We recorded the auditory-evoked magnetic fields from children and adults with absolute pitch during the following tasks: (1) hearing 1000 Hz pure tones inattentively, (2) hearing eight random tones inattentively and (3) listening to eight random tones and identifying each tone. In children with absolute pitch, there was no significant positive correlation between the appearance rate of N100m and the kinds of tasks. In adults with absolute pitch, only the right N100m dipole moments increased significantly in tasks (1) and (2). The present results suggest that the circuit for labeling in the right auditory cortex may lose a function from childhood to adulthood, which reveals neuroplasticity in the development of absolute pitch ability.

Acoustic Stimulation↗

PubMed2005

A magnetoencephalographic study of negative myoclonus in a patient with atypical benign partial epilepsy.

PURPOSE: To clarify the neurophysiological mechanism of epileptic negative myoclonus (NM) of a patient with atypical benign partial epilepsy whose NM was completely suppressed with ethosuximide. METHODS: Polygraphic recordings of whole-head type magnetoencephalography (MEG), EEG and electromyography were made during NM of the bilateral hands. The silent period of 200-400 ms duration in the bilateral biceps muscles was associated with paroxysmal spikes on EEG and MEG. Single equivalent current dipoles (ECD) were calculated for each spike component associated with NM and the estimated generator sources of spikes were superimposed on the patient's head MRI. RESULTS: The magnetic fields of each peak associated with NM showed clear single dipole pattern and ECDs of each peak were located in the neck and orofacial division of the primary motor cortex. CONCLUSIONS: Abnormal firing of the neck and orofacial division of the primary motor cortex was associated with NM generation. Taking the beneficial effect of ethosuximide (a T-type Ca2+ channel blocker in thalamic neurons and the corresponding cortex) and the MEG result together, it is suggested that abnormal interaction of the thalamo-cortical network might be closely related to the pathogenesis of NM.

Anticonvulsants↗

PubMed2004

Severe gastrointestinal dysmotility in a patient with congenital myopathy: causal relationship to decrease of interstitial cells of Cajal.

Interstitial cells of Cajal (ICC) are known to be essential regulators of gastrointestinal (GI) motility. Here, we report the clinical course and abnormalities of intestinal ICC distribution in a 5-year-old patient with congenital fiber type disproportion myopathy who demonstrated long-term GI dismotility. Full thickness biopsies of the small intestine and colon showed a normal enteric muscle layer and myenteric plexus. However, the density of ICC was strikingly decreased around the myenteric plexus compared to that in autopsied cases without GI tract disease. These findings suggest that a decline in ICC may contribute to disturbed GI motility in our patient with congenital myopathy.

Child, Preschool↗

PubMed2004

N100m in adults possessing absolute pitch.

We recorded the auditory evoked magnetic fields from adults with and without absolute pitch under the following conditions: hearing 1000 Hz pure tones inattentively (single tone session) and listening to eight random tones and identifying each tone (labeling session). In the adults with absolute pitch, the bilateral N100m dipole moments increased significantly in the labeling session. While, in the adults without absolute pitch, the left N100m dipole moment alone increased in the labeling session. These results suggest that the adults with absolute pitch execute the labeling task in the bilateral auditory cortices with interhemispheric cooperation, which does not operate in the adults without absolute pitch.

Adult↗

PubMed2004

Children are sensitive to averted eyes at the earliest stage of gaze processing.

Event-related responses to a face with forward gaze or averted gaze (gaze task) and two equiluminous mosaic images (mosaic task) were recorded from healthy children aged 8-12 years and adults, using MEG and EEG. In children, a clear occipito-temporal magnetic field activity (P1m, around 140 ms) was observed bilaterally, and the right P1m amplitude was increased when viewing a face with averted gaze compared with that when viewing a face with forward gaze. This effect was not observed in adults. Furthermore, the source for the right P1m in children in the gaze task was mainly located around the putative human MT/V5 area. These data suggest that the early occipito-temporal brain response observed as the P1m is a gaze-sensitive component in children.

Adult↗

PubMed2004

Alterations of fatty acid metabolism and membrane fluidity in peroxisome-defective mutant ZP102 cells.

We investigated lipid composition and FA metabolism in Chinese hamster ovary CHO-K1) cells and Pex5-mutated CHO-K1 (ZP102) cells to clarify the biochemical bases of peroxisome biogenesis disorders (PBD). ZP102 cells have defective peroxisomes and exhibit impairments of peroxisomal beta-oxidation of FA and plasmalogen biosynthesis. In addition, we identified FA metabolic alterations in the synthesis of several classes of lipids in ZP102 cells. The concentration of FFA in ZP102 cells was twice that in CHO-K1 cells, but methyl esters and TAG were decreased in ZP102 cells in comparison with control cells. Also, ceramide monohexoside (CMH) concentration with ZP102 cells was significantly increased compared with the control cells. The FA molecular species, particularly the saturated to unsaturated ratios, of individual lipids also differed between the two cell types. The rate of incorporation of [14C]-labeled saturated acids into sphingomyelin (SM) and CMH in ZP102 cells was higher than that in CHO-K1 cells. Lignoceric acid incorporated into cells was predominantly utilized for the synthesis of SM at 24 h after removal of [14C]lignoceric acid from the culture medium. ZP102 cells showed higher fluorescence anisotropy of 1,3,5-diphenylhexatriene, corresponding to lower membrane mobility than in CHO-K1 cells. In particular, alteration of lipid metabolism by a Pex5 mutation enhanced metabolism of saturated FA and sphingolipids. This may be related to the reduced membrane fluidity of ZP102 cells, which has been implicated in the dysfunction of membrane-linked processes in PBD.

Animals↗

PubMed2004

Beneficial effect of L-arginine for stroke-like episode in MELAS.

We here reported the clinical course and therapeutic details of a 16-year-old girl with mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) who had had five stroke-like episodes (two episodes were clinically mild, while the three subsequent episodes were severe). Among the three episodes, the symptoms improved earliest and magnetic resonance spectroscopy abnormality was minimal when given L-arginine in addition to prednisolone, glycerol and edalavone. L-arginine administration during the acute phase of MELAS might be a potential therapy to reduce brain damage due to mitochondrial dysfunction.

Adolescent↗

PubMed2004

A magnetoencephalographic study of astatic seizure in myoclonic astatic epilepsy.

To study the pathophysiologic mechanism of astatic seizures in a patient with myoclonic astatic epilepsy of early childhood, ictal magnetoencephalography was recorded and the neuronal pathway involved was analyzed. The patient was a 12-year-old female who developed myoclonic and astatic seizures including nodding and sudden falling at the age of 4. The current source of spikes during nodding attacks was located in the bilateral frontal area with left predominance, possibly in the premotor cortex. Although we could not claim, on the basis of our findings, that myoclonic astatic epilepsy of early childhood is a type of focal epilepsy, it seems likely that the premotor cortex might be more excitable than other areas. Thus we speculate that the functionally altered premotor-reticulospinal tract which normally controls postural adjustment might play an important role in the generation of myoclonic astatic seizures. Furthermore, the underlying mechanism in the brainstem seems to be common, at least in part, for infantile spasms when considering the efficacy of synthetic adrenocorticotropic hormone for nodding seizures.

Child↗

PubMed2004

Patients with benign rolandic epilepsy have a longer duration of somatosensory evoked high-frequency oscillations.

BACKGROUND: High-frequency oscillations (HFO) ranging between 300-900 Hz have been shown to be superimposed on an early component of somatosensory evoked potentials (SEP) to median nerve stimulation in humans. Although the HFO are speculated to be a localized activity of the GABAergic inhibitory interneurons, the significance in the epileptogenicity remains unclear. The authors of this study analyzed HFO using magnetoencephalography in patients with benign rolandic epilepsy (BRE) to clarify the neurophysio-logical basis of rolandic discharges (RD). METHODS: Nine patients with BRE and six patients with other epileptic syndrome (non-BRE) participated in the study. Somatosensory evoked fields (SEF) including HFO to median nerve stimulation were measured in a magnetically shielded room with a 37-channel neuromagnetometer. RESULTS: Two kinds of HFO, 300 Hz- and 600 Hz-HFO, were identified and the duration of the HFO in patients with BRE was significantly longer than that in patients with non-BRE. CONCLUSIONS: The results suggest that the longer part of HFO (P30m-related) is closely related to the pathogenesis of RD and that the longer HFO in patients with BRE might be mediated by altered GABAergic inhibition modulated by the cholinergic system.

Adolescent↗

PubMed2004

Magnetoencephalographic analysis of rolandic discharges in a patient with rolandic epilepsy associated with oromotor deficits.

The purpose of this study was to clarify the neurophysiologic basis of oromotor deficits in a patient with atypical rolandic epilepsy. We investigated magnetoencephalographic analysis of rolandic discharges with right predominance before and during clonazepam therapy. Before clonazepam administration, current sources of rolandic discharges were broadly distributed in the secondary sensory cortex, superior temporal gyrus, and parietal association area in addition to hand and orofacial division of the primary somatosensory cortex. During clonazepam therapy, oromotor deficits were improved, along with a decrease in rolandic discharge, and current sources of residual right-sided rolandic discharges were shifted to the right superior parietal lobule. Taking the clinical course and magnetoencephalographic findings together, the distributed rolandic discharge focus might be closely related to oromotor deficits, and clonazepam was effective for the disorder.

Anticonvulsants↗

PubMed2003

N100m in children possessing absolute pitch.

We recorded the auditory evoked magnetic fields from children with and without absolute pitch under the following conditions: (a) hearing 1000 Hz pure tones inattentively, (b) hearing eight random tones inattentively and (c) listening to eight random tones and identifying each tone. We calculated the appearance rate of N100m as the ratio of the subjects who had N100m. There was a significant positive correlation between the appearance rate of N100m and age in both groups. There was also a significant positive correlation between the appearance rate of N100m and the kinds of the task only in children without absolute pitch. These results suggest that, in the children with absolute pitch, N100m was elicited equally in every session because of their automatically driven auditory attention. No significant correlation was found between the appearance rate of N100m and the possession of absolute pitch.

Acoustic Stimulation↗

PubMed2003

High-dose immunoglobulin therapy for Guillain-Barré syndrome in Japanese children.

BACKGROUND: Guillain-Barré syndrome (GBS) is an acute acquired demyelinating polyneuropathy, presumed to be immune-mediated. Intravenous immunoglobulin (IVIg) has been used to treat GBS and was found to be effective. However, a well-controlled study of pediatric GBS has not been conducted in Japan. Therefore, to evaluate the efficacy of IVIg in the treatment of GBS, an open-labeled study was performed in pediatric patients. METHODS: Participants in the study were required to be younger than 15 years old, and diagnosed as having moderate or severe GBS. IVIg (400 mg/kg per day) was administered to patients for five consecutive days. Predefined outcome measures were defined on a seven-point scale of motor function (Hughes' functional grade [FG]). RESULTS: Eleven patients were treated with IVIg. The median time taken to improve by one grade on the FG scale was 10.0 days after initial treatment. Two weeks after initial treatment, 72.7% of patients treated with IVIg improved by one or more grades, and 36.4% improved by two or more grades, measured on the FG scale. After 4 weeks an improvement by one or more grades was observed in 81.8% of patients, and two or more grades in 63.6% of patients. These improvement rates were markedly greater than would occur with the natural course of GBS1. Adverse events (subjective symptoms or abnormal laboratory findings) were observed in four patients, although all were temporary and mild. CONCLUSIONS: The authors conclude that IVIg is a safe and effective treatment for childhood GBS, which shortens the time to recovery.

Child↗

PubMed2002

People with absolute pitch process tones with producing P300.

We recorded a P300 component of event-related potentials associated with auditory oddball tasks in nine absolute pitch (AP) possessors and seven non-AP possessors. The previous studies demonstrated that AP possessors did not appear to employ working memory during auditory oddball tasks because they have a fixed tonal template in their memories. However, the present findings showed that the AP possessors exhibited similar P300 as the non-AP possessors and did update the tonal context in the auditory oddball tasks. This result suggests that the AP possessors do not always refer to the fixed tonal template in their memories when executing the oddball tasks and they employ working memory properly according to the difficulty of the auditory tasks.

Adult↗

PubMed2002

Efficacy and safety of immunization for pre- and post- liver transplant children.

BACKGROUND: Infection is a serious complication after liver transplantation. Immunization is one means of controlling infections. The objective of this study was to investigate the efficacy and safety of simultaneous administration of several vaccines before transplantation and the efficacy and safety of administration under immunosuppressive conditions after transplantation. METHODS: Fifty-eight patients who underwent living-related liver transplantation between April 1994 and March 2000 were included in this study. Simultaneous administration of a maximum of six vaccines was performed in a short period of time before transplantation. We also readministered vaccines to 15 patients with waning antibody titers after transplantation from June 1999. We investigated whether patients could seroconvert for measles, rubella, mumps, and varicella after immunization and how long antibody titers could be retained by measuring them several times throughout the period before and after transplantation. We also examined side effects caused by immunization. RESULTS: The rates of seroconversion against measles, rubella, mumps, and varicella after the pretransplantation vaccination were 82%, 100%, 90%, and 95%, respectively. The rates of reseroconversion against measles, rubella, mumps, and varicella after the posttransplantation revaccination were 85%, 100%, 100%, and 71%, respectively. Although antibody titers against these viruses generally waned with time, no patient exhibited any serious illness or side effects. CONCLUSION: Although 12 of 58 patients (21%) had an infection, pretransplantation immunization was effective to prevent serious illness, especially for the 6 months after transplantation. Posttransplantation live-vaccine administration under immunosuppressive conditions is effective and safe.

Adolescent↗