Masaaki Ogihara
Tokyo Medical University
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Featured researches published by Masaaki Ogihara.
Brain & Development | 1993
Masaaki Ogihara; Keiko Kinoue; Hikari Takamiya; Shiori Nemoto; Tasuku Miyajima; Akinori Hoshika; Teruo Honda; Sachio Takashima; Pierre Genton; Michelle Bureau
The authors report a case of early encephalopathy with myoclonus, tonic spasms and a suppression-burst pattern on electroencephalography (EEG) associated with unilateral cerebral hypertrophy following hemiatrophy. This patient showed frequent myoclonus in relation to a suppression-burst pattern resembling that in early myoclonic encephalopathy (EME). Moreover, the case also showed tonic spasms, from the age of 13 days, in series, as seen in Ohtahara syndrome. On the other hand, there was a previously undescribed peculiar CT scan finding, which showed hypertrophy of the right cerebral hemisphere at birth, following hemiatrophy. Neuropathological examination revealed cerebral atrophy associated with heterotopia and an ependymal hyperplasia in the right hemisphere, suggesting hemimegalencephaly. This case should be classified as Ohtahara syndrome accompanied by myoclonus, because of the spasms in series interrupting the suppression-burst pattern, and the etiological factor of brain malformation. The nosological aspects of this epileptic encephalopathy are discussed.
Brain & Development | 1996
Hisashi Kawashima; Tasuku Miyajima; Takayuki Mori; Leipin Yuan; Masaaki Ogihara; Keiko Kinoue; Kouji Takekuma; Akinori Hoshika
We report a rare case of intractable frontal lobe epilepsy with mental deterioration, in which the measles virus gene was detected from the cerebrospinal fluid (CSF) and peripheral mononuclear cells (PBMC) obtained 9 years after the first epileptic episode using reverse transcriptase-polymerase chain reaction (RT-PCR). The patient had been immunized with an attenuated measles vaccine and had no history of clinically apparent acute measles infection. However the analysis of the sequence of the PCR product from CSF showed the circulating wild strain genotype at the time when the patient complained of his first epileptic episode.
Pediatric Neurology | 2010
Masaaki Ogihara; Shuuichirou Shirakawa; Tasuku Miyajima; Kouji Takekuma; Akinori Hoshika
This study sought to determine diurnal variations in febrile convulsions, and to investigate whether such variations influenced the severity of febrile convulsions. The study involved 326 children, between ages 6 months and 6 years, with simple febrile convulsions. Data were collected systematically by interviewing witnesses within the week after febrile convulsions occurred. The frequency of febrile convulsions was approximately 5 times greater in the evening than in early morning. An adaptation curve revealed that the maximum occurrence of febrile convulsions was at 4:00 pm (4:00-4:59 pm), and the minimum, at 4:00 am (4:00-4:59 am), similar to the pattern of human body temperature. Temperature and seizure duration did not differ significantly between high-frequency and low-frequency zones (2:00-7:00 pm and 2:00-7:00 am, respectively) (high-frequency zone vs low-frequency zone, 39.20 degrees C (S.D., 0.68 degrees C) vs 39.22 degrees C (S.D., 0.64 degrees C) and 3.82 minutes (S.D., 5.27 minutes) vs 3.14 minutes (S.D., 3.19 minutes)). These results suggest that the circadian rhythm does not change seizure propensity, but its hourly occurrence is attributable to an elevation in the temperature set point in the 24-hour period. The prevention of recurrent febrile convulsions by rectal administration of anticonvulsants in high-frequency zones would be clinically helpful.
Brain & Development | 2007
Yoshiaki Watanabe; Masaaki Ogihara; Akinori Hoshika
This study observed six cases of localization-related epilepsy (LRE) with a cluster of epileptic spasms (ES) preceded by focal seizures (FS), defined as FS-ES. Initially, the FS was observed at a mean age 13 months; subsequently FS-ES occurred at the mean age 6 years and 3 months. The average duration from FS to FS-ES was 5 years and 1 month. All cases showed plural types of seizure (more than 2), severe mental retardation, multifoci in an interictal electroencephalogram (EEG), and abnormal findings of brain magnetic resonance imaging or computed tomography. Moreover, it was noted that high-voltage spikes were observed in the occipital area in rapid eye movements sleep on overnight EEG. According to a long-term follow-up study (average 13 years and 4 months), the 6 cases with FS-ES were divided into two types of prognosis. In 2 cases of neural cell migration disorder, the FS-ES could be detected, but in 4 cases of cerebral disorder after birth, it had disappeared. To predict a risk factor for LRE with FS-ES, six cases of FS-ES were compared with 27 cases of LRE without FS-ES. As a result of this study, there is a possibility that infants with severe brain damage may thus demonstrate frequent partial seizures and subsequently develop FS-ES.
Pediatrics International | 1990
Tetsuro Tanaka; Tetsuya Shimazaki; Isao Kusakawa; Masaaki Ogihara; Teruo Honda; Masao Katayama; Katsuyuki Miyasaka
The breathing pattern in children with asthma was studied, using respiratory inductive plethysmography. The subjects were 31 children with mild to moderate asthma (15 males, 16 females; aged 6∼15 years, average 11 years). The respiratory rate was 25.5±10.7/min. (mean ± S.D.) during asthma attacks and 18.4 ± 5.0/min. between attacks with a significant increase during attacks (P < 0.001). The expiratory time was 1.774 ± 0.833 second during attacks, and 2.125 ± 0.602 seconds between attacks. The expiratory time to total respiratory time ratio (TE/TTOT) was 0.631 ± 0.056 during attacks and 0.608 ± 0.035 between attacks. Thus there was a slight prolongation at the time of attack, but the difference was not significant. The tidal volume was increased slightly during mild and moderate attacks. VT/TI (mean inspiratory flow) was increased during attacks. The respiratory pattern was thoracic during attacks and changed to the abdominal pattern with improvement.
Pediatrics | 2013
Emi Kasai-Yoshida; Masaaki Ogihara; Miwa Ozawa; Taiki Nozaki; Michiharu Morino; Atsushi Manabe; Ryota Hosoya
Of 71 acute lymphoblastic leukemia survivors at our hospital over the past 10 years, 2 children developed mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS). This is the first report to describe the clinical course of MTLE-HS observed longitudinally by EEG and MRI. Patient 1 experienced a seizure during chemotherapy involving intrathecal methotrexate. Postseizure MRI suggested methotrexate encephalopathy or leukemic invasion. Anticonvulsant therapy was initiated; subsequent EEGs and MRIs revealed normal results. Three years after chemotherapy, a diffuse, irregular spike-and-wave pattern was observed on interictal EEG. Five years after chemotherapy, the patient developed MTLE-HS comprising complex partial seizures, typical temporal spikes on EEG, and hippocampal sclerosis (HS). Patient 2 did not experience seizures during chemotherapy. Four years later, the patient started experiencing complex partial seizures, and a diffuse, irregular spike-and-wave pattern was observed on interictal EEG. A clinical picture of MTLE-HS developed 2 years later. In both patients, nonspecific EEG abnormalities (ie, diffuse, irregular spike-and-wave activity) preceded the appearance of HS on MRI by 2 years, suggesting an insidious advance of HS during the latent period. Such atypical EEG findings may indicate MTLE-HS during follow-up of leukemia patients. MTLE-HS develops several years after an initial precipitating incident such as prolonged seizures, central nervous system infection, and brain trauma. In our cases, the initial precipitating incident may have been chemotherapy and/or prolonged seizures. Thus, MTLE-HS associated with leukemia may not be as rare as generally believed. A large cohort study of late neurologic complications is warranted.
Psychiatry and Clinical Neurosciences | 1993
Masaaki Ogihara; Akinori Hoshika; Tasuku Miyajima; Tetsuhiko Matsuno; Wang Chuan Yu
Recently, a peculiar form of epileptic seizure has been proposed by Gobbi et al.’ ’ with the concept “periodic spasms” (PS). This seizure consisted of spasms in a series following focal seizure without hypsarrhythmia on EEG. Analogous seizures have been rarely reported in patients with West syndrome3 and Lennox-Gastaut syndrome’ 6, however, detailed studies focusing on symptomatology of PS have not yet been reported. We attempted to clarify the clinical manifestations of this entity, and discussed its pathophysiology .
Pediatrics International | 1987
Masaaki Ogihara; Sekoiya Aritaki
The case of a two‐year‐old Japanese girl is presented who had attacks of vomiting, hypertension and somnolence in a regular cycle. During the attacks, she showed increases in serum ACTH, ADH and Cortisol, decreases in plasma osmolality and sodium concentration, and increases in the urinary excretion of 17‐OHCS and 17‐KS. During attack‐free periods, all these findings became normal. Although this case is similar to cases of periodic ACTH ADH discharge syndrome described by Sato and associates [1, 2], certain differences exist:
Pediatrics International | 1986
Sekoiya Aritaki; Masaaki Ogihara; Isao Kusakawa; Hikari Takamiya; Yoshihiro Hori; Naoshi Kawashima; Tasuku Miyajima; Tomoyuki Chiba; Kazumitsu Tsuyuki; Koji Takekuma; Tetsuhiko Matsuno; Teruo Honda
Children with cyclic vomiting had high blood ADH, ACTH, cortisol and plasma renin activity (PRA) during vomiting, and urinary excretion of 170HCS, 17KGS, 17KS, norepinephrine (NE), epinephrine (E), normetanephrine (NMN), metanephrine (MN) and vanillylmandelic acid (VMA) was increased. After disappearance of the vomiting, the levels fell to within the normal range. Variation was not observed in blood prolactin (PRL), Na, osmotic pressure or urine dopamine (DA). Normal findings were obtained in the intravenous water loading test, response of anterior pituitary hormones and cortisol to the insulin, TRH and LH‐RH loading, the metopirone test and the dexamethasone suppression test which were performed 1 week after the vomiting.
Pediatric Neurology | 2012
Kentarou Nakashima; Masaaki Ogihara; Emi Kasai-Yoshida; Shio Tsuruta; Machiko Nakagawa; Isao Kusakawa
We describe a boy (aged 2 years and 7 months) with hemimegalencephaly who developed myoclonic status, which improved dramatically after total callosotomy. The patient experienced seizures beginning at age 2 days, at which time electroencephalography revealed a right unilateral burst suppression pattern, and cranial magnetic resonance imaging revealed an enlarged right hemisphere. At age 8 months, habitual seizures increased to more than daily frequency. At the same time, myoclonic status epilepticus appeared with frequent erratic, partial, massive myoclonic seizures and clouding of consciousness. These signs were accompanied by diffuse spike and spike-wave patterns on electroencephalography, indicating myoclonic status in nonprogressive encephalopathy. Total callosotomy performed at age 10 months resulted in the complete disappearance of myoclonic status and prominent decrease in habitual seizures. This description of hemimegalencephaly is the first, to our knowledge, in which total callosotomy alleviated myoclonic status epilepticus. Although the mechanism of myoclonic status epilepticus remains unknown, our results suggest that cortico-cortical pathways are involved in this type of myoclonic status.