Frontal Location Research Articles

Association between molecular alterations and tumor location and MRI characteristics in anaplastic gliomas.

The aim of this study was to determine if molecular alterations are associated with tumor location and radiological characteristics in anaplastic gliomas. We performed a retrospective analysis of 122 anaplastic gliomas for molecular alterations (IDH1/2 mutations, TP53 mutations, and 1p19q co-deletion) to compare MRI features (location and image characteristics). We observed that IDH mutation is strongly associated with frontal location (P=0.001). However, 13 tumors not located in the cerebral cortex were IDH intact tumors (P<0.0001). While IDH mutation and TP53 mutation are significantly associated with AA (p<0.0001), IDH mutation and 1p19q co-deletion were significantly associated with AO/AOA (p<0.0001). No tumors with IDH mutation and 1p19q co-deletion infiltrated the temporal lobe (P=0.003). The tumors with 1p19q co-deletion and histologically diagnosed as AO/AOA were associated with contrast enhancement on MR images (p=0.007, p=0.002, respectively) and those with TP53 mutation had a weak association with sharp tumor borders (p=0.043). MRI features might be useful to predict molecular profiles in anaplastic gliomas.

RT-20 * DELAYING RADIOTHERAPY IN 1p19q CO-DELETED AND PARTIALLY DELETED GLIOMAS

BACKGROUND: Radiotherapy with procarbazine, lomustine and vincristine improves overall survival (OS) in patients with 1p19q codeleted anaplastic oligodendroglioma (AOD)/anaplastic oligoastrocytoma (AOA). This retrospective study investigates outcomes with upfront temozolomide (TMZ) deferring radiotherapy in 1p19q codeleted/partially deleted AOD, AOA, oligodendroglioma (OD) or oligoastrocytoma (OA). METHODS: Patients with 1p19q codeleted/partially deleted AOD, AOA, OD and OA were analyzed for OS and progression-free survival (PFS) using Kaplan-Meier method. RESULTS: A total of 106 patients (Dec 97-Dec 13) were included. Median age was 40 years (19-66), 58 (55%) male, performance status (PS) 0 in 80 (75%) patients. 1p19q status; codeleted in 66 (62%), incompletely codeleted in 27 (25%), 1p or 19q loss alone in 4 (4%) and 9 (8%) patients respectively. Reason for presentation was seizures in 79 (75%), frontal lobe tumor location in 62 (58%) and contrast enhancement in 50 (47%). Upfront treatment was given in 72 (68%) patients; TMZ alone in 52 (49%) was well tolerated with med 12 cycles (1-24). Median time to radiotherapy in 47 patients (44%), 34.7mo. Median time to radiotherapy in AOD, AOA, OD, OA was 22.4mo, 1.4mo, 43.2mo and 43.4 mo respectively, given in median 3rd line of treatment (range 2-4), 41.2 mo (16.3-93.2) in 9 patients with codeleted/incompletely codeleted AOD who received upfront TMZ alone. Median OS was not reached for all groups (median follow up 5.1yrs). Median time to treatment for 36 patients with 1p19q codeleted/partially deleted AOD/AOA treated with TMZ alone upfront was 49.5 days (range 9-2248), median PFS was 46.3 months. On multivariable analysis, PS 1 vs 0 (Hazard ratio [HR]2.78, 95%confidence interval[CI] 1.57-4.93, p < 0.001) and 1p19q codeletion/incomplete deletion vs 1p or 19q loss alone (HR0.36, 95%CI 0.18-0.74, p = 0.005) were prognostic for PFS. Isocitrate dehydrogenase-1 status is pending. CONCLUSION: Delaying radiotherapy in 1p19q codeleted/incompletely deleted AOD/AOA may be a treatment option.

Epilepsy associated with Leukoaraiosis mainly affects temporal lobe: a casual or causal relationship?

To compare anatomo-electro-clinical findings between patients with epilepsy associated with leukoaraiosis only (EAL) and patients with a well-defined vascular lesion, i.e. post-stroke epilepsy (PSE). Two hundred eighty-three subjects with epilepsy and cerebrovascular disease, consecutively seen in our epilepsy centres from January 2000 to March 2014, were retrospectively considered. Inclusion criteria were: history of one or more unprovoked seizures and MRI evidence of one or more vascular lesions. Exclusion criteria were: inadequate neuroimaging data, coexistence of nonvascular lesions, and psychogenic seizures. Subjects were divided in two groups: PSE and EAL, based onclinical and MRI findings. Epileptogenic focus was identified according to ictal semiology and EEG findings. In PSE group, coherence between the vascular lesion(s) and epileptogenic focus was scored as likely or unlikely. One hundred seventeen subjects were included: 58 had PSE, 59 EAL. Coherence was identified as likely in 38 (95%) and unlikely in 2 (5%). At univariate analysis, abnormal EEG and frontal localization were associated with a lower EAL probability [odds ratio (OR) 0.36, 95% confidence interval (CI) 0.15-0.87, p=0.02 and OR 0.12, 95% CI 0.04-0.37, p<0.001, respectively], while temporal localization was associated with a higher EAL probability (OR 4.0, 95% CI 1.8-9.0, p<0.001). Multivariate confirmed these associations. While in PSE epileptogenic focus is coherent with the vascular lesions, in EAL temporal lobe epilepsy predominates. In EAL, causal relationship between vascular lesions and epilepsy is not straightforward, and the role of adjunctive factors needs to be elucidated.

P17.92 * GLIOBLASTOMA IN ELDERLY PATIENTS: SURVIVAL OUTCOME

BACKGROUND: The management of glioblastoma (GB) in elderly patients is not well established. The incidence is higher in this population and is expected to increase over the next decades in relation with an aging population in western countries. Otherwise GB is the most life-threatening primary brain tumor especially in elderly patients and survival is significantly less than seen in younger patients. Until recently, this patients have been excluded from randomized trials and the effectiveness of the conventional active treatment has been controversial, since benefit was attenuated in older and there are concerns about mental deterioration. Different treatment approaches have been proposed. Here we review our experience in this population. METHODS: The authors retrospectively reviewed 53 patients at a single institution from February 2005 to March 2013. Patients were 70 years of age and older with histologically confirmed GB. RESULTS: Median age was 75 years (range 70-88). Fifty-six percent were men and 43% women. Most had frontal lobe location (37.7%) followed by temporal lobe (32%). Majority of patients had some kind of morbidity (89%), mainly arterial hypertension (55%) diabetes (13%) and thyroid function alteration (17%). Partial resection was planned in 49% of cases and a complete resection in 45%. After surgery, 71% received radiotherapy, in 45% of cases the dose was 60 Gy and in 26% was 30 Gy. Nearly 40% were treated with concomitant and adjuvant temozolomide. The median umber of cycles was 4,43 (range 1-14). Median survival for the whole cohort was 7,36 m (95% CI 4,8-9,8) and 8,3m for those who received some kind of treatment after surgery. Treatment with temozolomide concomitant and adjuvant (Stupp regimen) was associated with longer overall survival ( 11,16 months vs 4,1m p = 0.008 ). The median overall survival was 8,3 months for those who received radiotherapy and 1,5m for those who did not (p = 0,046). Differences were found between those treated with 30 or 60 Gy in terms of overall survival in favor of 60Gy treatment ( 6,3 vs 11,1 m) but didnt reach the statistical significance level (p = 0.143). Compared with temporal location, patients with tumor located in parietal lobe had a better overall survival. In 10% of cases received a second line treatment after progression and median survival was 4,8 months. CONCLUSION: Elderly patients diagnosed with GB had worst prognosis. In our experience, in patients with newly diagnosed glioblastoma over the age of 70, more intensive treatment was associated with prolonged OS, and results are close to those obtained from younger patients. Nevertheless these are retrospective data and a selection bias may be the explanation. Further randomized trial should be conducted to investigate this topic.

Clinical Outcomes in Cranioplasty

Continuing advances in cranioplasty have enabled repair of increasingly complicated cranial defects. However, the optimal materials and approaches for particular clinical scenarios remain unclear. This study examines outcomes following cranioplasty for a variety of indications in patients treated with alloplastic material, autogenous tissue, or a combination of both. a retrospective analysis on 180 patients who had 195 cranioplasties performed between 1993 and 2010. Materials used for cranioplasty included alloplastic for 42.6 percent (83 of 195), autologous for 19.0 percent (37 of 195), and both combined for 38.5 percent (75 of 195). Mean defect size was 70.5 cm. A subset of patients had undergone previous irradiation (12.2 percent; 22 of 180) or had preoperative infections (30.6 percent; 55 of 180). The most common complication was postoperative infection (15.9 percent; 31 of 195). Factors that significantly predisposed to complications included preoperative radiation, previous infection, and frontal location. Preoperative radiation was the strongest predictor of having any postoperative complications, with an adjusted odds ratio of 6.91 (p < 0.005). Irradiated patients (OR, 7.96; p < 0.05) and patients undergoing frontal cranioplasties (OR, 2.83; p < 0.05) were more likely to require repeated operation. Preoperative infection predisposed patients to exposure of hardware in alloplastic reconstructions (OR, 3.13; p < 0.05). Despite the evolution of cranioplasty techniques and materials, complications are not uncommon. The choice of reconstructive material may modify the risk of developing postoperative complications but appears less important than the clinical history in affecting outcome. Risk, III.

2.12. A moot point! A case report on potential projectile movement on postmortem MR

Objective This homicide case we investigate potential projectile movement on postmortem MR (PMMR) in a lodged ricochet projectile in the skull. The purpose of this case report is to evaluate the different aspects of PMMR-related properties of projectiles in gunshot wounds. Material and method The case underwent whole body postmortem computed tomography (Somatom Definition Flash Dual Source, Siemens Medical Solutions, Forchheim, Germany) in supine position, 3D-suface scanning (Atos Compact Scan 5 m, GOM mbH, Braunschweig, Germany) with reposition of the corpse to prone position and PMMR (Achieva 3.0 TX MR scanner, Philips Medical System, Best, The Netherlands). For validation purposes a later head CT-scan in supine position and subsequent autopsy was performed. Ferromagnetic properties of the projectile were tested. Results Imaging revealed projectile movement between PMCT and PMMR. The ricochet projectile showed bullet migration along the wound channel on PMMR from midbrain position to a frontal location of the bullet. The bullet did not produce susceptibility artifacts on PMMR. Autopsy revealed no heating effects of the adjacent tissue indicating no thermal effects by the PMMR scanning. The bullet showed no ferromagnetic properties after being tested by a magnet and literature review of the metallic compounding of this specific projectile. Therefore, the bullet migration was caused by repositioning of the corpse from supine to prone position along the ricochet wound channel. Conclusion Presence of susceptibility artifacts on PMMR images depend on the material compounds of the projectile. PMMR allows for better anatomical detail of bullet path within the soft tissue and may be performed in the vast majority of projectiles.

Wind forced variability of the Antarctic Circumpolar Current south of Africa between 1993 and 2010

AbstractThe variability of the Antarctic Circumpolar Current (ACC) system is largely linked to the atmospheric forcing. The objective of this work is to assess the link between local wind forcing mechanisms and the variability of the upper‐ocean temperature and the dynamics of the different fronts in the ACC region south of South Africa. To accomplish this, in situ and satellite‐derived observations are used between 1993 and 2010. The main finding of this work is that meridional changes in the westerlies linked with the Southern Annular Mode (SAM) drive temperature anomalies in the Ekman layer and changes in the Subantarctic Front (SAF) and Antarctic Polar Front (APF) transports through Ekman dynamics. The development of easterly anomalies between 35°S and 45°S during positive SAM is linked to reduced (increased) SAF (APF) transports and a warmer mixed layer in the ACC. The link between the changes in the wind stress and the SAF and APF transport variations occurs through the development of Ekman pumping anomalies near the frontal boundaries, driving an opposite response on the SAF and APF transports. The observed wind‐driven changes in the frontal transports suggest small changes to the net ACC transport. In addition, observations indicate that the SAF and APF locations in this region are not linked to the local wind forcing, emphasizing the importance of other factors (e.g., baroclinic instabilities generated by bottom topography) to changes in the frontal location. Results obtained here highlight the importance of repeat XBT temperature sections and their combined analysis with other in situ and remote sensing observations.

Intensification and variability of the confluence of subtropical and subantarctic boundary currents east of New Zealand

AbstractThe confluence of subtropical and subantarctic boundary currents east of New Zealand creates strong fronts. The fronts have clear signatures in sea surface height (SSH) and sea surface temperature (SST) which make the confluence a good region to investigate the variability of the boundary currents of the South Pacific. Analysis of the 20 year time series of the SSH is used to investigate the location and strength of fronts, measured as the gradient in SSH (∇SSH), and the eddy kinetic energy (EKE) and their relationship to local and large‐scale wind forcing. The intensity of the ∇SSH and the EKE have increased at a rate of 0.02 cm km−1 and 32 cm2 s−2 decade−1, respectively. There is a significant correlation (r = 0.7, p &lt; 0.01) between the ∇SSH and EKE signals, reflecting baroclinic instabilities inherent in the fronts. Differences between northward and southward wind‐driven transports across the confluence from the Island Rule are also increasing at 7.5 Sv decade−1 along with an upward trend in the SST differences across the region. Time series of the Southern Annular Mode (SAM) and Southern Oscillation Index (SOI) and local winds were compared to the frontal strength. Although the positive trend in the SOI coincides with increasing subtropical inflows, there is little correspondence of the indices and local winds with short‐term variability. While these results indicate a connection between the intensification of the confluence and South Pacific winds, there is little change in frontal location north of Bollons Seamount which suggests bathymetry influences the location of the confluence.

Prognostic Implication of Preoperative Behavior Changes in Patients with Primary High-Grade Meningiomas

High-grade meningiomas are rare extra-axial tumors, frequently causing brain invasion and prominent brain edema. Patients harboring high-grade meningiomas occasionally present with behavior changes. Data about frequency and prognostic importance of preoperative behavior changes in patients with high-grade meningiomas is missing. 86 patients with primary high-grade meningiomas were analyzed. Statistical analysis was performed to determine correlation of preoperative behavior changes with tumor location, preoperative brain edema, tumor cleavability, tumor grade, Ki67 proliferation index, and microscopic brain invasion. Survival analysis was performed. 30 (34.9%) patients presented with preoperative behavior changes. These changes were more frequent with male patients (P = 0.066) and patients older than 55 years (P = 0.018). They correlated with frontal location (P = 0.013), tumor size (P = 0.023), microscopic brain invasion (P = 0.015), and brain edema (P = 0.006). Preoperative behavior changes did not correlate with duration of symptoms, tumor cleavability, tumor malignancy grade, and Ki67 proliferation index. They were not significantly related to overall survival or recurrence-free survival of patients with primary high-grade meningiomas. Preoperative behavior changes are frequent in patients harboring primary high-grade meningiomas. They correlate with tumor size, microscopic brain invasion, and brain edema. Preoperative behavior changes do not predict prognosis in patients with primary high-grade meningiomas.

Phenomenological Interpretation of the Experience of Nature in the Works of Le Corbusier

This research seeks to evaluate the experience of nature in the architectural instruments as created by Le Corbusier, in terms of the phenomenology of corporal experience. The architecture of Le Corbusier is active in viewing the spectacular landscape of nature through frontal localization, windows, ramps, and roof gardens. His architecture has the attitude of separating from earth and opposing and viewing nature as an autonomic machine. The nature experience of Le Corbusier is largely divided into seeing from on high and seeing while walking. Considering the senses of the body and the aspects of movement responding to each situation, the experience of seeing and contemplating nature on a large scale has an abstract quality. Seeing nature as an object from afar basically limits the experience in the information of the senses and the abstraction of nature. For the concrete experience of nature, what is needed is the idea that the body takes part in the diverse sensorial worlds and is simultaneously taken in by the situation. This research also aims to reconsider the qualities of experiences of nature, based on the modernity characterized by the separation of human from nature and sprit from body.

Correlation of IDH1/2 mutation with clinicopathologic factors and prognosis in anaplastic gliomas: a report of 203 patients from China

Isocitrate dehydrogenase (IDH) gene mutation is one of the most exciting new advances in these years. It has been reported that IDH gene frequently altered in grade II and grade III gliomas. We aimed to identify the mutation frequency of IDH genes in Chinese anaplastic glioma patients, the association of IDH gene mutation with other clinical and molecular pathological features and the prognostic value of it. We performed polymerase chain reaction-based IDH gene mutation detection in 203 anaplastic glioma patients from China. A total of 108 and 3 patients harbored IDH1 and IDH2 gene mutation, respectively. And there was a higher proportion of MGMT promoter methylation, frontal lobe location, and better outcome and lower proportion of temporal location in IDH-mutated samples. There were hardly any significant association between protein expression level of well-known markers and IDH mutation. Anaplastic oligoastrocytoma and anaplastic astrocytoma patients with IDH gene mutation showed similar prognosis with anaplastic oligodendroglioma patients with wild-type IDH gene. IDH gene mutation is a good prognostic marker and a potential substratification factor for anaplastic glioma patients.

118. Neonatal cortical auditory evoked potentials are affected by bronchopulmonary dysplasia occurring in early prematurity

Bronchopulmonary dysplasia, the most frequent respiratory sequelae of prematurity, usually occurs as part of the multiorgan foetal inflammatory response syndrome. The underlying mechanism is thought to be the same cytokine mediated leukemoid reaction associated with periventricular leukomalacia of premature infants. Event-related potentials have been shown to serve as early indicators of problems in cortical development. Our aim was to determine the effect of bronchopulmonary dysplasia on neonatal cortical auditory processing. Forty-five premature infants (23–34 weeks) were recorded at 35 post-conceptional weeks. Infants with genetic syndromes, clinical evidence of neonatal encephalopathy, intra-ventricular haemorrhage or periventricular leukomalacia were not recruited. The average of 330 responses to 1000 Hz pure tones (inter-stimulus interval 1250–1850 ms), were recorded at frontal location. Mean amplitudes calculated from the data points of 30 ms centered on P1 and N2 peaks in the waveforms of each subject were measured. The amplitude of P1 component resulted lower in infants with bronchopulmonary dysplasia (p = .004). Results show an association between bronchopulmonary dysplasia and alterations in brain auditory processing, even in absence of major neurological risk factors. This further support the hypothesis of an interference with brain development mediated by the foetal inflammatory response syndrome.

Factors Contributing to Survival in Patients With Anaplastic Astrocytoma: A Retrospective Study of Patients Treated at a Single Institution

Factors Contributing to Survival in Patients With Anaplastic Astrocytoma: A Retrospective Study of Patients Treated at a Single Institution

The panoply of field-dependent behavior in 1436 stroke patients. The mirror neuron system uncoupled and the consequences of loss of personal autonomy

Evaluation of the multifaceted nature of frontal network syndromes is uniquely challenging and rarely tested in the acute/sub-acute stroke period. Field-dependent behavior such as imitation behavior, utilization behavior, and environmental dependency syndrome, as a component of altered environmental autonomy, may be a reliable bedside test. This research focused on the frequency of field-dependent behavior in stroke, the subtypes and relation to frontal lobe lesion location and stroke etiology. A validated frontal network score incorporating a 10-point imitation behavior scale was applied to alert patients without significant aphasia, encephalopathy, dementia, or substance abuse. Discriminative validity assessment with magnetic resonance imaging, diffusion weight imaging (MRI-DWI brain) was performed and correlational validity was established using standard neuropsychological tests. Of the stroke patients (n = 1436), those with frontal network symptoms (335/1203; 28%) were analyzed further. In the 73 patients with lesions restricted to the frontal lobes or the frontal subcortical circuits, 56 complied with the 10-point imitation behavior scale testing. Forty-five of 56 (80%) demonstrated imitation behavior (sensitivity 73% and specificity 94%). Correlational validity testing with four commonly used frontal lobe neuropsychological tests was good. The stroke etiology included 26 (59%) “other” causes, 9 (20%) intracerebral hemorrhages, 3 (7%) cardioembolic causes, 3 (7%) large vessel disease, 2 (4%) small vessel disease, and 2 (4%) unknown etiology. Field-dependent behaviour subtypes included imitation behavior (n = 45), utilization behavior (n = 9), environmental dependency syndrome (n = 4), and complex other forms of environmental dependence syndrome (n = 5). It was concluded that imitation behavior is a relatively common occurrence with lesions in the frontal lobes in the acute/sub-acute stroke period and is associated predominantly with non-mainstream (other) stroke causes and intracerebral hemorrhage.

Family history and frontal lobe seizures predict long-term remission in newly diagnosed cryptogenic focal epilepsy

Cryptogenic focal epilepsy (CFE) is a heterogeneous clinical disorder including patients with severe refractory forms and patients with a fairly good prognosis. Predictors of prognosis in CFE are poorly understood. The aim of this retrospective study is to identify long-term (5-year) prognostic predictors in patients with newly diagnosed CFE. Subjects with cryptogenic focal epilepsy (CFE) seen from April 1987 to September 2011 in two twin Epilepsy Centres located in Reggio Calabria and Catanzaro, Calabria, Southern Italy, were screened. Patients were excluded if they had psychogenic seizures, major psychiatric disorders presence of brain lesions except for non-specific white matter T2-hyperintensities, short follow-up (less than five years) or for having received the diagnosis of CFE elsewhere. One hundred and eighty-six patients, firstly diagnosed in our Centres, constituted the study sample. Survival curves were generated according to the Kaplan-Meier method and compared with the log-rank test. The endpoint was the cumulative time-dependent chance of 5-year remission after treatment start. Independent predictors of remission were tested by multivariate analysis using Cox proportional hazards function models. The accuracy of the resulting model was tested with Receiver Operating Characteristics (ROC) curve analysis. The cumulative incidence of remission was 23%. At Kaplan-Meier analysis, the only factor predicting remission was family history of epilepsy or febrile seizures (FS; p=0.02). At Cox regression, family history and frontal lobe epilepsy showed to be independent predictors of outcome (p=0.02 and 0.03, respectively). The accuracy of these predictors was good (area under ROC curve 0.648, 95% CI 0.575-0.716). Interestingly, we also found a considerable (7 years) diagnostic delay that did not result in a worse prognosis. About one quarter of subjects with newly diagnosed CFE attains 5-year seizure remission during follow-up. Family history of epilepsy or FS and frontal localization are independent prognostic predictors.

New clinical, pathological and molecular prognostic models and calculators in patients with locally diagnosed anaplastic oligodendroglioma or oligoastrocytoma. A prognostic factor analysis of European Organisation for Research and Treatment of Cancer Brain Tumour Group Study 26951

BackgroundThe prognosis of patients with anaplastic oligodendrogliomas (AOD) and oligoastrocytomas (AOA) is variable. Biomarkers might be helpful to identify more homogeneous disease subtypes and improve therapeutic index. The aim of this study is to develop new clinical, pathological and molecular prognostic models for locally diagnosed anaplastic gliomas with oligodendroglial features (AOD or AOA). MethodsData from 368 patients with AOD or AOA recruited in The European Organisation for Research and Treatment of Cancer (EORTC) trial 26951 on adjuvant PCV (Procarbazine, CCNU, Vincristine) chemotherapy in anaplastic oligodendroglial tumours were used to develop multifactor models to predict progression free survival (PFS) and overall survival (OS). Different models were compared by their percentage of explained variation (PEV). Prognostic calculators were derived from these new models. ResultsTreatment (for PFS only), younger age, confirmed absence of residual tumour on imaging, frontal location, good World Health Organisation (WHO) performance status, absence of endothelial abnormalities and/or necrosis, 1p/19q codeletion and Isocitrate dehydrogenase 1 (IDH1) mutation were independent factors that predicted better PFS and OS. ConclusionsWe identified important prognostic factors for AOD and AOA and showed that molecular markers added a major contribution to clinical and pathological factors in explaining PFS and OS. With a positive predictive value of 92% for PFS and 94% for OS, our models allow physicians to precisely identify high risk patients and aid in making therapeutic decisions.

Late recurrence or secondary location? Towards a better understanding of the physiopathology of inverted papilloma

Inverted papilloma (IP) is the most frequent benign tumor of the nasal cavities. Recurrence is found in 12 to 14% of cases, mainly at the primary site, although also exceptionally in remote locations. The present paper discusses the physiopathogenesis of IP on the basis of a report of late second occurrence of IP at a remote location and a review of the literature. A man, who had undergone surgery in 1997 for ethmoid IP at the age of 56, presented 11 years later with nasal cavity IP at a second (frontal) location, discovered serendipitously during systematic follow-up and managed surgically without complication. The physiopathology of nasal cavity IP remains unexplained. No reliable histologic or biological markers predict risk of recurrence or of malignant transformation. The sole treatment is total surgical resection. The risk of local recurrence, often due to incomplete resection, is well known, but that of a secondary location is less so, and regular very long-term follow-up is justified.

Structural and Functional Changes of the Cingulate Gyrus following Traumatic Brain Injury: Relation to Attention and Executive Skills

Impairments of attention and executive functions are common sequelae of traumatic brain injury (TBI). The anterior cingulate is implicated in conflict-related task performance, such as the Stroop, and is susceptible to TBI-related injury due to its frontal location and proximity to the rough surface of the falx cerebri. We investigated the relationship between cingulate cortex volume and performance on tasks of selective attention and cognitive flexibility (single-trial Stroop and Auditory Consonant Trigrams [ACT]). Participants consisted of 12 adults with severe TBI and 18 controls. T1-weighted volumetric MRI data were analyzed using automated cortical reconstruction, segmentation, parcellation, and volume measurement. Cortical volume reductions were prominent bilaterally in frontal, temporal, and inferior parietal regions.Specific regional reduction of the cingulate cortex was observed only for cortical volume of right caudal anterior cingulate(cACC). The TBI group performed significantly worse than control participants on the Stroop and ACT tasks. Findings suggest that atrophy of the right cACC may contribute to reduced performance on executive function tasks, such as the Stroop and ACT, although this is likely but one node of an extensive brain network involved in these cognitive processes.

Phytoplankton abundance and community structure in the Antarctic polar frontal region during austral summer of 2009

The Antarctic polar front region in the Southern Ocean is known to be most productive. We studied the phytoplankton community structure in the Indian sector at this frontal location during late austral summer (February, 2009) onboard R/V Akademic Boris Petrov. We used the phytoplankton and microheterotrophs abundance, as also the associated physico-chemical parameters to explain the low phytoplankton abundance in the study region. This study emphasizes the shift of phytoplankton, from large (>10 μm) to small ( 10 μm) phytoplankton abundance during the late austral summer. This study highlights the highly productive polar front nevertheless becomes a region of low phytoplankton abundance, due to community shifts towards pico-phytoplankton (<10 μm) during late austral summer.

Unattended and attended visual change detection of motion as indexed by event-related potentials and its behavioral correlates

Visual mismatch negativity (vMMN) is a negative-going component amongst cognitive event-related potentials. It reflects an automatic change-detection process that occurs when an infrequent stimulus is presented that is incongruent with the representation of a frequent (standard) event. In our research we use visual motion (more specifically motion direction changes) to study vMMN. Since movement in the visual field is quite irresistible to our brain, the question in hand is, if the detection of motion direction changes is dependent on attention directed to the stimulus. We present a new continuous whole-display stimulus configuration, where the attention capturing primary task of motion onset detection is in the central part of the visual display and visual oddball sequence on the background. The visual oddball paradigm consisted of 85% standard and 15% deviant events, motion direction change being the deviant. We show that even though the unattended visual oddball sequence does not affect the performance in the demanding behavioral primary task, the differences appearing in that sequence are noticed by our brain and reflected in two distinguishable vMMN components in occipital and parietal scalp locations. When attention is directed toward the visual oddball sequence, we only see different processing of standards and deviants in later time-windows and task-related activity in frontal scalp location. Our results are obtained under strict attention manipulation conditions.