Ultrasound efficacy of targeted-synthetic disease-modifying anti-rheumatic drug treatment in rheumatoid arthritis: a multicenter prospective cohort study in Japan

OBJECTIVE

This study investigated the effectiveness of treatment with Janus kinase (JAK) inhibitors in rheumatoid arthritis (RA) assessed by ultrasonography (US) activity, and the influence of patient characteristics and previous treatments.

METHOD

This prospective study assessed 60 treatment initiations among 53 Japanese patients diagnosed with RA who underwent treatment with JAK inhibitors during June 2013 to February 2020. Of the 53 patients, seven patients were enrolled in duplicate because they were treated with two different JAK inhibitors at different periods. For each case, the improvement rate on the power Doppler (PD) score was assessed at 6 month follow-up. Median improvement rate of PD score was used to classify cases as either US responders or non-responders, and patient characteristics were compared between the two groups.

RESULTS

All indicators of clinical disease activity and US activity showed a significant improvement at 3 months compared with baseline. Although the JAK inhibitor-cycler group and the interleukin-6 (IL-6) inhibitor inadequate response (IR) group tended to show a later improvement for US activity, all indicators of clinical disease activity and US activity showed a significant improvement at 6 months compared with baseline for both groups. Multivariate analysis showed that concomitant methotrexate use and an IR to the previous biologic or targeted-synthetic disease-modifying anti-rheumatic drug (b/tsDMARD) treatment were independently and significantly associated with US responders.

CONCLUSION

Use of a JAK inhibitor in combination with methotrexate and an absence of IR to any previous b/tsDMARDs demonstrated superior effectiveness for patients with RA.

P–146 Differential impact of three embryo culture media for IVF on in vitro development and perinatal outcome: a single-center RCT

Study question

This report provides updated data from an RCT determining which embryo culture medium yields optimal IVF outcomes.

Summary answer

Embryo culture systems used for IVF differentially affected preimplantation development and resultant obstetric and perinatal outcomes, including birthweights of live-born singletons.

What is known already

Currently, multiple embryo culture medium systems are in use for IVF, raising questions regarding which is optimal. However, the ability of a medium to yield preimplantation embryos is not necessarily indicative of embryo viability. For example, supplementation of medium with serum was commonly used to increase animal blastocyst yields, but this impaired embryonic, fetal, and offspring health. In humans, medium composition and culture duration can influence IVF efficacy and offspring phenotype. Given the importance of culture systems in determining clinical outcomes, existing data regarding differential culture system impacts are insufficient and additional well-designed studies are required.

Study design, size, duration

Between February 2016 and August 2017, 795 couples undergoing their first autologous clinical IVF cycle and freeze-all strategy were recruited. Participants were randomized via computer-generated tables into three groups. Following standard oocyte retrieval and IVF/ICSI procedures, embryos were cultured using three different culture media, G1 Plus/G2 Plus (G1/G2; Vitrolife), Global Total (GT; LifeGlobal), or Sequential Cleav/Sequential Blast (SC/SB; Origio). Thirty-eight patients exhibiting no 2PN oocytes following insemination or those undergoing fresh embryo transfers were excluded.

Participants/materials, setting, methods

For patients yielding a single good-quality cleavage-stage (day–2 or day–3) embryo, that cleavage-stage embryo was vitrified. For patients yielding two or more good-quality cleavage-stage embryos, two or less good-quality cleavage-stage embryos were vitrified. The culture period of the remaining embryos was extended, and all good-quality blastocyst-stage (day–5 or day–6) embryos were vitrified. This report presents data for vitrified embryo transfer performed until the end of December 2020.

Main results and the role of chance

The mean per-cycle vitrified embryo yield (± SD) was comparable between groups for cleavage-stage embryos, but significantly different for blastocyst-stage embryos (G1/G2: 1.69 ± 2.2, GT: 2.53 ± 3.01, SC/SB: 2.04 ± 2.42; P = 0.001). Following vitrified cleavage- or blastocyst-stage embryo transfers, biochemical pregnancy rates were significantly different between groups (G1/G2: 55.6%, GT: 59.1%, SC/SB: 46.2%; P = 0.011). Furthermore, a between-group trend towards different live birth rates was observed (G1/G2: 41.7%, GT: 42.1%, SC/SB: 33.1%; P = 0.063). Of 382 live births, data for first-borns (n = 323; 295 singletons and 14 twin-pairs) are reported here. Perinatal data did not differ significantly between groups for both cleavage- and blastocyst-stage embryo transfers, including gestational age- and gender-adjusted singleton birthweight (z-score). Following multiple linear regression (including selected covariates), adjusted mean singleton birthweights were significantly lower in the G1/G2 and GT groups than in the SC/SB group (by 131 g; P = 0.011 and 110 g; P = 0.032, respectively) and tended to be lower for cleavage-stage embryo transfers than for blastocyst-stage embryo transfers (by 102 g; P = 0.053).

Limitations, reasons for caution

A larger cohort size and longer-term follow-up are required to verify and further elucidate the impact of embryo culture methods on child health. Such studies will raise awareness regarding the sensitivity of in vitro-cultured human embryos to their environment, ultimately resulting in practices that decrease IVF risks to offspring.

Wider implications of the findings: Pregnancy outcome of the medium yielding fewer blastocysts was comparable or superior to that of other media, highlighting the importance of differentiating between the ability to support preimplantation development versus the ability to yield viable embryos. Embryo culture medium had a greater impact than embryo transfer stage on live birthweight.

Trial registration number

UMIN000020910

Discrepancy between clinical and ultrasound remissions in rheumatoid arthritis: a multicentre ultrasound cohort study in Japan

Objectives: Using multicentre ultrasound (US) cohort data among patients with rheumatoid arthritis (RA), we aimed to identify baseline factors that permit differentiation between two patient cohorts achieving US remission and clinical remission, and to determine the factors contributing to the discrepancy.Method: We reviewed 248 Japanese patients diagnosed with RA who underwent treatment with biological disease-modifying anti-rheumatic drugs at 13 centres. We performed US assessments of the synovia of 22 joints. We assessed the percentages of patients with clinical remission and US remission, defined as total power Doppler scores of 0 at 12 months.Results: The 87 patients who achieved US remission were divided into a group that achieved both clinical and US remission (n = 53) and a group that achieved US remission only (n = 34). Baseline factors that were significantly and independently associated with clinical remission at 12 months among patients who also achieved US remission included short disease duration, the presence of concomitant methotrexate use, and low patient global assessment score (p < 0.05, p < 0.05, and p < 0.005, respectively).Conclusions: RA patients with baseline high patient global assessment scores and long disease duration at baseline were unlikely to achieve clinical remission even after achieving US remission. Objective joint assessments using US provide additional information of potential importance for the management of RA.

MRI, Magnetoencephalography, and Surgical Outcome of Oligodendrocytosis versus Focal Cortical Dysplasia Type I

BACKGROUND AND PURPOSE

Abnormalities of oligodendrocytes have been reported in surgical specimens of patients with medically intractable epilepsy. The aim of this study was to compare the MR imaging, magnetoencephalography, and surgical outcome of children with oligodendrocytosis relative to focal cortical dysplasia I.

MATERIALS AND METHODS

Oligodendrocytosis included oligodendroglial hyperplasia, oligodendrogliosis, and oligodendroglial-like cells in the white matter, gray matter, or both from children with medically intractable epilepsy. Focal cortical dysplasia I included radial and tangential cortical dyslamination. The MR imaging, magnetoencephalography, type of operation, location, and seizure outcome of oligodendrocytosis, focal cortical dysplasia I, and oligodendrocytosis + focal cortical dysplasia I were compared.

RESULTS

Eighteen subjects (39.1%) had oligodendrocytosis, 21 (45.7%) had focal cortical dysplasia I, and 7 (15.2%) had oligodendrocytosis + focal cortical dysplasia I. There were no significant differences in the type of seizures, focal or nonfocal epileptiform discharges, magnetoencephalography, and MR imaging features, including high T1 signal in the cortex, high T2/FLAIR signal in the cortex or subcortical white matter, increased cortical thickness, blurring of the gray-white junction, or abnormal sulcation and gyration among those with oligodendrocytosis, focal cortical dysplasia I, or oligodendrocytosis + focal cortical dysplasia I (P > .01). There were no significant differences in the extent of resection (unilobar versus multilobar versus hemispherectomy), location of the operation (temporal versus extratemporal versus both), or seizure-free outcome of oligodendrocytosis, focal cortical dysplasia I, and oligodendrocytosis + focal cortical dysplasia I (P > .05).

CONCLUSIONS

Oligodendrocytosis shared MR imaging and magnetoencephalography features with focal cortical dysplasia I, and multilobar resection was frequently required to achieve seizure freedom. In 15% of cases, concurrent oligodendrocytosis and focal cortical dysplasia I were identified. The findings suggest that oligodendrocytosis may represent a mild spectrum of malformations of cortical development.

Association between the PPARGC1A polymorphism and aerobic capacity in Japanese middle-aged men

OBJECTIVE

A lower frequency for the peroxisome proliferator-activated receptor γ coactivator 1α (PPARGC1A) Ser482 allele has been reported in elite-level endurance athletes among Caucasians, although this gene polymorphism has not been found to be associated with aerobic capacity in German, Dutch or Chinese populations. The purpose of the current study was to examine the associations between the Gly482Ser polymorphism and aerobic fitness in 112 Japanese middle-aged men.

METHODS

The PPARGC1A Gly482Ser polymorphism was identified according to a TaqMan(®) SNP genotyping assay. Habitual physical activity was objectively measured using an accelerometer. The lactate threshold (LT), an index of aerobic fitness, was measured based on a submaximal graded exercise test performed on an electric cycle ergometer. The association between the LT and the Gly482Ser polymorphism was assessed according to a multiple regression analysis and analysis of covariance, with adjustment for potential confounders (age, body mass index, cigarette smoking, physical activity level and regular exercise).

RESULTS

A significant association was observed between the PPARGC1A Gly482Ser polymorphism and LT, as carriers of the Ser482 had higher LT values than the Gly482 carriers.

CONCLUSION

The current results suggest that the PPARGC1A Ser482 allele is associated with a higher aerobic capacity in Japanese middle-aged men.

SLC26A3 gene analysis in patients with Bartter and Gitelman syndromes and the clinical characteristics of patients with unidentified mutations

We analyzed the SLC26A3 gene in patients with a clinical diagnosis of Bartter and Gitelman syndromes in whom genetic diagnoses could not be determined. We also examined the genetic and clinical characteristics of patients for whom genetic proof could not be obtained. The present study included 10 patients. With regard to genetic characteristics, 1 patient harbored a heterozygous mutation in the SLC12A3 gene (c.2573T>A, p.L858H), which was also reported in a previous report. With regard to clinical characteristics, 3 patients had abnormalities that were identified incidentally during medical examinations and other illnesses and 1 patient had polyhydramnios. One case of nephrocalcinosis was also noted. Eight patients were of below average height. Although we analyzed the SLC26A3 gene in these 10 patients, none were found to have pathological mutations. Investigation of the outcomes of these cases showed that examination findings had normalized and medication was no longer necessary for 3 patients, whereas hypokalemia and metabolic alkalosis were observed in another patient only in the presence of acute disease. We concluded that few patients develop illnesses because of SLC26A3 mutations. Other disease-related genes may also be involved. Although hypokalemia and metabolic alkalosis are clinical characteristics of Bartter and Gitelman syndromes, many other conditions also present such symptoms, and thus, differential diagnosis is of paramount importance.

High-frequency oscillations (HFOs) in clinical epilepsy

Epilepsy is one of the most frequent neurological diseases. In focal medically refractory epilepsies, successful surgical treatment largely depends on the identification of epileptogenic zone. High-frequency oscillations (HFOs) between 80 and 500Hz, which can be recorded with EEG, may be novel markers of the epileptogenic zone. This review discusses the clinical importance of HFOs as markers of epileptogenicity and their application in different types of epilepsies. HFOs are clearly linked to the seizure onset zone, and the surgical removal of regions generating them correlates with a seizure free post-surgical outcome. Moreover, HFOs reflect the seizure-generating capability of the underlying tissue, since they are more frequent after the reduction of antiepileptic drugs. They can be successfully used in pediatric epilepsies such as epileptic spasms and help to understand the generation of this specific type of seizures. While mostly recorded on intracranial EEGs, new studies suggest that identification of HFOs on scalp EEG or magnetoencephalography (MEG) is possible as well. Thus not only patients with refractory epilepsies and invasive recordings but all patients might profit from the analysis of HFOs. Despite these promising results, the analysis of HFOs is not a routine clinical procedure; most results are derived from relatively small cohorts of patients and many aspects are not yet fully understood. Thus the review concludes that even if HFOs are promising biomarkers of epileptic tissue, there are still uncertainties about mechanisms of generation, methods of analysis, and clinical applicability. Large multicenter prospective studies are needed prior to widespread clinical application.

Diffusion tensor imaging assessment of the epileptogenic zone in children with localization-related epilepsy

BACKGROUND AND PURPOSE

Patients with MR imaging-negative epilepsy could have subtle FCD. Our aim was to determine if structural changes could be identified by using DTI in children with intractable epilepsy, from MR imaging-visible FCD and MR imaging-negative localization-related epilepsy, that were concordant with the epileptogenic zone as defined by using the MEG dipole cluster.

MATERIALS AND METHODS

Eight children with MR imaging-visible FCD and 16 with MR imaging-negative epilepsy underwent DTI and MEG. Twenty-six age-matched healthy children underwent DTI. Analysis was performed on controls across individual patients. Agreement between the location of DTI abnormalities and FCD and MEG dipole clusters was assessed.

RESULTS

In patients with MR imaging-visible FCD, abnormal FA, MD, λ(1), λ(2), and λ(3) were lobar concordant with the MEG dipole cluster in 4/8 (50.0%), 5/8 (62.5%), 3/8 (37.5%), 6/8 (75.0%), and 5/8 (62.5%), respectively. In patients with MR imaging-visible FCD, abnormal FA, MD, λ(1), λ(2), and λ(3) overlapped the x-, y-, and z-axes of the MEG dipole cluster in 1/8 (12.5%), 4/8 (50%), 4/8 (50%), 6/8 (75%), and 4/8 (50%), respectively, and with FCD in 1/8 (12.5%), 3/8 (37.5%), 0/8 (0%), 3/8 (37.5%), and 1/8 (12.5%), respectively. In patients with MR imaging-negative epilepsy, abnormal FA, MD, λ(1), λ(2), and λ(3) were lobar-concordant with the MEG dipole cluster in 11/16 (68.8%), 11/16 (68.8%), 8/16 (50.0%), 10/16 (62.5%), and 10/16 (62.5%), respectively, and overlapped the x-, y-, and z-axes of the MEG dipole cluster in 9/16 (56.3%), 10/16 (62.5%), 8/16 (50%), 8/16 (50%), and 8/16 (50%), respectively. There was no significant difference between abnormal DTI lobar concordance with the MEG dipole cluster in patients with MR imaging-visible FCD and MR imaging-negative epilepsy.

CONCLUSIONS

White matter changes can be detected with DTI in children with MR imaging-visible FCD and MR imaging-negative epilepsy, which were concordant with the epileptogenic zone in more than half of the patients.

Induction of Fos expression in the rat forebrain after intragastric administration of monosodium L-glutamate, glucose and NaCl

l-glutamate, an umami taste substance, is a key molecule coupled to a food intake signaling pathway. Furthermore, recent studies have unveiled new roles for dietary glutamate on gut-brain axis communication via activation of gut glutamate receptors and subsequent vagus nerve. In the present study, we mapped activation sites of the rat forebrain after intragastric load of 60 mM monosodium l-glutamate (MSG) by measurement of Fos protein, a functional marker of neuronal activation. The same concentration of d-glucose (sweet) and NaCl (salty) was used as controls. MSG administration exclusively produced enhanced Fos expression in four hypothalamic regions (the medial preoptic area, lateral hypothalamic area, dorsomedial nucleus, and arcuate nucleus). On the other hand, glucose administration exclusively enhanced Fos induction in the nucleus accumbens. Both MSG and glucose enhanced Fos induction in three brain regions (the habenular nucleus, paraventricular nucleus, and central nucleus of the amygdala). However, MSG induced Fos inductions were more potent than those of glucose in the habenular nucleus and paraventricular nucleus. Importantly, the present study identified for the first time two brain areas (the paraventricular and arcuate hypothalamic nuclei) that are more potently activated by intragastric MSG loads compared with glucose and NaCl. Overall, our results suggest significant activation of a neural network comprising the habenular nucleus, amygdala, and the hypothalamic subnuclei following intragastric load with glutamate.

Seizure identification in the ICU using quantitative EEG displays

OBJECTIVE

To evaluate the diagnostic accuracy of 2 quantitative EEG display tools, color density spectral array (CDSA) and amplitude-integrated EEG (aEEG), for seizure identification in the intensive care unit (ICU).

METHODS

A set of 27 continuous EEG recordings performed in pediatric ICU patients was transformed into 8-channel CDSA and aEEG displays. Three neurophysiologists underwent 2 hours of training to identify seizures using these techniques. They were then individually presented with a series of CDSA and aEEG displays, blinded to the raw EEG, and asked to mark any events suspected to be seizures. Their performance was compared to seizures identified on the underlying conventional EEG.

RESULTS

The 27 EEG recordings contained 553 discrete seizures over 487 hours. The median sensitivity for seizure identification across all recordings was 83.3% using CDSA and 81.5% using aEEG. However, among individual recordings, the sensitivity ranged from 0% to 100%. Factors reducing the sensitivity included low-amplitude, short, and focal seizures. False-positive rates were generally very low, with misidentified seizures occurring once every 17-20 hours.

CONCLUSIONS

Both CDSA and aEEG demonstrate acceptable sensitivity and false-positive rates for seizure identification among critically ill children. Accuracy of these tools would likely improve during clinical use, when findings can be correlated in real-time with the underlying raw EEG. In the hands of neurophysiologists, CDSA and aEEG displays represent useful screening tools for seizures during continuous EEG monitoring in the ICU. The suitability of these tools for bedside use by ICU nurses and physicians requires further study.

Ghrelin potentiates miniature excitatory postsynaptic currents in supraoptic magnocellular neurones

Ghrelin is an orexigenic peptide discovered in the stomach as a ligand of the orphan G-protein coupled receptor, and participates in the regulation of growth hormone (GH) release. Previous studies have demonstrated that ghrelin suppressed water intake and stimulated the secretion of arginine vasopressin in rats. We examined the effect of ghrelin on the excitatory synaptic inputs to the magnocellular neurosecretory cells (MNCs) in the supraoptic nucleus (SON) using whole-cell patch-clamp recordings in in vitro rat and mouse brain slice preparations. The application of ghrelin (10(-7) approximately 10(-6) m) caused a significant increase in the frequency of the miniature excitatory postsynaptic currents (mEPSCs) in a dose-related manner without affecting the amplitude. The increased frequency of the spontaneous EPSCs persisted in the presence of tetrodotoxin (1 microM). Des-n-octanoyl ghrelin (10(-6) m) did not have a significant effect on the mEPSCs. The ghrelin-induced potentiation of the mEPSCs was significantly suppressed by previous exposure to the transient receptor potential vanilloid (TRPV) blocker, ruthenium red (10 microM) and GH secretagougue type 1a receptor selective antagonist, BIM28163 (10 microM). The effects of ghrelin on the supraoptic MNCs in trpv1 knockout mice were significantly attenuated compared to those in wild-type mice counterparts. These results suggest that ghrelin participates in the regulation of synaptic inputs to the MNCs in the SON via interaction with the GH secretagogue type 1a receptor, and that the TRPV1 channel may be involved in ghrelin-induced potentiation of mEPSCs to the MNCs in the SON.

Response of arginine vasopressin-enhanced green fluorescent protein fusion gene in the hypothalamus of adjuvant-induced arthritic rats

Arginine vasopressin (AVP) and corticotrophin-releasing hormone (CRH) in the parvocellular neurosecretory cells of the paraventricular nucleus (PVN) play a major role in activating the hypothalamic-pituitary-adrenal axis, which is the main neuroendocrine response against the many kinds of stress. We examined the effects of chronic inflammatory/nociceptive stress on the expression of the AVP-enhanced green fluorescent protein (eGFP) fusion gene in the hypothalamus, using the adjuvant arthritis (AA) model. To induce AA, the AVP-eGFP rats were intracutaneously injected heat-killed Mycobacterium butyricum (1 mg/rat) in paraffin liquid at the base of their tails. We measured AVP, oxytocin and corticosterone levels in plasma and changes in eGFP and CRH mRNA in the hypothalamus during the time course of AA development. Then, we examined eGFP fluorescence in the PVN, the supraoptic nucleus (SON), median eminence (ME) and posterior pituitary gland (PP) when AA was established. The plasma concentrations of AVP, oxytocin and corticosterone were significantly increased on days 15 and 22 in AA rats, without affecting the plasma osmolality and sodium. Although CRH mRNA levels in the PVN were significantly decreased, eGFP mRNA levels in the PVN and the SON were significantly increased on days 15 and 22 in AA rats. The eGFP fluorescence in the SON, the PVN, internal and external layers of the ME and PP was apparently increased in AA compared to control rats. These results suggest that the increases in the concentrations of ACTH and corticosterone in AA rats are induced by hypothalamic AVP, based on data from AVP-eGFP transgenic rats.

Magnetoencephalography for clinical pediatrics: the effect of head positioning on measurement of somatosensory-evoked fields

OBJECTIVE

At present, whole-head MEG systems are designed to accommodate adult heads, thereby introducing a technical issue unique to pediatric MEG. It is known that magnetic field strength decreases as a function of 1/distance(2). For pediatric patients, we questioned whether re-positioning the head to minimize the distance between the expected source location and the MEG sensor array would significantly improve source measurement.

METHODS

Somatosensory-evoked fields (SEFs) were recorded in 17 children (mean=4.96 years) with their head placed centrally in the MEG, and then re-positioned laterally to reduce the distance between the cortical source and sensors. Equivalent current dipole (ECD) source models were evaluated for changes in residual variance (RV), signal-to-noise ratio (SNR), moment (strength), and location.

RESULTS

Re-positioning the head closer to the sensors resulted in a significant shift in the mediolateral dipole coordinate location, accompanied by a significant increase in the SNR, decrease in the dipole RV, and a reduction in size of ECD confidence volumes.

CONCLUSIONS

We conclude that for clinical pediatric measurement of the SEF, repositioning of the head to minimize the distance between the expected SEF source location and the sensor array will significantly improve SEF source measurement and concomitant ECD source modeling.

SIGNIFICANCE

These issues are relevant to all pediatric MEG settings involving healthy or clinical populations and underscores the need for future development of a MEG helmet specifically designed for pediatric populations.

MEG source estimation from mesio-basal temporal areas in a child with a porencephalic cyst

BACKGROUND

A child whose left temporal lobe contained mesial, anterior and basal structures but lacked superio-lateral cortex had intractable epilepsy secondary to a porencephalic cyst. Magnetoencephalography (MEG) shows equivalent current dipoles (ECDs) as dipole modeling for temporal lobe epilepsy rather than in an exact location.

AIM

We hypothesized that the magnetic fields generated by the epileptic discharges in mesio-basal temporal areas could be detected by MEG without interference from the superio-lateral temporal cortices.

METHODS

We analyzed MEG spikes using single dipole analysis and synthetic aperture magnetometry (SAM), and compared with EEG spike topography.

RESULTS

Two MEG ECDs corresponding to T3 spikes localized to the anterior mesio-basal temporal region with vertical orientation. Sixteen MEG ECDs corresponding to T5 spikes localized to the middle to posterior mesio-basal temporal region with vertical orientation. SAM revealed maximum current density at hippocampus and anterior fusiform gyrus for T3 spikes, and at posterior hippocampus and fusiform gyrus for T5 spikes.

CONCLUSION

Vertically oriented ECDs were obtained without superio-lateral temporal cortices because of temporo-parieto-occipital porencephalic cyst. The absence of superio-lateral temporal cortices, prominent temporal EEG spikes, less prominent MEG spikes, and mesio-basal SAM spikes indicated that the vertically oriented ECDs were projected directly from the mesio-basal temporal region.

Benign epileptiform discharges in Rolandic region with mesial temporal lobe epilepsy: MEG, scalp and intracranial EEG features

AIM OF THE STUDY

To report benign epileptiform discharges (BEDs) in the Rolandic region, coexisting in a pediatric patient with intractable localization-related epilepsy, secondary to hippocampal sclerosis.

METHODS

We describe the clinical features, MRI, scalp video EEG, magnetoencephalography (MEG) and intracranial video EEG findings, and surgical outcome in a 9-year-old boy with BEDs and intractable complex partial seizures.

RESULTS

MRI showed left hippocampal sclerosis. Scalp video EEG interictally demonstrated left temporal spike and sharply contoured slow waves, and right fronto-centro-temporal spike and waves. Ictal scalp video EEG showed left temporal rhythmic sharp waves after the clinical onset of epigastric aura, followed by staring. MEG showed interictal dipoles in the bilateral Rolandic regions with a uniform orientation and right hemispheric predominance. Intracranial video EEG, with bilateral mesial temporal depth and fronto-temporo-parietal strip electrodes, interictally showed polyspikes and slow waves with superimposed low-amplitude fast waves in the left mesial and posterior lateral temporal regions, and spike and waves in the bilateral fronto-parietal regions. Ictal onset was marked by low-amplitude fast waves in the left mesial and posterior lateral temporal regions. He underwent left anterior temporal lobectomy with hippocampectomy. Pathology was hippocampal sclerosis. Predominant right fronto-centro-temporal spike and waves and MEG right Rolandic dipoles persisted after surgery. He was seizure-free 14 months after surgery.

CONCLUSION

This is the first report on MEG and intracranial video EEG features of BEDs in the Rolandic region, coexisting with hippocampal sclerosis. Persistence of contralateral benign MEG Rolandic dipoles after surgery indicates that BEDs are coincidental in mesial temporal lobe epilepsy. MEG identified Rolandic dipoles, although was unable to localize the deep and focal epileptogenic dipoles from the hippocampal sclerosis.

Magnetoencephalography for surgical treatment of refractory status epilepticus

Magnetoencephalography (MEG) provides accurate localizing information of the epileptogenic zones in localization-related epilepsies. Refractory status epilepticus (RSE) is a life-threatening emergency that often requires prolonged high-dose suppressive therapy (HDST) to stop frequent and prolonged seizures. Surgical treatments for patients with RSE secondary to pre-existing epilepsy were reported. This article addresses the role of MEG in localizing the epileptogenic zone for the surgical treatment of patients with RSE. Five pediatric patients with RSE underwent epilepsy surgery using MEG, scalp video EEG and magnetic resonance imaging (MRI). Ictal MEG spike sources (MEGSSs) were localized in the clustered interictal MEGSSs in right Rolandic region (patient 3) and right temporal region (patient 5). Interictal MEG revealed unilateral clustered MEGSSs in four patients (patients 1, 2, 4, and 5) and bilateral (patient 3). Ictal-onset EEG findings were localized to one region in three patients (patients 1, 3, and 5) and two regions in the other two patients (patients 2 and 4). In all five patients, interictal discharges were widespread involving over two lobes (patients 2 and 4) or three lobes (patients 1, 3, and 5). Suppression burst pattern was obtained by HDST (patient 5). MRI showed cortical dysplasia in three patients (patients 1, 3, and 4). Patient 2 had a normal MRI. Patient 5 had normal MRI at the onset. Repeat MRI 5 days later showed diffusion restriction in the right hippocampus associated with increased signal intensity on T2 and FLAIR sequences. We performed cortical excision in two patients (patients 1 and 4), hemispherectotomy one (patient 3) and anterior temporal lobectomy two patients (patients 2 and 5). Two patients (patients 1 and 3) became seizure free, the other three patients experienced residual seizures. MEG showed clustered MEGSSs during the RSE in the pre-existing epilepsy patients and at an early time window in the acute symptomatic RSE patients. The complete resection of clustered MEGSSs can control RSE and possibly lead to a seizure free outcome.

Magnetoencephalography for surgical treatment of refractory status epilepticus

Magnetoencephalography (MEG) provides accurate localizing information of the epileptogenic zones in localization-related epilepsies. Refractory status epilepticus (RSE) is a life-threatening emergency that often requires prolonged high-dose suppressive therapy (HDST) to stop frequent and prolonged seizures. Surgical treatments for patients with RSE secondary to pre-existing epilepsy were reported. This article addresses the role of MEG in localizing the epileptogenic zone for the surgical treatment of patients with RSE. Five pediatric patients with RSE underwent epilepsy surgery using MEG, scalp video EEG and magnetic resonance imaging (MRI). Ictal MEG spike sources (MEGSSs) were localized in the clustered interictal MEGSSs in right Rolandic region (patient 3) and right temporal region (patient 5). Interictal MEG revealed unilateral clustered MEGSSs in four patients (patients 1, 2, 4, and 5) and bilateral (patient 3). Ictal-onset EEG findings were localized to one region in three patients (patients 1, 3, and 5) and two regions in the other two patients (patients 2 and 4). In all five patients, interictal discharges were widespread involving over two lobes (patients 2 and 4) or three lobes (patients 1, 3, and 5). Suppression burst pattern was obtained by HDST (patient 5). MRI showed cortical dysplasia in three patients (patients 1, 3, and 4). Patient 2 had a normal MRI. Patient 5 had normal MRI at the onset. Repeat MRI 5 days later showed diffusion restriction in the right hippocampus associated with increased signal intensity on T2 and FLAIR sequences. We performed cortical excision in two patients (patients 1 and 4), hemispherectotomy one (patient 3) and anterior temporal lobectomy two patients (patients 2 and 5). Two patients (patients 1 and 3) became seizure free, the other three patients experienced residual seizures. MEG showed clustered MEGSSs during the RSE in the pre-existing epilepsy patients and at an early time window in the acute symptomatic RSE patients. The complete resection of clustered MEGSSs can control RSE and possibly lead to a seizure free outcome.

Effects of the short chain sugar acid 2-buten-4-olide on the hypothalamo-pituitary-adrenal axis in normal and adjuvant-induced arthritic rats

The effects of intraperitoneal (i.p.) administration of 2-buten-4-olide (2-B4O), an endogenous sugar acid, on the hypothalamo-adenohypophysial system were examined in Lewis rats that were normal and in adjuvant-induced arthritic (AA) rats. In comparison with vehicle-treated rats, the plasma corticosterone and c-fos mRNA levels in the paraventricular nucleus (PVN) of normal rats increased significantly after i.p. administration of 2-B4O. Dual immunostaining revealed that almost all corticotrophin-releasing factor (CRF)-immunopositive neurones in the parvocellular division of the PVN exhibited Fos-like immunoreactivity (LI) 120 min after i.p. administration of 2-B4O (100 mg/kg). In the AA rats, repeated i.p. administration of 2-B4O (100 mg/kg) after immunisation significantly suppressed the expression of clinical symptoms and significantly increased plasma concentrations of corticosterone. Further, repeated i.p. administration of 2-B4O significantly increased CRF mRNA levels in the PVN and pro-opiomelanocortin mRNA levels in the anterior pituitary; however, they did not change arginine vasopressin mRNA levels in the parvocellular division of the PVN. These results suggest that i.p. administration of 2-B4O activates the hypothalamo-pituitary-adrenal (HPA) axis via the activation of CRF neurones in the PVN, and the activation of the HPA axis by i.p. administration of 2-B4O may be associated with the inhibition of AA in rats.

Magnetoencephalographic spike sources associated with auditory auras in paediatric localisation-related epilepsy

OBJECTIVE

To characterise magnetoencephalographic spike sources in paediatric patients with auditory auras and recurrent localisation-related epilepsy.

METHODS

Six patients (four boys and two girls (ages 7-14 years) were retrospectively studied. All patients had auditory auras as part of their initial seizure manifestation, including four patients who underwent previous brain surgery. Scalp video electroencephalography and magnetoencephalography (MEG) were carried out in six patients, intraoperative electrocorticography in three patients and extraoperative intracranial video electroencephalography in one patient. MEG auditory-evoked fields (AEFs) were studied in four patients.

RESULTS

Three patients had elementary auditory auras, one had complex auditory aura and two had both complex and elementary auras. All six patients had clustered MEG spike sources with coexisting scattered spike sources. MEG clusters were localised in the superior temporal gyrus with surrounding scatters in four patients (two left and two right); two patients had scattered spikes in the superior temporal gyrus in addition to clustered MEG spike sources in the left inferior and middle frontal gyri or parieto-occipital region. AEFs were located within an MEG cluster in one patient and within 3 cm of a cluster in two patients. Surgical resection, including the regions of MEG clusters, was carried out in four patients. Three of four patients who had previous surgeries were seizure free at 2 years after excision of the MEG cluster region.

CONCLUSIONS

MEG spike sources clustered in the superior temporal gyrus in six patients with auditory auras. These spike sources were in close proximity or seemed to engulf the magnetic AEF. Areas with MEG spike sources contained the residual or recurrent epileptogenic zone after incomplete cortical excision for lesional epilepsy.

Persistent nucleated red blood cells in peripheral blood is a poor prognostic factor in patients undergoing stem cell transplantation

We compared detection rates and counts of nucleated red blood cell (NRBC) in the peripheral blood of survivors and nonsurvivors (total 44 patients) of stem cell transplantation. The rate of NRBC detection increased to 79.5% after transplantation. After engraftment, the detection rate of NRBC decreased to 17.0% in survivors, but increased to 100% in nonsurvivors. The NRBC count increased after transplantation in both groups. This increase was transient in survivors, but increased after engraftment in nonsurvivors. The mean NRBC count after engraftment was 872 vs. 40.3 for nonsurvivors vs. survivors, respectively. At postengraftment, all patients who were negative for NRBC survived, but 10 of the 15 patients who were positive for NRBC died (66.7%). The survival rates of patients with a NRBC count >200 x 10(6)/l were significantly lower than those of patients whose counts were <100 x 10(6)/l. These data indicated that persistent NRBC in peripheral blood is a poor prognostic factor, and suggested that monitoring NRBC after SCT might provide useful clinical information.

Dysembryoplastic neuroepithelial tumors in childhood: long-term outcome and prognostic features

BACKGROUND

Dysembryoplastic neuroepithelial tumors (DNTs) are associated with medically intractable epilepsy and a favorable prognosis after surgical resection. The authors describe the clinical, radiologic, and pathologic characteristics and outcomes in children after surgical resection of pathologically confirmed DNT to ascertain prognostic features for seizure recurrence following surgery.

METHODS

Neurology, neurosurgery, and pathology databases from 1993 to 2002 at the Hospital for Sick Children were searched to retrospectively identify children with confirmed DNT and presentation with seizures. Risk factors for postoperative seizure recurrence were examined with respect to seizure outcome at 12 months and long-term follow-up.

RESULTS

Of the 26 children identified (mean age at surgery 10.0 years) seizure outcome was good in 22 children (85%) at 12 months (Class 1). At longer follow-up (mean 4.3, range 1.0 to 11.0 years) only 16 (62%) remained seizure-free. Residual DNT was evident in 15 of the 24 children with available postoperative MRI. Three children demonstrated recurrence of tumor. At 12 months follow-up, older age (>10 years) and longer duration of epilepsy (>2 years) were associated with seizure recurrence. The presence of residual tumor was a risk factor for seizure recurrence at long-term follow-up (p = 0.02).

CONCLUSIONS

Children with DNT and epilepsy may benefit from surgical management; however, seizure outcome is not always favorable. Although the majority of children remain seizure free after surgical excision of DNT, a considerable number have recurrent seizures. Short-term outcome is influenced by older age at surgery and longer duration of epilepsy. Residual tumor is a significant risk factor for poor seizure outcome. Recurrent tumor can occur.

Secondary polycythemia as a paraneoplastic syndrome of testicular seminoma

A 45-year-old man was referred to our hospital because of polycythemia. A physical examination revealed a large tumor in his scrotum enlarged to the size of 13 x 10 cm. A laboratory examination revealed severe erythrocytosis with a red blood cell count of 6,820 x 10(9)/L, a hemoglobin concentration of 21.2 g/dL, and a hematocrit of 59.8%. The total red cell volume was increased. A right radical orchidectomy was done with minimum bleeding, and he was diagnosed as having pure seminoma. After the operation, polycythemia improved spontaneously. Polycythemia is a rare complication of seminoma and only two cases have been reported previously. The precise mechanism of polycythemia in our patient could not be clearly evaluated, but clinical course did indicate a close relationship between two distinct disorders.

Adhesion molecule expression by bone marrow CD34-positive cells in aplastic anemia before and after immunosuppressive therapy

Appropriate adhesion between bone marrow stem cells and the marrow microenvironment is necessary for hematopoiesis, since signals that promote maturation or apoptosis are transmitted from stromal cells to stem cells. In aplastic anemia (AA), interferon-gamma produced by stromal cells has more influence on the pathogenesis of marrow failure than interferon-gamma produced by lymphocytes. We evaluated the expression of cell adhesion molecules, such as very late antigen-4 (CD49d), and -5 (CD49e) or c-kit receptor (CD117), by CD34-positive bone marrow cells in patients with AA who achieved hematological complete remission after immunosuppressive therapy. Before treatment, CD34-positive cells showed markedly higher expression of CD49d and CD49e than cells from healthy controls, indicating the strong adhesion of stem cells to the bone marrow stroma. Expression of CD49d and CD49e was significantly decreased, reaching normal levels, after hematological recovery. These findings suggest that changes in adhesion molecule expression by stem cells are important in the pathology of AA.

Immunosuppressive therapy with antithymocyte globulin and cyclosporine for prolonged marrow failure after hemophagocytic syndrome

We describe a patient with typical hemophagocytic syndrome (HPS) in whom pancytopenia was refractory to steroid pulse therapy. He was successfully treated with immunosuppressive therapy using antithymocyte globulin (ATG) and cyclosporine (CyA), which is known to be effective for aplastic anemia (AA). Activation of histiocytes occurs in HPS as a response to several cytokines produced by activated T lymphocytes, while apoptosis of hematopoietic stem cells in AA is caused by T lymphocyte-derived cytokines. The response of this patient indicated that both diseases may have some similar immune-mediated conditions involving the activation of T lymphocytes and that intensive immunosuppressive therapy with ATG and CyA might be a useful strategy for steroid-resistant HPS.

Ictal magnetoencephalographic discharges from elementary visual hallucinations of status epilepticus

PURPOSE

To report the rare opportunity to study ictal magnetoencephalography (MEG) in a 26 year old man with simple partial status epilepticus that presented as elementary visual hallucinations (EVHs) in the right upper visual field.

METHODS

The patient described his EVHs as "snowing on TV," "flickering lights," and "rotating coloured balls" that continued for several days. MEG and simultaneous EEG were recorded twice: during an episode of EVHs (ictal recordings) and after EVHs were controlled by medications (interictal recordings).

RESULTS

During EVHs, MEG showed continuous periodic epileptiform discharges over the left posterior superior temporal region, while simultaneous EEG showed rhythmic theta waves and sporadic spikes over the left temporal region. The MEG discharge consisted of a three phase spike complex. Equivalent current dipoles (ECDs), modelled from spike complexes, localised in the left superior temporal area. After drug treatment controlled the EVHs, interictal MEG and EEG showed rare spikes over the same left temporal region. The average ictal ECD moment (mean (SD)) (128.7 (32.8 nAm)) was significantly weaker than the average interictal ECD moment (233.0 (63.9) nAm) (p<0.05).

CONCLUSIONS

The continuous, periodic, and clustered discharges seen on ictal MEG were the sources of EVH. The weaker ictal ECD sources were frequently not detected by scalp EEG, while the stronger interictal sources, presumably originating from an extensive interictal zone, were sufficiently large to be seen as EEG spikes.

Malformations of cortical development with balloon cells: clinical and radiologic correlates

BACKGROUND

Balloon cells are a key feature of tuberous sclerosis (TS) but are also seen in focal cortical dysplasia (FCD). The authors compare the clinical and MRI characteristics in children with medically refractory localization-related epilepsy who were found to have balloon cells on histology after cortical resections.

METHODS

A retrospective review of clinical and MRI data in cases ascertained from a search of pathology records from 1990 until 2000 for those with a diagnosis of FCD or TS. Seventeen patients were identified with malformations of cortical development with balloon cells on histology. Seven had clinical diagnosis of TS and the remaining 10, FCD with balloon cells (FCDBC).

RESULTS

Seventy percent of patients with FCDBC (mean follow-up 3.3 years) and 33% of patients with TS (mean follow-up 5.1 years) are seizure free after surgery. There was agreement between the diagnosis based on preoperative MR imaging and on histology in 60% of patients with FCDBC and 71% of patients with TS. Myelin depletion and calcification were noted more frequently in patients with TS.

CONCLUSIONS

No significant differences were noted between patients with refractory epilepsy caused by TS or FCDBC. There was a trend toward better postoperative seizure control in the FCDBC group. These two conditions are difficult to distinguish on the basis of MR and histologic appearances. The authors conclude that FCDBC likely represents a phenotypic variation of TS, and as such, all patients with balloon cell dysplasias should be carefully screened for other features of TS to enable appropriate genetic counseling.

Neuromagnetic spectral distribution of implicit processing of words

Neuromagnetic spectral distributions when silently viewing words and non-words were investigated using a 151-channel whole head MEG system. The data were analyzed with synthetic aperture magnetometry (SAM). The dominant changes of spectral power were identified in the parietal and occipital cortices in 15-30 Hz, 30-60 Hz and 60-125 Hz bands following both word and non-word stimulations. The changes in Broca's and Wernicke's areas were consistently observed in 60-125 Hz bands, mainly following word stimulation. The results indicated that the occipital and parietal cortices were most probably involved in visuospatial processing of words and non-words. The language areas, particularly Broca's and Wernickes's areas, might be involved in implicit word processing such as verbal searching and/or internal speech.

MEG predicts epileptic zone in lesional extrahippocampal epilepsy: 12 pediatric surgery cases

PURPOSE

To discover whether the spatial distribution of spike sources determined by magnetoencephalography (MEG) provides reliable information for planning surgery and predicting outcomes in pediatric patients with lesional extrahippocampal epilepsy.

METHODS

We retrospectively studied 12 children with extrahippocampal epilepsy secondary to cortical dysplasia (CD), tumor, or porencephalic cyst. We compared interictal MEG spike source locations and somatosensory evoked fields derived from equivalent-current dipole modeling with intraoperative or extraoperative electrocorticography (ECoG).

RESULTS

MEG spike sources were found in proximity to the lesion in all patients and extended from lesions in five patients with CD. Marginal spike sources were noted in three patients with tumors, one patient with a cyst, and one with CD, and extramarginal sources in three patients with tumors. Three patients with tumors underwent lesionectomy only; two had further cortical excisions. One patient with CD underwent lesionectomy only, three had lesionectomy and cortical excisions, and two had lesionectomy and multiple subpial transection. Asymmetric MEG spike sources correlated with ECoG findings in all patients. Residual epileptiform discharges on postexcisional ECoG corresponded to spike sources in three patients with tumors and one patient with a cyst. Eleven patients have been seizure free for 1-6 years (mean, 4 years). One patient had residual seizures after incomplete excision of right temporal CD.

CONCLUSIONS

MEG delineated asymmetric epileptogenicity surrounding lesions and the eloquent cortex. Complete tumor resection produced favorable outcomes despite residual postexcisional ECoG spikes and extramarginal MEG spike sources. CD characterized by clusters of MEG spike sources within and extending from lesions seen on magnetic resonance imaging (MRI) should be removed to prevent seizures.

Radiologic-pathologic correlation in focal cortical dysplasia and hemimegalencephaly in 18 children

To describe the radiologic-pathologic correlation in children who underwent epilepsy surgery for medically intractable epilepsy with pathologically confirmed focal cortical dysplasia and hemimegalencephaly, we conducted a retrospective review on the magnetic resonance imaging and pathology of 18 children (10 boys and 8 girls). The preoperative MRIs were reviewed by one neuroradiologist who did not know the radiologic diagnosis and the pathology reports. MRI revealed focal cortical dysplasia (10), hemimegalencephaly (3), hamartomas (2), polymicrogyria (1), pial hemosiderosis (1), and no abnormality (1). Pathologic examination revealed focal cortical dysplasia (9), forme fruste of tuberous sclerosis (5), hemimegalencephaly (3), and focal cortical dysplasia with mesial temporal sclerosis (1). MRI was accurate in making the preoperative diagnosis in 16 out of 18 patients. On MRI, 12 patients had abnormal gyral formation and 12 had abnormal cortical thickness. Eleven patients manifested loss of gray-white differentiation, and 11 patients had abnormal signal on T(2)-weighted image. Pathologically, 15 patients had neuronal heterotopia, 12 had misalignment or disorientation of neurons, 11 had large neurons, and 10 had abnormal cortical lamination. The presence of ectopic and large neurons and abnormal cortical lamination may be responsible for the MRI characteristics.

Comparison of electroencephalographic dipoles of interictal spikes from prolonged scalp video-electroencephalography and magnetoencephalographic dipoles from short-term recording in children with extratemporal lobe epilepsy

We retrospectively compared electroencephalographic (EEG) dipoles of interictal spikes from prolonged video-EEG monitoring with magnetoencephalographic dipoles from short-term recording in four children with extratemporal lobe epilepsy. We analyzed both sets of dipoles using individual interictal spikes and single moving dipole modeling and evaluated the profiles of spike appearance, dipole position, and orientation in EEG and magnetoencephalography. We obtained more than 100 magnetoencephalographic spikes in two patients who manifested frequent interictal EEG spikes throughout both day and night but fewer than 40 magnetoencephalographic spikes in two patients who had interictal EEG spikes mainly during sleep. The dipole positions of EEG and magnetoencephalography were in close proximity and included in the surgical resection area. Most of the dipoles between EEG and magnetoencephalography were oriented perpendicularly. A combination of EEG dipole analysis from prolonged video-EEG monitoring and magnetoencephalographic dipole analysis provides complementary information for presurgical evaluation in children with intractable extratemporal lobe epilepsy.

Malignant rolandic-sylvian epilepsy in children: diagnosis, treatment, and outcomes

OBJECTIVE

To describe the diagnosis, treatment, and outcomes in children with malignant rolandic-sylvian epilepsy (MRSE), defined as a form of epilepsy characterized by sensorimotor seizures, medical refractoriness, normal MRI, frontocentrotemporal EEG spikes, rolandic-sylvian spike sources on magnetoencephalography (MEG), and cognitive problems.

METHODS

A retrospective chart analysis of seven patients who had shown these characteristics and undergone extensive diagnostic testing, including MEG and intracranial video-EEG was performed.

RESULTS

Interictal scalp EEG spikes were seen over the frontocentrotemporal regions bilaterally (6) and unilaterally (1). MEG showed spike sources in the perisylvian region in two patients (both bilateral) and in the perirolandic fissure in five (two bilateral). Three patients required bilateral subdural strips to lateralize seizures before electrocorticography. Final electrocorticograms showed an ictal onset zone around the rolandic (four cases) and rolandic-sylvian regions (three cases). Six patients showed neuropsychological deficits. After cortical excision and multiple subpial transection, three were seizure free and four had seizures rarely (30 months' mean follow-up). No child had a permanent deficit in sensorimotor or cognitive functions, although two showed exacerbation of preexisting attentional deficits. Tissue analysis showed definite evidence of neuronal migration disorders (3) and gliosis (2).

CONCLUSIONS

MEG was helpful for localizing both malignant rolandic-sylvian neuronal activities and functional cortex. Successive neuropsychological assessments are necessary to detect cognitive deterioration and indicate remedial programming. If, after careful observation over at least 5 years, surgery is considered to control refractory seizures, intracranial video-EEG is needed to localize the epileptogenic zone.

Computerized brain-surface voltage topographic mapping for localization of intracranial spikes from electrocorticography. Technical note

The purpose of this paper is to describe the use of computerized brain-surface voltage topographic mapping to localize and identify epileptic discharges recorded on electrocorticographic (ECoG) studies in which a subdural grid was used during intracranial video electroencephalographic (IVEEG) monitoring. The authors studied 12 children who underwent surgery for intractable extrahippocampal epilepsy. Cortical surfaces and subdural grid electrodes were photographed during the initial surgery to create an electrode map that could be superimposed onto a picture of the brain surface. Spikes were selected from ictal discharges recorded at the beginning of clinically confirmed seizures and from interictal discharges seen on ECoG studies during IVEEG recording. A computer program was used to calculate the sequential amplitude of the spikes by using squared interpolation, and they were then superimposed onto the electrode map. Interictal discharges and high-amplitude spike complexes at seizure onset were plotted on the map. This mapping procedure depicted the ictal zone in nine patients and the interictal zone in 12, and proved to be an accurate and useful source of information for planning corrective surgery.

Image-guided, frameless stereotactic sectioning of the corpus callosum in children with intractable epilepsy

Corpus callosotomy is an effective neurosurgical procedure for children with intractable atonic or drop attack seizures. While this procedure has not changed significantly over the past three decades, some technical issues remain to be resolved. These include the intraoperative determination of the extent of the callosotomy, the need to stage the procedure, as well as side of approach of craniotomy. We report our 8-year experience with corpus callosotomy using a frameless stereotactic image-guided system (ISG Viewing Wand). Seventeen children with atonic seizures underwent sectioning of the corpus callosum. The mean patient age was 10.5 years. Six children underwent complete callosotomy while 11 underwent resection of the anterior two-thirds. MRI 3D reconstruction of the sagittal sinus and draining cerebral veins was undertaken in all cases. The side of the craniotomy was determined on the basis of favorability of the draining veins with respect to the extent of the callosotomy. The extent of the callosotomy was determined by intraoperative feedback using the ISG Viewing Wand((R)). Nine of 11 patients in the partial callosotomy group and 4 of 6 patients in the complete callosotomy group showed significant improvement in atonic seizures. We conclude that the use of frameless stereotaxy can function as an important adjunct in the planning and conduction of successful sectioning of the corpus callosum in children with intractable seizures.

Extraoperative cortical stimulation of motor function in children

The purpose of the study was to investigate factors altering the amperage threshold needed to provoke functional responses in children with epilepsy. Twenty patients (4-18 years of age) who underwent epilepsy surgery at our institution from 1996-2000 after insertion of subdural grid electrodes were reviewed retrospectively. Extraoperative electrical cortical stimulation was performed with 50-Hz biphasic pulses of 0.2 ms in duration using a "distance reference" technique. Amperage thresholds of primary motor responses and afterdischarges were evaluated. The patients were grouped according to underlying pathology: eight with neuronal migration disorders (group A) and 12 with other disorders (group B). The motor cortex was defined successfully in all children because the afterdischarges threshold was higher than the motor cortical threshold. Amperage thresholds ranged from 2-20 mA (mean = 7.7) for primary motor function. An inverse relationship was found between amperage threshold and age: the younger the patient, the higher the threshold (P = 0.0005). Patients in group A required a higher amperage (2-20 mA, mean = 8.6) for motor cortical mapping than those in group B (2-14 mA, mean = 6.4). Younger children with neuronal migration disorders require a higher amperage threshold to achieve adequate motor functional mapping with careful observation of afterdischarges.

Dipole localization for identification of neuronal generators in independent neighboring interictal EEG spike foci

PURPOSE

We evaluated dipole localizations of independent neighboring interictal spike foci using scalp electroencephalogram (EEG) to identify neuronal generators of epileptic discharges.

METHODS

Three pediatric patients with extratemporal lobe epilepsy who had two independent neighboring interictal spike foci on scalp EEG were studied. Prolonged video EEG was digitally recorded from 19 scalp electrodes, whose positions were registered using a three-dimensional digitizer. Interictal spikes were visually selected based on negative phase reversals on bipolar montages. We analyzed the dipole position and moment of each spike using a single moving dipole and three-shell spherical head model. The dipoles were overlaid onto magnetic resonance (MR) images and divided into two groups based on two spike foci.

RESULTS

The dipoles of the two groups were oriented either tangentially or radially to the scalp in close proximity to each other. The dipoles oriented radially were located underneath the electrode with a negative peak; those oriented tangentially were between electrodes with a negative and positive peak. The positions of tangential dipoles were more concentrated than those of radial dipoles. The epileptogenic regions corresponded to the dipole localizations. Surgical excisions were performed based on the results of electrocorticography. After surgery, two patients were seizure free, and one had rare seizures (follow-up period, 13-31 months).

CONCLUSIONS

We showed that dipoles in close proximity but with different orientations projected two negative maxima on scalp EEG in three patients with extratemporal localization-related epilepsy. Equivalent current dipole analysis of individual interictal spikes can provide useful information about the epileptogenic zone in these patients.

Magnetoencephalography and magnetic source imaging in children

Magnetoencephalography is a technique that detects the magnetic fields associated with the intracellular current flow within neurons, unlike electroencephalography, which measures extracellular volume currents. Superconducting quantum interference devices are used to amplify these very small magnetic field signals. Magnetic source imaging is the combination of functional data derived from magnetoencephalographic recordings coregistered with structural magnetic resonance imaging (MRI). The utility of magnetic source imaging lies in the combination of the submillisecond temporal resolution of magnetoencephalography with the precise anatomic images provided by magnetic resonance imaging. As such, magnetic source imaging is a useful tool for noninvasive localization of the epileptogenic zone in children who are candidates for epilepsy surgery. Similarly, using magnetoencephalographic recordings with evoked and event-related potentials, magnetic source imaging holds great promise as a noninvasive method for precise localization of somatosensory, motor, language, visual, and auditory cortex. Finally, magnetic source imaging is proving a valuable research tool in the investigation of epilepsy, head trauma, brain plasticity, and disorders of language, memory, cognition, and executive function in children.