Sellar metastasis: A rare intraoperative finding - surgical treatment, strategies and outcome

OBJECTIVE

The sellar region, though uncommon for metastatic spread, may become more prevalent due to longer survival of patients with metastatic malignancies. Compression of adjacent vital anatomy can cause disabling symptoms and endocrine disturbances, leading to significant morbidity METHODS: This study analyzed sellar pathologies treated via endonasal approach from January 2011 to December 2021 to assess the incidence of sellar metastases. Patient demographics, presenting symptoms, radiological and histological findings, management, and outcomes were evaluated RESULTS: Among 334 patients treated during the study period, eight (2.3 %) had metastases confirmed histopathologically, with one having a known malignant tumor history. Preoperative imaging suspected malignancy or metastasis in two cases. Diagnosis was unexpectedly confirmed in 57 % of cases. Subtotal resection was achieved in three cases, near-total resection in one. Mean follow-up was 2.4 years, with 71 % mortality CONCLUSIONS: The sellar region can manifest metastatic disease, with sellar symptoms potentially indicating neoplastic disease onset. Rapid hormonal dysfunction or ophthalmoplegia suggests metastasis, even without a known primary. Further meta analysis of reported cases is necessary to determine the incidence and optimal treatment of these rare metastases.

Acute low back pain: Epidemiology, etiology, and prevention: WFNS spine committee recommendations

Objective

Acute low back pain is a highly prevalent condition that poses significant challenges to healthcare systems worldwide. In this manuscript, we present the most current, evidence-based guidelines from the World Federation of Neurosurgical Societies (WFNS) Spine Committee on the epidemiology, etiology, and prevention of acute low back pain (LBP) lasting ≤ 4 weeks.

Methods

We performed a literature review 2012-2022 using the PubMed, Medline, and CENTRAL databases with the keywords "acute low back pain", "acute back pain", "low back pain", "epidemiology", "etiology", "costs", "risk factor", "cultural", "developed", "developing" and "prevention". Systematic screening criteria were applied, resulting in 13 final articles on epidemiology and etiology of LBP, 2 manuscripts on costs, 5 articles on risk factors, and 23 articles on prevention strategies for acute LBP. These were presented at two separate international meetings, where members of the WFNS Spine Committee voted on five final consensus statements presented here.

Results

and Conclusions: There is a high incidence and prevalence of acute LBP, particularly in high-income countries, which is felt to be at least partially due to demographic shifts with an aging population and lifestyle changes including higher rates of obesity and physical inactivity. Acute LBP has a significant impact on quality of life and ability to work, resulting in high direct and indirect costs worldwide. Early diagnosis and appropriate management of acute LBP is recommended to prevent this pain from turning into chronic LBP. The WFNS Spine Committee's recommendations respresent the latest guidelies to help improve patient care for acute LBP worldwide.

Cauda equina, conus medullaris and syndromes mimicking sciatic pain: WFNS spine committee recommendations

Introduction

Cauda equina syndrome (CES), conus medullaris syndrome (CMS), and sciatica-like syndromes or "sciatica mimics" (SM) may present as diagnostic and/or therapeutic dilemmas for the practicing spine surgeon. There is considerable controversy regarding the appropriate definition and diagnosis of these entities, as well as indications for and timing of surgery. Our goal is to formulate the most current, evidence-based recommendations for the definition, diagnosis, and management of CES, CMS, and SM syndromes.

Methods

We performed a systematic literature search in PubMed from 2012 to 2022 using the keywords "cauda equina syndrome", "conus medullaris syndrome", "sciatica", and "sciatica mimics". Standardized screening criteria yielded a total of 43 manuscripts, whose data was summarized and presented at two international consensus meetings of the World Federation of Neurosurgical Societies (WFNS) Spine Committee. Utilizing the Delphi method, we generated seven final consensus statements.

Results and conclusion

s: We provide standardized definitions of cauda equina, cauda equina syndrome, conus medullaris, and conus medullaris syndrome. We advocate for the use of the Lavy et al classification system to categorize different types of CES, and recommend urgent MRI in all patients with suspected CES (CESS), considering the low sensitivity of clinical examination in excluding CES. Surgical decompression for CES and CMS is recommended within 48 h, preferably within less than 24 h. There is no data regarding the role of steroids in acute CES or CMS. The treating physician should be cognizant of a variety of other pathologies that may mimic sciatica, including piriformis syndrome, and how to manage these.

RB1‑promoter methylation in glioblastoma: A rare event in glioblastoma

The retinoblastoma gene (RB1) is a tumor suppressor gene that serves a key role in the development of numerous tumor diseases that can be downregulated by DNA methylation within its promoter region. The present study analyzed the methylation status of the RB1 promoter of 85 glioblastomas to assess its role in this tumor. To elucidate the underlying mechanism, RB1 promoter methylation was evaluated using methylation‑specific PCR with subsequent evaluation of the results via gel electrophoresis using ethidium bromide. Of the 85 samples analyzed, only one demonstrated RB1‑promoter methylation. While there are contradictory results on this matter in the literature, this study is, to the best of our knowledge, the largest on this topic to date as well as the first to use the WHO 2016 classification. The results of the present indicated that the RB1 promoter methylation does not serve a role in the development and progression of glioblastoma.

From fixed-pressure paediGAV to programmable proGAV/proSA serial valves for pediatric hydrocephalus within the 1st year of life: a technical single-center analysis

OBJECTIVE

Programmable valves have gained increasing popularity in the complex treatment of pediatric hydrocephalus. Over the last decade, adjustable serial valves have gradually replaced fixed-pressure valves in the authors' department. The present study investigates this development by analyzing shunt- and valve-related outcomes for this vulnerable population.

METHODS

A retrospective analysis of all shunting procedures between January 2009 and January 2021 in children younger than 1 year of age was performed at the authors' single-center institution. Postoperative complications and surgical revisions were set as outcome parameters. Shunt and valve survival rates were evaluated. Statistical analysis compared children who underwent implantation of the Miethke proGAV/proSA programmable serial valves with those who underwent implantation of the fixed-pressure Miethke paediGAV system.

RESULTS

Eighty-five procedures were evaluated. The paediGAV system was implanted in 39 cases and the proGAV/proSA in 46 cases. The mean ± SD follow-up was 247.7 ± 140 weeks. In 2009 and 2010, paediGAV valves were used exclusively, but by 2019, the use of proGAV/proSA had evolved into the first-line therapy. The paediGAV system was significantly more often revised (p < 0.05). The main indication for revision was proximal occlusion, with or without impairment to the valve. The valve and shunt survival rates of proGAV/proSA were significantly prolonged (p < 0.05). The surgery-free valve survival of proGAV/proSA was 90% after 1 year and 63% after 6 years. There were no overdrainage-related revisions of proGAV/proSA valves.

CONCLUSIONS

Favorable shunt and valve survival validates the increasing use of programmable proGAV/proSA serial valves in this delicate population. Potential benefits in postoperative treatment should be addressed in prospective multicenter studies.

Endoscope-assisted resection of brainstem cavernous malformations

Targeted surgical precision and minimally invasive techniques are of utmost importance for resectioning cavernous malformations involving the brainstem region. Minimisation of the surgical corridor is desirable but should not compromise the extent of resection. This study provides detailed information on the role of endoscopy in this challenging surgical task. A retrospective analysis of medical documentation, radiologic studies and detailed intraoperative video documentation was performed for all consecutive patients who underwent surgical resection of brainstem cavernous malformations between 2010 and 2020 at the authors’ institution. A case-based volumetry of the corticotomy was performed and compared to cavernoma dimensions. A total of 20 procedures have been performed in 19 patients. Neuroendoscopy was implemented in all cases. The mean size of the lesion was 5.4 (± 5) mm3. The average size of the brainstem corticotomy was 4.5 × 3.7 (± 1.0 × 1.1) mm, with a median relation to the cavernoma’s dimension of 9.99% (1.2–31.39%). Endoscopic 360° inspection of the resection cavity was feasible in all cases. There were no endoscopy-related complications. Mean follow-up was 27.8 (12–89) months. Gross-total resection was achieved in all but one case (95%). Sixteen procedures (80%) resulted in an improved or stable medical condition. Eleven patients (61.1%) showed further improvement 12 months after the initial surgery. With the experience provided, endoscopic techniques can be safely implemented in surgery for BSCM. A combination of neuroendoscopic visualisation and neuronavigation might enable a targeted size of brainstem corticotomy. Endoscopy can currently be considered a valuable additive tool to facilitate the preparation and resection of BSCM.

Bisulfite profiling of the MGMT promoter and comparison with routine testing in glioblastoma diagnostics

Background

Promoter methylation of the DNA repair gene O⁶-methylguanine-DNA methyltransferase (MGMT) is an acknowledged predictive epigenetic marker in glioblastoma multiforme and anaplastic astrocytoma. Patients with methylated CpGs in the MGMT promoter benefit from treatment with alkylating agents, such as temozolomide, and show an improved overall survival and progression-free interval. A precise determination of MGMT promoter methylation is of importance for diagnostic decisions. We experienced that different methods show partially divergent results in a daily routine. For an integrated neuropathological diagnosis of malignant gliomas, we therefore currently apply a combination of methylation-specific PCR assays and pyrosequencing.

Results

To better rationalize the variation across assays, we compared these standard techniques and assays to deep bisulfite sequencing results in a cohort of 80 malignant astrocytomas. Our deep analysis covers 49 CpG sites of the expanded MGMT promoter, including exon 1, parts of intron 1 and a region upstream of the transcription start site (TSS). We observed that deep sequencing data are in general in agreement with CpG-specific pyrosequencing, while the most widely used MSP assays published by Esteller et al. (N Engl J Med 343(19):1350–1354, 2000. 10.1056/NEJM200011093431901) and Felsberg et al. (Clin Cancer Res 15(21):6683–6693, 2009. 10.1158/1078-0432.CCR-08-2801) resulted in partially discordant results in 22 tumors (27.5%). Local deep bisulfite sequencing (LDBS) revealed that CpGs located in exon 1 are suited best to discriminate methylated from unmethylated samples. Based on LDBS data, we propose an optimized MSP primer pair with 83% and 85% concordance to pyrosequencing and LDBS data. A hitherto neglected region upstream of the TSS, with an overall higher methylation compared to exon 1 and intron 1 of MGMT, is also able to discriminate the methylation status.

Conclusion

Our integrated analysis allows to evaluate and redefine co-methylation domains within the MGMT promoter and to rationalize the practical impact on assays used in daily routine diagnostics.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13148-022-01244-4.

Microseismicity Appears to Outline Highly Coupled Regions on the Central Chile Megathrust

We compiled a novel microseismicity catalog for the Central Chile megathrust (29°-35°S), comprising 8,750 earthquakes between April 2014 and December 2018. These events describe a pattern of three trenchward open half-ellipses, consisting of a continuous, coast-parallel seismicity band at 30-45 km depth, and narrow elongated seismicity clusters that protrude to the shallow megathrust and separate largely aseismic regions along strike. To test whether these shapes could outline highly coupled regions ("asperities") on the megathrust, we invert GPS displacement data for interplate locking. The best-fit locking model does not show good correspondence to seismicity, possibly due to lacking resolution. When we prescribe high locking inside the half-ellipses, however, we obtain models with similar data fits that are preferred according to the Bayesian Information Criterion (BIC). We thus propose that seismicity on the Central Chile megathrust may outline three adjacent highly coupled regions, two of them located between the rupture areas of the 2010 Maule and the 2015 Illapel earthquakes, a segment of the Chilean margin that may be in a late interseismic stage of the seismic cycle.

The Loss of 1p as a Reliable Marker of Progression in a Child with Aggressive Meningioma: A 16-Year Follow-Up Case Report

BACKGROUND

Here, we present the case of a 32-year-old female with a progressing history of meningioma for 16 years starting with an ethmoidal lesion in 2002. The initial tumor specimen of this patient showed a deletion of the short arm of chromosome 1 through a translocation between chromosomes 1 and 11 (t[1; 11]) as well as additional chromosomal aberrations, including partial or complete monosomy of chromosomes 2, 6, 7, 11, 13, and 22. These molecular characteristics were already known to be associated with an aggressive course of the disease, and the patient was, therefore, included in a strict follow-up regime. From 2003 to 2019, the patient suffered multiple relapses and consecutive tumor resections.

METHODS

Tumor specimen from 2017 was examined using a genome-wide methylation analysis as well as a whole-genome sequencing.

RESULTS

These analyses confirmed the findings of 2002 and proved genetic alteration in the meningioma to be very stable over the time. Yet SMO and AKT1 mutations, which have been described to be paradigmatic in frontobasal meningioma, could not be found.

CONCLUSIONS

Genetic characteristics seem to be very stable during progression of the disease. The loss of 1p represents to be a potential marker for the poor clinical course of our child meningioma. In 2019, our patient passed away due to the progress of her meningioma disease.

CSIG-14. PROTEIN KINASE CK2 REGULATES THE EXPRESSION OF NERVE/GLIAL ANTIGEN (NG)2 IN GLIOBLASTOMA

Nerve/glial antigen (NG)2 enhances cell proliferation, migration as well as chemoresistance and is associated with a poor clinical outcome in glioblastoma. Since regulatory mechanisms of NG2 expression are still largely unknown, we herein investigated the impact of protein kinase CK2 inhibition on NG2 expression in human glioblastoma cells. CK2 was inhibited in NG2-positive human glioblastoma cell lines (A1207, U87) and primary human glioblastoma cells by pharmacological treatment (CX-4945, TBB) or siRNA. NG2 expression was analyzed by flow cytometry, Western Blot and qRT-PCR. Cytotoxicity and viability were assessed by WST-1, LDH and BrdU assays. Scratch, sprouting and BrdU assays as well as growth curves were performed to examine cell migration and proliferation. Truncated fragments of the human NG2 promotor were generated and their transcriptional activity was assessed using reporter gene assays. The effect of CK2 inhibition on tumor growth was investigated in xenografts within the flanks of NOD/SCID mice. Finally, effects of CK2 inhibition were analyzed in primary human glioblastoma cells. We found that inhibition of CK2 significantly reduces NG2 protein levels in A1207 (19%±6.2; Mean±SD), U87 (35%±11.3) and primary human glioblastoma cells (41%) when compared to controls. Further analyses revealed that this is due to a decreased NG2 mRNA level. Of note, we identified a 200 base pair fragment, including a binding site for the CK2-dependent transcription factor SP-1. Functional assays showed no cytotoxic effects of the decreased NG2 expression after CK2 inhibition, whereas cell migration and proliferation were markedly reduced. Moreover, we found that CX-4945 treatment decreases tumor growth, which is associated with a diminished NG2 expression (56%±13.0) when compared to controls. In conclusion, we identified CK2 as a novel regulator of NG2 gene expression in human glioblastoma cells. Hence, pharmacological inhibition of CK2 may represent a novel strategy in the therapy of NG2-positive glioblastoma.

CSIG-18. NERVE/GLIAL ANTIGEN (NG)2 EXPRESSION IN GLIOBLASTOMA IS REGULATED BY miR-29b-3p

Overexpression of NG2 in human glioblastoma cells is associated with an elevated drug resistance and thereby worsens clinical outcome. However, the regulatory mechanisms of NG2 expression are largely unknown. In this study, we identified miR-29b-3p as a posttranscriptional factor of NG2 expression. The basal mRNA levels of miR-29b-3p and NG2 were detected in the NG2-positive glioblastoma cell lines A1207 and U87 by qRT-PCR. The cells were transfected with miR-29b-3p-mimic or scrambled-miR (control) and the expression of NG2 was analyzed by qRT-PCR, flow cytometry and Western blot. Reporter gene analyses of the NG2 promotor region and 3’UTR were performed to study the effect of miR-29b-3p on NG2 expression. Finally, we analyzed the mRNA levels of NG2 and miR-29b-3p in samples from glioblastoma patients. We found that the two NG2-positive glioblastoma cell lines A1207 and U87 are positive for miR-29b-3p. Transfection with miR-29b-3p-mimic reduced NG2 mRNA levels in A1207 (29%±9.9; Mean±SD) and U87 (6%±2.8), resulting in a significantly decreased NG2 protein expression in A1207 (67%±6.4) and U87 (75%±4) when compared to controls. The analysis of the 3’UTR revealed that miR-29b-3p is a posttranscriptional regulator of NG2 expression. Moreover, miR-29b-3p affects the pretranscriptional NG2 expression by diminishing SP-1-dependent NG2 promotor activity. These results were confirmed by the analysis of glioblastoma patient-derived samples, demonstrating that a high NG2 expression is associated with low levels of miR-29b-3p. In conclusion, we identified miR-29b-3p as a crucial regulator of NG2 expression in glioblastoma. Hence, targeting NG2 expression by miR-29b-3p may provide a novel therapeutic strategy to overcome drug resistance in NG2-positive glioblastoma cells.

miRNA-26a expression influences the therapy response to carmustine wafer implantation in patients with glioblastoma multiforme

BACKGROUND

Glioblastoma multiforme is the most frequent malignant brain tumor in adults being marked with a very poor prognosis. Therapy concept implies concomitant radio-chemotherapy and facultative implantation of carmustine-eluted wafer. Current literature suggests microRNA 26a expression in glioblastoma to interact with alkylating chemotherapy. Subsequently, the aim of this study was to investigate the correlation of miRNA-26a expression and carmustine wafer implantation and its potential usefulness as a predictive marker for therapy response.

METHODS

In total, 229 patients with glioblastoma multiforme were included into the final analysis. Of them, 80 cases were recruited from the Saarland University Medical Center for a retrospective matched-pair analysis stratified after therapy regime: One group (carmustine wafer group; n=40) received concomitant radio-chemotherapy with carmustine wafer implantation. The other group (control group; n=40) only received concomitant radio-chemotherapy. The results were confirmed by comparing them with an independent dataset of 149 patients from the TCGA database. All tumor specimens were evaluated for miRNA-26a expression, MGMT promoter methylation, and IDH1 R132H mutation status, and the results were correlated with the clinical data.

RESULTS

Twenty-three patients in the carmustine wafer group showed low expression of miRNA-26a, while 17 patients showed a high expression. In the control group, 28 patients showed low expression, while 12 patients showed a high expression. The patients with high miRNA-26a expression in the carmustine wafer group were characterized by a significantly longer overall (hazard ratio [HR] 2.750 [95% CI 1.352-5.593]; p=0.004) and progression-free survival (HR 3.091 [95% CI 1.436-6.657]; p=0.003) than patients with low miRNA-26a expression. The 17 patients in the carmustine wafer group with high miRNA-26a expression showed a significantly longer progression-free survival (p=0.013) and overall survival (p=0.007) compared with the control group. There were no such correlations identified within the control group. TCGA datasets supported these findings.

CONCLUSIONS

MiRNA-26a expression turned out to be a promising predictor of therapy response and clinical outcome in glioblastoma patients treated with carmustine wafer implantation. For evaluation of the role of miRNA-26a in a combined therapy setting, further studies are needed in order to translate general findings to the patient's individual situation.

A New Clip Generation for Microsurgical Treatment of Intracranial Aneurysms-The First Case Series

OBJECTIVE

Considerable effort has been made in order to reduce surgical invasiveness while maintaining optimal exploiting of the operative space in aneurysm surgery. One aspect of this evolution is represented by the Lazic (Peter Lazic GmbH, Tuttlingen, Germany) aneurysm clip system. The purpose of this study was to illustrate the new generation clip system in practiced aneurysm surgery.

METHODS

A retrospective analysis of all aneurysm surgeries in our departments between December 2015 and January 2018 using the new D-Clip system was performed. Evaluation included standardized retrospective review of the main surgeon, the nursing staff, as well as an analysis of surgical video documentation by objective reviewers.

RESULTS

Forty-five patients with 50 intracranial aneurysms underwent surgical clipping using the D-Clip system. A total of 64 permanent and 19 temporary D-Clips were applied. Nine clips needed to be replaced. All aneurysms could be occluded totally. Surgeons considered handling and manoeuvrability of clip application as feasible and good in all cases (100%), even under impaired visibility circumstances (14%). Objective video analysis revealed comparable results. Nursing staff scored handling and practicability of D-Clips equivalent to the preceding L-Clip generation. There were no intraoperative complications. Surgery-related postoperative morbidity was 6.7%.

CONCLUSIONS

The new D-Clip system combines an attenuated design for minimally invasive clipping procedures with traditional mechanisms of common clip systems. It therefore appears to be highly versatile in the context of variable different aneurysm morphologies and locations while maintaining high standard surgical safety and efficacy.

Changes in Posttraumatic Brain Edema in Craniectomy-Selective Brain Hypothermia Model Are Associated With Modulation of Aquaporin-4 Level

Both hypothermia and decompressive craniectomy have been considered as a treatment for traumatic brain injury. In previous experiments we established a murine model of decompressive craniectomy and we presented attenuated edema formation due to focal brain cooling. Since edema development is regulated via function of water channel proteins, our hypothesis was that the effects of decompressive craniectomy and of hypothermia are associated with a change in aquaporin-4 (AQP4) concentration. Male CD-1 mice were assigned into following groups (n = 5): sham, decompressive craniectomy, trauma, trauma followed by decompressive craniectomy and trauma + decompressive craniectomy followed by focal hypothermia. After 24 h, magnetic resonance imaging with volumetric evaluation of edema and contusion were performed, followed by ELISA analysis of AQP4 concentration in brain homogenates. Additional histopathological analysis of AQP4 immunoreactivity has been performed at more remote time point of 28d. Correlation analysis revealed a relationship between AQP4 level and both volume of edema (r² = 0.45, p < 0.01, ^**) and contusion (r² = 0.41, p < 0.01, ^**) 24 h after injury. Aggregated analysis of AQP4 level (mean ± SEM) presented increased AQP4 concentration in animals subjected to trauma and decompressive craniectomy (52.1 ± 5.2 pg/mL, p = 0.01; ^*), but not to trauma, decompressive craniectomy and hypothermia (45.3 ± 3.6 pg/mL, p > 0.05; ns) as compared with animals subjected to decompressive craniectomy only (32.8 ± 2.4 pg/mL). However, semiquantitative histopathological analysis at remote time point revealed no significant difference in AQP4 immunoreactivity across the experimental groups. This suggests that AQP4 is involved in early stages of brain edema formation after surgical decompression. The protective effect of selective brain cooling may be related to change in AQP4 response after decompressive craniectomy. The therapeutic potential of this interaction should be further explored.

Promoter methylation of RB1, P15, P16, and MGMT and their impact on the clinical course of pilocytic astrocytomas

Promoter methylation of P15, P16, RB transcriptional corepressor 1 (RB1) and O-6-methylguanine-DNA methyltransferase (MGMT) impacts the prognosis of numerous glioma subtypes. However, whether promoter methylation of these genes also has an impact on the clinical course of pilocytic astrocytoma remains unclear. Using methylation-specific polymerase chain reaction, the methylation status of the tumor suppressor genes P15, P16, RB1, and MGMT in pilocytic astrocytomas (n=18) was analyzed. Immunohistochemical staining for the R132H mutation of the isocitrate dehydrogenase (NADP(+)) 1, cytosolic (IDH1) gene was performed. Clinical data including age, gender, localization of tumor, extent of resection, treatment modality, progression-free survival and overall survival were collected. The methylation index for P15, P16, RB1 and MGMT was 0.0, 0.0, 5.6% (1/18) and 44.5% (8/18), respectively. If the MGMT promoter was methylated, the probability of relapse and second subsequent therapy was significantly increased (P=0.019). The one patient with methylation of P15 demonstrated a poor clinical course. The pilocytic astrocytomas of all 18 patients revealed wild-type IDH1. Clinically, there was a significant correlation of subtotal resection with the occurrence of relapse (P=0.005) and of the localization of the tumor with the extent of resection (P=0.031). Gross total resection was achieved significantly more often in pediatric patients than in adult patients (P=0.003). Adult patients demonstrated more relapses following the first tumor resection (P=0.001). The present study indicates that methylation of MGMT is associated with a poor clinical course and represents an age-independent risk factor for an unfavorable outcome. Other influential factors of outcome were the age of the patient and extent of resection.

Importance of biomarkers in glioblastomas patients receiving local BCNU wafer chemotherapy

Background

To assess the influence of molecular markers with potential prognostic value to groups of patients with newly diagnosed glioblastoma patients were examined: group A with 36 patients (surgical resection plus standard combined chemoradiotherapy) and group B with 36 patients (surgical resection, standard combined chemoradiotherapy plus carmustine wafer implantation).

Our aim was to determine chromosomal alterations, methylation status of MGMT, p15, and p16 (CDKN2A) in order to analyse the influence on patient survival time as well as radio- and chemotherapy responses. Promoter hypermethylation of MGMT, p16, and p15 genes were determined by MS-PCR. Comparative genomic hybridisation (CGH) analyses were performed with isolated, labelled DNA of each tumor to detect genetic alterations.

Results

Age of onset of the disease showed a significant effect on overall survival (OS) (p < 0.0001). Additional treatment with carmustine wafer (group B) compared to the control group (group A) did not result in improved OS (p = 0.562). Patients with a methylated MGMT promotor showed a significant longer OS compared to those patients with unmethylated MGMT promotor (p = 0.041). Subgroup analyses revealed that patients with methylated p15 showed a significant shorter OS when administered to group B rather than in group A (p = 0.0332). In patients additionally treated with carmustine wafer an amplification of 4q12 showed a significant impact on a reduced OS (p = 0.00835). In group B, a loss of 13q was significantly associated with a longer OS (p = 0.0364). If a loss of chromosome 10 occurred, patients in group B showed a significantly longer OS (p = 0.0123).

Conclusion

A clinical benefit for the widespread use of additional carmustine wafer implantation could not be found. However, carmustine wafer implantation shows a significantly improved overall survival if parts of chromosome 10 or chromosome 13 are deleted. In cases of 4q12 amplification and in cases of a methylated p15 promotor, the use of carmustine wafers is especially not recommended.

The MGMT promoter methylation is a strong prognostic Biomarker for benefit from temozolomide and BCNU chemotherapy.

Selective Brain Hypothermia Mitigates Brain Damage and Improves Neurological Outcome after Post-Traumatic Decompressive Craniectomy in Mice

Hypothermia and decompressive craniectomy (DC) have been considered as treatment for traumatic brain injury. The present study investigates whether selective brain hypothermia added to craniectomy could improve neurological outcome after brain trauma. Male CD-1 mice were assigned into the following groups: sham; DC; closed head injury (CHI); CHI followed by craniectomy (CHI+DC); and CHI+DC followed by focal hypothermia (CHI+DC+H). At 24 h post-trauma, animals were subjected to Neurological Severity Score (NSS) test and Beam Balance Score test. At the same time point, magnetic resonance imaging using a 9.4 Tesla scanner and subsequent volumetric evaluation of edema and contusion were performed. Thereafter, the animals were sacrificed and subjected to histopathological analysis. According to NSS, there was a significant impairment among all the groups subjected to trauma. Animals with both trauma and craniectomy performed significantly worse than animals with craniectomy alone. This deleterious effect disappeared when additional hypothermia was applied. BBS was significantly worse in the CHI and CHI+DC groups, but not in the CHI+DC+H group, compared to the sham animals. Edema and contusion volumes were significantly increased in CHI+DC animals, but not in the CHI+DC+H group, compared to the DC group. Histopathological analysis showed that neuronal loss and contusional blossoming could be attenuated by application of selective brain hypothermia. Selective brain cooling applied post-trauma and craniectomy improved neurological function and reduced structural damage and may be therefore an alternative to complication-burdened systemic hypothermia. Clinical studies are recommended in order to explore the potential of this treatment.

Decompressive Craniectomy Increases Brain Lesion Volume and Exacerbates Functional Impairment in Closed Head Injury in Mice

Decompressive craniectomy has been widely used in patients with head trauma. The randomized clinical trial on an early decompression (DECRA) demonstrated that craniectomy did not improve the neurological outcome, in contrast to previous animal experiments. The goal of our study was to analyze the effect of decompressive craniectomy in a murine model of head injury. Male mice were assigned into the following groups: sham, decompressive craniectomy, closed head injury (CHI), and CHI followed by craniectomy. At 24 h post-trauma, animals underwent the Neurological Severity Score test (NSS) and Beam Balance Score test (BBS). At the same time point, magnetic resonance imaging was performed, and volume of edema and contusion was assessed, followed by histopathological analysis. According to NSS, animals undergoing both trauma and craniectomy presented the most severe neurological impairment. Also, balancing time was reduced in this group compared with sham animals. Both edema and contusion volume were increased in the trauma and craniectomy group compared with sham animals. Histopathological analysis showed that all animals that underwent trauma presented substantial neuronal loss. In animals treated with craniectomy after trauma, a massive increase of edema with hemorrhagic transformation of contusion was documented. Decompressive craniectomy applied after closed head injury in mice leads to additional structural and functional impairment. The surgical decompression via craniectomy promotes brain edema formation and contusional blossoming in our model. This additive effect of combined mechanical and surgical trauma may explain the results of the DECRA trial and should be explored further in experiments.

What is the nature of the RGC-5 cell line?

The immortalized RGC-5 cell line has been widely used as a cell culture model to study the neurobiology of retinal ganglion cells (RGCs). The cells were originally introduced as derived from rat RGC showing expression of various neuronal markers, in particular the RGC-characteristic proteins Brn3 and Thy1. Recent data gave rise to concerns regarding the origin and nature of the cells. RGC-5 cells were identified to be of mouse origin and their expression of RGC characteristics was questioned by some laboratories. This article summarizes the available data on the properties of RGC-5, discusses common protocols for their differentiation and is aimed at providing researchers some guidelines on the benefits and limitations of RGC-5 for research.