Reinterpretation of magnetic resonance imaging findings with magnetoencephalography can improve the accuracy of detecting epileptogenic cortical lesions.

OBJECTIVE: This study examined whether the application of magnetoencephalography (MEG) to interpret magnetic resonance imaging (MRI) findings can aid the diagnosis of intractable epilepsy caused by organic brain lesions. METHODS: This study included 51 patients with epilepsy who had MEG clusters but whose initial MRI findings were interpreted as being negative for organic lesions. Three board-certified radiologists reinterpreted the MRI findings, utilizing the MEG findings as a guide. The degree to which the reinterpretation of the imaging results identified an organic lesion was rated on a 5-point scale. RESULTS: Reinterpretation of the MRI data with MEG guidance helped detect an abnormality by at least one radiologist in 18 of the 51 patients (35.2%) with symptomatic localization-related epilepsy. A surgery was performed in 7 of the 51 patients, and histopathological analysis results identified focal cortical dysplasia in 5 patients (Ia: 1, IIa: 2, unknown: 2), hippocampal sclerosis in 1 patient, and dysplastic neurons/gliosis in 1 patient. CONCLUSIONS: The results of this study highlight the potential diagnostic applications of MEG to detect organic epileptogenic lesions, particularly when radiological visualization is difficult with MRI alone.

Risk factors for motor coordination problems in preschool-age children.

BACKGROUND: Motor coordination problems (MCP) in children can sometimes be diagnosed as developmental coordination disorder. Early intervention for developmental coordination disorder is necessary because it often continues into adolescence, causing mental and physical complications. Few studies have investigated the prevalence of childhood MCP in the Japanese population, examining the risk factors for MCP. We therefore investigated the prenatal factors associated with MCP in preschool-age children. METHODS: This study was based on a prospective cohort study, the Hokkaido Study on Environment and Children's Health. Mothers of 4,851 children who reached the age of 5 years within the study-period received questionnaires, including the Japanese version of the Developmental Coordination Disorder Questionnaire (DCDQ-J). We examined the risk factors associated with MCP using logistic regression analysis. RESULTS: Of 3,402 returned DCDQ-J questionnaires, 3,369 were answered completely. From the 3,369 children, we categorized having MCP by using two cut-off scores: that of the DCDQ'07 and the cut-off at the 5th percentile of a total DCDQ-J score. Comparing children with and without MCP, we found significant differences in the education level of the mothers, annual household income during pregnancy, maternal alcohol consumption and smoking during pregnancy, and sex and age of the children at the time of completing the DCDQ-J by both categorizations. Adjusted logistic regression analysis revealed that maternal smoking during the first trimester of pregnancy and male sex were significantly associated with MCP. CONCLUSIONS: Our results suggest that maternal smoking during pregnancy is the main factor associated with MCP in preschool-age children.

Advanced dynamic statistical parametric mapping with MEG in localizing epileptogenicity of the bottom of sulcus dysplasia.

OBJECTIVE: To investigate whether advanced dynamic statistical parametric mapping (AdSPM) using magnetoencephalography (MEG) can better localize focal cortical dysplasia at bottom of sulcus (FCDB). METHODS: We analyzed 15 children with diagnosis of FCDB in surgical specimen and 3 T MRI by using MEG. Using AdSPM, we analyzed a ±50 ms epoch relative to each single moving dipole (SMD) and applied summation technique to estimate the source activity. The most active area in AdSPM was defined as the location of AdSPM spike source. We compared spatial congruence between MRI-visible FCDB and (1) dipole cluster in SMD method; and (2) AdSPM spike source. RESULTS: AdSPM localized FCDB in 12 (80%) of 15 children whereas dipole cluster localized six (40%). AdSPM spike source was concordant within seizure onset zone in nine (82%) of 11 children with intracranial video EEG. Eleven children with resective surgery achieved seizure freedom with follow-up period of 1.9 ±â€¯1.5 years. Ten (91%) of them had an AdSPM spike source in the resection area. CONCLUSION: AdSPM can noninvasively and neurophysiologically localize epileptogenic FCDB, whether it overlaps with the dipole cluster or not. SIGNIFICANCE: This is the first study to localize epileptogenic FCDB using MEG.

Advantageous information provided by magnetoencephalography for patients with neocortical epilepsy.

PURPOSE: We evaluated whether magnetoencephalography (MEG), in addition to surgery, was valuable for the diagnosis and management of epileptic syndromes in patients with neocortical epilepsy (NE). METHODS: We studied MEG in 73 patients (29 females; aged 1-26years; mean 10.3years) for the clinical diagnosis of epilepsy and for preoperative evaluation. MEG data were recorded by 204-channel whole head gradiometers with a 600Hz sampling rate. MEG spike sources were localized on magnetic resonance images (MRI) using a single dipole model to project equivalent current dipoles. RESULTS: MEG localized an epileptic focus with single clustered dipoles in 24 (33%) of 73 NE patients: 16 (25%) of 64 symptomatic localization-related epilepsy (SLRE) patients and eight (89%) of nine idiopathic localization-related epilepsy (ILRE) patients. MEG provided advantageous information in 12 (50%) of 24 patients with clustered dipoles and confirmed the diagnosis in the remaining 12 (50%). Furthermore, the use of MEG resulted in changes to surgical treatments in nine (38%) patients and in medical management in eight (33%). MEG confirmed the diagnosis in eight (16%) of 49 patients with scattered dipoles. MRI identified a single lesion (28 patients, 38%), multiple lesions (5, 7%), and no lesion (40, 55%). MRI provided confirming information in 19 of 28 patients with a single lesion and 18 of them required surgical resections. MRI did not provide any supportive information in 54 (74%) patients with a single (9), multiple (5) and no lesion (40). CONCLUSION: Our study shows that MEG provides fundamental information to aid the choice of diagnostic and therapeutic procedures including changes in medication in addition to surgical treatments for NE.

Childhood-onset anti-MuSK antibody positive myasthenia gravis demonstrates a distinct clinical course.

Anti-muscle-specific tyrosine kinase antibody (MuSK-Ab) is the second most frequent autoantibody identified in adult patients with myasthenia gravis (MG). Adult patients with MuSK-Ab demonstrate characteristic clinical features but very little information is available for childhood-onset patients with MuSK-positive MG. We report a childhood-onset female patient with MuSK-positive MG. This patient showed basic clinical features compatible with adult-onset MuSK-positive MG, but some features, including spontaneous improvement, are distinct from those in adult patients. Serial examination of MuSK-Ab titers revealed a gross correlation with clinical severity despite significantly high titers throughout the clinical course. Therefore, childhood-onset MuSK-positive MG may demonstrate a distinct clinical characteristics in the early period of illness.

Direct correlation between the facial nerve nucleus and hemifacial seizures associated with a gangliocytoma of the floor of the fourth ventricle: a case report.

A dysplastic neuronal lesion of the floor of the fourth ventricle (DNFFV) causes hemifacial seizures (HFS) from early infancy. However, it is still controversial whether HFS is generated by the facial nerve nucleus or cerebellar cortex. In this study, we confirm a direct correlation between the rhythmic activities in the DNFFV and HFS using intraoperative electroencephalography (EEG) and electromyography (EMG) monitoring. Our results support the theory that a DNFFV provokes ipsilateral HFS via the facial nerve nucleus.

The applications of time-frequency analyses to ictal magnetoencephalography in neocortical epilepsy.

PURPOSE: Ictal magenetoencephalographic (MEG) discharges convey significant information about ictal onset and propagation, but there is no established method for analyzing ictal MEG. This study sought to clarify the usefulness of time-frequency analyses using short-time Fourier transform (STFT) for ictal onset and propagation of ictal MEG activity in patients with neocortical epilepsy. METHODS: Four ictal MEG discharges in two patients with perirolandic epilepsy and one with frontal lobe epilepsy (FLE) were evaluated by time-frequency analyses using STFT. Prominent oscillation bands were collected manually and the magnitudes of those specific bands were superimposed on individual 3D-magnetic resonance images. RESULTS: STFT showed specific rhythmic activities from alpha to beta bands at the magnetological onset in all four ictal MEG records. Those activities were located at the vicinity of interictal spike sources, as estimated by the single dipole method (SDM), and two of the four ictal rhythmic activities promptly propagated to ipsilateral or bilateral cerebral cortices. The patients with FLE and perirolandic epilepsy underwent frontal lobectomy and resection of primary motor area, respectively including the origin of high-magnitude areas of a specific band indicated by STFT, and have been seizure free after the surgery. CONCLUSIONS: STFT for ictal MEG discharges readily demonstrated the ictal onset and propagation. These data were important for decisions on surgical procedure and extent of resection. Ictal MEG analyses using STFT could provide a powerful tool for noninvasive evaluation of ictal onset zone.

[Lineage switch on recurrence from minimally differentiated acute leukemia (M0) to acute megakaryocytic leukemia (M7)].

Phenotypic switch in acute leukemia is a rare phenomenon. We report on a female infant with minimally differentiated acute leukemia (M 0) which underwent a lineage switch on relapse. In March 1997, a 1-year-8-month old girl was admitted to our hospital with a high-grade fever and generalized purpura. Bone marrow showed 84% blasts. The blasts were negative for peroxidase, periodic acid-Schiff and alpha-naphthyl butyrate esterase. Immunophenotypic analyses of the blast cells were positive for CD 13, CD 33 antigens, as well as CD 34. Lymphoid markers all were negative. Though some blasts morphologically demonstrated cytoplasmic blebs, CD 41 was negative and ultrastructural platelet peroxidase was absent. Based on these hematological features, the patient was diagnosed as having AML-M 0. She was treated according to the Children's Cancer and Leukemia Study Group schedule and a complete remission was achieved 1.5 months after starting induction therapy. However, she relapsed in spite of continued chemotherapy in July 1997, when the cytomorphological pattern changed and the patient was diagnosed both morphologically and immunologically as having M 7. Electron microscopy revealed platelet peroxidase (+) and CD 41 (+). Cytogenetic studies on relapse demonstrated inv(3) (q 21 p 25). We attempted aggressive reinduction therapy, but without effect. The patient simultaneously developed severe pneumonia and died in February, 1998. A lineage switch on relapse and resistance to chemotherapy may be associated with the occurrence of genetic aberration.