Biomedical subjects

Makio Oka

Publications and source records attributed to Makio Oka.

14 recordsLinked to original sources

PubMed2006

Epilepsy development in infancy with epileptic discharges.

As a part of the study to prevent West syndrome (WS) by early treatment, we assessed what kind of epilepsy developed in infants who showed epileptic discharges in early infancy. EEG examinations were performed on 116 infants born from 1997 to September 2004, both before and after 3 months of corrected age (CA). We divided 45 infants who showed epileptic discharges in early infancy into two groups according to the existence of periventricular leukomalacia (PVL) and retrospectively performed the course observation at the survey point on April 1 in 2005. Out of 45 infants showing epileptic discharges in early infancy, 26 developed WS. Compared with infants without PVL, infants with PVL were more likely to develop WS than infants without PVL. Furthermore, infants with PVL were more likely to develop WS than other types of epilepsy. Namely, 11 out of 17 infants with PVL developed WS at the survey point. All infants with WS showed initial epileptic discharges before 5 months of corrected age (CA), and most of them (except for five) had initial epileptic discharges before 3 months of CA. There were two infants who once developed hypsarrhythmia on EEG; however, after starting VPA therapy, they did not develop WS with the improvement of EEG findings, and one was presented here in detail. We proposed that preterm infants with PVL who showed epileptic discharges before 3 months of CA should be treated by antiepileptic drugs to prevent the onset of WS syndrome.

Age Factors↗

PubMed2006

A population-based survey of childhood epilepsy in Okayama Prefecture, Japan: reclassification by a newly proposed diagnostic scheme of epilepsies in 2001.

The purpose of this study is to clarify the usefulness and problems of the newly proposed classification of epilepsies (International League Against Epilepsy: ILAE, 2001) in the epidemiological studies of epilepsy. We previously conducted an epidemiological study in Okayama Prefecture, Japan, in 1999, using the ILAE 1989 classification. Among 250,997 children under 13 years of age, 2220 epileptic patients were ascertained. In this study, we reclassified them according to the ILAE 2001 classification, focusing on axes 2 (seizure types) and 3 (syndromes). We were able to classify 1803 (95.0%) seizure types out of 1899 with detailed clinical information. In focal seizures, the most common were secondarily generalized seizures (88.6%), which generally do not represent a unique anatomic substrate. In generalized seizures, topic-clonic seizures (40.7%) and spasms (21.0%) were the most common. We identified only 269 (12.1%) patients with specific epilepsy syndromes out of the 2220. We classified 1761 patients without specific syndromic diagnoses only by axis 2, but the new concept of epileptic seizure types, representing a unique pathophysiologic mechanism and anatomic substrate, was not very meaningful in most cases, even in those with focal seizures.

Child↗

PubMed2006

Diagnostic issues and treatment of cryptogenic or symptomatic generalized epilepsies.

To clarify the diagnostic issues and treatment of patients with cryptogenic or symptomatic generalized epilepsies, not including West syndrome (WS), we investigated electroclinical change during the clinical course, and treatment effects in these patients. The selection criteria were minor generalized seizures as their main seizure type and diffuse epileptic discharges as their main EEG findings. Regarding EEG, we included EEGs that predominantly displayed multifocal spike-waves because of the inclusion of severe epilepsy with multiple independent spike foci (SE-MISF). We divided the subjects into two groups according to their main seizure types: Group A (54 patients) with brief tonic seizures and Group B (24 patients) with myoclonic seizures and/or atypical absences. The main epileptic syndromes were considered to be Lennox-Gastaut syndrome and SE-MISF in Group A, and epilepsy with myoclonic-astatic seizures in Group B. A history of WS was often seen in Group A, but it was exceptional in Group B. During the clinical course, seizure types did not basically change in Group A. EEG patterns were changeable in both groups. Although there was some overlap in electroclinical manifestations among epileptic syndromes, a transition between the two groups was not seen. High-dose valproate and ethosuximide were the most effective in Groups A and B, respectively. Long-term prognosis was significantly more favorable in Group B than in Group A.

Adolescent↗

PubMed2006

A developmental study of scores of the Boston Qualitative Scoring System.

To elucidate developmental changes of the Summary Scores of the Boston Qualitative Scoring System (BQSS) for the Rey-Osterrieth Complex Figure (ROCF). One hundred healthy children aged 6-16 (average 9.7 +/- 2.4; 60 boys, 40 girls). The ROCF was administered and graded based on the BQSS. The subjects were classified in four age-groups: 6- and 7-year-olds; 8- and 9-year-olds; 10- and 11-year-olds; and 12- and 16-year-olds. The differences in Summary Scores were examined among age-groups. All BQSS Summary Scores except Delayed Retention showed clear developmental changes. The Copy Presence Accuracy, the Immediate Presence Accuracy, the Delayed Presence Accuracy, and the Immediate Retention showed continuous development throughout childhood, though some differences were noted in the age ranges during which each score showed the most rapid development. The Organization score showed a somewhat peculiar pattern, with rapid development during the age ranges of 8-9 and 10-11 and with no distinctive development before and after these ranges. Five of the six BQSS Summary Scores showed clear developmental changes with a different developmental pattern in each score. Especially, the Organization score was unique and was supposed to reflect a different underlying process than the other Summary Scores, which might relate to the local and global processing style. BQSS is a promising tool for the evaluation of higher brain functions in childhood.

Adolescent↗

PubMed2006

Are pervasive developmental disorders and attention-deficit/hyperactivity disorder distinct disorders?

We studied the relationship between patients with attention-deficit/hyperactivity disorder (ADHD) and those with pervasive developmental disorders (PDD), using the High-Functioning Autism Spectrum Screening Questionnaire (ASSQ) and ADHD Rating Scale-IV. The ASSQ scores of the PDD group and the ADHD group were significantly higher than the control group. Furthermore, the PDD group scored higher than the ADHD group. Both groups also showed higher scores than the control group in all three domains, that is, restricted and repetitive behavior, social interaction, and communication problem. The PDD and the ADHD group showed no significant difference in the domains of communication problem, and restricted and repetitive behavior. The PDD group had a higher score than the ADHD group only in the social interaction domain. In total score, inattention score, and hyperactivity/impulsivity score on the ADHD Rating Scale-IV, both groups were significantly higher than the control group. Between the ADHD and the PDD groups, there was no significant difference in the three scores. The patients with strictly diagnosed ADHD had many PDD-related symptoms, and the patients with PDD had many ADHD-related symptoms. It therefore seems difficult to make a distinction between ADHD and PDD by using the present diagnostic criteria in the DSM-IV. We should evaluate each patient in terms of both sets of criteria.

Adolescent↗

PubMed2006

Treatment of epilepsy with electrical status epilepticus during slow sleep and its related disorders.

To elucidate an effective therapeutic strategy for 'ESES syndrome', epilepsy with electrical status epilepticus during slow sleep (ESES) and its related epileptic disorders, we studied the effect of treatment on the EEG pattern of continuous spike-waves during slow wave sleep (CSWS) in 15 afflicted patients. Basically performed in the following order, the employed therapies included (1) high-dose valproate (VPA) therapy (serum level >100 microg/ml); (2) a combination therapy of VPA and ethosuximide (ESM); (3) short cycles of high-dose diazepam (oral or intrarectal DZP, 0.5-1 mg/kg per day for 6-7 days); and (4) intramuscular synthetic ACTH-Z therapy (0.01-0.04 mg/kg per day for 11-43 days). Regarding the initial EEG effect, a remission of CSWS was achieved by high-dose VPA therapy in 7 of 15 trials (47%), by the combination therapy of VPA and ESM in 3/7 trials (43%), by short cycles of high-dose DZP in 2/4 trials (50%), and by ACTH-Z therapy in 2/5 trials (40%). A permanent remission of ESES syndrome was achieved by high-dose VPA therapy and/or combination therapy of VPA and ESM in 10 patients (67%). The effects of short cycles of high-dose DZP and ACTH-Z therapy were at best temporary. Our strategy for the treatment of ESES syndrome is therefore considered valid.

Adolescent↗

PubMed2006

EEG dipole characteristics in Panayiotopoulos syndrome.

PURPOSE: Panayiotopoulos syndrome (PS) is a type of benign childhood partial epilepsy that is frequently associated with abundant multifocal spikes other than main occipital spikes on the EEG. In this study, we investigated the characteristic features of dipoles in PS. METHODS: We performed dipole analysis of the interictal occipital spike discharges seen in 10 children with PS (group A) and in 10 children with other types of symptomatic localization-related epilepsy (group B). We analyzed the dipoles of the averaged spike in each patient. RESULTS: In group A, the averaged occipital spikes in each patient showed dense dipole locations in the mesial occipital area; in group B, widely scattered dipole locations were observed. In Group A, the geometric centers of the dipoles at each time point (such as at the main negative peak and before or after the main peak) were estimated in the neighboring locations. In contrast, they tended to be scattered in group B. CONCLUSIONS: Our study reveals that PS has high dipole stability, similar to that of rolandic epilepsy. From the electroencephalographic view, this seems to indicate a close link between these two syndromes.

Adolescent↗

PubMed2006

EEG and seizure exacerbation induced by carbamazepine in Panayiotopoulos syndrome.

We report on a 4-year 8-month-old boy with Panayiotopoulos syndrome who showed atypical evolution with newly developed absence seizures and EEG exacerbation induced by carbamazepine. Soon after the introduction of carbamazepine, EEGs began to worsen, and finally absence seizures and myoclonic seizures appeared. Immediately after we discontinued carbamazepine, the seizures disappeared and the EEG improved. Carbamazepine may induce unusual electroclinical features, electrophysiologically explained by bilateral synchrony. This case provides more evidence of the close links between Panayiotopoulos syndrome and benign childhood epilepsy with centrotemporal spikes.

Anticonvulsants↗

PubMed2006

[A case of benign neonatal sleep myoclonus].

We report on a male infant with benign neonatal sleep myoclonus (BNSM). At 12 days of age, he began to have frequent myoclonic jerks in the lower and/or upper extremities during sleep. Myoclonic jerks appeared bilaterally/synchronously and persisted for several minutes to 10 minutes. Both interictal and ictal EEG findings were normal. During follow-up, the patient did not take any medication, and his myoclonic jerks gradually decreased. They completely disappeared at 50 days of age. The patient's development was normal. BNSM is a benign disorder and myoclonic jerks generally disappear without medication. Early diagnosis is important to avoid unnecessary treatment. EEG-EMG recording is useful for diagnosis.

Electroencephalography↗

PubMed2005

Characteristics of slow waves on EEG associated with epileptic spasms.

PURPOSE: The high-voltage slow waves (HVSs) on EEG associated with epileptic spasms were investigated to clarify their characteristics and their relation to the pathophysiology of spasms in West syndrome and related disorders. METHODS: In 14 patients, digitally recorded EEG segments showing the ictal HVSs were extracted and their traces were overlaid by using an average reference. The ictal HVSs were also averaged to build maps for investigation of the pattern of potential distribution over the scalp. RESULTS: In a total of 685 recorded spasms, 346 (50.5%) with minimal artifacts were selected to demonstrate that the ictal HVSs had a largely consistent waveform and distribution in each patient. The ictal HVSs were symmetrical in 10 patients and asymmetrical in the other four, and were relatively negative over the posterior region and positive over the frontal or temporal regions in 11 patients. Two symptomatic patients showed a marked deviation of the distribution of HVSs to the pathologically more involved hemisphere. An infant with Aicardi syndrome had two different types of spasms, each type showing a consistent pattern of HVSs with a lateralized distribution. CONCLUSIONS: The patterns of distribution of the ictal HVS may be related to the abnormal activation of the brain in the generation of spasms.

Brain↗

PubMed2004

A study of spike-density on EEG in West syndrome.

To elucidate the pathophysiology of spasms in series, the distribution and density of spikes on hypsarrhythmia were studied in 13 patients with West syndrome by excluding slow waves from EEG using a digital filter. (1) Interictal spikes were mostly multifocal and dominant over the bilateral posterior head area with very few diffuse discharges. Therefore, spikes on hypsarrhythmia were demonstrated to occur actually depending on the brain regions although they appeared random. (2) The dominant region of interictal spikes did not correspond to the underlying focal cortical lesion in many patients, and was indicated to reflect the general process of cerebral maturation in infancy. (3) There were far fewer inter-spasm spikes, especially during the middle phase of a series of spasms, than interictal spikes. It was implied that the cortical activity of hypsarrhythmia was interfered with by the abnormal subcortical function, which might be related to the generation of spasms. (4) The dominant region of inter-spasm spikes tended to coincide with a focal cortical lesion shown by MRI and the focus of associated partial seizures.

Action Potentials↗

PubMed2004

Very fast rhythmic activity on scalp EEG associated with epileptic spasms.

PURPOSE: Very fast activity was investigated on the ictal EEGs of epileptic spasms to elucidate the pathophysiology of West syndrome (WS) and related disorders from a novel point of view. METHODS: The traces of scalp ictal EEG of spasms temporally were expanded in 11 patients whose clinical diagnosis was symptomatic WS in six, cryptogenic WS in two, Aicardi syndrome in one, and symptomatic generalized epilepsy after WS in the remaining two. Time evolution of averaged power spectra of the ictal fast activity also was analyzed in each patient. RESULTS: Rhythmic gamma activity with frequency ranging from 50 to 100 Hz was detected in a total of 345 of 537 spasms. Fast activity was seen bilaterally in nine patients, was lateralized to one hemisphere in another, and appeared independently on each hemisphere in the remaining infant with Aicardi syndrome. Power spectra showed a clear peak corresponding to spasm-associated gamma rhythm, with frequency centering approximately 65 Hz and ranging from 51 to 98 Hz. The morphology and spectral characteristics of ictal gamma rhythm were completely different from those of muscle activity or alternating current (AC) artifacts. CONCLUSIONS: Spasm-associated gamma activity was clearly detected on the scalp. This observation may provide a clue to the pathophysiology of spasms.

Cerebral Cortex↗

PubMed2003

Different attenuated phenotypes of GM2 gangliosidosis variant B in Japanese patients with HEXA mutations at codon 499, and five novel mutations responsible for infantile acute form.

Eight mutations of the alpha subunit of beta-hexosaminidase A gene ( HEXA) were identified in eight patients with GM2 gangliosidosis variant B. They were five missense mutations, two splice-site mutations, and one two-base deletion. Five of them, R252L (CGT-->CTT), N295S (AAT-->AAC), W420C (TGG-->TGT), IVS 13, +2A-->C, and del 265-266AC (exon 2), were novel mutations responsible for infantile acute form of GM2 gangliosidosis. Two missense mutations, R499H and R499C, were found in one allele of two patients with attenuated phenotypes. The patient with R499C showed a late infantile form, and the other patient with R499H showed a juvenile form. These two mutations have been reported previously in the patients of other ethnic groups, and they have been known to cause attenuated phenotypes. The milder phenotypes of GM2 gangliosidosis variant B, different from the infantile acute form, have not been reported so far in Japan, and this is the first report of Japanese patients with attenuated phenotypes and their molecular analysis.

Acute Disease↗

PubMed2003

A simulation study of the error in dipole source localization for EEG spikes with a realistic head model.

OBJECTIVE: We tried to determine the error range of dipole modeling for EEG spikes originating from various clinically important sources by a simulation study employing a realistic head model. The computed error range was also compared with the degree of disturbance of dipole modeling caused by adding background activity to the spike. METHODS: The scalp fields generated by temporal, frontal and rolandic epileptic sources with spatial extent were simulated, and the corresponding 3-dimensional maps of residual variance (RV) were built by computing the RV for a single dipole at each point on a fine imaginary grid in the brain. Single dipole modeling was also performed for the simulated scalp fields after adding real background activity. RESULTS: The brain volume corresponding to a small RV was compact for the frontal sources and the lateral and baso-mesial temporal sources, and large for the anterior and baso-lateral temporal sources. The distribution of dipoles estimated for spikes contaminated with background corresponded to that of the volume of small RV and to spike-amplitude. Estimates were improved by employing inferior temporal electrodes. CONCLUSIONS: When evaluating dipole models of epileptic spikes, error ranges can be estimated and they vary considerably from region to region. SIGNIFICANCE: This study illustrates the variability of the error in dipole modeling of epileptic spikes. This variability is important when considering the clinical interpretation of modeling results.

Brain Mapping↗