研究者業績

小坂 仁

オサカ ヒトシ  (Hitoshi Osaka)

基本情報

所属
自治医科大学 医学部小児科学講座 / 医学部小児科学講座 小児医学部門 教授

研究者番号
90426320
J-GLOBAL ID
201401039803985369
researchmap会員ID
B000238601

外部リンク

論文

 374
  • 松橋 徹郎, 及川 善嗣, 鈴木 健弘, 呉 繁夫, 村山 圭, 大竹 明, 小坂 仁, 阿部 高明
    日本小児科学会雑誌 124(2) 230-230 2020年2月  査読有り
  • 桑島 真理, 小坂 仁, 白井 育子, 濱田 悠介, 市本 景子, 村山 圭, 山形 崇倫
    日本小児科学会雑誌 124(2) 402-402 2020年2月  査読有り
  • 渡邉 知佳, 小坂 仁, 村山 圭, 大竹 明, 山形 崇倫
    日本小児科学会雑誌 124(2) 403-403 2020年2月  査読有り
  • Kawahara Y, Morimoto A, Oh Y, Furukawa R, Wakabayashi K, Monden Y, Osaka H, Yamagata T
    Brain & development 42(2) 185-191 2020年2月  査読有り
  • Kei Wakabayashi, Hitoshi Osaka, Hirokazu Yamagishi, Takahiro Ikeda, Hironori Shimozawa, Mari Kuwajima, Masahide Goto, Karin Kojima, Ayumi Matsumoto, Kazuhiro Muramatsu, Takanori Yamagata
    Journal of the Japan Epilepsy Society 37(3) 810-818 2020年1月31日  
    Lacosamide (LCM) is a novel class of anti-epileptic drug that selectively promotes slow inactivation of the sodium channel. Case studies, including pediatric cases, have not been described in Japan. We examined the efficacy and side effects of LCM in Japanese epilepsy patients, including those under 16 years old. Responders were defined when seizures were reduced by more than 50%. The responder rate for overall seizure was 40%. There were no significant differences in efficacy by seizure types or age (&lt 16 or ≥16 years old). Among epilepsy types, the efficacy in patients with focal epilepsy (17/39) was higher than in generalized epilepsy (0/8) (p=0.0045). Patients with ≤2 AEDs had significantly higher efficacy (16/27) than those with ≥3 AEDs (8/33) (p=0.0055). In patients with concomitant AEDs, LTG (2/16) and PER (0/10) were significantly less effective than other drugs (LTG: p=0.0055, PER: p=0.0007). Although adverse effects occurred in 23% of pa- tients, including somnolence 20%, dizziness 5%, agitation 2%, there was no significant difference by age (&lt 16 and ≥16 years). Our study suggests that LCM is effective focal-epilepsy patients especially those with ≤2 concomitant AEDs. Studies of more cases with long-term observation are needed to establish the role of LCM in childhood epilepsy treat- ment.
  • 熊谷 秀規, ジャネルケ・トゥレウ, 神保 恵理子, 渡邊 真弥, 幸喜 富, 横山 孝二, 小坂 仁, 山形 崇倫
    日本小児栄養消化器肝臓学会雑誌 33(2) 134-134 2019年12月  査読有り
  • Sekiguchi F, Tsurusaki Y, Okamoto N, Teik KW, Mizuno S, Suzumura H, Isidor B, Ong WP, Haniffa M, White SM, Matsuo M, Saito K, Phadke S, Kosho T, Yap P, Goyal M, Clarke LA, Sachdev R, McGillivray G, Leventer RJ, Patel C, Yamagata T, Osaka H, Hisaeda Y, Ohashi H, Shimizu K, Nagasaki K, Hamada J, Dateki S, Sato T, Chinen Y, Awaya T, Kato T, Iwanaga K, Kawai M, Matsuoka T, Shimoji Y, Tan TY, Kapoor S, Gregersen N, Rossi M, Marie-Laure M, McGregor L, Oishi K, Mehta L, Gillies G, Lockhart PJ, Pope K, Shukla A, Girisha KM, Abdel-Salam GMH, Mowat D, Coman D, Kim OH, Cordier MP, Gibson K, Milunsky J, Liebelt J, Cox H, El Chehadeh S, Toutain A, Saida K, Aoi H, Minase G, Tsuchida N, Iwama K, Uchiyama Y, Suzuki T, Hamanaka K, Azuma Y, Fujita A, Imagawa E, Koshimizu E, Takata A, Mitsuhashi S, Miyatake S, Mizuguchi T, Miyake N, Matsumoto N
    J Hum Genet. 64(12) 1173-1186 2019年12月  査読有り
  • Akihiko Miyauchi, Takeshi Kouga, Eriko F Jimbo, Tetsuro Matsuhashi, Takaaki Abe, Takanori Yamagata, Hitoshi Osaka
    Mitochondrion 49 111-120 2019年11月  
    Mitochondrial disease is a genetic disorder in which individuals suffer from energy insufficiency. The various clinical phenotypes of mitochondrial disease include Leigh syndrome (LS), myopathy encephalopathy lactic acidosis and stroke-like episodes (MELAS). Thus far, no curative treatment is available, and effective treatment options are eagerly awaited. We examined the cell protective effect of an existing commercially available chemical library on fibroblasts from four patients with LS and MELAS and identified apomorphine as a potential therapeutic drug for mitochondrial disease. We conducted a cell viability assay under oxidative stress induced by L-butionine (S, R)-sulfoximine (BSO), a glutathione synthesis inhibitor. Among the chemicals of library, 4 compounds (apomorphine, olanzapine, phenothiazine and ethopropazine) rescued cells from death induced by oxidative stress much more effectively than idebenone, which was used as a positive control. The EC50 value showed that apomorphine was the most effective compound. Apomorphine also significantly improved all of the assessed oxygen consumption rate values by the extracellular flux analyzer for fibroblasts from LS patients with complex I deficiency. In addition, the elevation of the Growth Differentiation Factor-15 (GDF-15), a biomarker of mitochondrial disease, was significantly reduced by apomorphine. Among 441 apomorphine-responsive genes identified by the microarray, apomorphine induced the expression of genes that inhibit the mammalian target of rapamycin (mTOR) activity and inflammatory responses, suggesting that apomorphine induced cell survival via a new potential pathway. In conclusion, apomorphine rescued fibroblasts from cell death under oxidative stress and improved the mitochondrial respiratory activity and appears to be potentially useful for treating mitochondrial disease.
  • Tulyeu J, Kumagai H, Jimbo EF, Watanabe S, Yokoyama K, Cui L, Osaka H, Mieno MN, Yamagata T
    Microorganisms 7(10) 463-; 2019年10月  査読有り
  • Kouga T, Koizume S, Aoki S, Jimbo E, Yamagata T, Inoue K, Osaka H
    Molecular genetics and metabolism reports 20 100474-100474 2019年9月  査読有り
  • Atsushi Takata, Mitsuko Nakashima, Hirotomo Saitsu, Takeshi Mizuguchi, Satomi Mitsuhashi, Yukitoshi Takahashi, Nobuhiko Okamoto, Hitoshi Osaka, Kazuyuki Nakamura, Jun Tohyama, Kazuhiro Haginoya, Saoko Takeshita, Ichiro Kuki, Tohru Okanishi, Tomohide Goto, Masayuki Sasaki, Yasunari Sakai, Noriko Miyake, Satoko Miyatake, Naomi Tsuchida, Kazuhiro Iwama, Gaku Minase, Futoshi Sekiguchi, Atsushi Fujita, Eri Imagawa, Eriko Koshimizu, Yuri Uchiyama, Kohei Hamanaka, Chihiro Ohba, Toshiyuki Itai, Hiromi Aoi, Ken Saida, Tomohiro Sakaguchi, Kouhei Den, Rina Takahashi, Hiroko Ikeda, Tokito Yamaguchi, Kazuki Tsukamoto, Shinsaku Yoshitomi, Taikan Oboshi, Katsumi Imai, Tomokazu Kimizu, Yu Kobayashi, Masaya Kubota, Hirofumi Kashii, Shimpei Baba, Mizue Iai, Ryutaro Kira, Munetsugu Hara, Masayasu Ohta, Yohane Miyata, Rie Miyata, Jun-Ichi Takanashi, Jun Matsui, Kenji Yokochi, Masayuki Shimono, Masano Amamoto, Rumiko Takayama, Shinichi Hirabayashi, Kaori Aiba, Hiroshi Matsumoto, Shin Nabatame, Takashi Shiihara, Mitsuhiro Kato, Naomichi Matsumoto
    Nature communications 10(1) 2506-2506 2019年6月7日  査読有り
    Although there are many known Mendelian genes linked to epileptic or developmental and epileptic encephalopathy (EE/DEE), its genetic architecture is not fully explained. Here, we address this incompleteness by analyzing exomes of 743 EE/DEE cases and 2366 controls. We observe that damaging ultra-rare variants (dURVs) unique to an individual are significantly overrepresented in EE/DEE, both in known EE/DEE genes and the other non-EE/DEE genes. Importantly, enrichment of dURVs in non-EE/DEE genes is significant, even in the subset of cases with diagnostic dURVs (P = 0.000215), suggesting oligogenic contribution of non-EE/DEE gene dURVs. Gene-based analysis identifies exome-wide significant (P = 2.04 × 10-6) enrichment of damaging de novo mutations in NF1, a gene primarily linked to neurofibromatosis, in infantile spasm. Together with accumulating evidence for roles of oligogenic or modifier variants in severe neurodevelopmental disorders, our results highlight genetic complexity in EE/DEE, and indicate that EE/DEE is not an aggregate of simple Mendelian disorders.
  • Miyamoto S, Nakashima M, Ohashi T, Hiraide T, Kurosawa K, Yamamoto T, Takanashi J, Osaka H, Inoue K, Miyazaki T, Wada Y, Okamoto N, Saitsu H
    Molecular genetics & genomic medicine 7(8) e814 2019年6月  査読有り
  • 白井 育子, 有坂 敦子, 小川 えりか, 市本 景子, 村山 圭, 桑島 真理, 小坂 仁, 濱田 悠介, 大竹 明, 熊田 聡子
    脳と発達 51(Suppl.) S397-S397 2019年5月  査読有り
  • 山岸 裕和, 小坂 仁, 後藤 昌英, 桑島 真理, 池田 尚広, 小島 華林, 村松 一洋, 山形 崇倫
    脳と発達 51(Suppl.) S272-S272 2019年5月  査読有り
  • Kuwajima M, Goto M, Kurane K, Shimbo H, Omika N, Jimbo EF, Muramatsu K, Tajika M, Shimura M, Murayama K, Kurosawa K, Yamagata T, Osaka H
    Brain & development 41(5) 465-469 2019年5月  査読有り
  • Matsumoto A, Nagashima M, Iwama K, Mizuguchi T, Makino S, Ikeda T, Muramatsu K, Matsumoto N, Yamagata T, Osaka H
    Brain & development 41(8) 726-730 2019年4月  査読有り
  • Tulyeu J, Tamaura M, Jimbo E, Shimbo H, Takano K, Iai M, Yamashita S, Goto T, Aida N, Tokuhiro E, Yamagata T, Osaka H
    Brain & development 41(2) 195-200 2019年2月  査読有り
  • Osaka H, Miyauchi A
    Brain & development 41(2) 224 2019年2月  査読有り
  • Kojima K, Nakajima T, Taga N, Miyauchi A, Kato M, Matsumoto A, Ikeda T, Nakamura K, Kubota T, Mizukami H, Ono S, Onuki Y, Sato T, Osaka H, Muramatsu SI, Yamagata T
    Brain : a journal of neurology 142(2) 322-333 2019年2月  査読有り
  • Kazuhiro Iwama, Hitoshi Osaka, Takahiro Ikeda, Satomi Mitsuhashi, Satoko Miyatake, Atsushi Takata, Noriko Miyake, Shuichi Ito, Takeshi Mizuguchi, Naomichi Matsumoto
    Journal of human genetics 63(10) 1049-1054 2018年10月  査読有り
    The mammalian Na+/H+ exchanger isoform one (NHE1), encoded by Solute Carrier Family 9, member 1 (SLC9A1), consists of 12 membrane domains and a cytosolic C-terminal domain. NHE1 plays an important role in maintaining intracellular pH homeostasis by exchanging one intracellular proton for one extracellular sodium ion. Mice with a homozygous null mutation in Slc9a1 (Nhe1) exhibited ataxia, recurrent seizures, and selective neuronal cell death. In humans, three unrelated patients have been reported: a patient with a homozygous missense mutation in SLC9A1, c.913G>A (p.Gly305Arg), which caused Lichtenstein-Knorr syndrome characterized by cerebellar ataxia and sensorineural hearing loss, a patient with compound heterozygous mutations, c.1351A>C (p.Ile451Leu) and c.1585C>T (p.His529Tyr), which caused a neuromuscular disorder, and a patient with de novo mutation, c.796A>C (p.Asn266His) which associated multiple anomalies. In this study, using whole exome sequencing, we identified a novel homozygous SLC9A1 truncating mutation, c.862del (p.Ile288Serfs*9), in two affected siblings. The patients showed cerebellar ataxia but neither of them showed sensorineural hearing loss nor a neuromuscular phenotype. The main clinical feature was similar to Lichtenstein-Knorr syndrome but deafness may not be an essential phenotypic feature of SLC9A1 mutation. Our report expands the knowledge of clinical features of SLC9A1 mutations.
  • Kuwajima Mari, Kojima Karin, Ikeda Takahiro, Goto Masahide, Hushimi Takuya, Murayama Kei, Kishita Yoshihito, Yamada Kenichirou, Osaka Hitoshi, Yamagata Takanori
    日本先天代謝異常学会雑誌 34 188-188 2018年9月  
  • 山岸 裕和, 後藤 昌英, 小坂 仁, 桑島 真理, 村松 一洋, 山形 崇倫
    てんかん研究 36(2) 590-590 2018年9月  査読有り
  • Matsumoto A, Tulyeu J, Furukawa R, Watanabe C, Monden Y, Nozaki Y, Mori M, Namekawa M, Jimbo EF, Aihara T, Yamagata T, Osaka H
    Brain & development 40(7) 587-591 2018年8月  査読有り
  • Masako Nagashima, Hitoshi Osaka, Takahiro Ikeda, Ayumi Matsumoto, Akihiko Miyauchi, Kimihiko Kaneko, Ichiro Nakashima, Yuko Nakano, Kei Wakabayashi, Yukifumi Monden, Takanori Yamagata
    Brain & development 40(7) 607-611 2018年8月  査読有り
    BACKGROUND: The effect of rituximab on acute disseminated encephalomyelitis (ADEM) followed by recurrent optic neuritis (ON) is not yet known. PATIENT: We are reporting the case of a 4-year-old Japanese girl who was diagnosed with anti-myelin oligodendrocyte glycoprotein (MOG) antibody positive ADEM followed by recurrent ON. She developed altered mental status, left facial paralysis, left paresis, and experienced three episodes of ON. She was treated with rituximab and azathioprine (AZA) as prevention for recurrent ON. She relapsed under treatment with AZA when CD19 cells reappeared 6 months after the first rituximab infusion. However, she has not relapsed since her CD19 count was reduced and kept low with rituximab infusion. CONCLUSIONS: It is conceivable that anti-MOG antibodies are involved in the pathology of "ADEM followed by recurrent ON," and that the early introduction of rituximab, which is involved in the suppression of antibody production and has effects on CD20 T lymphocytes, may be a feasible treatment for ON. Due to the small number of patients, additional reports on prospectively followed patients are needed.
  • Akihiko Miyauchi, Hitoshi Osaka, Masako Nagashima, Mari Kuwajima, Yukifumi Monden, Masakazu Kohda, Yoshihito Kishita, Yasushi Okazaki, Kei Murayama, Akira Ohtake, Takanori Yamagata
    Brain & development 40(6) 498-502 2018年6月  査読有り
    Leigh syndrome, which is a common phenotype of pediatric mitochondrial disease, is a progressive neurodegenerative disease. The typical neuroimaging findings of Leigh syndrome include bilateral symmetric lesions in the basal ganglia and/or the brainstem. However, there are a few reports on spinal cord involvement in patients with Leigh syndrome. In the present case, magnetic resonance imaging (MRI) obtained during infancy revealed symmetric lesions in the substantia nigra of a patient with Leigh syndrome with an NDUFA1 mutation; lesions of the bilateral putamen and brainstem were subsequently observed. Additionally, our patient presented large and extended spinal cord lesions. Therefore, this case is suggesting that we should consider the occurrence of spinal cord lesions as an atypical finding in Leigh syndrome.
  • 桑島 真理, 小坂 仁, 後藤 昌英, 池田 尚広, 村山 圭, 新保 裕子, 山形 崇倫
    脳と発達 50(Suppl.) S393-S393 2018年5月  査読有り
  • Nakamura Sachie, Osaka Hitoshi, Muramatsu Shin-ichi, Takino Naomi, Ito Mika, Jimbo Eriko F, Shimazaki Kuniko, Onaka Tatsushi, Ohtsuki Sumio, Terasaki Tetsuya, Yamagata Takanori
    MOLECULAR THERAPY 26(5) 130-131 2018年5月  査読有り
  • Osaka H, Kouga T
    Brain & development 40(5) 444 2018年5月  査読有り
  • Sachie Nakamura, Shin-Ichi Muramatsu, Naomi Takino, Mika Ito, Eriko F Jimbo, Kuniko Shimazaki, Tatsushi Onaka, Sumio Ohtsuki, Tetsuya Terasaki, Takanori Yamagata, Hitoshi Osaka
    The journal of gene medicine 20(4) e3013 2018年4月  査読有り
    BACKGROUND: We generated an adeno-associated virus (AAV) vector in which the human SLC2A1 gene, encoding glucose transporter type 1 (GLUT1), was expressed under the human endogenous GLUT1 promoter (AAV-GLUT1). We examined whether AAV-GLUT1 administration could lead to functional improvement in GLUT1-deficient mice. METHODS: We extrapolated human endogenous GLUT1 promoter sequences from rat minimal Glut1 promoter sequences. We generated a tyrosine-mutant AAV9/3 vector in which human SLC2A1-myc-DDK was expressed under the human GLUT1 promoter (AAV-GLUT1). AAV-GLUT1 was administered to GLUT1-deficient mice (GLUT1+/- mice) via intracerebroventricular injection (1.85 × 1010 vg/mouse or 6.5 × 1010 vg/mouse). We analyzed exogenous GLUT1 mRNA and protein expression in the brain and other major organs. We also examined improvements of cerebral microvasculature, motor function using rota-rod and footprint tests, as well as blood and cerebrospinal fluid (CSF) glucose levels. Additionally, we confirmed exogenous GLUT1 protein distribution in the brain and other organs after intracardiac injection (7.8 × 1011 vg/mouse). RESULTS: Exogenous GLUT1 protein was strongly expressed in the cerebral cortex, hippocampus and thalamus. It was mainly expressed in endothelial cells, and partially expressed in neural cells and oligodendrocytes. Motor function and CSF glucose levels were significantly improved following intracerebroventricular injection. Exogenous GLUT1 expression was not detected in other organs after intracerebroventricular injection of AAV-GLUT1, whereas it was detected in the liver and muscle tissue after intracardiac injection. CONCLUSIONS: Exogenous GLUT1 expression after AAV-GLUT1 injection approximated that of physiological human GLUT1 expression. Local central nervous system administration of AAV-GLUT1 improved CSF glucose levels and motor function of GLUT1-deficient mice and minimized off-target effects.
  • Ayumi Matsumoto, Eri Imagawa, Noriko Miyake, Takahiro Ikeda, Mizuki Kobayashi, Masahide Goto, Naomichi Matsumoto, Takanori Yamagata, Hitoshi Osaka
    Brain and Development 40(4) 325-329 2018年4月1日  査読有り
    SOX9 is responsible for campomelic dysplasia (CMPD). Symptoms of CMPD include recurrent apnea, upper respiratory infection, facial features, and shortening of the lower extremities. The variant acampomelic CMPD (ACMPD) lacks long bone curvature. A patient showed macrocephaly (+3.9 standard deviations [SD]) and minor anomalies, such as hypertelorism, palpebronasal fold, small mandible, and a cleft of soft palate without long bone curvature. From three months of age, he required tracheal intubation and artificial respiration under sedation because of tracheomalacia. Cranial magnetic resonance imaging was normal at one month of age but showed ventriculomegaly, hydrocephaly, and the corpus callosum thinning at two years of age. Exome sequencing revealed a de novo novel mutation, c. 236A &gt C, p (Q79P), in SOX9. Sox9 is thought to be crucial in neural stem cell development in the central and peripheral nervous system along with Sox8 and Sox10 in mice. In humans, neuronal abnormalities have been reported in cases of CMPD and ACMPD, including relative macrocephaly in 11 out of 22 and mild lateral ventriculomegaly in 2 out of 22 patients. We encountered a two-year old boy with ACMPD presenting with tracheomalacia and macrocephaly with a SOX9 mutation. We described for the first time an ACMPD patient with acquired diminished white matter and corpus callosal thinning, indicating the failure of oligodendrocyte/astrocyte development postnatally. This phenotype suggests that SOX9 plays a crucial role in human central nervous system development. Further cases are needed to clarify the relationship between human neural development and SOX9 mutations.
  • N. Tsuchida, M. Nakashima, A. Miyauchi, S. Yoshitomi, T. Kimizu, V. Ganesan, K. W. Teik, G. S. Ch'ng, M. Kato, T. Mizuguchi, A. Takata, S. Miyatake, N. Miyake, H. Osaka, T. Yamagata, H. Nakajima, H. Saitsu, N. Matsumoto
    Clinical Genetics 93(2) 266-274 2018年2月1日  査読有り
    The seizure threshold 2 (SZT2) gene encodes a large, highly conserved protein that is associated with epileptogenesis. In mice, Szt2 is abundantly expressed in the central nervous system. Recently, biallelic SZT2 mutations were found in 7 patients (from 5 families) presenting with epileptic encephalopathy with dysmorphic features and/or non-syndromic intellectual disabilities. In this study, we identified by whole-exome sequencing compound heterozygous SZT2 mutations in 3 patients with early-onset epileptic encephalopathies. Six novel SZT2 mutations were found, including 3 truncating, 1 splice site and 2 missense mutations. The splice-site mutation resulted in skipping of exon 20 and was associated with a premature stop codon. All individuals presented with seizures, severe developmental delay and intellectual disabilities with high variability. Brain MRIs revealed a characteristic thick and short corpus callosum or a persistent cavum septum pellucidum in each of the 2 cases. Interestingly, in the third case, born to consanguineous parents, had unexpected compound heterozygous missense mutations. She showed microcephaly despite the other case and previous ones presenting with macrocephaly, suggesting that SZT2 mutations might affect head size.
  • Takeshi Kouga, Mariko Takagi, Akihiko Miyauchi, Hiroko Shimbo, Mizue Iai, Sumimasa Yamashita, Kei Murayama, Matthew B. Klein, Guy Miller, Tomohide Goto, Hitoshi Osaka
    Brain and Development 40(2) 145-149 2018年2月1日  査読有り
    Background Leigh syndrome is a mitochondrial disease caused by respiratory chain deficiency, and there are no proven effective therapies. EPI-743 is a potent cellular oxidative stress protectant and results of clinical trials for mitochondrial diseases are accumulating. Case At 5 months, a girl presented with the scarce eye movement and diminished muscle tone. She was diagnosed with Leigh encephalopathy from blood and cerebrospinal fluid lactate elevation and MRI findings. Sequence analysis for mitochondrial DNA revealed a T10158C mutation in the mitochondrial encoded ND3 gene in complex I. Results At 8 months, succinate was prescribed expected to restore the electron transport chain system. After that her condition got worse and succinate was discontinued. Subsequent administration of EPI-743 improved her eye movement, fine motor movements of the extremities, and bowel movement. She is now 5 years old. Although brain atrophy has progressed, she has still respiratory free time. Conclusion Our patient showed visible improvement with EPI-743 treatment and the only patient surviving after 4 years. There is a possibility that EPI-743 is modifying the natural course of the syndrome.
  • Atsushi Takata, Noriko Miyake, Yoshinori Tsurusaki, Ryoko Fukai, Satoko Miyatake, Eriko Koshimizu, Itaru Kushima, Takashi Okada, Mako Morikawa, Yota Uno, Kanako Ishizuka, Kazuhiko Nakamura, Masatsugu Tsujii, Takeo Yoshikawa, Tomoko Toyota, Nobuhiko Okamoto, Yoko Hiraki, Ryota Hashimoto, Yuka Yasuda, Shinji Saitoh, Kei Ohashi, Yasunari Sakai, Shouichi Ohga, Toshiro Hara, Mitsuhiro Kato, Kazuyuki Nakamura, Aiko Ito, Chizuru Seiwa, Emi Shirahata, Hitoshi Osaka, Ayumi Matsumoto, Saoko Takeshita, Jun Tohyama, Tomoko Saikusa, Toyojiro Matsuishi, Takumi Nakamura, Takashi Tsuboi, Tadafumi Kato, Toshifumi Suzuki, Hirotomo Saitsu, Mitsuko Nakashima, Takeshi Mizuguchi, Fumiaki Tanaka, Norio Mori, Norio Ozaki, Naomichi Matsumoto
    Cell reports 22(3) 734-747 2018年1月16日  査読有り
    Recent studies have established important roles of de novo mutations (DNMs) in autism spectrum disorders (ASDs). Here, we analyze DNMs in 262 ASD probands of Japanese origin and confirm the "de novo paradigm" of ASDs across ethnicities. Based on this consistency, we combine the lists of damaging DNMs in our and published ASD cohorts (total number of trios, 4,244) and perform integrative bioinformatics analyses. Besides replicating the findings of previous studies, our analyses highlight ATP-binding genes and fetal cerebellar/striatal circuits. Analysis of individual genes identified 61 genes enriched for damaging DNMs, including ten genes for which our dataset now contributes to statistical significance. Screening of compounds altering the expression of genes hit by damaging DNMs reveals a global downregulating effect of valproic acid, a known risk factor for ASDs, whereas cardiac glycosides upregulate these genes. Collectively, our integrative approach provides deeper biological and potential medical insights into ASDs.
  • Hirokazu Yamagishi, Hitoshi Osaka, Masako Nagashima, Mari Kuwajima, Akihiko Miyauchi, Takahiro Ikeda, Karin Kojima, Ayumi Matsumoto, Takanori Yamagata
    Journal of the Japan Epilepsy Society 35(3) 693-701 2018年  査読有り
    Perampanel (PER) is a novel class of anti-epileptic drug and a noncompetitive inhibitor of the AMPA receptor. Some reports have described the efficacy and side-effects of PER in Japan. We prescribed PER to 33 refractory epilepsy patients, including some with intellectual disabilities and/or an age under 12 years. A "Good response" was defined as more than 50% seizure reduction, and we investigated the responder rates for focal seizure (Fs) and generalized tonic clonic seizure (GTCS). The effective rate for Fs and GTCS were both 50%, and the overall seizure rate was 52%. The efficacy in patients &lt 12 years of age was similar to those &gt 12 years of age. Although there were no significant differences in the responder rates among the concomitant antiepileptic drugs (AEDs), two patients who received KBr combination treatment showed a good response. The responder rates with CYP3A4-inducing AEDs such as CBZ and PHT tended to be low (30% and 18%, respectively). Adverse events occurred in 55% of patients, including emotional and behavioral abnormalities in 30%, somnolence in 18%, and dizziness in 15%. We should therefore closely monitor young patients and those with intellectual disabilities, as emotional and behavioral abnormalities tend to occur with the administration of PER.
  • Ueda A, Shimbo H, Yada Y, Koike Y, Yamagata T, Osaka H
    Human genome variation 5 18013-18013 2018年  査読有り
  • Yuri Matsubara, Hitoshi Osaka, Takanori Yamagata, Ryusuke Ae, Jun Shimizu, Noriko Oguro
    Brain and Development 40(9) 807-812 2018年  査読有り
    Background: Acute encephalopathy causes various sequelae, including motor disabilities and intellectual delays. Previous studies reported that cognitive impairments can also occur after acute encephalitis. Although the incidence of acute encephalopathy is high in Japan, there have been few reports on its sequelae. Objective: To characterize the neurological outcomes of pediatric patients who sought motor rehabilitation for motor dysfunction after acute encephalopathy. Method: Subjects were 26 children who were healthy before suffering from motor dysfunction following acute encephalopathy and were referred to our pediatric rehabilitation institute during a 9-year period (August 2007–April 2017). We examined subjects’ neurological status and followed sequelae for at least 8 months. Results: Of 26 individuals, 21 became ambulatory after several months or years during the observation period. Patients who could sit without support within 5 months after the onset of acute encephalopathy were able to walk within several months or years. Patients showing high intensity on T2-weighted sequences or “bright tree appearance” in the frontal region took an average of 7 months to develop walking, which was longer than other patients. Among ambulatory subjects, 16(76%) exhibited mild to moderate intellectual delay with a developmental quotient (DQ) under 70, and 20 (95%) exhibited cognitive impairment. There was a significant correlation between DQ scores and motor disability (p = 0.013, r = −0.481). Conclusions: Although 80% of patients who had motor dysfunction caused by acute encephalopathy and visited out motor rehabilitation outpatient clinic were eventually able to walk, the time taken to develop walking ability depended on which region exhibited magnetic resonance imaging abnormalities. DQ scores and motor disability were significantly correlated.
  • Takahiro Ikeda, Hitoshi Osaka, Hiroko Shimbo, Makiko Tajika, Masayo Yamazaki, Ayako Ueda, Kei Murayama, Takanori Yamagata
    Human genome variation 5 25-25 2018年  査読有り
    Approximately 80% of cases of mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) harbor a heteroplasmic m.3243A>G transition in the tRNALeu (UUR) (MTTL1) gene. We report a MELAS case with a rare heteroplasmic m.3243A>T mutation found by direct sequencing of MTTL1. This mutation has been previously reported in 5 cases, of which 2 cases had the MELAS phenotype. Our case also strengthens the hypothesis that the m.3243A>T mutation can cause the MELAS phenotype.
  • Karin Kojima, Kentaro Shirai, Mizuki Kobayashi, Akihiko Miyauchi, Hirotomo Saitsu, Naomichi Matsumoto, Hitoshi Osaka, Takanori Yamagata
    Brain and Development 40(1) 69-73 2018年1月1日  査読有り
    Background The potassium voltage-gated channel subfamily Q member 2 (KCNQ2) gene has been reported to be associated with various types of epilepsy, including benign familial neonatal seizure (BFNS), early infantile epileptic encephalopathy (EIEE), and unclassified early onset encephalopathies. We herein report a patient with early myoclonic encephalopathy (EME) caused by a KCNQ2 mutation. Case report A male infant started to exhibit erratic myoclonus several days after birth and apnea attacks lasting for seconds with desaturation. One month after birth, his myoclonuses worsened in frequency. Electroencephalogram (EEG) showed a burst and suppression pattern, and myoclonuses occurred in the burst phase with diffuse polyspikes on EEG. At five months, inter-ictal EEG revealed hypsarrhythmia, but his attacks were still only myoclonuses. ACTH treatment was effective and the myoclonus frequency markedly decreased. At one year of age, whole-exome sequencing revealed a heterozygous mutation of the KCNQ2 gene (NM_172107.2): c.601C &gt T p.(Arg201Cys), which was confirmed as de novo by Sanger sequencing. This mutation lies within the extracellular portion of the S4 voltage sensor. Conclusion Most patients with a KCNQ2 mutation present with seizures starting in the neonatal period with varying severity, ranging from BFNS to Ohtahara syndrome. Furthermore, KCNQ2 appears to be a causative gene for EME.
  • Miho Usui, Akihiko Miyauchi, Yuko Nakano, Sachie Nakamura, Eriko Jimbo, Shinji Itamura, Kaori Adachi, Eiji Nanba, Aya Narita, Takanori Yamagata, Hitoshi Osaka
    BRAIN & DEVELOPMENT 39(10) 886-890 2017年11月  査読有り
    Niemann-Pick disease type C (NPC) is a rare, progressive autosomal recessive disease. It is caused by mutations in either the NPCI or NPC2 genes, resulting in defective regulation of intracellular lipid trafficking. Miglustat, which reversibly inhibits glucosylceramide synthase, reportedly has beneficial effects on the progressive neurological symptoms of NPC and was approved in Japan in 2012. Some reports suggested that miglustat therapy delayed the onset or progression of NPC when treatment was initiated before the onset of neurological manifestation or at an early stage. We report here a patient with the early-infantile form of NPC who started on miglustat at 4 months of ages. To our knowledge, this patient is the youngest reported patient with NPC in which miglustat therapy was initiated. Our patient, who had hypotonia and developmental delay before treatment, remained stable and showed no new neurological symptoms. In addition, pulmonary involvement was improved during miglustat therapy. Our case and previous reports underscore the importance of early initiation of miglustat therapy for NPC. (C) 2017 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.
  • Tsuyoshi Kodachi, Shizuko Matsumoto, Masashi Mizuguchi, Hitoshi Osaka, Nobuyuki Kanai, Eiji Nanba, Kousaku Ohno, Takanori Yamagata
    NEUROPATHOLOGY 37(5) 426-430 2017年10月  査読有り
    Niemann-Pick disease type C (NPC) is a cholesterol storage disease caused by defective cellular cholesterol transportation. The onset and progression of NPC are variable, and autopsy findings have mainly been reported for the adult and juvenile forms of this disease. Here we report the clinical and pathological findings from a 9-year-old female patient with the late infantile form of NPC due to NPC1 gene mutation. She had notable splenomegaly at 4 months of age. She lost the ability to speak at 18months of age. She learned to walk, but often fell and could no longer walk after 30months. At 3 years of age, she was diagnosed with NPC. Sequence analysis of the NPC1 gene revealed compound heterozygous mutation of T2108C (F703S) and C2348G (S813X) (both novel). Thereafter, the patient suffered repeated respiratory infections and died of respiratory failure at 9 years of age. Pathological findings included cerebral atrophy (particularly of white matter), severe demyelination, and the loss of neurons from the cerebrum and from the nuclei of the brain stem. Remnant neuronal cells and microglia in the cerebrum, cerebellum, and brain stem had become swollen and foamy. Neurons of the hippocampal CA1 and Purkinje cells were relatively spared, and senile plaques and axonal spheroids were not present. Foamy cells were also observed in other organs, especially the spleen and bone marrow. The F703S mutation in this patient was localized in a sterol-sensing domain (SSD). Severe neurological phenotypes have been previously reported in patients with missense mutations in an SSD. It is considered that the combination of a nonsense mutation and missense mutation in an SSD was responsible for the severe neurological phenotype of our present patient. While pathological findings of adult/juvenile forms of NPC have included swollen neurons and glia, neuronal cell loss, and NFTs, demyelination may be a predominant finding in the infantile form of NPC.
  • Shin Hayashi, Daniela Tiaki Uehara, Kousuke Tanimoto, Seiji Mizuno, Yasutsugu Chinen, Shinobu Fukumura, Jun-ichi Takanashi, Hitoshi Osaka, Nobuhiko Okamoto, Johji Inazawa
    PLOS ONE 12(8) e0181791 2017年8月  査読有り
    The CASK gene (Xp11.4) is highly expressed in the mammalian nervous system and plays several roles in neural development and synaptic function. Loss-of-function mutations of CASK are associated with intellectual disability and microcephaly with pontine and cerebellar hypoplasia (MICPCH), especially in females. Here, we present a comprehensive investigation of 41 MICPCH patients, analyzed by mutational search of CASK and screening of candidate genes using an SNP array, targeted resequencing and whole-exome sequencing (WES). In total, we identified causative or candidate genomic aberrations in 37 of the 41 cases (90.2%). CASK aberrations including a rare mosaic mutation in a male patient, were found in 32 cases, and a mutation in ITPR1, another known gene in which mutations are causative for MICPCH, was found in one case. We also found aberrations involving genes other than CASK, such as HDAC2, MARCKS, and possibly HS3ST5, which may be associated with MICPCH. Moreover, the targeted resequencing screening detected heterozygous variants in RELN in two cases, of uncertain pathogenicity, and WES analysis suggested that concurrent mutations of both DYNC1H1 and DCTN1 in one case could lead to MICPCH. Our results not only identified the etiology of MICPCH in nearly all the investigated patients but also suggest that MICPCH is a genetically heterogeneous condition, in which CASK inactivating mutations appear to account for the majority of cases.
  • Tetsuro Matsuhashi, Takeya Sato, Shin-ichiro Kanno, Takehiro Suzuki, Akihiro Matsuo, Yuki Oba, Motoi Kikusato, Emi Ogasawara, Tai Kudo, Kosuke Suzuki, Osamu Ohara, Hiroko Shimbo, Fumika Nanto, Hiroaki Yamaguchi, Daisuke Saigusa, Yasuno Mukaiyama, Akiko Watabe, Koichi Kikuchi, Hisato Shima, Eikan Mishima, Yasutoshi Akiyama, Yoshitsugu Oikawa, Hsin-Jung Ho, Yukako Akiyama, Chitose Suzuki, Mitsugu Uematsu, Masaki Ogata, Naonori Kumagai, Masaaki Toyomizu, Atsushi Hozawa, Nariyasu Mano, Yuji Owada, Setsuya Aiba, Teruyuki Yanagisawa, Yoshihisa Tomioka, Shigeo Kure, Sadayoshi Ito, Kazuto Nakada, Ken-ichiro Hayashi, Hitoshi Osaka, Takaaki Abe
    EBIOMEDICINE 20 27-38 2017年6月  査読有り
    Mitochondrial dysfunction increases oxidative stress and depletes ATP in a variety of disorders. Several antioxidant therapies and drugs affecting mitochondrial biogenesis are undergoing investigation, although not all of them have demonstrated favorable effects in the clinic. We recently reported a therapeutic mitochondrial drug mitochonic acid MA-5 (Tohoku J. Exp. Med., 2015). MA-5 increased ATP, rescued mitochondrial disease fibroblasts and prolonged the life span of the disease model "Mitomouse" (JASN, 2016). To investigate the potential of MA-5 on various mitochondrial diseases, we collected 25 cases of fibroblasts from various genetic mutations and cell protective effect of MA-5 and the ATP producing mechanism was examined. 24 out of the 25 patient fibroblasts (96%) were responded to MA-5. Under oxidative stress condition, the GDF-15 was increased and this increase was significantly abrogated by MA-5. The serum GDF-15 elevated in Mitomouse was likewise reduced by MA-5. MA-5 facilitates mitochondrial ATP production and reduces ROS independent of ETC by facilitating ATP synthase oligomerization and supercomplex formation with mitofilin/Mic60. MA-5 reduced mitochondria fragmentation, restores crista shape and dynamics. MA-5 has potential as a drug for the treatment of various mitochondrial diseases. The diagnostic use of GDF-15 will be also useful in a forthcoming MA-5 clinical trial. (C) 2017 The Authors. Published by Elsevier B.V.
  • Miyauchi Akihiko, Matsumoto Ayumi, Nagashima Masako, Monden Yukifumi, Oguro Noriko, Shintaku Haruo, Uchiyama Yuri, Nakashima Mitsuko, Matsumoto Naomichi, Osaka Hitoshi, Yamagata Takanori
    脳と発達 49(Suppl.) S289-S289 2017年5月  
  • Sakamoto Saori, Monden Yukifumi, Fukai Ryoko, Miyake Noriko, Saito Hiroshi, Nagashima Masako, Osaka Hitoshi, Matsumoto Naomichi, Yamagata Takanori
    脳と発達 49(Suppl.) S289-S289 2017年5月  
  • Ikeda Takahiro, Monden Yukifumi, Nagashima Masako, Shimoizumi Hideo, Osaka Hitoshi, Dan Ippeita, Yamagata Takanori
    脳と発達 49(Suppl.) S293-S293 2017年5月  
  • Mary Kay Koenig, Ryan Hodgeman, James J. Riviello, Wendy Chung, Jennifer Bain, Claudia A. Chiriboga, Kazushi Ichikawa, Hitoshi Osaka, Megumi Tsuji, K. Michael Gibson, Penelope E. Bonnen, Phillip L. Pearl
    NEUROLOGY 88(20) 1919-1924 2017年5月  査読有り
    Objective: We report a case series of 10 patients with gamma-aminobutyric acid (GABA)-transaminase deficiency including a novel therapeutic trial and an expanded phenotype. Methods: Case ascertainment, literature review, comprehensive evaluations, and long-term treatment with flumazenil. Results: All patients presented with neonatal or early infantile-onset encephalopathy; other features were hypotonia, hypersomnolence, epilepsy, choreoathetosis, and accelerated linear growth. EEGs showed burst-suppression, modified hypsarrhythmia, multifocal spikes, and generalized spike-wave. Five of the 10 patients are currently alive with age at last follow-up between 18 months and 9.5 years. Treatment with continuous flumazenil was implemented in 2 patients. One patient, with a milder phenotype, began treatment at age 21 months and has continued for 20 months with improved alertness and less excessive adventitious movements. The second patient had a more severe phenotype and was 7 years of age at initiation of flumazenil, which was not continued. Conclusions: GABA-transaminase deficiency presents with neonatal or infantile-onset encephalopathy including hypersomnolence and choreoathetosis. A widened phenotypic spectrum is reported as opposed to lethality by 2 years of age. The GABA-A benzodiazepine receptor antagonist flumazenil may represent a therapeutic strategy.
  • Mikako Enokizono, Noriko Aida, Tetsu Niwa, Hitoshi Osaka, Takuya Naruto, Kenji Kurosawa, Chihiro Ohba, Toshifumi Suzuki, Hirotomo Saitsu, Tomohide Goto, Naomichi Matsumoto
    JOURNAL OF THE NEUROLOGICAL SCIENCES 376 7-12 2017年5月  査読有り
    Purpose: Little is known regarding neuroimaging-genotype correlations in Joubert syndrome (JBTS). To elucidate one of these correlations, we investigated the neuroimaging findings of JBTS patients with C5orf42 mutations. Materials and methods: Neuroimaging findings in five JBTS patients with C5orf42 mutations were retrospectively assessed with regard to the infratentorial and supratentorial structures on T1-magnetization prepared rapid gradient echo (MPRAGE), T2-weighted images, and color-coded fractional anisotropy (FA) maps; the findings were compared to those in four JBTS patients with mutations in other genes (including three with AHI1 and one with TMEM67 mutations). Results: In C5orf42-mutant patients, the infratentorial magnetic resonance (MR) images showed normal or minimally thickened and minimally elongated superior cerebellar peduncles (SCP), normal or minimally deepened interpeduncular fossa (IF), and mild vermian hypoplasia (VH). However, in other patients, all had severe abnormalities in the SCP and IF, and moderate to marked VH. Supratentorial abnormalities were found in one individual in other JBTS. In JBTS with all mutations, color-coded FA maps showed the absence of decussation of the SCP (DSCP). Conclusion: The morphological neuroimaging findings in C5orf42-mutant JBTS were distinctly mild and made diagnosis difficult. However, the absence of DSCP on color-coded FA maps may facilitate the diagnosis of JBTS. (C) 2017 Elsevier B.V. All rights reserved.
  • Saori Sakamoto, Yukifumi Monden, Ryoko Fukai, Noriko Miyake, Hiroshi Saito, Akihiko Miyauchi, Ayumi Matsumoto, Masako Nagashima, Hitoshi Osaka, Naomichi Matsumoto, Takanori Yamagata
    Brain & development 39(5) 439-443 2017年5月  査読有り
    We report the case of a 19-year-old female patient who had progressive chorea associated with a GNAO1 mutation. Chorea was refractory to multiple anticonvulsants, and the patient suffered from tiapride-induced neuroleptic malignant syndrome. After identification of a GNAO1 missense mutation at the age of 18years, topiramate treatment was initiated and the frequency of chorea decreased dramatically. The efficacy of topiramate may have been related to the inhibitory modulation of voltage-activated Ca2+ channels. Given the side effects and complications associated with neuroleptics and deep brain stimulation, respectively, topiramate is recommended for the first-line management of severe chorea associated with a GNAO1 mutation.
  • Sachie Nakamura, Hitoshi Osaka, Shin-Ichi Muramatsu, Naomi Takino, Mika Ito, Shiho Aoki, Eriko F Jimbo, Kuniko Shimazaki, Tatsushi Onaka, Sumio Ohtsuki, Tetsuya Terasaki, Takanori Yamagata
    Molecular genetics and metabolism reports 10 67-74 2017年3月  査読有り
    OBJECTIVE: We generated an adeno-associated virus (AAV) vector in which the human SLC2A1 gene was expressed under the synapsin I promoter (AAV-hSLC2A1) and examined if AAV-hSLC2A1 administration can lead to functional improvement in GLUT1-deficient mice. METHODS: AAV-hSLC2A1 was injected into heterozygous knock-out murine Glut1 (GLUT1+/-) mice intraperitoneally (systemic; 1.85 × 1011 vg/mouse) or intra-cerebroventricularly (local; 1.85 × 1010 vg/mouse). We analyzed GLUT1 mRNA and protein expression, motor function using rota-rod and footprint tests, and blood and cerebrospinal fluid (CSF) glucose levels. RESULTS: Vector-derived RNA was detected in the cerebrum for both injection routes. In the intra-cerebroventricular injection group, exogenous GLUT1 protein was strongly expressed in the cerebral cortex and hippocampus near the injection site. In the intraperitoneal injection group, exogenous GLUT1 protein was mildly expressed in neural cells throughout the entire central nervous system. The motor function test and CSF/blood glucose ratio were significantly improved following intra-cerebroventricular injection. CONCLUSIONS: AAV-hSLC2A1 administration produced exogenous GLUT1 in neural cells and improved CSF glucose levels and motor function of heterozygous knock-out murine Glut1 mice.
  • Shin Iida, Masataka Nakamura, Shinya Asayama, Takenobu Kunieda, Satoshi Kaneko, Hitoshi Osaka, Hirofumi Kusaka
    BMC NEUROLOGY 17(1) 47 2017年2月  査読有り
    Background: Methylenetetrahydrofolate reductase (MTHFR) deficiency is a rare inborn error of metabolism inherited in autosomal recessive pattern and is associated with a wide spectrum of neurological abnormalities. Case presentation: We herein describe a 15-year-old boy with MTHFR deficiency who presented with a slowly progressive decline of school performance and a spastic gait. Rapidly deteriorating psychosis and repetitive seizures triggered by a febrile infection prompted neurological investigation. He had significantly elevated total plasma homocysteine and urinary homocystine levels, as well as a decreased plasma methionine level. Brain magnetic resonance imaging (MRI) revealed leukoencephalopathy. DNA gene sequencing showed c.446_447 del GC ins TT and c.137G > A, and c.665C > T heterozygous mutations in the MTHFR gene of the patient. Oral administration of betaine drastically improved his clinical symptoms within a few months. After 8 months of treatment, his total plasma homocysteine level moderately decreased; and the plasma methionine concentration became normalized. Furthermore, the white matter lesions on MRI had disappeared. Conclusion: This patient demonstrates the possibility that MTHFR deficiency should be considered in mentally retarded adolescents who display an abnormally elevated plasma level of homocysteine in association with progressive neurological dysfunction and leukoencephalopathy. Febrile infections may be an aggravating factor in patients with MTHFR deficiency.

MISC

 143
  • 阿久津萌, 月田貴和子, 三谷忠宏, 末盛智彦, 望月響子, 山田香里, 新開真人, 青柳順, 村松一洋, 小坂仁, 田島敏広
    日本小児科学会雑誌 127(11) 2023年  
  • 木下善仁, 木下善仁, 杉浦歩, 小貫孝則, 海老原知博, 松橋徹郎, 志村優, 伏見拓矢, 市野紀子, 長滝谷芳恵, 西畑瞳, 新田和広, 八塚由紀子, 岡崎敦子, WU Yibo, WU Yibo, 小坂仁, 大竹明, 大竹明, 村山圭, 村山圭, 岡崎康司, 岡崎康司
    日本ミトコンドリア学会年会要旨集 21st 2023年  
  • 松本歩, 津田英利, 池田尚広, 宮内彰彦, 橋口万里奈, 門田行史, 轡田行信, 渡邊和寿, 村松一洋, 小坂仁, 岩本禎彦, 山形崇倫
    日本人類遺伝学会大会プログラム・抄録集 67th (CD-ROM) 2022年  
  • 田中大輔, 池田尚広, 橋口万里奈, 松本歩, 門田行史, 村松一洋, 小坂仁, 山形崇倫
    脳と発達 54(1) 2022年  
  • Hirokazu Yamagishi, Masahide Goto, Hitoshi Osaka, Mari Kuwajima, Kazuhiro Muramatsu, Takanori Yamagata
    Epileptic disorders : international epilepsy journal with videotape 22(2) 214-218 2020年4月16日  
    Ring chromosome 20 syndrome is an epileptic and neurodevelopmental encephalopathy that occurs in children, characterised by a triad of refractory frontal lobe seizures, recurrent non-convulsive status epilepticus and frontal lobe-dominant paroxysmal discharges. However, details of other clinical features associated with ring chromosome 20 syndrome remain unknown. Here, we report two patients with ring chromosome 20 syndrome who had praxis-induced reflex seizures. Case 1 was an 11-year-old girl who presented with seizures triggered by specific activities such as mental and written calculations, writing, decision-making, recall, sudden changes in routine or ambient temperature and bathing. During calculations, left frontal lobe-dominant, 3-Hz slow-wave bursts were observed on EEG. Lacosamide effectively suppressed her tonic seizures. Case 2 was a six-year-old boy who presented with seizures triggered by specific activities such as calculations, recall and bathing. During calculations, frontal lobe-dominant, 3-Hz spike and slow-wave bursts were observed on EEG. Although his epilepsy was refractory, gabapentin reduced the frequency of focal seizures. In both cases, the hyperexcitability in the frontal lobe may have spread to the motor cortex and precipitated praxis-induced seizures. Therefore, in addition to the known characteristic triad, praxis-induced reflex seizures may also be a feature of ring chromosome 20 syndrome.

共同研究・競争的資金等の研究課題

 8