, although complete left hemiplegia was sustained. However, they recovered up to being able to walk independently with assistance devices, and to have an ordinary life with family support within 1.5 to 5 months through rehabilitation. At the same time, the interictal EEG improved on the unaffected side of hemisphere, exhibiting a posterior alpha rhythm. Their IQ also improved, and they were able to attend school. Early functional hemispherectomy should be considered before patients with RE are left in a serious condition due to progressive worsening of hemiplegia and seizures refractory to the available treatment.

Lesions in the central tegmental tract in autopsy cases of developmental brain disorders

We retrospectively analyzed central tegmental tract (CTT) lesions in 120 consecutive autopsy cases of developmental brain disorders to investigate the significance of symmetrical CTT lesions. Magnetic resonance imaging (MRI) findings of CTT lesions have been sporadically reported in various cases of child neurological diseases. In this study, symmetrical CTT lesions were observed in 25 (20.8%) among 120 cases of developmental brain disorders. These 25 cases were classified into three groups (groups I-III) in decreasing order of the severity of the lesion. Compared to five cases of group I in which CTT lesions were accompanied by diffuse tegmental damage, 20 cases of groups II or III developed relatively selective CTT lesions in which the medial longitudinal fasciculus and/or medial or lateral lemniscus were preserved. The causes of brain disorders in all three groups seemed to be different, and lysosomal disorders and congenital brain anomalies were frequently seen in cases in groups II and III, respectively. The dentato-rubro-olivary system is known to be involved in palatal myoclonus, and five out of 13 cases in group II showed myoclonic epilepsy. Compared with 95 cases without the CTT lesion, the changes in the pontine reticular formation were more closely associated with the CTT lesion than those in the inferior olivary nucleus. In conclusion, in cases of developmental brain disorders, the neuropathology of the symmetrical CTT lesion should be investigated.