Koyo Ohno
Tottori University
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Featured researches published by Koyo Ohno.
Brain & Development | 2016
Akiko Tamasaki; Yoshiaki Saito; Riyo Ueda; Koyo Ohno; Katsutoshi Yokoyama; Takahiro Satake; Hiroshi Sakuma; Yukitoshi Takahashi; Tatsuro Kondoh; Yoshihiro Maegaki
A 14-year-old boy with Down syndrome (DS) showed a gradual decline in his daily activities and feeding capacities, and a marked deterioration triggered by a streptococcal infection was observed at the age of 15 years. He became bedridden, accompanied by sleep disturbance, sustained upward gaze, and generalized rigidity. Magnetic resonance imaging showed unremarkable findings, but antiglutamate receptor autoantibodies were positive in his cerebrospinal fluid. Treatment with thiamine infusion and steroid pulse therapy showed little effect, but gross motor dysfunction and appetite loss were ameliorated by the administration of l-DOPA and serotonin reuptake inhibitors. Thereafter, autistic behaviors predominated, including loss of social interaction, oral tendency, water phobia, and aggressiveness. Initiation of donepezil, an acetylcholinesterase inhibitor, resulted in the disappearance of these symptoms and total recovery of the patient to his previous psychosocial levels. We hypothesize that the acute regression in adolescence represents a process closely related to the defects of serotonergic and cholinergic systems that are innate to DS brains and not just a nonspecific comorbidity of depression or limbic encephalitis.
Brain & Development | 2015
Tohru Okanishi; Hiroyuki Yamamoto; Takatoshi Hosokawa; Naoki Ando; Yoshihisa Nagayama; Yuji Hashimoto; Toshiro Maihara; Tomohide Goto; Tetsuo Kubota; Chiharu Kawaguchi; Hiroshi Yoshida; Katsumi Sugiura; Seiko Itomi; Koyo Ohno; Jun-ichi Takanashi; Masahiro Hayakawa; Hiroshi Otsubo; Akihisa Okumura
AIM To determine the early changes and evolutions of brain diffusion-weighted imaging (DWI), and analyze prognostic factors of the early changes among patients with neonatal herpes simplex encephalitis (NHSE). METHOD We selected patients who developed encephalitis by 28 d after birth; had herpes simplex infection; and who underwent magnetic resonance imaging, including DWI, ⩽7 d of symptom onset. Thirty-two DWI scans between 0 and 28 d after onset in 13 patients and the clinical data were recruited. The distribution, evolution of the lesions, and neurological outcome were analyzed. RESULTS DWI frequently showed multiple cortical lesions in both hemispheres in the early period and both hemispheres on DWI (8/9 scans at ⩽48 h, 7/7 patients). As time from onset increased, the cortical lesions tended to coincide with subcortical white matter lesions beneath the initial cortical lesions (p<0.01). Lesions from the cortex extended to the subcortical white matter in 7 patients. Deep cerebral lesions, involving basal ganglia, internal capsules, thalamus, were also found in 9 patients ⩽7 d of onset. The distributions of deep cerebral lesions (none/unilateral/bilateral) ⩽7 d of onset showed significant correlations with neurological prognoses (gross motor functions: p<0.01; developmental or intellectual quotient scores: p<0.01). INTERPRETATION Cortical lesions were main findings of DWI in NHSE in the early period. Bilateral deep cerebral lesions ⩽7 d were highly indicative of poor motor and cognitive outcomes.
Brain & Development | 2017
Keita Kuya; Shinya Fujii; Fuminori Miyoshi; Koyo Ohno; Yuki Shinohara; Yoshihiro Maegaki; Toshihide Ogawa
A 1-year-old boy was admitted because of febrile status epilepticus (FSE). A secondary cluster of seizures was seen on day 5 after onset, and the patient eventually displayed developmental delay. Conventional magnetic resonance imaging (MRI) showed no abnormal findings on day 1 after onset, but showed reduced diffusion in the subcortical regions of bilateral frontal lobes on day 5 after onset. Acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) was diagnosed. Arterial spin labeling (ASL) revealed reduced cerebral blood flow (CBF) in bilateral frontal lobes on day 1 after onset and showed increased CBF in the corresponding region in the subacute phase. Outcomes after prolonged febrile seizures are usually good, but mental deficit and/or epilepsy often remain in AESD. Discriminating between these syndromes is difficult, because no useful biomarkers have been identified. Reduced CBF in bilateral frontal lobes was observed on ASL on day 1 of FSE in the present case, and this finding may be predictive of developing AESD.
Clinical Genetics | 2016
Hirofumi Kurata; Hiroshi Terashima; Mitsuko Nakashima; Tetsuya Okazaki; Wataru Matsumura; Koyo Ohno; Yoshiaki Saito; Yoshihiro Maegaki; Masaya Kubota; Eiji Nanba; Hirotomo Saitsu; Naomichi Matsumoto; Mitsuhiro Kato
Mutations in SPATA5 have recently been shown to result in a phenotype of microcephaly, intellectual disability, seizures, and hearing loss in childhood. Our aim in this report is to delineate the SPATA5 syndrome as a clinical entity, including the facial appearance, neurophysiological, and neuroimaging findings. Using whole‐exome sequencing and Sanger sequencing, we identified three children with SPATA5 mutations from two families. Two siblings carried compound heterozygous mutations, c.989_991del (p.Thr330del) and c.2130_2133del (p.Glu711Profs*21), and the third child had c.967T>A (p.Phe323Ile) and c.2146G>C (p.Ala716Pro) mutations. The three patients manifested microcephaly, psychomotor retardation, hypotonus or hypertonus, and bilateral hearing loss from early infancy. Common facies were a depressed nasal bridge/ridge, broad eyebrows, and retrognathia. Epileptic spasms or tonic seizures emerged at 6–12 months of age. Interictal electroencephalography showed multifocal spikes and bursts of asynchronous diffuse spike‐wave complexes. Augmented amplitudes of visually evoked potentials were detected in two patients. Magnetic resonance imaging revealed hypomyelination, thin corpus callosum, and progressive cerebral atrophy. Blood copper levels were also elevated or close to the upper normal levels in these children. Clinical delineation of the SPATA5‐related encephalopathy should improve diagnosis, facilitating further clinical and molecular investigation.
Annals of clinical and translational neurology | 2014
Aya Narita; Kentarou Shirai; Norika Kubota; Rumiko Takayama; Yukitoshi Takahashi; Takanori Onuki; Chikahiko Numakura; Mitsuhiro Kato; Yusuke Hamada; Norio Sakai; Atsuko Ohno; Maya Asami; Shoko Matsushita; Anri Hayashi; Tomohiro Kumada; Tatsuya Fujii; Asako Horino; Takeshi Inoue; Ichiro Kuki; Ken Asakawa; Hitoshi Ishikawa; Koyo Ohno; Yoko Nishimura; Akiko Tamasaki; Yoshihiro Maegaki; Kousaku Ohno
The hallmark of neuronopathic Gaucher disease (GD) is oculomotor abnormalities, but ophthalmological assessment is difficult in uncooperative patients. Chromatic pupillometry is a quantitative method to assess the pupillary light reflex (PLR) with minimal patient cooperation. Thus, we investigated whether chromatic pupillometry could be useful for neurological evaluations in GD. In our neuronopathic GD patients, red light‐induced PLR was markedly impaired, whereas blue light‐induced PLR was relatively spared. In addition, patients with non‐neuronopathic GD showed no abnormalities. These novel findings show that chromatic pupillometry is a convenient method to detect neurological signs and monitor the course of disease in neuronopathic GD.
Pediatric Neurology | 2016
Koyo Ohno; Yoshiaki Saito; Riyo Ueda; Masami Togawa; Takanori Ohmae; Eriko Matsuda; Misato Fujiyama; Yoshihiro Maegaki
BACKGROUND Rett syndrome is characterized by psychomotor regression during early childhood, autistic-like behaviors, and aberrant breathing patterns. Dysfunction of the serotonergic system has been postulated to play a role in the pathophysiology of these symptoms. PATIENT DESCRIPTION We present an 11-year-old girl with Rett syndrome who exhibited marked respiratory symptoms, including frequent apneic events during sleep. She had been treated for these respiratory symptoms using noninvasive positive pressure ventilation since age six years. Treatment with serotonin 1A receptor agonist was initiated at age eight years, whereas treatment using a selective serotonin reuptake inhibitor began at age nine years. Noninvasive positive pressure ventilation therapy was effective in reducing symptoms of sleep apnea, and administration of serotonergic agents resulted in amelioration of sleep apneic events even in the absence of noninvasive positive pressure ventilation. In addition, improvements in hand stereotypy and social skills were observed after initiation of serotonin-based therapy. DISCUSSION The respiratory difficulties our patient experienced during non-rapid eye movement (REM) sleep are characteristic of post-sigh central apnea. Exaggerated activity of expiratory neurons during such apneic events has been observed in mouse models of Rett syndrome. We suggest that prescribed serotonergic agents might serve to inhibit such activity, attenuating the imbalance between inspiratory and expiratory neurons. These agents might also be useful in the treatment of autistic-like behaviors caused by impaired serotonergic transmission in the brain.
Brain & Development | 2016
Ayako Itakura; Yoshiaki Saito; Yoko Nishimura; Tetsuya Okazaki; Koyo Ohno; Hitoshi Sejima; Toshiyuki Yamamoto; Yoshihiro Maegaki
A girl with mild psychomotor developmental delay developed right or left hemiclonic convulsion at 10months of age. One month later, clusters of hemiclonic or bilateral tonic seizures with eyelid twitching emerged, resulting in status epilepticus. Treatment with phenobarbital and potassium bromide completely terminated the seizures within 10days. Ictal electroencephalography revealed a migrating focus of rhythmic 3-4Hz waves from the right temporal to right frontal regions and then to the left frontal regions. Genetic analysis was conducted based on the characteristic facial appearance of the patient, which identified a 2.1-Mb terminal deletion on chromosome 4p. This is the first case of Wolf-Hirschhorn syndrome complicated by epilepsy with migrating partial seizures.
Brain & Development | 2015
Riyo Ueda; Yoshiaki Saito; Koyo Ohno; Kanako Maruta; Kunihiro Matsunami; Yusuke Saiki; Tatsuyuki Sokota; Susumu Sugihara; Yoko Nishimura; Akiko Tamasaki; Aya Narita; Atsushi Imamura; Yoshihiro Maegaki
AIM To clarify the effect of levetiracetam (LEV) for acute and chronic seizure control in acute encephalitis with refractory, repetitive partial seizures (AERRPS). METHODS We retrospectively reviewed the clinical course of six AERRPS cases treated with LEV, and explored the acute phase termination by withdrawal from barbiturate-induced coma under artificial ventilation, and the reduction in seizure frequency during the chronic phase. LEV was administrated orally or via nasogastric tubes as an add-on agent during acute (n=3; age 8-10 years) and chronic (n=3; age 19-30 years) AERRPS. RESULTS In the acute phase, administration of LEV (50-60 mg/kg/d) in combination with phenobarbital (n=3; peak 57.9-76.1 μg/ml) and potassium bromide (n=2; 30-36 mg/kg/d)) resulted in successful reduction of intravenous barbiturate dosage and withdrawal from artificial ventilation. In the chronic phase, seizure frequency reduced by >75% for 5-18 months with LEV 750-1500 mg/d. CONCLUSION LEV may affect seizure control in AERRPS, particularly during the chronic phase, through its unique action of inhibition of excitatory neurotransmitter release. The regimen of oral barbiturate, potassium bromide and LEV would be worth for trial during the acute phase of AERRPS.
Brain & Development | 2015
Koyo Ohno; Yoshiaki Saito; Masami Togawa; Yuki Shinohara; Takamichi Ito; Hidenori Sugano; Shinji Itamura; Yoko Nishimura; Akiko Tamasaki; Yoshihiro Maegaki
A 2-year-old boy had glaucoma, bilateral facial haemangioma and widespread blue nevi on the trunk and extremities since birth. Dilated medullary veins were detected in the left cerebral periventricular white matter on magnetic resonance imaging (MRI). Macrocephaly and delayed psychomotor development were observed during late infancy, and susceptibility-weighted angiography revealed an extensive developmental venous anomaly with multiple caput medusae throughout bilateral hemispheres, accompanied by periventricular hyperintense alterations on MRI and progressive diffuse atrophy of the cerebral mantle with left-sided predominance. Hypoperfusion in the left cerebral and cerebellar hemisphere was also uncovered. No meningeal haemangioma was observed. This patient may represent a novel subgroup of phakomatosis cases that can be regarded as a variant of Sturge-Weber syndrome.
Brain & Development | 2018
Hirofumi Kurata; Kentaro Shirai; Yoshiaki Saito; Tetsuya Okazaki; Koyo Ohno; Masayoshi Oguri; Kaori Adachi; Eiji Nanba; Yoshihiro Maegaki
PURPOSE To clarify the relationship between macrocephaly and neurodevelopmental disorders, as well as identify the prevalence of PTEN mutations in autism spectrum disorders with macrocephaly in Japan. SUBJECTS AND METHODS Diagnostic and other medical information of children with macrocephaly younger than 4years (n=93) were collected for analysis. PTEN gene mutation analysis was conducted in another set of 16 macrocephalic individuals aged 3-22years. RESULTS Sixteen macrocephalic children were associated with neurodevelopmental disorders, including autism spectrum disorders (ASDs) (n=6), autistic traits (n=5), intellectual disability (n=5), attention deficit hyperactivity disorder (n=1), developmental coordination disorders (n=1), and language disorder (n=1). Male gender was significantly linked to these disorders, whereas a family history and degree of macrocephaly were not significantly linked to the diagnosis. A novel mutation in the PTEN gene was identified in a 16-year-old girl with autism, mental retardation, language delay, extreme macrocephaly (+4.7SD) with a prominent forehead, and digital minor anomalies. CONCLUSION Children with macrocephaly, particularly males, are at a higher risk of neurodevelopmental disorders, rather than progressive etiologies, such as hydrocephalus and neurodegenerative disorders. The data provide a basis for routine health checks for young children in Japan, including the follow-up management and possible screening of PTEN mutations in children with ASDs and macrocephaly.