Insights from a Multicenter Study on Adult H3 K27M-Mutated Glioma: Surgical Resection's Limited Influence on Overall Survival, ATRX as Molecular Prognosticator.

BACKGROUND: H3 K27M-mutated gliomas were first described as a new grade 4 entity in the 2016 WHO classification. Current studies have focused on its typical appearance in children and young adults, increasing the need to better understand the prognostic factors and impact of surgery on adults. Here, we report a multicentric study of this entity in adults. METHODS: We included molecularly confirmed H3 K27M-mutated glioma cases in patients >18 years diagnosed between 2016 and 2022. Clinical, radiological, and surgical features were analyzed. Univariate and multivariate analyses were performed to identify prognostic factors. RESULTS: Among 70 patients with a mean age of 36.1 years, the median overall survival (OS) was 13.6 + 14 months. Gross-total resection was achieved in 14.3% of patients, whereas 30% had a subtotal resection and 54.3% a biopsy.Tumors located in telencephalon/diencephalon/myelencephalon were associated with a poorer OS, while a location in the mesencephalon/metencephalon showed a significantly longer OS (8.7 vs. 25.0 months, p=0.007). Preoperative Karnofsky Performance Score (KPS) < 80 showed a reduced OS (4.2 vs. 18 months, p=0.02). Furthermore, ATRX loss, found in 25.7%, was independently associated with an increased OS (31 vs. 8.3 months, p=0.0029). Notably, patients undergoing resection showed no survival benefit over biopsy (12 vs. 11 months, p=0.4006). CONCLUSION: The present study describes surgical features of H3 K27M-mutated glioma in adulthood in a large multicentric study. Our data reveal that ATRX status, location and KPS significantly impact OS in H3 K27M-mutated glioma. Importantly, our dataset indicates that resection does not offer a survival advantage over biopsy.

[Traumatic brain injury]. / Schädel-Hirn-Trauma.

Traumatic brain injury (TBI) describes parenchymal brain damage caused by external forces to the head. It has a massive personal and socioeconomic impact, as it is a disease with high morbidity and mortality. Both young and old people are affected, as a result of traffic or sports accidents as well as due to falls at home. The term TBI encompasses various clinical pictures, differing considerably in cause, prognosis and therapy. What they all have in common is the pathophysiological cascade that develops immediately after the initial trauma and which can persist for several days and weeks. In this phase, medical treatment, whether surgical or pharmacological, attempts to reduce the consequences of the primary damage. The aim is to maintain adequate cerebral perfusion pressure and to reduce intracranial pressure.

Noninvasive CSF shunt patency evaluation by superb microvascular imaging.

Occlusion of a ventriculoperitoneal shunt system is a potentially life-threatening complication in patients suffering from hydrocephalus. However, there is no imaging established as standard approach in this acute setting. In the present study, we evaluate the use of superb microvascular imaging for investigation of the patency of ventriculoperitoneal shunt systems. Simulation of low flow rates of cerebrospinal fluid through a small diameter CSF shunt system was performed in a dedicated phantom in order to proof the principle of superb microvascular imaging (SMI) being feasible for the measurement of slow CSF flow through the dedicated CSF shunt system. SMI is able to detect low flow rates in CSF shunt systems effectively and fast. Visualization of a Duplex ultrasound flow and Doppler wave pattern in the VP shunt system after the reservoir has been pressed confirms patency. SMI is an effective method for evaluating CSF shunt patency and diagnosing shunt obstruction. This bears the potential to facilitate evaluation of clinically symptomatic VP shunt patients in an acute setting. Further evaluation of ultrasound flow patterns is granted.

Evaluate the safety and efficacy of dura sealant patch in reducing cerebrospinal fluid leakage following elective cranial surgery (ENCASE II): study protocol for a randomized, two-arm, multicenter trial.

BACKGROUND: Cerebrospinal fluid (CSF) leakage is a frequent and challenging complication in neurosurgery, especially in the posterior fossa, with a prevalence of 8%. It is associated with substantial morbidity and increased healthcare costs. A novel dural sealant patch (LIQOSEAL) was developed for watertight dural closure. The objective of this study is to clinically assess the safety and effectiveness of LIQOSEAL as a means of reducing intra- as well as postoperative CSF leakage in patients undergoing elective posterior fossa intradural surgery with a dural closure procedure compared to the best currently available dural sealants. METHODS: We will conduct a two-arm, randomized controlled, multicenter study with a 90-day follow-up. A total of 228 patients will be enrolled in 19 sites, of which 114 will receive LIQOSEAL and 114 an FDA-approved PEG sealant. The composite primary endpoint is defined as intraoperative CSF leakage at PEEP 20 cm H2O, percutaneous CSF leakage within 90 days of, wound infection within 90 days of or pseudomeningocele of more than 20cc on MRI or requiring intervention. We hypothesize that the primary endpoint will not be reached by more than 10 patients (9%) in the investigational arm, which will demonstrate non-inferiority of LIQOSEAL compared to control. DISCUSSION: This trial will evaluate whether LIQOSEAL is non-inferior to control as a means of reducing CSF leakage and safety TRIAL REGISTRATION: ClinicalTrials.gov NCT04086550 . Registered on 11 September 2019.

A snapshot of European neurosurgery December 2019 vs. March 2020: just before and during the Covid-19 pandemic.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2 or Covid-19), which began as an epidemic in China and spread globally as a pandemic, has necessitated resource management to meet emergency needs of Covid-19 patients and other emergent cases. We have conducted a survey to analyze caseload and measures to adapt indications for a perception of crisis. METHODS: We constructed a questionnaire to survey a snapshot of neurosurgical activity, resources, and indications during 1 week with usual activity in December 2019 and 1 week during SARS-CoV-2 pandemic in March 2020. The questionnaire was sent to 34 neurosurgical departments in Europe; 25 departments returned responses within 5 days. RESULTS: We found unexpectedly large differences in resources and indications already before the pandemic. Differences were also large in how much practice and resources changed during the pandemic. Neurosurgical beds and neuro-intensive care beds were significantly decreased from December 2019 to March 2020. The utilization of resources decreased via less demand for care of brain injuries and subarachnoid hemorrhage, postponing surgery and changed surgical indications as a method of rationing resources. Twenty departments (80%) reduced activity extensively, and the same proportion stated that they were no longer able to provide care according to legitimate medical needs. CONCLUSION: Neurosurgical centers responded swiftly and effectively to a sudden decrease of neurosurgical capacity due to relocation of resources to pandemic care. The pandemic led to rationing of neurosurgical care in 80% of responding centers. We saw a relation between resources before the pandemic and ability to uphold neurosurgical services. The observation of extensive differences of available beds provided an opportunity to show how resources that had been restricted already under normal conditions translated to rationing of care that may not be acceptable to the public of seemingly affluent European countries.

Comparación entre la PET/TC con 18F-DOPA y la PET/TC con 68Ga-DOTATOC para la localización del paraganglioma maligno extra-adrenal y el feocromocitoma / 68Ga-DOTATOC PET/CT in the localization of metastatic extra-adrenal paraganglioma and pheochromocytoma compared with 18F-DOPA PET/CT

Objetivo: La PET con 18F-fluoro-L-dihidroxifenilalanina (18F-DOPA) ofrece alta sensibilidad y especificidad en el diagnóstico del paraganglioma extraadrenal no maligno (PGL) y el feocromocitoma (FEO), pero menor sensibilidad en la enfermedad metastásica. Estos tumores son de origen neuroendocrino y pueden detectarse mediante PET con 68Ga-DOTA-Tyr3-octreótido (68Ga-DOTA-TOC). Por tanto, comparamos 68Ga-DOTA-TOC y 18F-DOPA como radiotrazadores para PET/TC para el diagnóstico de PGL extradrenal metastásico y FEO. Las imágenes tomográficas anatómicas y funcionales fusionadas se utilizaron como estándar de referencia. Métodos: Se incluyó en el estudio a un total de 6 varones y 4 mujeres (rango de edad de 22 a 72 años), con PGL metastásico y FEO anatómica y/o histológicamente demostrados. De entre estos pacientes, 2 varones padecían FEO y los 8 pacientes restantes PGL extraadrenal metastásico. La evaluación comparativa incluyó imagen morfológica con TC e imagen funcional mediante PET con 68Ga-DOTA-TOC y 18F-DOPA. Se analizaron los resultados de las imágenes por lesión. Se midió el valor máximo de captación estandarizado (SUVmáx) de cada modalidad de imagen funcional en las lesiones tumorales concordantes. Resultados: En comparación con la imagen anatómica, la tasa de detección por lesión mediante PET con 68Ga-DOTA-TOC fue del 100% (McNemar, p<0,01), y la de PET con 18F-DOPA fue del 82,3% (McNemar, p<0,8) para PGL extraadrenal metastásico y FEO. En general, la PET con 68Ga-DOTA-TOC identificó 67 lesiones, la imagen anatómica identificó 62 lesiones y la PET con 18F-DOPA identificó 56 lesiones. El valor SUVmáx (media±DE) de todas las lesiones concordantes fue de 29,3±19,9 para la PET con 68Ga-DOTA-TOC, y de 12,3±9,1 para la PET con 18F-DOPA (prueba U de Mann-Whitney, p<0,0001). Conclusión: La PET con 68Ga-DOTA-TOC proporciona un índice de detección más elevado en el PGL extra-adrenal metastásico y PHEO, en comparación con la PET con 18F-DOPA, e incluso con la TC diagnóstica, particularmente en lo referente a lesiones óseas. La imagen funcional/anatómica combinada (PET/TC con 68Ga-DOTA-TOC) permite detectar la extensión exacta del tumor en estas entidades tumorales infrecuentes, especialmente en caso de correlación anatómica incierta

Objective: 18F-Fluoro-L-dihydroxyphenylalanine (18F-DOPA) PET offers high sensitivity and specificity in the imaging of non-malignant extra-adrenal paraganglioma (PGL) and pheochromocytoma (PHEO) but lower sensitivity in metastatic disease. These tumours are of neuroendocrine origin and can be detected by 68Ga-DOTA-Tyr3-octreotide (68Ga-DOTA-TOC) PET. Therefore, we compared 68Ga-DOTA-TOC and 18F-DOPA as radiolabels for PET/CT imaging for the diagnosis of metastatic extra-adrenal PGL and PHEO. Combined cross-sectional imaging was the reference standard. Methods: A total of 6 men and 4 women (age range 22-72 years) with anatomical and/or histologically proven metastatic PGL and PHEO were included in this study. Of these patients, 2 male patients suffered from PHEO, while the remaining 8 patients were diagnosed as metastatic extra-adrenal PGL disease. Comparative evaluation included morphological imaging with CT and functional imaging with 68Ga-DOTA-TOC and 18F-DOPA PET. The imaging results were analyzed on a per-lesion basis. The maximum standardized uptake value (SUVmax) of each functional imaging modality in concordant tumour lesions was measured. Results: Compared with anatomical imaging, the per-lesion detection rate of 68Ga-DOTA-TOC was 100% (McNemar, P<0.01), and that of 18F-DOPA PET was 82.3% (McNemar, P<0.8) in metastatic extra-adrenal PGL and PHEO. Overall, 68Ga-DOTA-TOC PET identified 67 lesions; anatomical imaging identified 62 lesions, and 18F-DOPA PET identified 56 lesions. The SUVmax (mean±SD) of all concordant lesions was 29.3±19.9 for 68Ga-DOTA-TOC PET and 12.3±9.1 for 18F-DOPA PET (Mann-Whitney U test, P<0.0001). Conclusion: 68Ga-DOTA-TOC PET offers the highest detection rate in metastatic extra-adrenal PGL and PHEO compared to 18F-DOPA PET and even to diagnostic CT, particularly in bone lesions. Combined functional/anatomical imaging (68Ga-DOTA-TOC PET/CT) enables exact tumour extension to be detected in these rare tumour entities, especially in the case of unclear anatomical correlation

68Ga-DOTATOC PET/CT in the localization of metastatic extra-adrenal paraganglioma and pheochromocytoma compared with 18F-DOPA PET/CT. / Comparación entre la PET/TC con 18F-DOPA y la PET/TC con 68Ga-DOTATOC para la localización del paraganglioma maligno extra-adrenal y el feocromocitoma.

OBJECTIVE: 18F-Fluoro-L-dihydroxyphenylalanine (18F-DOPA) PET offers high sensitivity and specificity in the imaging of non-malignant extra-adrenal paraganglioma (PGL) and pheochromocytoma (PHEO) but lower sensitivity in metastatic disease. These tumours are of neuroendocrine origin and can be detected by 68Ga-DOTA-Tyr3-octreotide (68Ga-DOTA-TOC) PET. Therefore, we compared 68Ga-DOTA-TOC and 18F-DOPA as radiolabels for PET/CT imaging for the diagnosis of metastatic extra-adrenal PGL and PHEO. Combined cross-sectional imaging was the reference standard. METHODS: A total of 6 men and 4 women (age range 22-72 years) with anatomical and/or histologically proven metastatic PGL and PHEO were included in this study. Of these patients, 2 male patients suffered from PHEO, while the remaining 8 patients were diagnosed as metastatic extra-adrenal PGL disease. Comparative evaluation included morphological imaging with CT and functional imaging with 68Ga-DOTA-TOC and 18F-DOPA PET. The imaging results were analyzed on a per-lesion basis. The maximum standardized uptake value (SUVmax) of each functional imaging modality in concordant tumour lesions was measured. RESULTS: Compared with anatomical imaging, the per-lesion detection rate of 68Ga-DOTA-TOC was 100% (McNemar, P<0.01), and that of 18F-DOPA PET was 82.3% (McNemar, P<0.8) in metastatic extra-adrenal PGL and PHEO. Overall, 68Ga-DOTA-TOC PET identified 67 lesions; anatomical imaging identified 62 lesions, and 18F-DOPA PET identified 56 lesions. The SUVmax (mean±SD) of all concordant lesions was 29.3±19.9 for 68Ga-DOTA-TOC PET and 12.3±9.1 for 18F-DOPA PET (Mann-Whitney U test, P<0.0001). CONCLUSION: 68Ga-DOTA-TOC PET offers the highest detection rate in metastatic extra-adrenal PGL and PHEO compared to 18F-DOPA PET and even to diagnostic CT, particularly in bone lesions. Combined functional/anatomical imaging (68Ga-DOTA-TOC PET/CT) enables exact tumour extension to be detected in these rare tumour entities, especially in the case of unclear anatomical correlation.

Early thrombosis prophylaxis with enoxaparin is not associated with hematoma expansion in patients with spontaneous intracerebral hemorrhage.

BACKGROUND AND PURPOSE: Early pharmacological deep vein thrombosis (DVT) prophylaxis is recommended by guidelines, but rarely started within 48 h. We aimed to analyze the effect of early (within 48 h) versus late (>48 h) DVT prophylaxis on hematoma expansion (HE) and outcome in patients with spontaneous intracerebral hemorrhage (ICH). METHODS: We analyzed 134 consecutive patients admitted to a tertiary neurointensive care unit with diagnosed spontaneous ICH, without previous anticoagulation, severe coagulopathy, hematoma evacuation, early withdrawal of therapy or ineligibility for DVT prophylaxis according to our institutional protocol. Significant late HE was defined as ≥6 mL increase of hematoma volume between neuroimaging within 48 h and day 3-6. Multivariate analysis was performed to identify risk factors for late HE, poor 3-month outcome (modified Rankin Scale score ≥ 4) and mortality. RESULTS: Patients had a median Glasgow Coma Scale score of 14 [interquartile range (IQR), 10-15], ICH volume of 11 (IQR, 5-24) mL and were 71 (IQR, 61-76) years old. A total of 56% (n = 76) received early DVT prophylaxis, 37% (n = 50) received late DVT prophylaxis and 8 (6%) had unknown bleeding onset. Patients with early DVT prophylaxis had smaller ICH volume [9.5 (IQR, 4-18.5) vs. 17.5 (IQR, 8-29) mL, P = 0.038] and were more often comatose (26% vs. 10%, P = 0.025). Significant late HE [n = 5/134 (3.7%)] was associated with larger initial ICH volume (P = 0.02) and lower thrombocyte count (P = 0.03) but not with early DVT prophylaxis (P = 0.36). Early DVT prophylaxis was not associated with worse outcome. CONCLUSION: Significant late HE is uncommon and DVT prophylaxis within 48 h of symptom onset may be safe in selected patients with ICH.

[Surgical treatment of adult spinal deformities]. / Operative Behandlung adulter spinaler Deformitäten.

BACKGROUND: Adult spinal deformity (ASD) is mostly a progressive disease which usually leads to chronic pain. Due to increased prevalence in older people many patients suffer from comorbidities, which make conservative and surgical treatment even more complex. OBJECTIVE: This article provides an overview on the current conservative and surgical treatment options. MATERIAL AND METHODS: An extensive literature search was carried out via Medline plus an additional evaluation of the authors' personal experiences was performed. RESULTS: The current conservative and surgical treatments are outlined and potential risk factors and predictors which may lead to inferior clinical outcome are discussed. CONCLUSION: Patients for whom even conservative treatment leads to success should be identified earlier and better. The surgical treatment ranges from minimally invasive decompression to multilevel fusions. Complications in large corrective interventions can be substantial but if the indications are correctly assessed, such complex surgical treatment has excellent clinical results in terms of pain and quality of life.

[Operative treatment of degenerative diseases of the lumbar spine]. / Operative Versorgung degenerativer Erkrankungen der Lendenwirbelsäule.

BACKGROUND: Degenerative diseases of the lumbar spine and associated lower back pain represent a major epidemiological and health-related economic challenge. A distinction is made between specific and unspecific lower back pain. In specific lower back pain lumbar disc herniation and spinal canal stenosis with or without associated segment instability are among the most frequent pathologies. Diverse conservative and operative strategies for treatment of these diseases are available. OBJECTIVES: The aim of this article is to present an overview of current data and an evidence-based assessment of the possible forms of treatment. MATERIAL AND METHODS: An extensive literature search was carried out via Medline plus an additional evaluation of the authors' personal experiences. RESULTS: Conservative and surgical treatment represent efficient treatment options for degenerative diseases of the lumbar spine. Surgical treatment of lumbar disc herniation shows slight advantages compared to conservative treatment consisting of faster recovery of neurological deficits and a faster restitution of pain control. Surgical decompression is superior to conservative measures for the treatment of spinal canal stenosis and degenerative spondylolisthesis. In this scenario conservative treatment represents an important supporting measure for surgical treatment in order to improve the mobility of patients and the outcome of surgical treatment. CONCLUSION: The treatment of specific lower back pain due to degenerative lumbar pathologies represents an interdisciplinary challenge, requiring both conservative and surgical treatment strategies in a synergistic treatment concept in order to achieve the best results for patients.

[Operative treatment of the degenerative cervical spine]. / Operative Versorgung der degenerativen Halswirbelsäule.

BACKGROUND: Degenerative alterations of the cervical spine often entail disc herniations and stenoses of the spinal canal and/or neural foramen. Mediolateral or lateral compression of nerve roots causes cervical radiculopathy, which is an indication for surgery in cases of significant motor deficits or refractory pain. Median canal encroachment may result in compression of the spinal cord and cervical myelopathy. Its natural history is typically characterized by episodic deterioration, so that surgical decompression is indicated in cases of clear myelopathic signs. OBJECTIVE: The aim of the present article is to outline the operative options for patients with cervical radiculopathy and myelopathy. Furthermore, we describe the operative complications and the outcome in these patients. MATERIAL AND METHODS: For this manuscript a systematic PubMed search was carried out, the papers were systematically analyzed for the best evidence and this was combined with the authors' experience. RESULTS AND CONCLUSION: Depending on the cervical pathology, the most prevalent surgical options for radiculopathy include anterior cervical discectomy and fusion (ACDF), cervical arthroplasty or posterior cervical foraminotomy. Cervical myelopathy may be decompressed by ACDF, corpectomy or posterior approaches like laminectomy plus instrumented fusion or laminoplasty. The outcome depends on the cervical pathology and the type of operation. Overall, in long-term follow-up studies the results of all surgical techniques on the cervical spine are generally considered to be very good, although specific patient characteristics are more suited for a particular approach.

Retrospective analysis of cervical corpectomies: implant-related complications of one- and two-level corpectomies in 45 patients.

Cervical corpectomies are increasingly used to treat degenerative, metastatic, inflammatory and traumatic multisegmental diseases. The postoperative results are thought to correlate mainly with the number of resected vertebral bodies. Thus, the aim of the study was to analyse complications and early outcome of these procedures to document the implant-related complications in order to set up a prospective clinical trial. Forty-five patients, who were treated in our department from 2011 to 2014 and who were available for a minimum follow-up of 1 year, were consecutively included in this retrospective evaluation. The median age was 61 (±11) years with a female to male sex ratio of 19 to 26, respectively. In these patients, cervical corpectomies (one-, two- and three-level procedures) were performed. The average number of resected levels was 1.2 levels. The intraoperative loss of blood (LOB), the red cell transfusions (rcT), the length of operation (LOO) and the usage of drains were investigated and correlated with intra- and postoperative complications. The mean LOO was 244 min (±68) with a mean LOB of 511 ml (±531). The overall complication rate was 22.9% (10 patients). Six patients (13.3%) had implant-related complications due to loosening and toggling of the screws and/or cage subsidence. Two patients (4.4%) had a postoperative haematoma and another two patients (4.4%) suffered from neurological deterioration due to an ongoing and severe myelopathic syndrome. All these patients received revision surgery. The average time from the first to revision surgery was 90 days. Cervical corpectomies still remain procedures with a high complication rate mainly represented by implant-related failures. These implant-related complications range from screw/plate loosening or toggling to graft dislocation with subsidence and might be associated with constructs extended to the C7 vertebral body. In our study population, the rate of implant failure was comparable to the literature, but not obviously correlated with the number of vertebral bodies resected. This may be attributed to the different disease entities. Thus, our results support the use of circumferential approaches for selected instability scenarios (metastatic or inflammatory diseases, kyphosis, osteoporosis, etc.) of one- and two-level corpectomies.

How I do it-optimizing radiofrequency ablation in spinal metastases using iCT and navigation.

BACKGROUND: Exact positioning of the radiofrequency ablation (RFA) probe for tumor treatment under fluoroscopic guidance can be difficult because of potentially small inaccessible lesions and the radiation dose to the medical staff in RFA. In addition, vertebroplasty (VP) can be significantly high. METHOD: Description and workflow of RFA in spinal metastasis using iCT (intraoperative computed tomography) and 3D-navigation-based probe placement followed by VP. CONCLUSION: RFA and VP can be successfully combined with iCT-based navigation, which leads to a reduction of radiation to the staff and optimal probe positioning due to 3D navigation.

Asymmetric pedicle subtractionosteotomy (aPSO) guided by a 3D-printed model to correct a combined fixed sagittal and coronal imbalance.

Surgical correction of fixed thoracolumbar deformity is usually achieved by estimating the preoperatively planned correction angles during surgery and is therefore prone to inaccuracy. This is particularly problematic in biplanar deformities. To overcome these difficulties, 3D model for planning, preparation, and simulation of an asymmetric pedicle subtraction osteotomy (aPSO) was printed and used to realign coronal and sagittal balance in case of rigid degenerative kyphoscoliosis. A 59-year-old woman presented with severe back pain and spinal claudication and was diagnosed with a rigid kyphoscoliosis with multilevel spinal stenosis. Spino-pelvic parameters were measured preoperatively (pelvic incidence 47° [PI], lumbar lordosis 18° [LL]; pelvic tilt 42° [PT], T1 pelvic angle 40° [TPA], Cobb angle 33°, sagittal vertical axis 10.5 cm [SVA]). To aid the complex deformity in the sagittal and coronal plane, a 1:1 3D model of the spine was printed according to the preoperative computed tomography (CT). With the use of a rebalancing software, the spine was prepared in vitro as a model for intraoperative realignment and the correction was preoperatively simulated. Surgery was accomplished according to the preoperative software-guided plan. Asymmetric pedicle subtraction osteotomy (aPSO) of L3 identical to the 3D model was performed. Additionally, a Smith-Peterson osteotomy of L4/5 with transforaminal lumbar interbody fusion (TLIF) and laminectomy of L2-S1 with pedicle screw instrumentation TH12-S1 was accomplished. Postoperative radiological parameters revealed good success (LL 40°, SVA 6 cm, PT 19°, TPA 22°, and a Cobb angle of 8°). Improvement of the Oswestry disability index (ODI) of 42 to 18, the visual analog scale (VAS) of 8 to 1, and walking distance 100 to 8000 m compared to preoperatively resulted at 24 months follow-up. The precise coronal and sagittal correction of a rigid degenerative kyphoscoliosis presents a major challenge. Asymmetric PSO is able to realign the thoracolumbar spine in both the coronal and sagittal planes. The creation of an in vitro 3D-printed model of a patient's spinal deformity in combination with a software to calculate the correction angles facilitates preoperative planning and implementation of aPSO.

Preoperative prediction of language function by diffusion tensor imaging.

For surgery of eloquent tumors in language areas, the accepted gold standard is functional mapping through direct cortical stimulation (DCS) in awake patients. Ever since, neuroscientists are searching for reliable noninvasive detection of function in the human brain, with variable success. The potential of diffusion tensor imaging (DTI) in combination with computational cortical parcellation to predict functional areas in language eloquent tumors has not been assessed so far. We present a proof-of-concept report involving awake surgery for a temporodorsal tumor. Postoperatively, the imaging was extensively studied and a predictive value of multimodal MR imaging for the possible extent of resection was analyzed. After resection using DCS, the extent of resection and functional outcome were correlated with the processed imaging. Preoperative imaging of our patient was taken to compute the lesion volume as a seed for tractography (DTI) and combined with a tractography of the entire hemisphere. For better spatial resolution, an elastic image fusion was performed to correct the distortion of DTI data. After subtotal resection and imaging analysis, the status of the superior part of the lesion could be identified and predicted as functional cortex. There was a strong correlation between the tumor remnant during surgery and the imaging parameters of DTI connectivity of the eloquent tissue. A combination of complex DTI processing may be able to predict function in a patient suffering eloquent brain tumors and thus allow estimation of extent of resection.

Transoral vertebroplasty of the lateral mass of C1 using image guidance.

BACKGROUND: Osteolytic lesions of the anterior aspects of C1 (lateral mass) are difficult to address in a minimally invasive fashion and are often treated by craniocervical instrumentation. METHODS: We report the feasibility and technical method of transoral vertebroplasty of the lateral mass of the atlas using image guidance and describe the workflow of the procedure. To our knowledge, there has not yet been a technical description of a transoral vertebroplasty using image guidance. RESULTS: Adequate positioning of the pedicle access needle using image guidance for addressing the lateral mass of C1 through a transoral, permuceous access can be achieved. CONCLUSIONS: With the assistance of image guidance, it is safe and feasible to access the lateral mass of the atlas. This constitutes a minimally invasive and fast alternative for introducing the bone needle to C1 rather than using a fluoroscopic device alone.

Serious tumor seeding after brainstem biopsy and its treatment-a case report and review of the literature.

Stereotactic brain biopsies for histopathological diagnosis are a common technique in case of intracranial lesions, particularly in those not amenable for resection. Tumor seeding alongside the surgical trajectory after fine-needle aspiration is a known problem in several visceral tumors. Whereas in these cases a complete resection of the biopsy trajectory may later be performed, this strategy is not feasible in stereotactic brain biopsy. We report a case of tumor seeding along the entire biopsy tract after stereotactic biopsy of a brainstem metastasis. A 68-year-old male patient with a concomitantly diagnosed kidney lesion presented with a singular lesion in the brainstem. After confirmation of metastasis by stereotactic biopsy, stereotactic radiosurgery (SRS) was applied. The primary tumor was treated by laparoscopic nephrectomy. Three months after SRS, the patient presented with a secondary clinical deterioration for only a few weeks. The MRI scan showed tumor seeding along the entire biopsy tract. Salvage treatment including hypofractionated stereotactical irradiation and seven cycles of bevacizumab was administered to obtain symptom control. Massive seeding of tumor after stereotactic biopsy accordingly rare, taking into account that stereotactic biopsy is a very common neurosurgical intervention. Nonetheless, we think that the potential risk has to be kept in mind, as it might be neglected.

Cervical arthroplasty with ROTAIO® cervical disc prosthesis: first clinical and radiographic outcome analysis in a multicenter prospective trial.

BACKGROUND: Cervical Disc Arthroplasty (CDA) seems to be an alternative to Anterior Cervical Decompression and Fusion (ACDF) and was developed to minimize the risk of Adjacent Segment Disease (ASD). The ROTAIO Cervical Disc Prosthesis represents a new unconstrained implant with a variable centre of rotation which should enable physiological facet-guided movement. The aim of this current study was to evaluate the clinical outcomes after arthroplasty using ROTAIO Cervical Disc Prosthesis. METHOD: Twenty-seven female and 18 male patients (n = 45) with a mean age of 43.7 ± 7.8 years were prospectively followed up for a maximum of 24 month. Clinical outcomes were assessed by Neck Disability Index (NDI), visual analogue scale (VAS) scores for neck and arm pain, patients´ overall satisfaction and the usage of analgesics. Additionally, radiographic information including ROM of the functional spinal unit (FSU) and signs of adjacent segment disease were recorded. RESULTS: NDI and VAS scores showed significant improvement 6 months after surgery and at last follow-up (p < 0.001). Concerning overall satisfaction 95.7% of the patients showed good to excellent results at the last visit and a significant reduction of analgesic usage was observed (p < 0.001). Radiographic measurements showed a mean increase of ROM up to 8.40° in the treated FSU at last follow-up (p < 0.001). No signs of anterior migration or dislocation of the prosthesis and no subsidence was recorded radiographically. There were no major complications and a low rate of secondary procedures (2.2%). CONCLUSION: In the 24-months follow-up the ROTAIO Cervical Disc Prosthesis provided excellent clinical and radiographical results and seems to be safe and effective for the treatment of symptomatic single-level degenerative disc disease.

Embryonic development of lake whitefish Coregonus clupeaformis: a staging series, analysis of growth and effects of fixation.

A reference staging series of 18 morphological stages of laboratory reared lake whitefish Coregonus clupeaformis is provided. The developmental processes of blastulation, gastrulation, neurulation as well as development of the eye, circulatory system, chromatophores and mouth are included and accompanied by detailed descriptions and live imaging. Quantitative measurements of embryo size and mass were taken at each developmental stage. Eggs were 3·19 ± 0·16 mm (mean ± s.d.) in diameter at fertilization and embryos reached a total length (LT ) of 14·25 ± 0·41 mm at hatch. Separated yolk and embryo dry mass were 0·25 ± 0·08 mg and 1·39 ± 0·17 mg, respectively, at hatch. The effects of two common preservatives (formalin and ethanol) were examined throughout development and post hatch. Embryo LT significantly decreased following fixation at all points in development. A correction factor to estimate live LT from corresponding fixed LT was determined as live LT = (fixed LT )(1·025) . Eye diameter and yolk area measurements significantly increased in fixed compared with live embryos up to 85-90% development for both measurements. The described developmental stages can be generalized to teleost species, and is particularly relevant for the study of coregonid development due to additionally shared developmental characteristics. The results of this study and staging series are therefore applicable across various research streams encompassing numerous species that require accurate staging of embryos and descriptions of morphological development.