Biomedical subjects

Masaya Kubota

Publications and source records attributed to Masaya Kubota.

17 recordsLinked to original sources

PubMed2006

A case of Panayiotopoulos syndrome showing an atypical course.

We describe herein a patient with Panayiotopoulos syndrome (PS) showing an atypical course. The patient initially had seizures typical of this syndrome from 3 to 5 years of age. EEG showed right occipital high-amplitude sharp and slow-wave complexes followed by brief generalized discharges of slow waves. Sequential EEGs obtained from 5 to 11 years of age showed both multifocal discharges and generalized spike and wave complexes. With these changes in EEG findings, the patient experienced various types of seizures. The seizures were frequent and showed oculocephalic deviation followed by absence, atonic seizures, generalized tonic clonic convulsions and clonic seizures of the eyelids, which were observed between 7 and 10 years of age. Antiepileptic drugs were only partially effective for these seizures. Ictal EEG recorded at 8 years of age revealed high-voltage slow waves from the bilateral frontal and occipital regions prior to diffuse high-amplitude spike-wave bursts. At 9 years of age, magnetoencephalography (MEG) revealed the calculated dipoles of the preceding bifrontal spike-wave discharges to be in the frontal areas, while those of the following generalized spike-wave bursts were in the bilateral mid-temporal areas. In PS, reportedly, dipoles of multifocal epileptic discharges are usually located in the occipital and Rolandic areas. The unique clinical evolution in our case may be associated with the unusual frontal localization of dipoles detected by MEG.

Anticonvulsants↗

PubMed2006

Clinical analysis of gastroesophageal reflux after PEG.

BACKGROUND: It is difficult to predict whether or not gastroesophageal reflux (GER), such as aspiration or vomiting, will occur after PEG. OBJECTIVE: To identify factors that would support the prediction of aspiration after PEG. DESIGN: Case-control study. SETTING: Patients who underwent PEG from February 1998 to June 2005 in our hospital. PATIENTS: The study included 178 patients. INTERVENTIONS: Endoscopic observation was carried out during PEG tube placement and at PEG tube replacement to determine the presence of hiatus hernia and/or reflux esophagitis. MAIN OUTCOME MEASUREMENTS: Gastric emptying and GER index (GERI) were measured by using a radioisotope technique. RESULTS: The patients were divided into 2 groups: the non-GER (NGER) group (n = 108), who had no symptoms of GER, and the GER group (n = 70), who showed these symptoms. No significant differences were observed between the groups in age, sex, morbidity, the presence of reflux esophagitis at PEG tube placement, gastric emptying, or serum albumin levels. The presence of a hiatus hernia (P = .028) and reflux esophagitis grading Los Angeles classification C or D (P = .008) were significantly more frequent in the GER group compared with the NGER group. The GERI was also significantly higher in the GER group than in the NGER group (P < .0001). CONCLUSIONS: The presence of hiatus hernia, severe reflux esophagitis, and a high GERI might be predictive factors of aspiration or vomiting after PEG tube placement.

Aged↗

PubMed2006

[Setting up of a day group service system for severely disabled children, the "Koala Club"].

This is a report of the setting up of a day group service system for severely disabled children, the "Koala Club". The "Koala Club" was started in 1993, and has been running outside of the hospital since 1997. A support group for the "Koala Club" was established in 1999. Currently 13 children attend the "Koala Club". The staff of the "Koala Club" consists of one coordinater, four nurses and eight care workers. The medical care is fulfilled by nurses. The "Koala Club" open two days a week. It has been supervised by a doctor and a case worker. There is an important role for physicians in the regional care of disabled children.

Adolescent↗

PubMed2006

[High-dose phenobarbital therapy is effective for the control of intractable tonic seizure with apnea in a case of multiple anomalies syndrome].

An 11-month-old boy with multiple surface anomalies and respiratory distress due to upper airway narrowing developed generalized tonic seizures coinciding with apnea. The ictal electroencephalography showed an abrupt onset of right-sided unilateral rapid activity with increasing amplitude followed by bursts of spike and wave complexes. The seizures were completely controlled with non-intravenous high-dose phenobarbital therapy. The serum level of phenobarbital at seizure control was 8 microg/ml. The serum level of phenobarbital peaked as high as 123 microg/ml; the patient developed neither liver function abnormality nor hypotension which necessitated any pressor agents. Although the patient was intubated, spontaneous respiration was intact after seizure control. Extubation, however, failed twice because of diminished cough reflex. After decrease of the phenobarbital dose and the development of drug tolerance, the patient was successfully weaned from respiratory support. High-dose phenobarbital therapy is effective for refractory epilepsy in patients complicated by respiratory distress. Although it was reported that respiratory depression was not severe with high-dose phenobarbital therapy, respiratory status may worsen in such patients due to the diminished cough reflex. Therefore the careful and prolonged management is essential.

Abnormalities, Multiple↗

PubMed2005

Increased right auditory cortex activity in absolute pitch possessors.

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

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↗

PubMed2004

[Dramatic improvement of urinary retention and the left lower limb paresis with methylprednisolone in a case of regional encephalitis following varicella zoster infection].

We report a previously well 14-year-old male who developed left-sided hemiconvulsion, urinary retention and hemiplegia 1 months after varicella-zoster virus (VZV) infection. Brain T2-weighted MRI showed hyperintensity in medial fronto-parietal area including cyngulate gyrus, foot division of the motor cortex, para-central lobule and corpus callosum with right predominance, which corresponded to hyperperfusion area in SPECT study. MR angiography revealed no occlusion or narrowing of vessels. Cerebrospinal fluid (CSF) showed mononuclear pleocytosis. After methylprednisolone pulse tharapy under diagnosis of regional encephalitis, the patient recovered completely. Although polymerase chain reaction(PCR) could not detect VZV-DNA in CSF, antecedent VZV infection might be closely related to pathomechanism of the regional encephalitis. Dramatic response to steroid, rapid recovery on MRI and good prognosis supported that the underlying pathology was mainly vasogenic edema rather than cytotoxic edema.

Adolescent↗

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↗

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

[A case of focal epilepsy associated with focal cortical dysplasia and crossed cerebellar diaschisis].

We here reported a 24-year-old woman who presented complex partial seizure from 15 years of age. Her brain MRI showed the right perirolandic focal cortical dysplasia (FCD) corresponding to the orofacial division of the primary sensori-motor area. On SPECT (Tc-99 mECD) study, hypoperfusion was demonstrated at the FCD, the right pons and the left cerebellum (crossed cerebellar diaschisis (CCD)). Magnetoencephalography disclosed the current source of the focal spikes was localized on the FCD. To our knowledge, no previous report of a case associated with FCD and CCD was found. We speculated the pathomechanism of the CCD might be related to the persistent epileptogenic firing which inhibited the cerebellar metabolism transsynaptically through cortico (FCD)-ponto-cerebellar pathway.

Adult↗