Long-term follow up of patients with WHO grade 2 oligodendroglioma.

PURPOSE: Since the introduction of the molecular definition of oligodendrogliomas based on isocitrate dehydrogenase (IDH)-status and the 1p19q-codeletion, it has become increasingly evident how this glioma entity differs much from other diffuse lower grade gliomas and stands out with longer survival and often better responsiveness to adjuvant therapy. Therefore, apart from using a molecular oligodendroglioma definition, an extended follow-up time is necessary to understand the nature of this slow growing, yet malignant condition. The aim of this study was to describe the long-term course of the oligodendroglioma disease in a population-based setting and to determine which factors affect outcome in terms of survival. METHODS: All adults with WHO-grade 2 oligodendrogliomas with known 1p19q-codeletion from five Scandinavian neurosurgical centers and with a follow-up time exceeding 5 years, were analyzed regarding survival and factors potentially affecting survival. RESULTS: 126 patients diagnosed between 1998 and 2016 were identified. The median follow-up was 12.0 years, and the median survival was 17.8 years (95% CI 16.0-19.6). Factors associated with shorter survival in multivariable analysis were age (HR 1.05 per year; CI 1.02-1.08, p < 0.001), tumor diameter (HR 1.05 per millimeter; CI 1.02-1.08, p < 0.001) and poor preoperative functional status (KPS < 80) (HR 4.47; CI 1.70-11.78, p = 0.002). In our material, surgical strategy was not associated with survival. CONCLUSION: Individuals with molecularly defined oligodendrogliomas demonstrate long survival, also in a population-based setting. This is important to consider for optimal timing of therapies that may cause long-term side effects. Advanced age, large tumors and poor function before surgery are predictors of shorter survival.

Cranioplasty in Brain Tumor Surgery: A Single-Center Retrospective Study Investigating Cranioplasty Failure and Tumor Recurrence.

OBJECTIVE: Cranioplasty with synthetic implant can be performed to restore function and form of the skull after resection of malignancy infiltrating the bone. The aim of this study was to examine the rate of implant failure and tumor recurrence in patients undergoing nonautologous cranioplasty and tumor resection. METHODS: In this retrospective single-center study, 48 patients were identified who had undergone cranioplasty with synthetic implants after tumor resection between 2010 and 2020. The medical records were analyzed to investigate patient demographics, surgery data, cranioplasty failure rates, and rate of tumor recurrence. RESULTS: Cranioplasty failed in 8 patients. The median time to implant failure was 220 days with most failures occurring within 1 year (5 of 8). There was no significant difference in rate or time to failure between the different cranioplasty materials (P = 0.39). Low body mass index (P < 0.05), previous craniectomy/cranioplasty (P < 0.05), previous radiation therapy to the brain/skull (P < 0.05), and skin closure with sutures (P < 0.05) were associated with an increased risk of implant failure. Tumors recurred in 15 patients. CONCLUSIONS: Cranioplasty surgery with synthetic implants carries a relatively high risk of failure, regardless of type of cranioplasty material used. Skin closure with staples may be beneficial in these patients.

Global neurosurgery over a 60-year period: Conceptual foundations, time reference, emerging Co-ordinates and prospects for collaborative interventions in low and middle income countries.

Introduction: We evaluated salient initiatives invested in global neurosurgery over a 60-year period. Research question: What are the Phases, Achievements, Challenges, and Lessons of Global Neurosurgery. Methods: A 60-year retrospective study from 1960 to 2020 analyzing the major phases, lessons, and progress notes. We reviewed the foundational need questions and innovated tools used to answer them. Results: Three phases defining our study period were identified. In the early phase, birthing academic units and the onset of individual volunteerism were dominant concepts. The 2nd phase is summarized by the rise of volunteerism and surgical camps.The third phase is heralded by advocacy and strategies for achieving care equity. The defining moment is the Lancet commission for global surgery summit in 2015. Lessons include the need for evaluation of the resources of recipient and donor locations using novel global surgery tools. Conclusion: Global neurosurgery over the 60-year study period is summarized by indelible touchstones of personal and group efforts as well as triumphs derived from innovations in the face of formidable challenges.

Dynamics in cognition and health-related quality of life in grade 2 and 3 gliomas after surgery.

BACKGROUND: The focus of clinical management and research in gliomas has been on survival, but the interest in the treatment effects on cognition and health-related quality of life (HRQoL) is emerging. The primary aim of this study was to investigate the dynamics in cognition after brain tumor surgery for astrocytomas and oligodendrogliomas grade 2 and 3. The secondary aim was to investigate the association of postoperative changes in cognition with changes HRQoL. METHODS: In this observational study, 48 patients operated for an astrocytoma or oligodendrogliomas, grade 2 or 3, at the Department of Neurosurgery, Uppsala, Sweden, 2016-2021, were included. Cognitive and language skills were assessed with a selected test battery and HRQoL was patient-reported as assessed with RAND-36 pre- and approximately 3 months postoperatively. RESULTS: There was a significant postoperative decrease in attention span and verbal learning, but the patients improved in the test for visual memory. There was no change in visual attention, executive function, verbal memory, visual organization and construction, verbal fluency, and confrontation naming. The RAND-36 variables physical function, role physical, general health, vitality, and social functioning decreased significantly after surgery. Patients operated for tumor recurrence exhibited greater deterioration in attention and a greater extent of resection correlated with a less pronounced decrease in verbal memory, but there were otherwise weak associations between the dynamics in cognition and patient-, tumor-, and treatment-variables. A decline in cognitive variables was not associated with worse HRQoL. CONCLUSIONS: Although both several cognitive and HRQoL domains deteriorated postoperatively, these changes did not correlate with each other. This highlights the complexity of cognitive and HRQoL dynamics in the early postoperative phase.

Continuous subcortical language mapping in awake glioma surgery.

Repetitive monopolar short-train stimulation (STS) delivered from a suction probe enables continuous mapping and distance assessment of corticospinal tracts during asleep glioma resection. In this study, we explored this stimulation technique in awake glioma surgery. Fourteen patients with glioma involving language-related tracts were prospectively included. Continuous (3-Hz) cathodal monopolar STS (five pulses, 250 Hz) was delivered via the tip of a suction probe throughout tumor resection while testing language performance. At 70 subcortical locations, surgery was paused to deliver STS in a steady suction probe position. Monopolar STS influence on language performance at different subcortical locations was separated into three groups. Group 1 represented locations where STS did not produce language disturbance. Groups 2 and 3 represented subcortical locations where STS produced language interference at different threshold intensities (≥7.5 and ≤5 mA, respectively). For validation, bipolar Penfield stimulation (PS; 60 Hz for 3 s) was used as a "gold standard" comparison method to detect close proximity to language-related tracts and classified as positive or negative regarding language interference. There was no language interference from STS in 28 locations (Group 1), and PS was negative for all sites. In Group 2 (STS threshold ≥ 7.5 mA; median, 10 mA), there was language interference at 18 locations, and PS (median, 4 mA) was positive in only one location. In Group 3 (STS threshold ≤ 5 mA; median, 5 mA), there was language interference at 24 locations, and positive PS (median 4 mA) was significantly (p < 0.01) more common (15 out of 24 locations) compared with Groups 1 and 2. Despite the continuous stimulation throughout tumor resection, there were no seizures in any of the patients. In five patients, temporary current spread to the facial nerve was observed. We conclude that continuous subcortical STS is feasibly also in awake glioma surgery and that no language interference from STS or interference at ≥7.5 mA seems to indicate safe distance to language tracts as judged by PS comparisons. STS language interference at STS ≤ 5 mA was not consistently confirmed by PS, which needs to be addressed.

Patient-reported quality of life in grade 2 and 3 gliomas after surgery, can we do more?

OBJECTIVE: To study the effects of surgery and the explanatory variables for patient-reported health-related quality of life (HRQoL) after brain tumor surgery for astrocytomas and oligodendrogliomas grade 2 and 3. METHODS: Patients operated for an astrocytoma or an oligodendrogliomas, grade 2 or 3, at the Department of Neurosurgery, Uppsala, Sweden, 2016-2021, were included. HRQoL was assessed with RAND-36 preoperatively and 4 months postoperatively. Demographic, tumor, and treatment data were prospectively collected. RESULTS: Sixty-two patients were included, 34 with an astrocytoma and 28 with an oligodendroglioma. Physical function, role physical, general health, vitality, and social functioning decreased significantly (p-values < 0.01) 4 months after surgery, whereas bodily pain, role emotional, and mental health remained unchanged. In Spearman analyses, younger patients deteriorated more in role physical, females worsened less often in general health but more often in social functioning than males, a higher level of education correlated with a more pronounced drop in social functioning, and a greater extent of resection corresponded to a worsening in physical function postoperatively (p-values < 0.05). CONCLUSIONS: Several HRQoL domains deteriorated after glioma surgery in specific groups of patients, particularly general health, vitality, physical, and social functions. This was only weakly explained by surgical variables. Specific groups of patients may need closer follow-ups and tailored support/rehabilitation to detect and address these HRQoL deteriorations.

Pilot application of Lecture-Panel-Discussion Model (LPDM) in global collaborative neurosurgical education: a novel training paradigm innovated by the Swedish African Neurosurgery Collaboration.

BACKGROUND: Disruptions in global surgery educational routines by the COVID-19 pandemic have elicited demands for alternative formats for rendering qualitative neurosurgical education. This study presents application of a novel model of online neurosurgical course, the Lecture-Panel-Discussion Model (LPDM). METHODS: This is a cross-sectional survey of participants who attended the Swedish African Neurosurgery Collaboration (SANC)-100A course. Participants evaluated the course through an online self-administered questionnaire using a 5-point Likert scale ranging from very poor-1, poor-2, average (fair)-3, good-4, to excellent-5. SANC-100A comprises a tripod of Lectures, Panel review, and interactive case Discussion. This model (LPDM) was innovated by SANC and applied at the Enugu International Neurosurgery course in February 2021. RESULTS: There were 71 attendees, 19 were course faculty, while 52 were participants. Thirty-five attended from Nigeria, 11 from Sweden, 3 from Malawi, 2 from Senegal, and 1 from the UK. Among 44 participants who completed the questionnaire, there were 9 fellows and 35 residents. The overall median course Likert rating was 4.65 ± 0.1. The median overall rating for course events was similar between day 1 (Likert score = 4.45) and day 2 (Likert score = 4.55), U = 55, Z score = 1.10, P = 0.27. The median rating for lectures was 4.50 ± 0.2 and varied from 4.40 on day 1 to 4.55 on day 2. The median rating for panel review was 4.60 ± 0.1 and varied from 4.55 on day 1 to 4.65 on day 2. Interactive case discussions were rated 4.80 on both course days. There was a significant variability in the rating profiles of the course tripod: U = 24.5, P = 0.03. Fifty-one (98%) participants believe LPDM was COVID-19-compliant, while 90% believe the course was beneficial to training and practice. CONCLUSION: Initial application of LPDM is rewarded with both high acceptance and high rating among participants.

The link between gliomas infiltration and white matter architecture investigated with electron microscopy and diffusion tensor imaging.

Diffuse low-grade gliomas (DLGG) display different preferential locations in eloquent and secondary associative brain areas. The reason for this tendency is still unknown. We hypothesized that the intrinsic architecture and water diffusion properties of the white matter bundles in these regions may facilitate gliomas infiltration. Magnetic resonance imaging of sixty-seven diffuse low-grade gliomas patients were normalized to/and segmented in MNI space to create three probabilistic infiltration weighted gradient maps according to the molecular status of each tumor group (IDH mutated, IDH wild-type and IDH mutated/1p19q co-deleted). Diffusion tensor imaging (DTI)- based parameters were derived for five major white matter bundles, displaying regional differences in the grade of infiltration, averaged over 20 healthy individuals acquired from the Human connectome project (HCP) database. Transmission electron microscopy (TEM) was used to analyze fiber density, fiber diameter and g-ratio in 100 human white matter regions, sampled from cadaver specimens, reflecting areas with different gliomas infiltration in each white matter bundle. Histological results and DTI-based parameters were compared in anatomical regions of high- and low grade of infiltration (HIF and LIF) respectively. We detected differences in the white matter infiltration of five major white matter bundles in three groups. Astrocytomas IDHm infiltrated left fronto-temporal subcortical areas. Astrocytomas IDHwt were detected in the posterior-temporal and temporo-parietal regions bilaterally. Oligodendrogliomas IDHm/1p19q infiltrated anterior subcortical regions of the frontal lobes bilaterally. Regional differences within the same white matter bundles were detected by both TEM- and DTI analysis linked to different topographical variables. Our multimodal analysis showed that HIF regions, common to all the groups, displayed a smaller fiber diameter, lower FA and higher RD compared with LIF regions. Our results suggest that the both morphological features and diffusion parameters of the white matter may be different in regions linked to the preferential location of DLGG.

Role of Preoperative Assessment in Predicting Tumor-Induced Plasticity in Patients with Diffuse Gliomas.

When diffuse gliomas (DG) affect the brain's potential to reorganize functional networks, patients can exhibit seizures and/or language/cognitive impairment. The tumor-brain interaction and the individual connectomic organization cannot be predicted preoperatively. We aimed to, first, investigate the relationship between preoperative assessment and intraoperative findings of eloquent tumors in 36 DG operated with awake surgery. Second, we also studied possible mechanisms of tumor-induced brain reorganization in these patients. FLAIR-MRI sequences were used for tumor volume segmentation and the Brain-Grid system (BG) was used as an overlay for infiltration analysis. Neuropsychological (NPS) and/or language assessments were performed in all patients. The distance between eloquent spots and tumor margins was measured. All variables were used for correlation and logistic regression analyses. Eloquent tumors were detected in 75% of the patients with no single variable able to predict this finding. Impaired NPS functions correlated with invasive tumors, crucial location (A4C2S2/A3C2S2-voxels, left opercular-insular/sub-insular region) and higher risk of eloquent tumors. Epilepsy was correlated with larger tumor volumes and infiltrated A4C2S2/A3C2S2 voxels. Language impairment was correlated with infiltrated A3C2S2 voxel. Peritumoral cortical eloquent spots reflected an early compensative mechanism with age as possible influencing factor. Preoperative NPS impairment is linked with high risk of eloquent tumors. A systematic integration of extensive cognitive assessment and advanced neuroimaging can improve our comprehension of the connectomic brain organization at the individual scale and lead to a better oncological/functional balance.

Bone formation in custom-made cranioplasty: evidence of early and sustained bone development in bioceramic calcium phosphate implants. Patient series.

BACKGROUND: Implant failure (IF) rates in cranioplasty remain high despite efforts to reduce the incidence. New biomaterials may be part of the solution for this problem. Formation of autologous bone in implants may reduce rates of infection and subsequent failure. OBSERVATIONS: Four patients with calcium phosphate implants supported by titanium mesh and undergoing surgery for reasons unrelated to IF were included in this series. Samples from the implants were microscopically examined. Pathological studies proved the formation of autologous bone in the calcium phosphate implants. LESSONS: Bone and blood vessel formation in the implants and diminished foreign body reaction to autologous bone may reduce the rates of IF.

Pediatric brain tumor care in a Sub-Saharan setting: current poise of a precariously loaded dice.

OBJECTIVE: To evaluate the current status of pediatric brain tumor (PBT) care and identify determinants and profiles of survival and school attendance. METHODS: An 8-year institution-based prospective longitudinal study. All cases investigated with neuroimaging and treated were enrolled. Data was analyzed with SPSS (Inc) Chicago IL, USA version 23. Chi Square test, One-way ANOVA and confidence limits were used to evaluate associations at the 95% level of significance. Ethical approval for our study was obtained Health Research Ethics Committee of our hospital. RESULTS: Among 103 patients enrolled, 92 satisfied our study criteria. There were 45 males and 39 females, M: F = 0.8. The mean age was 9.5 ± 2.1 years 95%CI with a range of 7 months to 16 years. The most common symptom was headache for supratentorial lesions (73%) and gait disturbance (80.2%) for infratentorial lesions. More tumors were supratentorial in location 51 (55.4%), 35 (38.1%) were infratentorial and 6 (6.5%) were transtentorial. Craniopharyngiomas (n = 23), medulloblastomas (n = 22) and astrocytomas (n = 15) were the most common tumors. Hemoglobin genotype (AA and AS) had some influence on tumor phenotype FT, P = 0.033. 76 cases were microsurgically resected while 16 patients were treated with radiotherapy alone. The 30-day mortality for operated cases is 7.2 ± 0.7%. Overall 1-year and 5-year survival was 66.7 and 52.3%, respectively. School attendance, performance and outcome varied among treatment subgroups. CONCLUSION: Survival profile in this series suggests some improvement in comparison to previous studies from our region, Hemoglobin genotype profiles may signature paediatric brain tumor phenotypes in our setting.

Differences in the preferential location and invasiveness of diffuse low-grade gliomas and their impact on outcome.

BACKGROUND: Low-grade gliomas (LGGs) are primary diffuse slow-growing brain tumors derived from glial cells. The management of these tumors is dependent on their location, which often harbors eloquent areas. We retrospectively recorded the location of diffuse gliomas to identify whether specific differences exist between the histological types. METHODS: We analyzed 102 patients with previous histological diagnosis of WHO-II astrocytomas (62) and WHO-II oligodendrogliomas (40) according to WHO-2016 classification. MRI sequences (T2-FLAIR) were used for tumor volume segmentation and to create a frequency map of their locations within the Montreal Neurological Institute (MNI) space. The Brain-Grid (BG) system (standardized radiological tool of intersected lines according to anatomical landmarks) was created and merged with a tractography atlas for infiltration analysis. RESULTS: Astrocytomas frequently infiltrated association and projection white matter pathways within fronto-temporo-insular regions on the left side. Oligodendrogliomas infiltrated larger white matter networks (association-commissural-projection) of the frontal lobe bilaterally. A critical number of infiltrated BG voxels (7 for astrocytomas, 10 for oligodendrogliomas) significantly predicted shorter overall survival (OS) in both groups. Bilateral tumor extension in astrocytomas and preoperative tumor volume in oligodendrogliomas were independent prognostic factors for shorter OS. CONCLUSIONS: Astrocytomas and oligodendrogliomas differ in preferential location, and this has an impact on the type and the extent of white matter involvement. The number of BG voxels infiltrated reflected different tumor invasiveness and its impact on OS in both groups. All this new information may be valuable in neurosurgical oncology to classify and plan treatment for patients with diffuse gliomas.

Acute necrotizing encephalopathy with SARS-CoV-2 RNA confirmed in cerebrospinal fluid.

Here, we report a case of COVID-19-related acute necrotizing encephalopathy where SARS-CoV-2 RNA was found in CSF 19 days after symptom onset after testing negative twice. Although monocytes and protein levels in CSF were only marginally increased, and our patient never experienced a hyperinflammatory state, her neurologic function deteriorated into coma. MRI of the brain showed pathologic signal symmetrically in central thalami, subinsular regions, medial temporal lobes, and brain stem. Extremely high concentrations of the neuronal injury markers neurofilament light and tau, as well as an astrocytic activation marker, glial fibrillary acidic protein, were measured in CSF. Neuronal rescue proteins and other pathways were elevated in the in-depth proteomics analysis. The patient received IV immunoglobulins and plasma exchange. Her neurologic status improved, and she was extubated 4 weeks after symptom onset. This case report highlights the neurotropism of SARS-CoV-2 in selected patients and emphasizes the importance of repeated lumbar punctures and CSF analyses in patients with suspected COVID-19 and neurologic symptoms.

Scaling Up Global Collaborations for Neurosurgical Education and Care Capacity Development in West Africa: Are There Low-Hanging Fruits Where It Tolls?

BACKGROUND: Six decades after birth, the path to sustainable neurosurgical education and care in West Africa remains slow paced. We highlight plain sailing local attributes and global interventions for accelerated progress. METHODS: This was a 20-year study of neurosurgical practice and training status from 1999 to 2018. We prospectively evaluated development of neurosurgical units between 2009 and 2018 and compared with retrospective data both from 1999 to 2018 and from the origin of West African neurosurgery in 1962. RESULTS: The number of neurosurgeons rose from 1 in 1962 to 221 in 2018 with a mean of 3.95 neurosurgeons per year. Between 1998 and 2018, the subregional annual neurosurgeon birthrate varied significantly between 0.72 and 3.95. In 1998, 7 countries contributed to a neurosurgeon population of 26. In 2018, 13 countries contributed to a total of 221 neurosurgeons. The period 2009-2018 recorded the highest growth of neurosurgeons with a neurosurgeon birthrate of 7.5. Nigeria accounts for 51.6% (200.9 million) of the West African population and has 57% (11) of the 19 fully accredited training centers, while Ghana and Senegal account for 7.7% and 4.3% of the West African population, respectively, and each has 11% of the training centers. The 10-year unit procreativity index for the period 2009-2018 was 1.3, with Nigeria accounting for 0.7 (53.8%). CONCLUSIONS: The low unit procreativity index across West Africa, a major cause of the low neurosurgeon birthrate, can be resolved using tailored kindling and procreative strategies.

Improving capacity and access to neurosurgery in sub-Saharan Africa using a twinning paradigm pioneered by the Swedish African Neurosurgical Collaboration.

BACKGROUND: The unmet need for neurosurgery in sub-Saharan Africa is staggering. Resolving this requires strategies that synergize salient local resources with tailored foreign help. This study is a trial of a twinning model adopted by the Swedish African Neurosurgical Collaboration (SANC). METHODS: A multi-step neurosurgical twinning technique, International Neurosurgical Twinning Modeled for Africa (INTIMA), developed through a collaboration between African and Swedish neurosurgical teams was adopted for a neurosurgical mission in March 2019. The pioneering steps are evaluated together with data of treated patients prospectively acquired using SPSS Chicago Inc., Version 23. Associations were analyzed using chi-square tests, while inferences were evaluated at 95% level of significance. RESULTS: The SANC global neurosurgery mission targeted microsurgical brain tumor resection. Fifty-five patients were operated on during the mission and subsequent 3 months. Patients' ages ranged from 3 months to 69 years with a mean of 30.6 ± 2.1 years 95% CL. Seven cases were performed during the first mission, while 48 were performed after the mission. Compared to 3 months before SANC when only 9 brain tumors were resected, more tumors were resected (n = 25) within the 3 consecutive months from the mission (X2 = 14.2, DF = 1, P = 0.000). Thirty-day mortality following tumor resection was also lower, X2 = 4.8, DF = 1, P = 0.028. CONCLUSION: Improvements in capacity and short-term outcome define our initial pioneering application of a neurosurgical twinning paradigm pioneered by SANC.

Teaching Anatomy to Neuroscientific Health-Care Professionals: Are They Receiving the Best Anatomical Education?

University neuroanatomical courses seldom teach the anatomical-functional connectivity of the brain. White matter dissection improves understanding of brain connectivity, but until now has been restricted to neurosurgeons and in some cases to medical students, never to health-care non-medical professionals. Our aim was to teach white matter anatomy to medical and non-medical students to evaluate this technique in groups with different education. A standardized lab demonstration of white matter anatomy was performed with high appreciation rate in both groups, suggesting a suboptimal neuroanatomical education provided by basic course. We encourage to include this technique of teaching brain anatomy into basic neuroanatomical courses to improve the level of comprehension and competence in all health-care staff within the field of neuroscience.

New Insights Into the Anatomy, Connectivity and Clinical Implications of the Middle Longitudinal Fasciculus.

The middle longitudinal fascicle (MdLF) is a long, associative white matter tract connecting the superior temporal gyrus (STG) with the parietal and occipital lobe. Previous studies show different cortical terminations, and a possible segmentation pattern of the tract. In this study, we performed a post-mortem white matter dissection of 12 human hemispheres and an in vivo deterministic fiber tracking of 24 subjects acquired from the Human Connectome Project to establish whether a constant organization of fibers exists among the MdLF subcomponents and to acquire anatomical information on each subcomponent. Moreover, two clinical cases of brain tumors impinged on MdLF territories are reported to further discuss the anatomical results in light of previously published data on the functional involvement of this bundle. The main finding is that the MdLF is consistently organized into two layers: an antero-ventral segment (aMdLF) connecting the anterior STG (including temporal pole and planum polare) and the extrastriate lateral occipital cortex, and a posterior-dorsal segment (pMdLF) connecting the posterior STG, anterior transverse temporal gyrus and planum temporale with the superior parietal lobule and lateral occipital cortex. The anatomical connectivity pattern and quantitative differences between the MdLF subcomponents along with the clinical cases reported in this paper support the role of MdLF in high-order functions related to acoustic information. We suggest that pMdLF may contribute to the learning process associated with verbal-auditory stimuli, especially on left side, while aMdLF may play a role in processing/retrieving auditory information already consolidated within the temporal lobe.

A novel radiological classification system for cerebral gliomas: The Brain-Grid.

PURPOSE: Standard radiological/topographical classifications of gliomas often do not reflect the real extension of the tumor within the lobar-cortical anatomy. Furthermore, these systems do not provide information on the relationship between tumor growth and the subcortical white matter architecture. We propose the use of an anatomically standardized grid system (the Brain-Grid) to merge serial morphological magnetic resonance imaging (MRI) scans with a representative tractographic atlas. Two illustrative cases are presented to show the potential advantages of this classification system. METHODS: MRI scans of 39 patients (WHO grade II and III gliomas) were analyzed with a standardized grid created by intersecting longitudinal lines on the axial, sagittal, and coronal planes. The anatomical landmarks were chosen from an average brain, spatially normalized to the Montreal Neurological Institute (MNI) space and the Talairach space. Major white matter pathways were reconstructed with a deterministic tracking algorithm on a reference atlas and analyzed using the Brain-Grid system. RESULTS: In all, 48 brain grid voxels (areas defined by 3 coordinates, axial (A), coronal (C), sagittal (S) and numbers from 1 to 4) were delineated in each MRI sequence and on the tractographic atlas. The number of grid voxels infiltrated was consistent, also in the MNI space. The sub-cortical insula/basal ganglia (A3-C2-S2) and the fronto-insular region (A3-C2-S1) were most frequently involved. The inferior fronto-occipital fasciculus, anterior thalamic radiation, uncinate fasciculus, and external capsule were the most frequently associated pathways in both hemispheres. CONCLUSIONS: The Brain-Grid based classification system provides an accurate observational tool in all patients with suspected gliomas, based on the comparison of grid voxels on a morphological MRI and segmented white matter atlas. Important biological information on tumor kinetics including extension, speed, and preferential direction of progression can be observed and even predicted with this system. This novel classification can easily be applied to both prospective and retrospective cohorts of patients and increase our comprehension of glioma behavior.

Removal of giant intraosseous meningioma followed by cranioplasty using a custom-made bioceramic implant: case report.

Intraosseous meningioma of the chordoid type is a rare clinical entity. Radical surgical removal and subsequent cranioplasty is the treatment of choice. Here, the authors report a severe case involving more than 70% of the calvarial surface area, which was removed and repaired using a prefabricated custom-made, titanium-reinforced, bioceramic implant and bone-cutting guides. Tumor removal and good esthetic outcome were achieved, along with a 17.1% increase of intracranial volume. Bioceramic implants have shown promising initial results and may represent an important new tool in the surgeon's armamentarium.

Segmentation of the inferior longitudinal fasciculus in the human brain: A white matter dissection and diffusion tensor tractography study.

The inferior longitudinal fascicle (ILF) is one of the major occipital-temporal association pathways. Several studies have mapped its hierarchical segmentation to specific functions. There is, however, no consensus regarding a detailed description of ILF fibre organisation. The aim of this study was to establish whether the ILF has a constant number of subcomponents. A secondary aim was to determine the quantitative diffusion proprieties of each subcomponent and assess their anatomical trajectories and connectivity patterns. A white matter dissection of 14 post-mortem normal human hemispheres was conducted to define the course of the ILF and its subcomponents. These anatomical results were then investigated in 24 right-handed, healthy volunteers using in vivo diffusion tensor imaging (DTI) and streamline tractography. Fractional anisotropy (FA), volume, fibre length and the symmetry coefficient of each fibre group were analysed. In order to show the connectivity pattern of the ILF, we also conducted an analysis of the cortical terminations of each segment. We confirmed that the main structure of the ILF is composed of three constant components reflecting the occipital terminations: the fusiform, the lingual and the dorsolateral-occipital. ILF volume was significantly lateralised to the right. The examined indices of ILF subcomponents did not show any significant difference in lateralisation. The connectivity pattern and the quantitative distribution of ILF subcomponents suggest a pivotal role for this bundle in integrating information from highly specialised modular visual areas with activity in anterior temporal territory, which has been previously shown to be important for memory and emotions.