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Masatoshi Ito

Publications and source records attributed to Masatoshi Ito.

At least 19 recordsLinked to original sources
PubMed2006

Three Japanese patients with glucose transporter type 1 deficiency syndrome.

We report three Japanese patients with glucose transporter type 1 deficiency syndrome (Glut1DS). Two patients had a normal erythrocyte 3-O-methylglucose (3OMG) uptake, one with a previously reported T295M substitution and the other with a novel 12-bp insertion at nt 1034-1035, ins CAGCAGCTGTCT. The third patient, with deficient 3OMG uptake, had a previously reported hot-spot mutation, R333W. All three patients responded to a ketogenic diet. All patients showed a significant improvement in ataxia, with blood beta-hydroxybutyrate (BOHB) levels ranging from 0.1 to 3mM. BOHB levels of at least 3mM were necessary to control seizures, and higher ketone levels are recommended to meet brain energy needs during development. FDG-PET scan, performed before and after a ketogenic diet in the R333W patient, did not change despite a clinical improvement. This clinical condition is treatable and early diagnosis is important.

3-Hydroxybutyric Acid↗
PubMed2006

Focal glucose hypermetabolism in interictal state of West syndrome.

This report concerns two siblings from a tetrad, both of whom had West syndrome with atypical findings on positron emission tomography using [(18)F] fluorodeoxyglucose. One manifested periventricular leukoencephalopathy, and the other had periventricular leukoencephalopathy as well as porencephaly because of fetal distress and brain parenchymal hemorrhage in the neonatal period. They developed West syndrome at the age of 9 months. Fluorodeoxyglucose-positron emission tomography study performed after cessation of their seizures revealed an increase in glucose metabolism. The corresponding region presented low-level accumulation in [(11)C]flumazenil positron emission tomography. The patients remained seizure-free for more than 1 month, and their electroencephalograms only occasionally disclosed sporadic paroxysmal discharges. Because of the decreased density of benzodiazepine receptor in these lesions, the activity of the excitatory neuron system may overexpress that of the inhibitory neuron system, thus resulting in epileptogenesis of the lesions. It is suggested that fluorodeoxyglucose and flumazenil-positron emission tomography revealed functional abnormalities and that epileptogenesis of these patients is still active even when the patient is seizure-free and there are mild epileptogenic discharges on electroencephalogram.

Brain↗
PubMed2005

Multi-institutional study on the correlation between chromosomal abnormalities and epilepsy.

While there is an abundance of literature describing the association of chromosome aberrations with epilepsy, only a few refer to the detailed features of epilepsy. It is important to investigate the associations between specific chromosome abnormalities and features of epilepsy to identify genes involved in epilepsy and treat them more effectively. We investigated the correlation between specific chromosome aberrations and epilepsy by sending questionnaires to the members of Kyoto Multi-institutional Study Group of Pediatric Neurology. Seventy-six patients were collected from 10 institutions. Chromosome abnormalities included: Down syndrome (n = 19); Angelman syndrome (n = 8); Prader-Willi syndrome (n = 4); 4p- syndrome (n = 3); 1q- syndrome (n = 2); 5p- syndrome (n = 2); Miller-Dieker syndrome (n = 2); 18q- syndrome; (n = 2); Klinefelter syndrome; (n = 2); and 32 other individual chromosomal aberrations. Overall, the severity of mental retardation correlated with the severity of epilepsy. We could abstract characteristic features of epilepsy in some syndromes. In Angelman and Prader-Willi syndromes, febrile seizures occurred frequently, the onset of epilepsy was in early childhood and seizure phenotype was multiple. Paroxysmal discharge of the occipital region and diffuse high voltage slow wave on electroencephalography were characteristic in Angelman syndrome. In Down syndrome, West syndrome and focal epilepsy were common and the prognosis of epilepsy in West syndrome with Down syndrome was good. In 4p- syndrome, febrile seizures were often seen, and unilateral or generalized clonic or tonic-clonic status epilepticus were characteristic. For the other chromosomal aberrations investigated here, the patient numbers were too small to abstract common features of epilepsy.

Adolescent↗
PubMed2005

[Treatment of adult patients with epilepsy in the children's hospital].

During one year from November 2002 to October 2003, 810 patients with epilepsy were examined in Shiga Medical Center for Children, and 186 patients (23%) were over 18 years old. Among them, 162 adult patients (male; 52%, female; 48%) were regularly examined at the outpatient-clinic. Seizures persisted in 56% of these adult patients. Over 80% of the patients were classified as symptomatic epilepsy. Seventy-eight percent of the cases were combined with physical or mental disability. Six percent of the patients had psychological disorders and 11% of the patients had internal diseases. Fifteen percent of the patients had jobs, 4% were married, and 8% had driver's licenses. Seventy percent of the patients were not independent because of their handicap. In our children's hospital, adult patients with epilepsy are increasing, and a countermeasure is necessary. It is important to join networks between regional adult hospitals and clinics. On the other hand, pediatric neurologists must study psychological and internal diseases, management of women with epilepsy, and employment and driving in patients with epilepsy.

Adolescent↗
PubMed2004

A new form of congenital proprioceptive sensory neuropathy associated with arthrogryposis multiplex.

We report two siblings who presented with non-progressive marked sensory ataxia associated with arthrogryposis multiplex congenita (AMC). Deep tendon reflexes and H reflex were completely absent, but F waves were preserved. The sensory nerve conduction studies indicated the presence of relatively mild sensory polyneuropathy. The conventional somatosensory evoked potentials (SEPs) showed mildly prolonged latency for both the peripheral and cortical responses, suggesting a slowed conduction through the peripheral as well as central pathway. However, the 'proprioceptive SEPs' were absent, in conformity with complete loss of joint sense. Sural nerve biopsy revealed only mild thinning of myelin in the younger sister but was entirely normal in her brother. Taken together with the characteristic electrophysiological findings, the symptoms were considered to be due to predominant involvement of a selective population of somatosensory ganglions. The present cases showed no progression of the neurological deficit what-so-ever since birth, which strongly suggests a developmental anomaly or aplasia of a limited population of peripheral sensory neurons.

Action Potentials↗
PubMed2004

Cloxazolam treatment for patients with intractable epilepsy.

We examined the antiepileptic effect of cloxazolam on seizures in 23 patients with intractable epilepsy. Most of the patients had central nervous system complications, as well as frequent seizures, and were being treated with polypharmacy. Cloxazolam was administered 1 to 5 mg/day (0.05 to 0.14 mg/kg) at initiation, in two divided doses daily, and gradually increased (1 to 4 mg/day; 0.05 to 0.15 mg/kg) every month at the outpatient clinic. Plasma levels of the main active metabolite, chloro-N-desmethyldiazepam, were measured in 13 patients. Four of 23 patients (17%) became seizure-free, and nine patients (39%) manifested a good response. Both patients with generalized and partial epilepsy manifested a good response. The spectrum of cloxazolam as an antiepileptic was wide. Effective doses were 0.07 to 0.56 mg/kg, and plasma effective levels of chloro-N-desmethyldiazepam were 12.3-115.1 ng/mL. Cloxazolam may be an effective and safe antiepileptic for intractable epilepsy, and should be used as an adjunct to other antiepileptic drugs or administered after other agents.

Adolescent↗
PubMed2004

Seizure phenotypes of a family with missense mutations in SCN2A.

The seizure phenotypes of a Japanese family with missense mutations in SCN2A are described. The proband of the family had partial epilepsy after febrile seizures plus. He had three missense mutations of SCN2A (R19K, R188W, and R524Q). The R188W mutation was suggested by electrophysiologic studies to be the main disease mutation. However, it is suggested that the penetrance rate of this pedigree is extremely low, or that other genes may have modified the phenotype of the proband.

Child↗
PubMed2004

[Driving license of patients with epilepsy, management of their oral drugs and suppositories by non-medical professionals, and the role of pediatric neurologists].

In June 2002, the following new driving regulations were enforced in Japan: 1. A person with epilepsy may be granted a driving license after a seizure-free period of two years. 2. A person with simple partial seizures that would not impair driving safety may be granted a driving license if no other seizures that may impair driving safety have occurred over a period of at least one year. 3. A person with seizures occurring only in sleep may be granted a driving license if no seizures have occurred in waking over a period of at least two years. 4. In case that the above requirements are going to be met within 6 months, driving should be prohibited for 6 months. 5. A person with epilepsy is recommended to apply for a license to drive heavy and/or public vehicles only after a seizure-free period of 5 years without medication. The committee for legal problems of the Japan Epilepsy Society proposed a guideline for non-medical teaching or caring professionals to give children with epilepsy antiepileptic medication or to insert suppositories, if needed, at schools or care institutions. The guideline indicated the following preconditions as important: 1. There must be a wish and consent of the patient or his/her family. 2. Drugs or suppositories are usually taken or used at home and regarded as a safe procedure. 3. Attending doctor should provide clear information about the use and risk of the medication or suppository. 4. Privacy of the patient should be protected. Pediatric neurologists are expected to play an important role on these issues.

Anticonvulsants↗
PubMed2003

Leigh syndrome associated with West syndrome.

Leigh syndrome (LS) (sub-acute necrotizing encephalomyelopathy) is characterized by symmetric brain lesions occurring mainly in the basal ganglia and associated with variable clinical manifestations such as hypotonia, psychomotor retardation, and feeding difficulties. Patients with LS may develop seizures. Only three patients with LS have been identified in the literature as having West syndrome (WS). We have seen 12 children with LS in the past 20 years, and noticed that as many as five of them developed WS. This report discusses five LS children with WS, comparing them with seven LS children without WS. In all five patients, infantile spasms developed after LS had become evident, in addition to other type(s) of seizures. The onset of LS in all the patients with WS was before 10 months of age. Although not statistically proven, early onset of LS, spasticity, nystagmus, apnea, poor feeding, and cardiac problems seemed to be associated with the development of WS. We were not able to conclude that certain types of symptoms or examination results of patients with LS indicated the development of WS. The association of LS with WS did not markedly influence the prognoses of the children. WS may not be a rare complication of LS, especially in infants under 12 months of age. This report is the first review of LS associated with WS.

Female↗
PubMed2003

A patient with epilepsia partialis continua with anti-glutamate receptor epsilon 2 antibodies.

This report concerns a 6-year-old female with epilepsia partialis continua. Autoantibodies against amino- and carboxyl-terminal regions of the N-methyl-D-aspartate receptor subunit glutamate receptor epsilon 2 were detected in the serum and cerebrospinal fluid. The anti-glutamate receptor epsilon 2 subunit antibodies have been demonstrated in the serum and cerebrospinal fluid in some patients with chronic progressive epilepsia partialis continua of childhood and those with Rasmussen's encephalitis. The patient, however, did not develop any neurologic deterioration or intractable seizures. Therefore, anti-glutamate receptor epsilon 2 subunit antibodies are not specific for chronic progressive epilepsia partialis continua of childhood and Rasmussen's encephalitis.

Autoantibodies↗
PubMed2003

Skeletal muscle glucose uptake response to exercise in trained and untrained men.

PURPOSE: Endurance training enhances skeletal muscle glucose uptake at rest, but the responses to different exercise intensities are unknown. In the present study, we tested whether glucose uptake is enhanced in trained men during low-, moderate-, and high-intensity exercise as compared with untrained men. METHODS: Seven trained and untrained men were studied without any dietary manipulation during bicycle exercise at relative intensities of 30%, 55%, and 75% of maximal oxygen consumption ([OV0312]O(2max)) on three separate days. Glucose uptake in the quadriceps femoris muscle was directly measured using positron emission tomography (PET) and 18F-fluoro-deoxy-glucose ([18F]FDG). [18F]FDG was injected 10 min after the start of the exercise. Thereafter exercise was continued for another 25 min. PET scanning was conducted immediately after completion of the exercise. The measured glucose uptake values reflect the situation during exercise due to chemical characteristics of the [18F]FDG. RESULTS: Muscle glucose uptake increased from 30% to 55% [OV0312]O(2max) intensity exercise similarly in both groups (P < 0.05). However, from 55% to 75% [OV0312]O(2max) intensity exercise, only athletes were able to further enhance glucose uptake. Furthermore, at highest intensity, glucose uptake was significantly higher in trained than in untrained men (236.6 +/- 29.6 vs 176.3 +/- 22.4 micromol.kg-1.min-1, P < 0.05). There were no differences in plasma glucose, insulin, or lactate in any time point at 75% [OV0312]O(2max) intensity between groups. CONCLUSIONS: These results show that skeletal muscle glucose uptake is higher in trained than in untrained men at high relative exercise intensity, although at lower relative exercise intensities no differences are observed. Thus, endurance training improves the capacity of contraction-induced glucose uptake in skeletal muscle.

Adult↗
PubMed2003

[Intractable epilepsy (apneic seizure) in an infant with 18q deletion syndrome].

We report here an infant with 18q deletion syndrome, and intractable apneic seizures. He had intrauterine growth retardation and dysmorphic features. Chromosomal analysis demonstrated mosaicism of 18q interstitial deletion (q12.3-q22.3). From the age of 3 months, apneic attacks occurred from once a week to over 10 times a day despite many oral antiepileptic agents, and were diagnosed as complex partial seizures. Ictal electroencephalogram and 18F-fluorodeoxyglucose-positron emission tomography at the age of 10 months identified the epileptic focus in the right parieto-temporal region. He also had severe psychomotor retardation. Head MRI examination revealed diffuse cerebral atrophy and severe white matter dysmyelination, which was caused by the deletion of myelin basic protein gene at the locus of 18q22.3. This locus may be responsible for the clinical manifestations of 18q deletion syndrome. Detailed description of the onset, seizure types, and prognosis of epilepsy associated with 18q deletion syndrome is rare. It was suggested that the locus of 18q21.3-q22.3 was responsible for autonomic seizures in 18q deletion syndrome.

Apnea↗
PubMed2002

Incidence patterns of cerebral palsy in Shiga Prefecture, Japan, 1977-1991.

The prevalence of cerebral palsy (CP) in 6-year-old children in Shiga Prefecture, Japan, born between 1977 and 1991, was compared in three successive 5-year periods: period I (1977-1981), period II (1982-1986) and period III (1987-1991). Data on the accumulated age-specific prevalence of CP were collected and analyzed. During the study period, 242293 children entered elementary school, and 325 cases (194 boys, 131 girls) of CP were ascertained in Shiga Prefecture. The overall prevalence of CP per 1000 6-year-old children was 1.34. The prevalence of CP for 6-year-old children increased from period II to period III, although it did not vary from period I to period II. The proportion of low birth weight (LBW) infants and preterm infants among those with CP increased with time during the study periods. The prevalence of CP in infants born at term and with birth weight > or =2500 g did not vary over the study period. The prevalence of CP in preterm and LBW infants, especially in infants with gestational age<32 weeks and birth weight<1500 g, increased from period II to period III, while the prevalence did not increase from period I to period II. Multiple births and use of mechanical ventilation increased from period II to period III. The changes in the prevalence of CP in Shiga Prefecture may have been due to increased survival of preterm and LBW infants in period II owing to better obstetric and neonatal care, and to further improvement in the survival of very small babies receiving intensive care, which increased the prevalence of CP in period III. Further improvement of perinatal care might decrease the incidence of CP in Shiga Prefecture in the future.

Cerebral Palsy↗
PubMed2002

Genetic abnormalities underlying familial epilepsy syndromes.

Genetic defects have been recently identified in certain inherited epilepsy syndromes in which the phenotypes are similar to common idiopathic epilepsies. Mutations in the neuronal nicotinic acetylcholine receptor 4 and 2 subunit genes have been detected in families with autosomal dominant nocturnal frontal lobe epilepsy. Both receptors are components of neuronal acetylcholine receptor, a ligand-gated ion channel in the brain. Furthermore, mutations of two K+-channel genes were also identified as the underlying genetic abnormalities of benign familial neonatal convulsions. Mutations in the voltage-gated Na+-channel 1, 2 and 1 and the gamma aminobutyric acid (GABAA) receptor 2 subunit genes were found as a cause of generalized epilepsy with febrile seizures plus, a clinical subset of febrile convulsions. Na+-channels, GABAA receptor and their auxiliaries may be involved in the pathogenesis of this subtype and even in simple febrile convulsions. Mutation of a voltage-gated K+-channel gene can cause partial seizures associated with periodic ataxia type 1 and some forms of juvenile myoclonic epilepsy and idiopathic generalized epilepsy can result from mutations of a Ca2+-channel. This line of evidence suggests the involvement of channels expressed in the brain in the pathogenesis of certain types of epilepsy. Our working hypothesis is to view certain idiopathic epilepsies as disorders of ion channels, i.e. 'channelopathies'. Such hypothesis should provide a new insight to our understanding of the genetic background of epilepsy.

Epilepsy, Generalized↗
PubMed2002

Dichloroacetate therapy in Leigh syndrome with a mitochondrial T8993C mutation.

A 6-year-old female with Leigh syndrome associated with a T-to-C mutation at nucleotide 8993 of mitochondrial deoxyribonucleic acid (T8993C) was treated with dichloroacetate, once during the first acute deterioration after a febrile illness and another time when she demonstrated subacute regression without precipitating events. Dichloroacetate reversed the clinical course on both occasions, and diffuse lesions in the midbrain revealed on magnetic resonance imaging during the second episode disappeared completely. However, dichloroacetate could not prevent the second acute deterioration associated with a febrile illness that occurred during the second treatment. Thus dichloroacetate treatment, although limited, was effective for T8993C-associated Leigh syndrome.

Brain↗
PubMed2002

Mutation (Ser284Leu) of neuronal nicotinic acetylcholine receptor alpha 4 subunit associated with frontal lobe epilepsy causes faster desensitization of the rat receptor expressed in oocytes.

To date five mutations in two major constituents of neuronal nicotinic acetylcholine receptor (nAChR) in the brain, i.e. alpha4 and beta2 subunits, have been identified to be associated with autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE). Among them, only Ser284Leu, a point mutation in alpha4 subunit identified in ADNFLE as well as in a sporadic case with nocturnal frontal lobe epilepsy, remains to be characterized electrophysiologically. We examined the properties of rat nAChR harboring Ser284Leu reconstituted on Xenopus oocytes. Currents elicited in response to application of acetylcholine to oocytes expressing wild type or mutant nAChR were measured by a standard two-microelectrode voltage clamp method. Compared with wild-type nAChR, the mutant nAChR had a comparable EC(50) value for acetylcholine whereas it showed faster desensitization and lower Cs(+)/Na(+) permeability ratio. Ser284Phe, a putative mutation constructed for comparison, exhibited similar properties. These findings indicate that Ser(284) plays an important role in gating of nAChR along with Thr(276) and Ser(280), and suggest that mutation at Ser(284) could reduce nAChR activity similar to other mutations of alpha4 subunit found in ADNFLE.

Acetylcholine↗
PubMed2002

A novel missense mutation in the DKC1 gene in a Japanese family with X-linked dyskeratosis congenita.

The authors report 2 male patients with dyskeratosis congenita (DC) in a Japanese kindred. Sequencing of the complementary DNA of the dyskerin gene (DKC1) revealed a T-to-C transition at nucleotide 1285 in exon 12 that resulted in a novel missense mutation L398P. Despite harboring the same mutation in the DKC1 gene, one patient had significantly milder hematological symptoms than the other, indicating that there may be other factors that determine the severity of DC.

Cell Cycle Proteins↗