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Biomedical subjects

Hirokazu Oguni

Publications and source records attributed to Hirokazu Oguni.

At least 19 recordsLinked to original sources
PubMed2006

Panayiotopoulos syndrome: a consensus view.

The aim of this paper is to promote the correct classification of, and provide guidelines on, the diagnosis and management of Panayiotopoulos syndrome (PS). An international consortium of established researchers in the field collaborated to produce a consensus document. The resulting document defines PS, characterizes its electro-clinical features, considers its likely pathogenesis, and provides guidance on appropriate management. We conclude that PS is a common idiopathic, benign seizure disorder of childhood, which should be classified as an autonomic epilepsy, rather than an occipital epilepsy.

Child↗
PubMed2006

Hypothalamic hamartoma associated with anterior paraclinoid aneurysm of the internal carotid artery.

A 15-year-old boy presented with a history of medically refractory gelastic seizures and cognitive impairments. Neuroimaging demonstrated a sessile type hypothalamic hamartoma, which was treated by gamma knife surgery. However, the gelastic seizures only partially decreased and the frequency of seizures remained unchanged. One year later, angiography before surgery detected anterior paraclinoid aneurysm of the left internal carotid artery. Blood pressure and endocrinological examinations showed no abnormality. Direct surgery was performed to treat the aneurysm and hamartoma. No sclerotic changes were noted in the arterial wall. The aneurysm was treated with clipping, and the hamartoma was partially removed. Postoperative course was uneventful and the gelastic seizures disappeared. No evidence for a causal relationship between the hamartoma and aneurysm was found.

Adolescent↗
PubMed2005

Extremely low-dose ACTH step-up protocol for West syndrome: maximum therapeutic effect with minimal side effects.

We studied the effectiveness of our new ACTH treatment strategy for West syndrome (WS), which was based on the results of our previous extremely low-dose ACTH study. The subjects were 31 infants with WS (cryptogenic WS in nine; symptomatic WS in 22). Synthetic ACTH-Z in a dose of 0.005 mg (= 0.2 IU)/kg/day was injected once every morning for at least 2 weeks, up to a maximum of 3 weeks. When this first treatment course achieved full seizure and EEG control, ACTH was tapered to zero over the subsequent 1 or 2 weeks. In the absence of a documented response, the dosage was increased to 0.025 mg (= 1.0 IU)/kg/day for the next 2 weeks (second treatment course). We analyzed the short-term as well as long-term effects, and the incidence of side effects. The first treatment course successfully controlled both spasms and hypsarrhythmia in 17 patients (55%), only spasms in one, and hypsarrhythmia in two. The second treatment course was then introduced in eight of the remaining 14 patients, providing complete suppression of WS in an additional two patients. Regarding the long-term effects, 13 patients (48%), with excellent short-term results and a longer than 1-year follow-up, remained seizure-free. Side effects of a mild degree were seen in 13 patients during ACTH treatment. Our new ACTH step-up method brought 61 and 48% of the patients into short-term and long-term remission, respectively, without significant side effects. The dose of ACTH required to control WS appears to be unexpectedly smaller than the dose we previously used.

Adrenocorticotropic Hormone↗
PubMed2005

Zonisamide for West syndrome: a comparison of clinical responses among different titration rate.

We administered zonisamide (ZNS) to patients with West syndrome in different titration protocols and compared their short-term therapeutic effects. We designed three protocols to raise the serum ZNS concentration (SZC): (1) increase the dose in three steps, from 3 to 10 mg/kg every 3 days, (2) increase the dose from 5 to 10 mg/kg over 3-7 days, and (3) start with 10 mg/kg and maintain this dosage for 2 weeks. The subjects were 23 infants with West syndrome, 8 of whom comprised the 1st group, 5 the 2nd group, and the remaining 10, the 3rd group. As a result, excellent and good effects were obtained in a total of seven patients (30.4%) and one patient, respectively (1/8 in the 1st step-up group, 3/5 in the 2nd step-up group, and 4/10 in the 3rd group). The maximum SZC was higher in the excellent and good effect groups (n=8; 32.0+/-8.0 microg/ml) than in the ineffective group (n=15; 22.4+/-8.2 microg/ml) (P<0.05). The period of time required for cessation of spasms appeared shorter in the 3rd group (n=4; mean=5.7 days) than in the 1st and 2nd groups (n=4; mean=10.3 days). There were few side effects except for transient hyperthermia and gastrointestinal symptoms. Our new protocol of starting with 10 mg/kg of ZNS can be introduced safely and make a therapeutic judgment feasible within 2 weeks.

Anticonvulsants↗
PubMed2005

Symptomatic epilepsies imitating idiopathic generalized epilepsies.

The diagnosis of idiopathic generalized epilepsies (IGEs) is not generally difficult if one follows the clinical and electroencephalogram (EEG) definitions of each subsyndrome that constitutes IGEs. In contrast, symptomatic epilepsies develop based on organic brain lesions and are easily diagnosed by the presence of developmental delay, neurologic abnormalities, and a characteristic seizure and EEG pattern. However, in clinical practice, it is sometimes difficult to differentiate IGEs from symptomatic epilepsies, especially when the clinical course from the onset of epilepsy is too short to exhibit typical clinical and EEG findings of either epilepsy type, or when patients with symptomatic epilepsies have atypical features that imitate the clinical characteristics of IGEs. The neurodegenerative or metabolic disorders at times start during the clinical course with epileptic seizures and later show typical neurologic abnormalities. The newly recognized metabolic disorder of glucose transporter type 1 deficiency syndrome (Glut-1 DS) may start with myoclonic seizures at an age of less than 1 year and imitate benign myoclonic epilepsy in infancy early in the clinical course. Progressive myoclonus epilepsies (PMEs) that develop at 1-4 years of age at times imitate epilepsy with myoclonic-astatic seizures with respect to the presence of astatic seizures and an epileptic encephalopathic EEG pattern. In addition, young children with focal cortical dysplasia may also have similar clinical and EEG patterns, although the latter may become localized after treatment. Approximately 15% of patients with juvenile myoclonic epilepsy (JME) are resistant to antiepileptic drugs (AEDs) and may require extensive study to make a differential diagnosis from symptomatic epilepsies. PMEs that develop during adolescence may imitate JME early in the clinical course; however, a detailed history and the differentiation between myoclonic seizures and myoclonus would help to distinguish both conditions. The diagnosis of IGEs is very demanding for patients with atypical features with regard to seizure type, EEG findings, and response to appropriate AEDs.

Adolescent↗
PubMed2005

Effect of ACTH therapy for epileptic spasms without hypsarrhythmia.

PURPOSE: We analyzed the short- and long-term effects of adrenocorticotropic hormone (ACTH) therapy for patients with epileptic spasms (ESs) who did not meet the criteria of West syndrome (WS). METHODS: The subjects were 30 patients, including 13 boys and 17 girls, who had received ACTH therapy between 1970 and 2003. We excluded patients with WS, but included those with a history of WS who no longer showed hypsarrhythmia at the period of ACTH therapy. The age at onset of ESs and at ACTH therapy ranged from 2 to 82 months with a median of 18 months, and from 11 to 86 months with a median of 29 months, respectively. RESULTS: Excellent and poor responses were obtained in 19 (63%) and 11 (37%) patients, respectively, as a short-term effect. Although the patients could be subclassified into five subgroups according to the previous reports, no difference was seen in short- term response to ACTH. Among 17 of the 19 patients with excellent short-term outcomes and a follow-up of >1 year after the ACTH therapy, eight patients have continued to be seizure free (29%; excellent long-term effect), whereas the remaining nine patients had a recurrence of seizures (complex partial seizures, four; generalized tonic seizures, three; ESs, two) at 9 months to 198 months (median, 49 months) after ACTH therapy. In addition, nine of the 17 patients demonstrated a localized frontal EEG focus after the ACTH therapy, although most of these had previously shown diffuse epileptic EEG abnormality. CONCLUSIONS: ACTH therapy is worth trying for patients with resistant ESs, even without features of WS. However, the long-term effect is uncertain because recurrences of various types of seizures, including focal, were frequently observed.

Adolescent↗
PubMed2005

[Clinical and electroencephalogram study of 5 children with hypothalamic hamartoma].

We retrospectively studied 5 children with hypothalamic hamartoma (HH) to elucidate the clinical, neuroimaging and electroencephalogram (EEG) characteristics of this disorder. In all cases, high resolution MRI scans demonstrated an intrahypothalamic mass protruding into the 3rd ventricle. An initial symptom was epileptic attack in 4 cases and precocious puberty in the remaining one. Gelastic seizures developed in 4 of 5 patients at ranging from 2 days to 11 years of age. The ictal EEGs during the gelastic seizures showed diffuse attenuation of background activity, followed by rhythmic slow discharges either diffusely or in the central area. Gamma-knife radiosurgery was performed on 2 cases whose seizures were resistant to available antiepileptic drugs. One of the 2 patients was responded significantly to this treatment, showing the disappearance of combined attacks and a marked reduction of the generalized spike-waves discharges. A more aggressive therapy, including gamma-knife radiosurgery and surgical treatment, should be considered for patients whose seizures are resistant to the medical treatment and causing deterioration of intelligence and behavioral problem.

Adolescent↗
PubMed2004

Clinical presentation, EEG studies, and novel mutations in two cases of GLUT1 deficiency syndrome in Japan.

We report the first two Japanese children diagnosed with glucose transporter type 1 (GLUT1) deficiency syndrome. Both boys had been treated under the initial diagnosis of epilepsy and were reinvestigated for previously unexplainable hypoglycorrhachia. Myoclonic seizures developed at 4 months of age in Patient #1 (7 years old), and at 2 months of age in Patient #2 (11 years old), followed by cerebellar ataxia, spastic diplegia, and mental retardation. Both patients had hypoglycorrhachia, and the symptoms were more severe in the latter. CSF and serum glucose levels determined simultaneously showed a CSF/serum glucose ratio of below 0.4 in both patients. In mildly affected Patient #1, the postprandial waking EEG showed improvement in the background activity, as compared to that recorded after overnight fasting, while no significant changes were observed in severely affected Patient #2. In both patients, the functional GLUT1 defect was confirmed by 3-O-methyl-D-glucose uptake into erythrocytes. Molecular analyses identified heterozygous novel mutations in both patients, within exons 6 and 2 of the GLUT1 gene, respectively. The ketogenic diet was refused in Patient #1, but started in Patient #2 with significant clinical benefit. Fasting CSF analysis and pre-/postprandial EEG changes in children with epileptic seizures and unexplainable neurological deterioration help in diagnosing this potentially treatable disorder.

Base Sequence↗
PubMed2004

Mutations in EFHC1 cause juvenile myoclonic epilepsy.

Juvenile myoclonic epilepsy (JME) is the most frequent cause of hereditary grand mal seizures. We previously mapped and narrowed a region associated with JME on chromosome 6p12-p11 (EJM1). Here, we describe a new gene in this region, EFHC1, which encodes a protein with an EF-hand motif. Mutation analyses identified five missense mutations in EFHC1 that cosegregated with epilepsy or EEG polyspike wave in affected members of six unrelated families with JME and did not occur in 382 control individuals. Overexpression of EFHC1 in mouse hippocampal primary culture neurons induced apoptosis that was significantly lowered by the mutations. Apoptosis was specifically suppressed by SNX-482, an antagonist of R-type voltage-dependent Ca(2+) channel (Ca(v)2.3). EFHC1 and Ca(v)2.3 immunomaterials overlapped in mouse brain, and EFHC1 coimmunoprecipitated with the Ca(v)2.3 C terminus. In patch-clamp analysis, EFHC1 specifically increased R-type Ca(2+) currents that were reversed by the mutations associated with JME.

Animals↗
PubMed2004

Mutations of neuronal voltage-gated Na+ channel alpha 1 subunit gene SCN1A in core severe myoclonic epilepsy in infancy (SMEI) and in borderline SMEI (SMEB).

PURPOSE: Severe myoclonic epilepsy in infancy (SMEI) is a distinct epilepsy syndrome. Patients with borderline SMEI (SMEB) are a subgroup with clinical features similar to those of core SMEI but are not necessarily consistent with the accepted diagnostic criteria for core SMEI. The aim of this study was to delineate the genetic correlation between core SMEI and SMEB and to estimate the frequency of mutations in both phenotypes. METHODS: We examined 96 healthy volunteers and 58 unrelated individuals whose clinical features were consistent with either core SMEI (n = 31) or SMEB (n = 27). We screened for genetic abnormalities within exons and their flanking introns of the genes encoding major subunits of the Na+ channels (SCN1A, SCN2A, SCN1B, and SCN2B) by using a direct sequencing method. RESULTS: In both core SMEI and SMEB, various mutations of SCN1A including nonsense and missense mutations were identified, whereas no mutations of SCN2A, SCN1B, and SCN2B were found within the regions examined. All mutations were heterozygous and not found in 192 control chromosomes. Mutations were identified in 26 (44.8%) of the 58 individuals and were more frequent (p < 0.05) in core SMEI (19 of 31) than in SMEB (seven of 27), as assessed by the continuity-adjusted chi2 test. Mutations resulting in a molecular truncation were found only in core SMEI. Among the mutations, two missense mutations were found in both core SMEI and SMEB. CONCLUSIONS: Our findings confirm that SMEB is part of the SMEI spectrum and may expand the recognition of SMEI and suggest other responsible or modifying genes.

Amino Acid Sequence↗
PubMed2004

Diagnosis and treatment of epilepsy.

PURPOSE: The correct diagnosis of epilepsy leads to an appropriate treatment. METHODS: The first step is to distinguish epileptic seizures from nonepileptic attacks, and to make a precise seizure diagnosis and classification. The next step is to identify the etiology or basic disorders underlying the epilepsy by physical and neurologic examinations, laboratory tests, including EEGs and neuroradiologic examinations. Although the EEG is the most important laboratory examination for the diagnosis of epilepsy, limitations of EEG interpretations must be recognized. RESULTS: A syndromic classification of the patients, to determine whether they fit known syndromes, should be attempted. If patients do not match a described syndrome, a neurobiologic approach, utilizing genetic, neurophysiological, and neuropharmacologic knowledge, alternatively provides useful information to understand the neurobiologic background of epilepsy. CONCLUSIONS: Both approaches have advantages and disadvantages for diagnosing and treating epilepsy. Both approaches can be used interchangeably with patients with seizure disorders, depending upon their condition. The epilepsy diagnosis, etiology, and seizure-type diagnosis should be reevaluated when seizure control is insufficient with first- and second-line antiepileptic drugs.

Anticonvulsants↗
PubMed2003

Analysis of photo-pattern sensitivity in patients with Pokemon-related symptoms.

This study was designed to analyze photo-pattern sensitivity in patients who developed acute neurologic symptoms associated with watching an animated television program, "Pokemon." The 18 patients (13 females and five males) underwent electroencephalograms and photo-pattern stimulation testing, including special stimulation test batteries (strobe-pattern test and cathode ray tube-pattern test). Photo-pattern sensitivity was confirmed in 16 patients with and without seizure episodes. The strobe-pattern test including a white flickering light test (with eyes open, closed, and open or closed), and the cathode ray tube-pattern test each induced a photo-paroxysmal response in more than 80% of patients. However, with the eyes closed only, as is common in Japan, the photo-paroxysmal response induction rate with a white flickering light stimulus was significantly lower (43%). In the cathode ray tube-pattern test, higher spatial frequencies produced higher rates of photo-paroxysmal response induction. It was demonstrated that underlying photo-pattern sensitivity is more accurately investigated by our method than by standard intermittent photic stimulation alone. By characterizing underlying photo-pattern sensitivity and identifying predisposing factors more precisely, we can develop better guidelines for prevention of a second "Pokemon" incident. According to the results of the present cathode ray tube-pattern test, pattern sensitivity (especially spatial resolution) appears to also be involved in Pokemon-related symptoms, in addition to chromatic sensitivity.

Adolescent↗
PubMed2003

EEG in children with early-onset benign occipital seizure susceptibility syndrome: Panayiotopoulos syndrome.

PURPOSE: We analyzed sequential changes in the localization of EEG foci along with age to identify a specific EEG pattern, and the relation between the clinical manifestations and the EEG pattern in patients with Panayiotopoulos syndrome (PS). METHODS: The subjects were 76 children, who had been followed up >2 years with repeated EEG examinations at 6-month intervals. Analysis of EEG findings included the determination of localization of spike foci, as a function of age, by using cross-sectional data, and the identification of subgroups with homogeneous EEG patterns. Then we compared certain clinical features among these subgroups. RESULTS: In the cross-sectional EEG study, the occipital EEG spike focus was most frequently seen between ages 2 and 5 years. Independent and synchronous frontopolar and occipital spikes (Fp-O spikes) and centroparietotemporal (CPT) EEG spike foci had increased incidences between ages 4 and 7 years, and between ages 6 and 10 years, respectively. We subclassified the 76 patients into the following five subgroups based on the evolutional changes in epileptic EEG foci, which frequently showed shifting, multiplications, and generalization: (a) persistent occipital focus group (O group), (b) Fp-O spikes group (Fp-O pattern group), (c) generalized EEG pattern group, (d) CPT foci group (CPT group), and (e) no epileptic EEG focus group. The Fp-O group showed the latest age at onset of epilepsy. The generalized EEG pattern group had the highest frequency of seizures as well as recurrences of status epilepticus (SE), as well as the longest active seizure period among the five groups. CONCLUSIONS: These results indicated that the EEG foci in most of patients with PS are frequently shifting location, multiplying, and propagating diffusely with age, rather than persistently localizing in the occipital region. In addition, the EEG patterns showed a certain trend and roughly corresponded to certain clinical characteristics. However, the prognosis of the seizures appeared to be favorable regardless of the EEG pattern.

Age Factors↗
PubMed2003

Rasmussen syndrome: multifocal spread of inflammation suggested from MRI and PET findings.

BACKGROUND: A 6-year-old girl with Rasmussen syndrome (RS) showed multiple small high-signal-intensity areas independently in the right hemisphere by fluid-attenuated inversion recovery (FLAIR) imaging on magnetic resonance imaging (MRI) 1 year after the onset of epilepsy. METHODS: MRI performed 4 months later demonstrated a further increase in the number of these foci and enlargement in the size of the previous FLAIR lesions. RESULTS: An [18F]-fluorodeoxyglucose-positron emission tomography (FDG-PET) study showed a strong, spotty uptake in the right temporooccipital regions, corresponding to the sites of continuous EEG seizure discharges. In contrast, [11C]methionine PET demonstrated multifocal uptake regions, which corresponded anatomically to the FLAIR lesions, suggesting sites of underlying chronic inflammation. CONCLUSIONS: These neuroimaging findings suggested that the inflammatory process in RS spreads either multifocally at the same time, as seen in this case, or from one discrete area to the adjacent region, as reported previously.

Autonomic Nervous System Diseases↗