Hemisphere In Children Research Articles

Glioneuronal tumors of cerebral hemisphere in children: correlation of surgical resection with seizure outcomes and tumor recurrences

Glioneuronal tumors are common neoplasms among the cerebral hemisphere during childhood. They consist of several histological types, of which gangliogliomas (GGs) and dysembryoplastic neuroepithelial tumors (DNTs) are most common and often present with seizures. A great majority of glioneuronal tumors are benign. However, there are conflict reports regarding postoperative tumor recurrence rates and seizure control. The authors analyzed and compared these tumors for their locations and histology and the tumor and seizure control following resection. The authors conducted a retrospective analysis of patients with pediatric glioneuronal tumors in the cerebral hemisphere. All histology reports and neuroimaging are reviewed. Seizure group and non-seizure group were compared with their tumor types and locations. The extent of tumor resections were divided into gross total resection (GTR) and subtotal resection (STR). Postoperative tumor recurrence-free survival (RFS) and seizure-free survival for patients who had the initial surgery done at our institution were calculated using Kaplan-Meier method. There were 90 glioneuronal tumors including 58 GGs, 22 DNTs, 3 papillary glioneuronal tumor, 3 desmoplastic infantile gangliogliomas, 3 anaplastic GGs, and 1 central neurocytoma. Seventy-one patients (seizure group) presented with seizures. The temporal lobe is the most common location, 50% in this series. GTR was attained in 79 patients and STR in 11. All of the patients with GTR had lesionectomy, and only six of them had extended corticectomy or partial lobectomy. Postoperative seizure outcome showed that 64 (90%) of seizure group had Engel's class I, but five patients subsequently developed recurrent seizures. Patients with DNTs had a higher seizure recurrence rate. Tumor RFS was 87% at 5years and 75.5% at 10years. There are no significant difference in tumor recurrences between GGs and DNTs (p = 0.876). Comparison between GRT (67) and STR (9) showed that in spite of the better 5-year tumor RFSs among GRT group (94%) than STR group (66%), the 10-year RFSs showed no significant difference between GRT and STR groups (p = 0.719). Recurrent seizures are often related to recurrent tumor. Lesionectomy alone often provides a high-rate seizure freedom. GGs and DNTs are benign tumor, but recurrences of GGs and DNTs are not uncommon. They may show late recurrences in spite of GTR. These patients need longer follow-up for 10years. Recurrent seizures are often related to a tumor recurrence.

Cerebral Reorganization after Hemispherectomy: A DTI Study.

Hemispherectomy is a neurosurgical procedure to treat children with intractable seizures. Postsurgical improvement of cognitive and behavioral functions is observed in children after hemispherectomy suggesting plastic reorganization of the brain. Our aim was to characterize changes in DTI scalars in WM tracts of the remaining hemisphere in children after hemispherectomy, assess the associations between WM DTI scalars and age at the operation and time since the operation, and evaluate the changes in GM fractional anisotropy values in patients compared with controls. Patients with congenital or acquired neurologic diseases who required hemispherectomy and had high-quality postsurgical DTI data available were included in this study. Atlas- and voxel-based analyses of DTI raw data of the remaining hemisphere were performed. Fractional anisotropy and mean, axial, and radial diffusivity values were calculated for WM and GM regions. A linear regression model was used for correlation between DTI scalars and age at and time since the operation. Nineteen patients after hemispherectomy and 21 controls were included. In patients, a decrease in fractional anisotropy and axial diffusivity values and an increase in mean diffusivity and radial diffusivity values of WM regions were observed compared with controls (P < .05, corrected for multiple comparisons). In patients with acquired pathologies, time since the operation had a significant positive correlation with white matter fractional anisotropy values. In all patients, an increase in cortical GM fractional anisotropy values was found compared with controls (P < .05). Changes in DTI metrics likely reflect Wallerian and/or transneuronal degeneration of the WM tracts within the remaining hemisphere. In patients with acquired pathologies, postsurgical fractional anisotropy values correlated positively with elapsed time since the operation, suggesting a higher ability to recover compared with patients with congenital pathologies leading to hemispherectomy.

NIMG-19NEURORADIOLOGIC CHARACTERISTICS OF ASTROBLASTOMA: A META-ANALYSIS BASED ON 127 PATIENTS IN 59 PUBLICATIONS

BACKGROUND AND AIMS: Astroblastoma is a rare tumor of uncertain origin most commonly presenting in the cerebral hemispheres of children and young adults. The literature has a few case reports and series regarding its radiologic features. This meta-analysis is the largest review of imaging findings to date and serves to differentiate astroblastoma from other neoplasms. METHODS: A PubMed search identified reports of astroblastoma with neuroimaging findings. Data collected included patient age, sex, tumor location, morphology, calcifications, calvarial changes and findings on computed tomography (CT) and magnetic resonance imaging (MRI), including diffusion weighted imaging (DWI). RESULTS: Patient age range at diagnosis was 0-70 years (mean 18 years; median 14 years) with a female:male ratio of 8:1. Of 127 cases, 65 reported CT, 78 reported MRI and 47 reported both CT and MRI findings. Tumor location was supratentorial in 96% (122/127), superficial in 71% (47/66), well-demarcated in 96% (79/82), cystic-solid in 93% (79/85), and enhancing in 99% (77/78). On CT, 84% (26/31) of astroblastomas were hyperattenuated. Calcifications were present in 77% (27/35), with five cases also reporting adjacent calvarial erosion. Astroblastomas were hypointense on T1 in 58% (25/43) and hypointense on T2 in 50% (23/46). Peritumoral edema was present in 79% (38/48) of cases, but typically described as slight. Few cases reported DWI sequences, with 100% (4/4) showing hyperintensity and decreased ADC values indicating restricted diffusion. CONCLUSION: Most astroblastomas occur in young females. 96%, 71%, 96%, 93%, 99% are supratentorial, superficial, well-defined, cystic-solid, and enhancing, respectively. On CT, most are hyperattenuated, have calcifications, and if superficial, may erode adjacent bone. On MRI, astroblastomas are characteristically dark on both T1 and T2 with 100% of cases showing restricted diffusion on DWI.

Interhemispheric Connectivity in Drug-Naive Benign Childhood Epilepsy With Centrotemporal Spikes

Decreased intelligence quotients (IQ) have been consistently reported in drug-naive benign childhood epilepsy with centrotemporal spikes (BECTS). We aimed to identify the neurophysiological basis of IQ deficits by studying interhemispheric and anatomical functional connectivity in BECTS patients. Resting-state functional and structural magnetic resonance images were acquired in 32 children with BECTS and 25 healthy controls. The IQ was estimated using Wechsler Intelligence Scale for Children China-Revised. The functional connectivity between bilateral homotopic voxels was calculated and compared between groups. Homotopic regions showing abnormal functional connectivity in patients were adopted as regions of interest for analysis by diffusion-tensor imaging tractography. The fractional anisotropy, fiber length, and fiber number were compared between groups. Abnormal homotopic connectivities were correlated with IQ in BECTS patients. Compared with control subjects, patients showed decreased IQ, and decreased voxel-mirrored homotopic connectivity (VMHC) in the bilateral frontal lobule and cerebellum. The performance and full scale IQ significantly increased with the VMHC strength of the middle frontal gyrus (MFG) in controls but not in BECTS patients. A significant negative correlation was observed between VMHC in the premotor cortex and disease duration. Microstructural features within white matter tracts connecting functionally abnormal regions did not reveal any differences between groups. This study provides preliminary evidence for the disrupted functional cooperation between hemispheres in children with BECTS. The findings suggest that the hyposynchrony between the bilateral MFG may be involved in the decreased IQ of BECTS patients.

Rapid eye movement sleep reveals epileptogenic spikes for resective surgery in children with generalized interictal discharges.

Epilepsy surgery can be successful in children with extensive congenital or early acquired focal or hemispheric brain lesion on magnetic resonance imaging (MRI) despite generalized interictal epileptiform discharges (IEDs). The aim of this study was to assess if rapid eye movement (REM) sleep reduced generalized IEDs and revealed lateralized IEDs to identify the epileptogenic hemisphere in children with generalized IEDs and normal/subtle changes on MRI. We studied 20 children with generalized IEDs on scalp electroencephalography (EEG) and normal/subtle changes on MRI who underwent intracranial video-EEG for epilepsy surgery. We assessed a minimum of 100 IEDs during REM, non-REM, and wakefulness, and assigned the distribution (generalized, left, or right hemisphere) to each IED. The number of lobes in the resected areas and seizure outcome were compared between 20 children with generalized IEDs and a comparison group of 28 children without generalized IEDs. The mean occurrence rate of generalized IEDs during REM (37%) was significantly lower than that during non-REM (67%, p < 0.001) and wakefulness (54%, p = 0.003). The number of children whose largest number of IEDs was lateralized in REM was significantly higher than that in non-REM (15 vs. 3 children, 75% vs. 15%, p < 0.001). The hemisphere with lateralized IEDs among three states corresponded with the surgical side in 16 children with generalized IEDs. Seventeen children (85%) with generalized IEDs and 27 (96%) without generalized IEDs underwent resective surgery. Multilobar resection was required for 16 children (94%) with generalized IEDs more frequently than 7 children (26%) without generalized IEDs (p < 0.001). Thirteen children (77%) with generalized IEDs and 19 (73%) without generalized IEDs were seizure-free with a mean of 3.3 years of follow-up. Our study demonstrates the importance of assessing REM in children with generalized IEDs as it reveals lateralized epileptogenic spikes. Seizure freedom may be achieved with multilobar resection in these children with generalized IEDs and normal/subtle changes on MRI. Generalized IEDs in children with normal/subtle changes on MRI should not preclude surgical resection.

EEG Abnormalities in Children with Speech and Language Impairment.

Epilepsy, a chronic condition of recurrent seizures, affects language, but the extent and nature of the language disturbance varies widely according to the type, severity, and cause of the epilepsy. There is paucity of literature on the electroencephalographic abnormalities in children with speech and language impairment. The present study was therefore planned to find the association of epileptiform EEG abnormalities in children with speech and language impairment and if present, their localization and lateralization to the language areas of the brain that are present predominantly in the left hemisphere. The study was conducted on Paediatric patients having speech and language impairment (n=94, age-2 to 8 years) selected on the basis of detailed history and neurologic examination. Video Electroencephalography (EEG) was performed as per American Clinical Neurophysiology Society guidelines using 16 channel RMS computerized EEG machine for a minimum of 40 minutes to capture both wakefulness and sleep along with activation procedures like hyperventilation (if feasible) and photic stimulation. EEG was reviewed for any abnormal EEG background, benign variants, interictal epileptiform discharges and ictal discharges. In our cohort, 19.7% boys and 22.2% girls presented with seizures in their infancy and this gender difference was found to be statistically significant (p<0.05). EEG was abnormal in 47.9% children (45 out of 94) with no significant gender difference. Epileptiform EEG was seen in 73.6% of children with history of seizures and 41.3% of children without history of seizures (p<0.05). The EEG abnormities included: abnormal background (64.5%), presence of generalized interictal epileptiform discharges (57.8%), focal epileptiform discharges (20%) exclusively from left hemisphere and multifocal interictal epileptiform discharges (33.3%), each occurring in isolation or associated with other abnormities. In the current study, it is definite that presence of generalized abnormalities in EEG are seen in higher frequency and focal interictal epileptiform discharges are solely seen in left hemisphere in children with speech and language impairment. Although, there is no distinct pattern of EEG abnormalities in such patients, we recommend a routine EEG in them and also brain imaging to complement the EEG findings.

Structural connectivity of the anterior cingulate in children with unilateral cerebral palsy due to white matter lesions.

In this work we investigate the structural connectivity of the anterior cingulate cortex (ACC) and its link with impaired executive function in children with unilateral cerebral palsy (UCP) due to periventricular white matter lesions.Fifty two children with UCP and 17 children with typical development participated in the study, and underwent diffusion and structural MRI. Five brain regions were identified for their high connectivity with the ACC using diffusion MRI fibre tractography: the superior frontal gyrus, medial orbitofrontal cortex, rostral middle frontal gyrus, precuneus and isthmus cingulate. Structural connectivity was assessed in pathways connecting these regions to the ACC using three diffusion MRI derived measures: fractional anisotropy (FA), mean diffusivity (MD) and apparent fibre density (AFD), and compared between participant groups. Furthermore we investigated correlations of these measures with executive function as assessed by the Flanker task.The ACC–precuneus tract had significantly different MD (p < 0.0001) and AFD (p = 0.0072) between groups, with post-hoc analysis showing significantly increased MD in the right hemisphere of children with left hemiparesis compared with controls. The ACC–superior frontal gyrus tract had significantly different FA (p = 0.0049) and MD (p = 0.0031) between groups. AFD in this tract (contralateral to side of hemiparesis; right hemisphere in controls) showed a significant relationship with Flanker task performance (p = 0.0045, β = −0.5856), suggesting that reduced connectivity correlates with executive dysfunction.Reduced structural integrity of ACC tracts appears to be important in UCP, in particular the connection to the superior frontal gyrus. Although damage to this area is heterogeneous it may be important in early identification of children with impaired executive function.

Intensity of functional connection between bilateral hemispheres of children with attention-deficit hyperactivity disorder by functional magnetic resonance imaging

To explore the neural mechanisms of attention-deficit hyperactivity disorder (ADHD) through analyzing the intensity of functional connection between bilateral hemispheres of children with ADHD by resting-state functional magnetic resonance imaging (rs-fMRI). The approach of voxel-mirrored homotopic connectivity (VMHC) was employed to analyze 31 school-age and 31 ADHD children by rs-fMRI scans. Positively activated brain regions were visualized when comparing ADHD and normal children, suggesting that ADHD children's VMHC scores were higher in bilateral frontal lobe (t = 5.81), bilateral occipital lobe (t = 5.82) and bilateral cerebellar posterior lobe (t = 6.17). Statistically significant differences existed between two groups (FDR correction, Q<0.01). The increased intensity of functional connection between bilateral prefrontal lobes in children with ADHD reflects attention disorder and leads to a decline of working memory . The strengthening of bilateral occipital lobes slows down memory process. And the increased intensity of cerebellar connections may damage neural circuits and aggravate ADHD symptoms.

Reduced integrity of sensorimotor projections traversing the posterior limb of the internal capsule in children with congenital hemiparesis

There is reduced integrity of corticospinal projections that traverse the posterior limb of the internal capsule (PLIC) in children with unilateral cerebral palsy (CP). It remains unclear whether there are changes in integrity of other projections traversing the PLIC. Forty children with congenital hemiparesis and 15 typically developing children underwent structural and diffusion-weighted MRI. All children with congenital hemiparesis showed lesions to the periventricular white matter. Structural images were parcellated into 34 cortical regions per hemisphere and posterior limb of the internal capsule was identified. PLIC connections to each cortical region were extracted using probabilistic tractography. Differences between hemispheres for each cortical projection (asymmetry index (AI)) and tract microstructure (fractional anisotropy (FA), mean diffusivity (MD)) were assessed. The results showed that 17 children (42.5%) with congenital hemiparesis showed bilateral lesions on structural MRI. Projections to the primary motor cortex (precentral gyrus and paracentral lobule) showed greater asymmetry in unilateral CP group compared to typically developing children and indicate reduced projections on the hemisphere contralateral to the impaired limb (i.e., contralateral hemisphere). Reduced FA and increased MD were also observed for connections with the primary motor cortex, primary sensory cortex (postcentral gyrus) and precuneus on the contralateral hemisphere in children with congenital hemiparesis. Similar changes were observed between children with unilateral and bilateral lesions on structural MRI. Notably, microstructural changes were associated with deficits in both sensory and motor function. The findings further unravel the underlying neuroanatomical correlates of sensorimotor deficits in children with congenital hemiparesis.

Changes in the integrity of thalamocortical connections are associated with sensorimotor deficits in children with congenital hemiplegia

Preservation of thalamocortical projections to the sensorimotor cortex is related to improved hand function in children with cerebral palsy (CP). Whether CP is associated with altered microstructure of these sensorimotor projections or other thalamocortical pathways remains unclear. Forty-two children with congenital hemiplegia and fifteen typically developing children (TDC) underwent structural and diffusion-weighted imaging (high-angular-resolution diffusion imaging) using a 3T MRI. Structural T1-images were parcellated into 34 cortical regions and the thalamus per hemisphere. Thalamocortical projections were extracted using probabilistic tractography and the top tan cortical regions with the greatest number of thalamocortical streamlines for the TDC group were selected for further analysis. The thalamus was parcellated based on its cortical connections. Differences between hemispheres for thalamocortical streamline numbers to each cortical region [asymmetry index (AI)], tract volume and tract microstructure [weighted mean fractional anisotropy (FA) and mean diffusivity (MD)] were calculated. Correlations between these measures (AI, FA and MD) and sensorimotor function were performed. Thalamocortical projections showed topographical organisation based on cortical connectivity. Projections to paracentral lobule, pre-central and post-central gyri showed greater AI in CP group, which indicates reduced streamlines on the ipsilesioned hemisphere. Reduced FA, reduced tract volume and increased MD were also found for these thalamocortical projections on the ipsilesioned hemisphere in children with CP. Changes in AI and tract microstructure of these projections were associated with poorer sensorimotor function. The findings suggest CP is associated with reorganisation of thalamocortical projections to the sensorimotor cortex. Integrity in these projections may underpin deficits in sensorimotor function.

Electrophysiological Correlates of Category Induction in Children and Adults

Category induction involves abstraction of features common to two or more stimuli. Event-related potentials (ERPs) during induction and non-induction tasks were recorded for 12 children and 12 adults. We found that (1) ERP waves, except P2 amplitude, decreased significantly with age, (2) Compared to non-induction tasks, induction tasks elicited larger fronto-central N2 components in both age groups, (3) The amplitude of the late positive component was significantly greater in the induction condition than in the non-induction condition, and (4) The difference wave suggested that category induction was mainly located in the left hemisphere in children but was not lateralized in adults.

Xantoastrocitoma pleomórfico con extensión intraventricular y transformación anaplásica en paciente adulto: caso clínico

Pleomorphic xanthoastrocytoma (PXA) is a rare, low-grade astrocytic tumour that usually occurs in the superficial cerebral hemispheres of children and young adults. Although it has a relatively favourable prognosis, malignant progression of these tumours has been described. Therefore, we present an unusual case of a 54-year-old male with a right, multicystic, parietooccipital tumour extending through the ipsilateral ventricle. After surgical resection, histological examination revealed a lesion with pleomorphic cells, cytoplasmic lipidisation, intensely eosinophilic granular bodies, well-delimitated unique nuclei and focal, positive immunoreactivity for synaptophysin, glial fibrillary acidic protein (GFAP), S-100 protein, vimentin and CD56. Once other tumours, such as giant cell metastatic carcinoma or primary lesion like subependymal giant cell astrocytoma, were ruled out, a final diagnosis of XAP was established. After a follow-up period of 9 months, the patient suffered an extensive and local tumour relapse considered inoperable, with progressive neurological deterioration and radiological findings of malignant progression. The brain biopsy procedure revealed anaplastic changes, including necrosis foci, higher mitotic activity (5×10 high-power fields) and a 10% proliferation index measured by Ki67 labelling. The present case showed intraventricular extension and a more aggressive behaviour, both uncommon in these tumours (similar to anaplastic astrocytoma or glioblastoma multiforme), thus demanding an initial, optimal surgical treatment with close clinical and radiological follow-up, due to the high potential for malignant transformation of XAPs.

Lateralized interictal epileptiform discharges during rapid eye movement sleep correlate with epileptogenic hemisphere in children with intractable epilepsy secondary to tuberous sclerosis complex

We assessed lateralization of interictal epileptiform discharges (IEDs) in children with intractable epilepsy secondary to tuberous sclerosis complexes (TSCs) during rapid eye movement sleep (R), compared with non-rapid eye movement sleep (NR) and wakefulness (W), to determine epileptogenicity of R-IEDs. We retrospectively studied 23 children with TSC, who underwent prolonged scalp video-electroencephalography (EEG) and magnetic resonance imaging (MRI). We determined the lateralization of ictal EEG, clinical semiology, and the largest tuber on MRI. We analyzed a minimum of 100 IEDs during R, NR, and W to classify right/left/generalized spikes to compare the lateralization with ictal EEG, clinical semiology, and MRI. R-IEDs were lateralized in 22 patients (96%), W-IEDs in 19 (83%), and NR-IEDs in 16 (70%). Ictal EEGs were lateralized in 15 patients (65%) and clinical semiology in 5 (22%). Ictal EEG lateralization was concordant to R-IEDs in 14 patients (93%), W-IEDs in 11 (73%), and NR-IEDs in 10 (67%). The lateralization of clinical semiology was concordant with R-IEDs in 4 (80%), W-IEDs in 3 (60%), and NR-IEDs in 2 (40%). MRI lateralization of the largest tuber was concordant with R-IEDs in 16 (70%), W-IEDs in 12 (52%), and NR-IEDs in 11 (48%). Thirteen patients (57%) underwent resective surgery, the hemisphere of which was concordant with R-IEDs in 13 (100%), W-IEDs in 8 (62%), and NR-IEDs in 8 (62%). Nine (69%) of them achieved good seizure control after surgery. R provoked the most lateralized IEDs compared to NR and W in children with TSC. Lateralization of R-IEDs corresponded with the hemisphere of ictal EEG and largest tuber, and can be used to identify surgical candidacy in TSC children with intractable epilepsy.

Auditory event-related potentials show altered hemispheric responses in dyslexia

Dyslexia is characterized by deficits in phonological processing abilities. However, it is unclear what the underlying factors for poor phonological abilities or speech sound representations are. One hypothesis suggests that individuals with dyslexia have problems in basic acoustic perception which in turn can also cause problems in speech perception. Here basic auditory processing was assessed by auditory event-related potentials recorded for paired tones presented in an oddball paradigm in 9-year-old children with dyslexia and a familial background of dyslexia, typically reading children at familial risk for dyslexia and control children without risk for dyslexia. The tone pairs elicited a P1–N250 complex with emerging N1–P2 complex. Control children showed larger responses over the left-than-right hemisphere at the P1 and P2 time windows for both short and long within-pair intervals (WPI; 10 and 255 ms) whereas children with dyslexia showed this pattern only for the tone pairs with the long WPI. The response for the pairs with the short WPI showed equal amplitudes over both hemispheres in children with dyslexia. The findings indicate that individuals with dyslexia process basic auditory information differently when the tones are within the temporal window of integration.

The frequency profile of somatosensory evoked magnetic fields in the developing brain

Event Abstract Back to Event The frequency profile of somatosensory evoked magnetic fields in the developing brain Yingying Wang1, 2*, Jing Xiang2, Douglas Rose1, 2, Tom Holroyd3, Elana Harris2 and Ton DeGrauw2 1 University of Cincinnati, United States 2 Cincinnati Children's Hospital Medical Center, United States 3 National Institute of Mental Health, United States The objective of this paper is to study the variations of magnetic fields evoked by index finger stimulation in four age groups (6-9, 10-13, 14-17 and 18-49 years old) of normal population. We recorded magnetic fields during unilateral electrical stimulation of the index finger in 60 healthy children (7±1.2, 12±1.3 and 15±1.1) and 20 healthy adults (30±5.7) using a 275-channel whole head magnetoencephalography (MEG) system. Each group consisted of 10 females and males. Electrical stimulation was applied in randomized order to the right or left index finger with two digital rings. One hundred trials were recorded for both the right and left index finger stimulations. MEG data were analyzed in both the time and frequency domains. Brain regions associated with finger stimulations were localized with the equivalent current dipoles (ECDs). Time-frequency analysis was at the source level with a vector beamformer and Morlet wavelets. Our data have revealed evoked neuromagnetic signals in low-frequency ranges (10-40 Hz). In addition, the spectrograms revealed consistent focal increases of spectral power around 120-200 Hz in the left and right hemispheres in children. Furthermore, the neuromagnetic activation above 200 Hz was also observed, which were in the frequency range of 600-890 Hz. The preliminary data suggest that neuromagnetic signals above 120 Hz in the developing brain are noninvasive detectable. Conference: Biomag 2010 - 17th International Conference on Biomagnetism , Dubrovnik, Croatia, 28 Mar - 1 Apr, 2010. Presentation Type: Poster Presentation Topic: Sensory Processing and Functional Connectivity Citation: Wang Y, Xiang J, Rose D, Holroyd T, Harris E and DeGrauw T (2010). The frequency profile of somatosensory evoked magnetic fields in the developing brain. Front. Neurosci. Conference Abstract: Biomag 2010 - 17th International Conference on Biomagnetism . doi: 10.3389/conf.fnins.2010.06.00134 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 25 Mar 2010; Published Online: 25 Mar 2010. * Correspondence: Yingying Wang, University of Cincinnati, Cincinnati, United States, wang2yg@mail.uc.edu Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Yingying Wang Jing Xiang Douglas Rose Tom Holroyd Elana Harris Ton DeGrauw Google Yingying Wang Jing Xiang Douglas Rose Tom Holroyd Elana Harris Ton DeGrauw Google Scholar Yingying Wang Jing Xiang Douglas Rose Tom Holroyd Elana Harris Ton DeGrauw PubMed Yingying Wang Jing Xiang Douglas Rose Tom Holroyd Elana Harris Ton DeGrauw Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Paradoxical ictal EEG lateralization in children with unilateral encephaloclastic lesions

Describe an ictal EEG pattern of paradoxical lateralization in children with unilateral encephaloclastic hemispheric lesion acquired early in life. Of 68 children who underwent hemispherectomy during 2003-2005, scalp video-EEG and brain MRI of six children with an ictal scalp EEG pattern discordant to the clinical and imaging data were reanalyzed. Medical charts were reviewed for clinical findings and seizure outcome. Age of seizure onset was 1 day-4 years. The destructive MRI lesion was an ischemic stroke in 2, a post-infectious encephalomalacia in 2, and a perinatal trauma and hemiconvulsive-hemiplegic syndrome in one patient each. Ictal EEG pattern was characterized by prominent ictal rhythms with either 3-7 Hz spike and wave complexes or beta frequency sharp waves (paroxysmal fast) over the unaffected (contralesional) hemisphere. Scalp video-EEG was discordant, however, other findings of motor deficits (hemiparesis; five severe, one mild), seizure semiology (4/6), interictal EEG abnormalities (3/6), and unilateral burden of MRI lesion guided the decision for hemispherectomy. After 12-39 months of post-surgery follow up, five of six patients were seizure free and one has brief staring spells. We describe a paradoxical lateralization of the EEG to the "good" hemisphere in children with unihemispheric encephaloclastic lesions. This EEG pattern is compatible with seizure free outcome after surgery, provided other clinical findings and tests are concordant with origin from the abnormal hemisphere.

The Early Attachment Experiences are the Roots of Psychopathy

This review proposes the ‘attachment and the deficient hemispheric integration hypothesis’ as explanation for psychopathy. The hypothesis states that since secure attachment to the parents is essential for the proper development of both the hemispheres in children, psychopaths with histories of neglect and abuse are unable to develop efficient interaction of both the hemispheres, important for emotional processing and regulation. Various studies have shown that without an efficient interaction between the two hemispheres psychopaths fail to perform adequately on tasks that require both language abilities and non-verbal emotional processing. The hypothesis also explains why psychopaths will perform inefficiently in conditions that selectively prime the left hemisphere resources as these people would have learnt to rely more on the language based mode of this hemisphere. The childhood of psychopaths is marked by insecure attachment with their parents where the parents fail to respond to the needs of the preverbal infant thus leading to improper development of the right hemisphere abilities, one of which is decoding and showing appropriate non-verbal emotional signals resembling a pattern shown by the parents. The hypothesis is useful in explaining different findings on laterality in psychopathy as well as answering the nature-nurture debate of the disorder. Research carried out under the proposed framework can be helpful in understanding the nature of the disorder which will be ultimately useful in the prevention of its full blown manifestation.

Is streamlined evaluation of children for epilepsy surgery possible?

The presurgical evaluation of children with intractable epilepsy includes evaluation by an experienced clinician, MRI, video EEG, and functional imaging techniques to localize seizure onset. However, the contributions of each investigation to surgical decision making has not been systematically assessed. Data used for decision on eligibility for surgery on 353 children was discussed at a presurgical multidisciplinary meeting and systematically recorded. The relationships between MRI, EEG, SPECT findings, and the probability of being offered epilepsy surgery were investigated retrospectively using a quick unbiased statistical tree (QUEST). Sixteen children were offered nonresective surgery. Of the remaining, 236 (70%) were offered resective surgery. The proportion of children with a localized lesion on MRI offered resective surgery was 92%[95% CI: 88 to 95%], and EEG telemetry did not modify decision making in this group (p < 0.001). In children with bilateral MRI changes or normal scan the probability of being offered resective surgery was 78% in those with localized ictal onset on EEG compared to 9% with nonlocalized EEG (p < 0.001). SPECT did not appear to systematically influence decision making in any group. Children with medically intractable epilepsy and localized lesions on MRI may not necessarily need ictal EEG recordings or SPECT prior to offering resective surgery. More targeted use of EEG telemetry could allow more children with less obvious surgical targets to be investigated without increasing resources.

Hemispheric Differences in Cerebral Autoregulation in Children with Moderate and Severe Traumatic Brain Injury

To examine hemispheric differences in cerebral autoregulation in children with traumatic brain injury (TBI). After IRB approval and consent, subjects underwent static cerebral autoregulation testing during the first 9 days after PICU admission. Cerebral autoregulation was quantified using the autoregulatory index (ARI). Forty-two (27 M:15 F) children (10 +/- 5 years) with TBI and admission Glasgow coma scale score (5 +/- 2) were enrolled. Seven (54%) of the 13 children with focal TBI and 8 (28%) of 29 children with diffuse TBI had impairment or absence of cerebral autoregulation of at least one hemisphere. In patients with isolated focal TBI, ARI was lower (0.40 +/- 0.40 vs. 0.67 +/- 0.40; P = 0.03) in the side of TBI than in the unaffected hemisphere, but cerebral autoregulation was often impaired on the side without TBI or shift (5/13) on head CT. There was no difference in ARI between hemispheres in children with diffuse TBI, with or without superimposed focal lesions (P = 0.17). Patients with bilateral intact cerebral autoregulation tended to have higher 6 month Glasgow Outcome Score (GOS) than patients with either unilateral or bilateral cerebral autoregulation impairment (GOS 4.0 +/- 0.60 vs. 3.6 +/- 0.80; P = 0.08). Hemispheric differences in cerebral autoregulation were common in children with isolated focal TBI. Absence of TBI on CT was not always associated with intact cerebral autoregulation. Patients with bilaterally intact cerebral autoregulation tended to have better outcomes.

Evaluation of RB Gene and Cyclin-Dependent Kinase Inhibitors P21 and P27 in Pleomorphic Xantoastrocytoma

Pleomorphic xantoastrocytoma (PXA) is a rare, circumscribed astrocytic tumor that usually occurs in the superficial cerebral hemispheres in children and young adults. Most patients have a favorable prognosis, but recurrence and malignant transformation have been reported. In diffuse gliomas, approximately one third demonstrate mutations of the RB gene. Low expression level and high activity of p27 are known to constitute an independent prognostic factor in patients with malignant gliomas, while p21 expressions have variable labeling ranges. The molecular and genetic basis for tumorigenesis and progression of PXA are still largely unknown. In this study, 13 PXAs were examined immunohistochemically for pRb, p21, and p27 expression. Nine PXAs expressed homogeneous pRb positivity in the most nuclei of the tumor cells. Four cases showed an abnormal pRb staining pattern. All PXAs were positive for nuclear expression of p21. Diffuse nuclear positivity of p27 was seen in 10 cases, focal in 2, and in 1 case was not present. The cases with focal and negative p27 nuclear expression had few pRb-positive nuclei. The majority of PXAs appear to have preserved pRb, p21, and p27 functions. Additional studies are necessary to investigate whether cases with altered pRb and p27 expressions are associated with increased risk of recurrence or malignant transformation.