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Introduction In spinal surgery, precise instrumentation is essential. This study aims to evaluate the accuracy of navigated, O-arm-controlled screw positioning in thoracic and lumbar spine instabilities. Materials and methods Posterior instrumentation procedures between 2010 and 2015 were retrospectively analyzed. Pedicle screws were placed using 3D rotational fluoroscopy and neuronavigation. Accuracy of screw placement was assessed using a 6-grade scoring system. In addition, screw length was analyzed in relation to the vertebral body diameter. Intra- and postoperative revision rates were recorded. Results Thoracic and lumbar spine surgery was performed in 285 patients. Of 1704 pedicle screws, 1621 (95.1%) showed excellent positioning in 3D rotational fluoroscopy imaging. The lateral rim of either pedicle or vertebral body was protruded in 25 (1.5%) and 28 screws (1.6%), while the midline of the vertebral body was crossed in 8 screws (0.5%). Furthermore, 11 screws each (0.6%) fulfilled the criteria of full lateral and medial displacement. The median relative screw length was 92.6%. Intraoperative revision resulted in excellent positioning in 58 of 71 screws. Follow-up surgery due to missed primary malposition had to be performed for two screws in the same patient. Postsurgical symptom relief was reported in 82.1% of patients, whereas neurological deterioration occurred in 8.9% of cases with neurological follow-up. Conclusions Combination of neuronavigation and 3D rotational fluoroscopy control ensures excellent accuracy in pedicle screw positioning. As misplaced screws can be detected reliably and revised intraoperatively, repeated surgery for screw malposition is rarely required.

Background Little is known about delivery of neurosurgical care, complication rate and outcome of patients with high-grade glioma (HGG) during the coronavirus disease 2019 (Covid-19) pandemic. Methods This observational, retrospective cohort study analyzed routine administrative data of all patients admitted for neurosurgical treatment of an HGG within the Helios Hospital network in Germany. Data of the Covid-19 pandemic (March 1, 2020—May 31, 2022) were compared to the pre-pandemic period (January 1, 2016—February 29, 2020). Frequency of treatment and outcome (in-hospital mortality, length of hospital stay [LOHS], time in intensive care unit [TICU] and ventilation outside the operating room [OR]) were separately analyzed for patients with microsurgical resection (MR) or stereotactic biopsy (STBx). Results A total of 1763 patients underwent MR of an HGG (648 patients during the Covid-19 pandemic; 1115 patients in the pre-pandemic period). 513 patients underwent STBx (182 [pandemic]; 331 patients [pre-pandemic]). No significant differences were found for treatment frequency (MR: 2.95 patients/week [Covid-19 pandemic] vs. 3.04 patients/week [pre-pandemic], IRR 0.98, 95% CI: 0.89–1.07; STBx (1.82 [Covid-19 pandemic] vs. 1.86 [pre-pandemic], IRR 0.96, 95% CI: 0.80–1.16, P > .05). Rates of in-hospital mortality, infection, postoperative hemorrhage, cerebral ischemia and ventilation outside the OR were similar in both periods. Overall LOHS was significantly shorter for patients with MR and STBx during the Covid-19 pandemic. Conclusions The Covid-19 pandemic did not affect the frequency of neurosurgical treatment of patients with an HGG based on data of a large nationwide hospital network in Germany. LOHS was significantly shorter but quality of neurosurgical care and outcome was not altered during the Covid-19 pandemic.

The original article has been updated to correct Row 2 of Table 4 “04-Jul” to “4–7”. in press

Background Guillain–Barré syndrome (GBS) often carries a favorable prognosis. Of adult patients with GBS, 10–30% require mechanical ventilation during the acute phase of the disease. After the acute phase, the focus shifts to restoration of motor strength, ambulation, and neurological function, with variable speed and degree of recovery. The objective of these guidelines is to provide recommendations on the reliability of select clinical predictors that serve as the basis of neuroprognostication and provide guidance to clinicians counseling adult patients with GBS and/or their surrogates. Methods A narrative systematic review was completed using Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology. Candidate predictors, including clinical variables and prediction models, were selected based on clinical relevance and presence of appropriate body of evidence. The Population/Intervention/Comparator/Outcome/Time frame/Setting (PICOTS) question was framed as follows: “When counseling patients or surrogates of critically ill patients with Guillain–Barré syndrome, should [predictor, with time of assessment if appropriate] be considered a reliable predictor of [outcome, with time frame of assessment]?” Additional full-text screening criteria were used to exclude small and lower quality studies. Following construction of an evidence profile and summary of findings, recommendations were based on four GRADE criteria: quality of evidence, balance of desirable and undesirable consequences, values and preferences, and resource use. In addition, good practice recommendations addressed essential principles of neuroprognostication that could not be framed in PICOTS format. Results Eight candidate clinical variables and six prediction models were selected. A total of 45 articles met our eligibility criteria to guide recommendations. We recommend bulbar weakness (the degree of motor weakness at disease nadir) and the Erasmus GBS Respiratory Insufficiency Score as moderately reliable for prediction of the need for mechanical ventilation. The Erasmus GBS Outcome Score (EGOS) and modified EGOS were identified as moderately reliable predictors of independent ambulation at 3 months and beyond. Good practice recommendations include consideration of both acute and recovery phases of the disease during prognostication, discussion of the possible need for mechanical ventilation and enteral nutrition during counseling, and consideration of the complete clinical condition as opposed to a single variable during prognostication. Conclusions These guidelines provide recommendations on the reliability of predictors of the need for mechanical ventilation, poor functional outcome, and independent ambulation following GBS in the context of counseling patients and/or surrogates and suggest broad principles of neuroprognostication. Few predictors were considered moderately reliable based on the available body of evidence, and higher quality data are needed.

Background Among cardiac arrest survivors, about half remain comatose 72 h following return of spontaneous circulation (ROSC). Prognostication of poor neurological outcome in this population may result in withdrawal of life-sustaining therapy and death. The objective of this article is to provide recommendations on the reliability of select clinical predictors that serve as the basis of neuroprognostication and provide guidance to clinicians counseling surrogates of comatose cardiac arrest survivors. Methods A narrative systematic review was completed using Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology. Candidate predictors, which included clinical variables and prediction models, were selected based on clinical relevance and the presence of an appropriate body of evidence. The Population, Intervention, Comparator, Outcome, Timing, Setting (PICOTS) question was framed as follows: “When counseling surrogates of comatose adult survivors of cardiac arrest, should [predictor, with time of assessment if appropriate] be considered a reliable predictor of poor functional outcome assessed at 3 months or later?” Additional full-text screening criteria were used to exclude small and lower-quality studies. Following construction of the evidence profile and summary of findings, recommendations were based on four GRADE criteria: quality of evidence, balance of desirable and undesirable consequences, values and preferences, and resource use. In addition, good practice recommendations addressed essential principles of neuroprognostication that could not be framed in PICOTS format. Results Eleven candidate clinical variables and three prediction models were selected based on clinical relevance and the presence of an appropriate body of literature. A total of 72 articles met our eligibility criteria to guide recommendations. Good practice recommendations include waiting 72 h following ROSC/rewarming prior to neuroprognostication, avoiding sedation or other confounders, the use of multimodal assessment, and an extended period of observation for awakening in patients with an indeterminate prognosis, if consistent with goals of care. The bilateral absence of pupillary light response > 72 h from ROSC and the bilateral absence of N20 response on somatosensory evoked potential testing were identified as reliable predictors. Computed tomography or magnetic resonance imaging of the brain > 48 h from ROSC and electroencephalography > 72 h from ROSC were identified as moderately reliable predictors. Conclusions These guidelines provide recommendations on the reliability of predictors of poor outcome in the context of counseling surrogates of comatose survivors of cardiac arrest and suggest broad principles of neuroprognostication. Few predictors were considered reliable or moderately reliable based on the available body of evidence.

Introduction This study was conducted to compare bone-filled intervertebral cages with autologous bone chips for instrumented lumbar interbody fusion in patients with spinal stenosis and degenerative spondylolisthesis. Methods Surgery consisted of posterior instrumentation and decompression, diskectomy, and intervertebral fusion using a polyetheretherketone (PEEK) cage surrounded and filled with spongious bone chips (group 1, n = 57) or spongious bone chips alone (group 2, n = 37). The choice of method was left to the discretion of the surgeon. Postoperative results were prospectively evaluated using a standardized protocol. Radiological assessment included fusion rates and vertebral height, while clinical assessment included the visual analog scale (VAS) and Oswestry Disability Index (ODI). Results In group 1, a mean of 1.38 ± 0.64 segments were fused. In group 2, a mean of 1.58 ± 0.65 segments were fused. In both groups, the VAS for back pain and leg pain and the ODI improved without significant differences between the two groups. Osseous fusion was documented by computerized tomography in 73% in group 1 and 89% in group 2 after a mean of 18 months. The loss of height was 2.8 ± 4.0% in group 1 and 2.4 ± 5.2% in group 2. Conclusion Regardless of whether a PEEK cage filled with spongious bone chips or spongious bone chips alone were used for lumbar interbody fusion, clinical parameters improved significantly after surgery. There were no significant differences in the rate of bony fusion and loss of height between the two groups. The results of this nonrandomized cohort study indicate that the implantation of autologous spongious bone chips harvested during the decompression procedure is a useful and cheap alternative to an intervertebral cage in patients with degenerative pseudospondylolisthesis.

A 2016 published randomized multicenter phase III trial of prophylactic nimodipine treatment in vestibular schwannoma surgery showed only a tendency for higher hearing preservation rates in the treatment group. Gender was not included in statistical analysis at that time. A retrospective analysis of the trial considering gender, preoperative hearing, and nimodipine treatment was performed. The treatment group received parenteral nimodipine from the day before surgery until the seventh postoperative day. The control group was not treated prophylactically. Cochlear nerve function was determined by pure-tone audiometry with speech discrimination preoperatively, during in-patient care, and 1 year after surgery and classified according to the Gardner-Robertson grading scale (GR). Logistic regression analysis showed a statistically significant effect for higher hearing preservation rates (pre- and postoperative GR 1–4) in 40 men comparing the treatment (n = 21) and the control (n = 19) groups (p = 0.028), but not in 54 women comparing 27 women in both groups (p = 0.077). The results were also statistically significant for preservation of postoperative hearing with pre- and postoperative GR 1–3 (p = 0.024). There were no differences in tumor sizes between the treatment and the control groups in men, whereas statistically significant larger tumors were observed in the female treatment group compared with the female control group. Prophylactic nimodipine is safe, and an effect for hearing preservation in 40 men with preoperative hearing ability of GR 1–4 was shown in this retrospective investigation. The imbalance in tumor size with larger tumors in females of the treatment group may falsely suggest a gender-related effect. Further investigations are recommended to clarify whether gender has impact on nimodipine’s efficacy.

No abstract available.

OBJECTIVEPatient positioning in vestibular schwannoma (VS) surgery is a matter of ongoing discussion. Factors to consider include preservation of cranial nerve functions, extent of tumor resection, and complications. The objective of this study was to determine the optimal patient positioning in VS surgery.METHODSA subgroup analysis of a randomized, multicenter trial that investigated the efficacy of prophylactic nimodipine in VS surgery was performed to investigate the impact of positioning (semisitting or supine) on extent of resection, functional outcomes, and complications. The data of 97 patients were collected prospectively. All procedures were performed via a retrosigmoid approach. The semisitting position was chosen in 56 patients, whereas 41 patients were treated while supine.RESULTSComplete resection was obtained at a higher percentage in the semisitting as compared to the supine position (93% vs 73%, p = 0.002). Logistic regression analysis revealed significantly better facial nerve function in the early postoperative course in the semisitting group (p = 0.004), particularly concerning severe facial nerve paresis (House-Brackmann grade IV or worse; p = 0.002). One year after surgery, facial nerve function recovered. However, there was still a tendency for better facial nerve function in the semisitting group (p = 0.091). There were no significant differences between groups regarding hearing preservation rates. Venous air embolism with the necessity to terminate surgery occurred in 2 patients in the semisitting position (3.6%). Supplementary analysis with a 2-tailed permutation randomization with 10,000 permutations of treatment choice and a propensity score matching showed either a tendency or significant results for better facial nerve outcomes in the early postoperative course and extent of resection in the semisitting group.CONCLUSIONSAlthough the results of the various statistical analyses are not uniform, the data indicate better results concerning both a higher rate of complete removal (according to the intraoperative impression of the surgeon) and facial nerve function after a semisitting as compared to the supine position. These advantages may justify the potential higher risk for severe complications of the semisitting position in VS surgery. The choice of positioning has to consider all individual patient parameters and risks carefully.

Background and Purpose— EG-1962 is a sustained release formulation of nimodipine administered via external ventricular drain in patients with aneurysmal subarachnoid hemorrhage. A randomized, open-label, phase 1/2a, dose-escalation study provided impetus for this study to evaluate efficacy and safety of a single intraventricular 600 mg dose of EG-1962 to patients with aneurysmal subarachnoid hemorrhage, compared with standard of care oral nimodipine. Methods— Subjects were World Federation of Neurological Surgeons grades 2–4, modified Fisher grades 2–4 and had an external ventricular drain inserted as part of standard of care. The primary end point was the proportion of subjects with favorable outcome at day 90 after aneurysmal subarachnoid hemorrhage (extended Glasgow outcome scale 6–8). The proportion of subjects with favorable outcome at day 90 on the Montreal cognitive assessment, as well as the incidence of delayed cerebral ischemia and infarction, use of rescue therapy and safety were evaluated. Results— The study was halted by the independent data monitoring board after planned interim analysis of 210 subjects (289 randomized) with day 90 outcome found the study was unlikely to achieve its primary end point. After day 90 follow-up of all subjects, the proportion with favorable outcome on the extended Glasgow outcome scale was 45% (65/144) in the EG-1962 and 42% (62/145) in the placebo group (risk ratio, 1.01 [95% CI, 0.83–1.22], P =0.95). Consistent with its mechanism of action, EG-1962 significantly reduced vasospasm (50% [69/138] EG-1962 versus 63% [91/144], P =0.025) and hypotension (7% [9/138] versus 10% [14/144]). Analysis of prespecified subject strata suggested potential efficacy in World Federation of Neurological Surgeons 3–4 subjects (46% [32/69] EG-1962 versus 32% [24/75] placebo, odds ratio, 1.22 [95% CI, 0.94–1.58], P =0.13). No safety concerns were identified that halted the study or that preclude further development. Conclusions— There was no significant increase in favorable outcome for EG-1962 compared with standard of care in the overall study population. The safety profile was acceptable. Registration— URL: https://www.clinicaltrials.gov ; Unique identifier: NCT02790632.

Background Glioblastoma multiforme (GBM) is the most frequent malignant neoplasm in the adult brain. In contrast, arteriovenous malformations (AVMs) are presumably congenital lesions, usually presenting with hemorrhage. Hypervascular low-grade gliomas associated with AVMs were previously called “angioglioma.” An association of AVMs and GBM was also described. Study Aims We discuss the data of the largest series of locally coincident GBM with AVM in a single institution so far. All analyses were explorative only. Patients We report a series of four patients presenting at our department from 2006 to 2014. All patients underwent surgery. The cases were analyzed regarding initial presentation, clinical findings, tumor localization, and histopathologic results. Conclusions A local coincidence of cerebral AVM and GBM is rare. Only a few reports can be found in the literature. The radiologic as well as the clinical presentations are individual. Proangiogenic factors are discussed as involved in the appearance of both entities in the same location. However, the presence of pathologic vessels within malignant gliomas is well known to all neurosurgeons and proangiogenic activity has been proven. Therefore, it seems possible that tumor activity itself contributes to the pathogenesis of a vascular malformation.

BackgroundAim of this study was to investigate the time point at which the cerebral blood flow (CBF) enhancing effect of controlled hypercapnia in patients with severe aneurysmal subarachnoid hemorrhage (SAH) starts to extenuate. This point is assumed to be the time at which buffer systems become active and annihilate a possible therapeutic effect. MethodsIn this prospective interventional study in a neurosurgical ICU the arterial partial pressure of carbon dioxide (PaCO2) was increased to a target range of 50 - 55 mmHg for 120 minutes by modification of the respiratory minute volume (RMV) one time a day between day 4 and 14 in 12 mechanically ventilated poor-grade SAH-patients. Arterial blood gases were measured every 15 minutes. CBF and brain tissue oxygen saturation (StiO2) were the primary and secondary end points. Intracranial pressure (ICP) was controlled by an external ventricular drainage. ResultsUnder continuous hypercapnia (PaCO2 of 53.17 ± 5.07), CBF was significantly elevated between 15 and 120 minutes after the start of hypercapnia. During the course of the trial intervention, cardiac output also increased significantly. To assess the direct effect of hypercapnia on brain perfusion, the increase of CBF was corrected by the parallel increase of cardiac output. The maximum direct CBF enhancing effect of hypercapnia of 31% was noted at 45 minutes after the start of hypercapnia. Thereafter, the CBF enhancing slowly declined. No relevant adverse effects were observed. Conclusion CBF and StiO2 reproducibly increased by controlled hypercapnia in all patients. After 45 minutes, the curve of CBF enhancement showed an inflection point when corrected by cardiac output. Temporary hypercapnia of 45 minutes is, thus, likely to be the optimum duration for a therapeutic use and for a controlled comparative trial. Longer intervals bear the risk of a negative rebound effect after return to normal ventilation parameters and may be counterproductive inducing ischemia in a state of critical perfusion after SAH. Trial registrationThe study was approved by the institutional ethics committee (AZ 230/14) and registered at ClinicalTrials.gov (Trial-ID: NCT01799525). Registered 01 January 2015. Retrospectively registered.

Als Folge der hoheren Lebenserwartung und der veranderten Bevolkerungsstruktur nimmt die Anzahl an alten Patienten mit Subarachnoidalblutungen zu. Das es sich um eine Erkrankung mit oft schweren Verlaufen und Folgen handelt, sind nicht nur die allgemeinen Uberlegungen zur Therapie der Blutungsfolgen und Behandlung der Blutungsquelle in die Therapieentscheidungen zu inkludieren, sondern auch spezielle Aspekte der Behandung alter Menschen, wie Vorerkrankungen, neurologischer Zustand vor der Blutung, Mobilitat und selbstandige Lebensfuhrung. Dieses Kapitel gibt Einblicke in die Besonderheiten bei alten Patienten mit Subarachnoidalblutungen im Hinblick auf diagnostische und therapeutische Uberlegungen. Obwohl das Outcome alter Patienten nach Subarachnoidalblutung schlechter ist als bei jungeren Patienten, ist eine gute Erholung nicht ausgeschlossen. Die hohere Nachblutungsrate erfordert jedoch eine rasche Entscheidung, ob und welche Art der Therapie eingeleitet wird. Wenn die Entscheidung fur eine Therapie getroffen wird, ist eine schnelle Behandlung der Blutungsquelle erforderlich sowie ein entsprechendes intensivmedizinisches Management und eine fruhe Mobilisierung.

OBJECTIVEIn clinical routines, neuroprotective strategies in neurosurgical interventions are still missing. A pilot study (n = 30) and an analogously performed Phase III trial (n = 112) pointed to a beneficial effect of prophylactic nimodipine and hydroxyethyl starch (HES) in vestibular schwannoma (VS) surgery. Considering the small sample size, the data from both studies were pooled.METHODSThe patients in both investigator-initiated studies were assigned to 2 groups. The treatment group (n = 70) received parenteral nimodipine (1–2 mg/hour) and HES (hematocrit 30%–35%) from the day before surgery until the 7th postoperative day. The control group (n = 72) was not treated prophylactically. Facial and cochlear nerve functions were documented preoperatively, during the inpatient care, and 1 year after surgery.RESULTSPooled raw data were analyzed retrospectively. Intent-to-treat analysis revealed a significantly lower risk for hearing loss (Class D) 12 months after surgery in the treatment group compared with the control group (OR 0.46, 95% CI 0.22–0.97; p = 0.04). After exclusion of patients with preoperative Class D hearing, this effect was more pronounced (OR 0.38, 95% CI 0.17–0.83; p = 0.016). Logistic regression analysis adjusted for tumor size showed a 4 times lower risk for hearing loss in the treatment group compared with the control group (OR 0.25, 95% CI 0.09–0.63; p = 0.003). Facial nerve function was not significantly improved with treatment. Apart from dose-dependent hypotension (p < 0.001), the study medication was well tolerated.CONCLUSIONSProphylactic nimodipine is safe and may be recommended in VS surgery to preserve hearing. Prophylactic neuroprotective treatment in surgeries in which nerves are at risk seems to be a novel and promising concept.Clinical trial registration no.: DRKS 00000328 (https://drks-neu.uniklinik-freiburg.de/drks_web/)

Glioblastoma multiforme (GBM) treatment consists of surgery, radiotherapy and chemotherapy with Temozolomide (TMZ). After subtotal resection (STR), residual tumors rarely undergo spontaneous regression. Overall survival (OS) and progression-free survival (PFS) are reduced when compared with gross total resection. There is evidence that adding Tumor Treating Fields (TTFields) to standard management may lead to a significant increase in PFS and OS. In 2015 and 2016, STR was performed in 27 patients with GBM. Of these, four subsequently received TTFields therapy in addition to chemotherapy. The present study presents a series of three patients with GBM (44-54 years; isocitrate dehydrogenase wild-type, methylated O6-methylguanine-DNA methyltransferase promoter) that were treated with radiochemotherapy and TTFields after STR. Therapy with TTFields started concomitantly to TMZ following radiotherapy and was maintained for 14, 24 and 37 months. TTFields were used as monotherapy in one case, as TMZ treatment had to be stopped due to toxicity for 1 month. In all patients, TTFields therapy was well tolerated at high compliance levels, resulting in complete response (CR) after 4, 5 and 7 months, respectively. Two patients remain tumor-free at 16 and 40 months after STR. One patient exhibited multifocal recurrence 11 months after the beginning of TTFields treatment but remains alive, presenting a mild neurological decline 24 months after starting TTFields. All three presented patients gave written informed consent for their data to be published. In conclusion, the current report detailed three patients with GBM who underwent STR and were subsequently treated with TMZ and TTFields. TTFields treatment was tolerated well and was applied accurately and with high compliance by these patients, which may have contributed to the complete response. Four of the 27 patients treated with STR received additional TTFields treatment. Three of these 4 showed a CR, while a CR was observed only 2 of the remaining 23 patients without TTFields. The current series supports the effects in clinical practice, as demonstrated in recent clinical trials. The results also demonstrated that adjuvant TTFields therapy can structurally affect residual tumors after STR.

Regulation of the host immune response serves a pivotal role in the persistence and progression of malignant glioma. To date, cytotoxic cluster of differentiation (CD)-8+ T and natural killer cells are considered the main cellular components of host tumor control. The influence of macrophages in an orthotropic C6 tumor implantation model was investigated and the aim of the present study was to characterize the effects of systemic macrophage-activation on glioma growth by using the granulocyte macrophage colony stimulating factor (rhGM-CSF). A total of 20 male Sprague-Dawley rats were orthotopically implanted with C6 glioma spheroids and treated subcutaneously with 10 µg/kg rhGM-CSF every other day; 9 animals served as controls. Serial magnetic resonance imaging was performed on days 7, 14, 21, 28, 32 and 42 post-implantation to monitor tumor volume. Histological work-up included hematoxylin and eosin, CD68/ED-1 macrophage, CD8 T-cell and Ki-67 MIB1 proliferation staining in gliomas and spleen. Experimental C6-gliomas developed in 15/20 (75%) animals. In rhGM-CSF treated rats, tumors developed significantly later and reached a smaller size (median, 134 mm3) compared with the controls (median, 262 mm3). On day 14, solid tumors presented in 11/17 (65%) rhGM-CSF-treated animals; in control animals tumor growth was detected in 3/9 animals on day 7 and in all animals on day 14. The mean survival time was 35 days in the rhGM-CSF group and significantly longer when compared with the control group (24 days). Immunohistochemistry exhibited significantly more macrophages in tumors, particularly in the perivascular zone of the rhGM-CSF group when compared with untreated animals; intratumoral CD8+ counts were equal in both groups. A systemic stimulation of macrophages by rhGM-CSF resulted in significantly reduced and delayed tumor growth in the rodent C6 glioma model. The present data suggested a significant role of macrophages in host control of experimental gliomas on the innate immune response. Until now, the role of macrophages may have been underestimated in host glioma control.

Evidence of a high interobserver variability of the subjective House-Brackmann facial nerve grading system (HBGS) would justify cost- and time-consuming technological enhancements of objective classifications for facial nerve paresis. A total of 112 patients were recruited for a randomized multi-center trial to investigate the efficacy of prophylactic nimodipine treatment in vestibular schwannoma (VS) surgery. For the present investigation both treatment groups were pooled for the assessment of facial nerve function preoperatively, in the early postoperative course and 1 year after the surgery. Facial nerve function was documented photographically at rest and in motion and classified according to the HBGS by three independent observers (neurosurgeon, neurologist, ENT) and by the investigator of each center. Interobserver variability was considerably different with respect to the three time points depending upon the severity of facial nerve paresis. Preoperative facial nerve function was normal or only mildly impaired (HB grade I or II) and was assessed consistently in 97%. Facial nerve function deteriorated during the early postoperative course and was subsequently documented without dissent in only 36%, with one grade difference in 45%, two grade difference in 17% and three grade difference in 2%. One year after surgery, facial nerve function predominantly improved resulting in a consistent assessment in 66%. Differing ratings were observed in 34% with one grade deviation in 88% and of two grades in 12%. Patients with differing ratings of two or more grades exhibited considerably worse facial nerve function (p

A lack of nitric oxide (NO) may be a possible factor in the pathogenesis of an acute decrease of cerebral blood flow (CBF) after subarachnoid hemorrhage (SAH). This study was conducted to investigate whether early therapy with an NO-donor can improve CBF and offer neuroprotection after experimental SAH in rats. Male Sprague-Dawley rats were subjected to SAH by the endovascular filament model and treated with 1.5μg/kg/min of intravenous sodium nitroprusside (SNP) or vehicle (n=10) starting 15min after induction of SAH until 180min thereafter. SNP caused a moderate decrease of arterial blood pressure and cerebral perfusion pressure. Conversely, CBF measured by laser-Doppler flowmetry increased significantly in SNP-treated animals. The rate of injured neurons in the hippocampal CA1-field was significantly reduced in SNP-treated animals (10.5±5%) compared to controls (14.2±7%), as well as the number of Caspase-3 positive neurons. Low-dose treatment with SNP can attenuate an early perfusion deficit after SAH and reduce neuronal damage in spite of a hypotensive side effect. This may reflect the reversal of an early NO-deficit. In the clinical setting, the moderate hypotensive effect may be welcome since SAH-patients frequently present with elevated blood pressure.

Background Surgical resection of intra-axial tumors is a challenging procedure because of indistinct tumor margins, infiltration, and displacement of white matter tracts surrounding the lesion. Hence, gross total tumor resection without causing new neurologic deficits is demanding, especially in tumor sites adjoining eloquent structures. Feasibility of the combination of navigated probabilistic fiber tracking to identify eloquent fiber pathways and navigated ultrasonography to control brain shift was tested. Methods Eleven patients with lesions adjacent to eloquent white matter structures (pyramidal tract, optic radiation and arcuate fascicle) were preoperatively subjected to magnetic resonance imaging including diffusion-weighted imaging on a 3-T magnetic resonance system (Trio [Siemens, Erlangen, Germany]). Probabilistic fiber tracking was performed using the tools of the FMRIB Software Library (FSL). Results of probabilistic fiber tracking and high-resolution anatomic images were integrated into the neuronavigation system Stealth Station (Medtronic, Minneapolis, Minnesota, USA) together with the navigated ultrasonography (SonoNav [Medtronic]). Results FSL-based probabilistic fiber tracking depicted the pyramidal tract, the optic radiation, and arcuate fascicle anatomically plausibly. Integration of the probabilistic fiber tracking into neuronavigation was technically feasible and allowed visualization of the reconstructed fiber pathways. Navigated ultrasonography controlled brain shift. Conclusions Integration of probabilistic fiber tracking and navigated ultrasonography into intraoperative neuronavigation facilitated anatomic orientation during glioma resection. FSL-based probabilistic fiber tracking integrated sophisticated fiber tracking algorithms, including modeling of crossing fibers. Combination with navigated ultrasonography provided a three-dimensional estimation of intraoperative brain shift and, therefore, improved the reliability of neuronavigation.

Arteriovenous malformations (AVMs) of the fourth ventricle are exceptionally rare subtypes of brainstem AVMs. This report illustrates the case of a young man who suffered intraventricular and subarachnoid hemorrhage. Angiography depicted a fourth ventricular AVM that was supplied by branches of the right posterior inferior cerebellar artery and drained via a posterior medullary midline vein into the marginal sinus and cervical radicular and nuchal veins. The drainage pattern is highly uncommon and constitutes a particular challenge for the operative approach.

OBJECT A pilot study of prophylactic nimodipine and hydroxyethyl starch treatment showed a beneficial effect on facial and cochlear nerve preservation following vestibular schwannoma (VS) surgery. A prospective Phase III trial was undertaken to confirm these results. METHODS An open-label, 2-arm, randomized parallel group and multicenter Phase III trial with blinded expert review was performed and included 112 patients who underwent VS surgery between January 2010 and February 2013 at 7 departments of neurosurgery to investigate the efficacy and safety of the prophylaxis. The surgery was performed after the patients were randomly assigned to one of 2 groups using online randomization. The treatment group (n = 56) received parenteral nimodipine (1–2 mg/hr) and hydroxyethyl starch (hematocrit 30%–35%) from the day before surgery until the 7th postoperative day. The control group (n = 56) was not treated prophylactically. RESULTS Intent-to-treat analysis showed no statistically significant effects of the treatment on either preservation of facial nerve function (35 [67.3%] of 52 [treatment group] compared with 34 [72.3%] of 47 [control group]) (p = 0.745) or hearing preservation (11 [23.4%] of 47 [treatment group] compared with 15 [31.2%] of 48 [control group]) (p = 0.530) 12 months after surgery. Since tumor sizes were significantly larger in the treatment group than in the control group, logistic regression analysis was required. The risk for deterioration of facial nerve function was adjusted nearly the same in both groups (OR 1.07 [95% CI 0.34–3.43], p = 0.91). In contrast, the risk for postoperative hearing loss was adjusted 2 times lower in the treatment group compared with the control group (OR 0.49 [95% CI 0.18–1.30], p = 0.15). Apart from dose-dependent hypotension (p < 0.001), no clinically relevant adverse reactions were observed. CONCLUSIONS There were no statistically significant effects of the treatment. Despite the width of the confidence intervals, the odds ratios may suggest but do not prove a clinically relevant effect of the safe study medication on the preservation of cochlear nerve function after VS surgery. Further study is needed before prophylactic nimodipine can be recommended in VS surgery.

BACKGROUND: After subtotal resection (STR), residual contrast-enhancing glioblastoma multiforme (GBM) rarely undergo complete regression following radiochemotherapy and adjuvant chemotherapy. Moreover, in comparison to gross total resection (GTR) overall survival (OS) and progression-free survival (PFS) is significantly decreased in GBM patients with STR. GBM therapy following resection consists of radio- and chemotherapy with Temozolomide (TMZ). In addition Tumor Treating Fields (TTFields), low intensity (1–3 V/cm), intermediate frequency (100–300 kHz) alternating electric fields, are applied during adjuvant chemotherapy. The addition of TTFields led to a significant increase in PFS, OS and long-term survival in the EF-14 phase III trial. Here, we report three patients with subtotally resected GBMs localized in eloquent areas. These patients received TTFields (200 kHz) in addition to TMZ after surgery and radiochemotherapy. All patients showed complete radiological response (CR) under TTFields therapy. CASE PRESENTATION: A 54-year-old woman with primary IDH1/2-wildtype and O6-methylguanine-DNA methyltransferase promoter methylated GBM (IDH1/2 WT, MGMT+) received combined radiochemotherapy after STR. TTFields therapy was initiated in parallel to 6 cycles of adjuvant TMZ. CR was observed after 5 months of TTFields treatment and remained stable for 7 months before new tumor growth was detected. A 46-year-old woman with a primary GBM, IDH1/2 WT, MGMT+, sustained nuclear ATRX expression (ATRX+) received combined radiochemotherapy followed by 6 cycles of TMZ after STR. TTFields were initiated simultaneously to the first cycle of adjuvant TMZ and continued for 6 months. CR was seen after 4 months of TTFields treatment, for 16 month up to date no recurrent tumor growth occurred. A 44-year-old man developed a secondary GBM (IDH1 WT, MGMT+) while receiving radiochemotherapy according to the Stupp-protocol due to an anaplastic astrocytoma WHO°III (cycle 4 of TMZ). Concomitant to additional 6 cycles of TMZ, TTFields therapy was initiated 4 months after STR and was continued for 37 months. After 35 months of ongoing TTFields treatment as monotherapy CR is still stable. CONCLUSION: We report on three GBM patients with newly diagnosed and recurrent GBM who underwent STR, radiochemotherapy and were subsequently treated with temozolomide and TTFields at our institution. The reported patients showed complete radiological responses under TTFields treatment.

Subarachnoid hemorrhage (SAH) results in a rapid decrease of cerebral perfusion. While cerebral perfusion pressure (CPP) may quickly recover, a sustained decrease of cerebral blood flow (CBF) has been observed. Acute vasospasm has been concluded from this mismatch. This study was conducted to visualize and investigate immediate vascular reactions during and after experimental SAH. Male Sprague-Dawley rats were subjected to SAH by the endovascular filament model (n = 7) or served as controls (n = 4). Videomicroscopy was performed via a cranial window. Regions of interest were defined in areas covered by videomicroscopy and arterial diameters measured at defined time-points from 15 min before until 3 h after SAH. Local CBF was monitored over the opposite hemisphere by laser-Doppler flowmetry. Local CBF showed a typical decrease immediately after vessel perforation followed by an incomplete recovery in the 3 h thereafter. Videomicroscopy demonstrated a sharp decrease of the arterial diameter in the first minutes after SAH. In some animals, SAH was followed by a complete disappearance of arterial vessel filling. In the following minutes, arterial filling reappeared or improved, respectively. All animals subjected to SAH showed significant vasospasm in subarachnoid arteries. This is the first study to visualize acute vascular reactions during and immediately after SAH. Although the cranial window technique only covers a part of the cerebral vasculature, it covers cerebral vessels rather distant from the site of endovascular perforation. Therefore, it is likely that acute vasospasm observed in the monitored areas reflects a global vascular reaction.

Case report and review of literature. Detailed description of case and review of literature to determine its uniqueness with special regard to intradural gout tophus formation without any boney attachment or underlying systemic gout. Gout tophi commonly involve the peripheral joints of the upper and lower extremities. Rarely, gout tophi are located within the spinal cord, especially without any underlying hyperuricemia. We report the case of a 64-year-old patient presenting with radiculopathy along the right L2-dermatome and bladder dysfunction and review literature for further discussion. Imaging studies showed a partly calcified round intradural lesion at the level L2 without contrast enhancement. The lesion was removed via a hemilaminectomy L2. It was adherent to a dorsal sensory fascicle exiting with the L2 nerve root. The neuropathological examination showed a gout tophus. Serologic testing revealed no signs of hyperuricemia. To the best of our knowledge, this is the first report of a gout tophus originating from an intradural fascicle and without any boney attachment or underlying systemic gout. The literature is reviewed and possible pathophysiological mechanisms are discussed.

Close relatives (CR) of patients with severe traumatic brain injury (TBI) and high-grade subarachnoid hemorrhage (SAH) suffer extraordinary distress during the treatment: Distress may lead to persisting mental illness symptoms within the spectrum of post-traumatic stress disorder (PTSD), anxiety disorders, and depression. The primary goal of this study was to determine the prevalence and severity of these symptoms in CR. The secondary goal was identification of associated factors. Standardized interviews were conducted with 53 CR (mean age of 57.7 ± 11.4 years) of patients with TBI °III (n = 27) and high-grade SAH H&H °III–V (n = 26) between 5 and 15 months after the event. The interviews contained a battery of surveys to quantify symptoms of PTSD, anxiety disorders, and depression, i.e., Impact of Event Scale (IES-R), 36-item Short-Form General Health Survey (SF-36), and Hospital Anxiety and Depression Scale (HADS). Fixed and modifiable possibly influencing factors were correlated. Twenty-eight CR (53 %) showed IES-R scores indicating a probable diagnosis of PTSD. Twenty-five CR (47 %) showed an increased anxiety score and 18 (34 %) an increased depression score using HADS. Mean physical component summary of SF-36 was not abnormal (49.1 ± 9.1), whereas mean mental component summary was under average (41.0 ± 13.2), indicating a decreased quality of life caused by mental effects. Perception of the interaction quality with the medical staff and involvement into medical decisions correlated negatively with severity of mental illness symptoms. Evasive coping strategies were highly significantly associated with symptoms. This study quantifies an extraordinarily high prevalence of mental illness symptoms in CR of patients with critical acquired brain injury due to SAH and TBI. Modifiable factors were associated with severity of mental illness symptoms. Prospective studies testing efficiency of early psychotherapeutic interventions are needed.

Background Intraoperative imaging of cerebral aneurysms may be desirable in emergency situations with large space-occupying hematomas or to visualize vessels after clip placement. Mobile 3-dimensional fluoroscopes are available in a number of neurosurgical departments and may be useful in combination with simple image postprocessing to depict cerebral vessels. Objective To assess whether intracranial aneurysms are detectable with appropriate image quality with intraoperative 3-dimensional fluoroscopy with intravenous contrast administration. Methods Eight patients were included in the study. The patients' heads were fixed in a radiolucent Mayfield clamp. First, a rotational fluoroscopy scan was performed without contrast agent. Then, a second scan with 50 mL iodine contrast agent was performed. The DICOM (digital imaging and communications in medicine) data of both scans were transferred to an Apple PowerMac workstation, subtracted, and reconstructed with OsiriX imaging software. The images were compared with preoperative angiograms. Results No adverse effects were observed during contrast administration. The entire procedure from fluoroscope positioning to the production of usable 3-dimensional images took 5 to 6 minutes with an image acquisition time of 2 × 24 seconds. The configuration of the aneurysm and the vessel anatomy were assessable. Previous coiling limited image quality in 1 patient. Conclusion This technique quickly provides images of adequate quality to assess the configuration of intracranial aneurysms, which may be helpful when immediate intraoperative information about intracranial vessel pathologies is required. The positioning of the fluoroscope, image acquisition, and processing can be completely integrated into the surgical workflow.

Background Intraoperative resection or occlusion control is indispensable in the surgery of vascular anomalies. This can be conducted using local vascular imaging modalities or angiographic techniques. This series was performed to assess whether cerebral arteriovenous malformations (AVMs) and dural arteriovenous fistulae (dAVFs) can be detected in a sufficient quality by intraoperative 3-dimensional (3D) fluoroscopy with intravenous contrast application. Materials and Methods Five patients were included in the analysis (2 AVMs, 3 dAVFs). All patients had preoperative digital subtraction angiography. The head was fixed in a carbon MAYFIELD clamp. After a 3D rotational fluoroscopy scan without contrast agent, a second scan with 50 mL of iodine contrast agent was performed. The Digital Imaging and Communications in Medicine data of both scans were subtracted and reconstructed using the OsiriX imaging software. In 2 patients with dAVF, occlusion control was performed after obliteration of the fistula. Results In the 2 patients with cerebral AVM, 3D fluoroscopy with intravenous contrast administration resulted in good image quality. Preoperative embolization with Onyx produces significant artifacts that can be largely removed by simple digital subtraction techniques. In dural AVF, occlusion control was well feasible after obliteration of the draining vein at its dural origin. Conclusions This technique quickly supplies intraoperative images of adequate quality to locate cerebral AVM and dAVF. However, it does not produce dynamic images. Thus, early draining veins cannot be located unless anatomically identified based on the preoperative DSA. In this case, it can be used for intraoperative obliteration control.

Early cytotoxic brain edema may be a decisive factor that maintains cerebral malperfusion after subarachnoid hemorrhage (SAH). In addition, endothelial cell swelling may be an independent factor restricting cerebral blood flow (CBF) in a very early stage after SAH. Immediate and aggressive treatment may be able to restore CBF in this critical period.Male Sprague-Dawley rats were subjected to SAH by the endovascular filament model and treated by a bolus of hyperoncotic-hypertonic hydroxyethyl starch (4 mL/kg body weight) immediately after vessel perforation and 150 minutes later (n = 12) or by the same amount of normal saline (n = 9). Mean arterial blood pressure, intracranial pressure, and local CBF over both hemispheres were continuously measured by laser-Doppler flowmetry. Neurologic assessment was performed 24 hours later. Hippocampal damage was assessed by hematoxylin-eosin and Caspase-3 staining.Arterial blood gases and mean arterial blood pressure were not significantly different between the 2 groups. Intracranial pressure was significantly reduced in the treatment group (P0.05). Local CBF was significantly improved in the treatment group over both hemispheres (P 0.05; 180 minutes after treatment, P0.01). There was a trend to better neurologic performance in the treatment group. The rate of injured neurons was significantly reduced in animals of the treatment group compared with controls (P0.01). The number of Caspase-3-positive neurons in the hippocampal CA1 field was not reduced.In this study, the effects of very early and repeated treatment with a high-dose hyperoncotic-hypertonic hydroxyethyl starch were investigated. The results of this series show that this therapy can be highly effective to improve CBF and attenuate hippocampal cell damage in the early stage of SAH. Whether delayed cell death could be treated by longer therapy cannot be answered by this study. Because no differential diagnosis of the clinical suspicion of SAH prohibits the administration of hypertonic-hyperoncotic solutions, it may be useful as a first-tier preclinical therapy in suspected SAH and could even be used by emergency rescue services before the patient is admitted to a hospital.

Study design A retrospective analysis of clinical records and radiologic imaging by 3 independent reviewers to assess the indication for surgical treatment with and without myelography and postmyelographic computed tomography (MCT). Objective To evaluate whether myelography and MCT obtained in addition to magnetic resonance imaging (MRI) influence therapeutic decisions in degenerative diseases of the cervical spine. Summary of background data MRI has become the standard examination in spinal diseases. The role of myelography and MCT is not clearly defined in the modern diagnostic setup. In many departments, they are used if MRI leaves some diagnostic uncertainty. It has not been examined yet whether additional myelography and MCT change therapeutic strategies. Materials and methods Three investigators independently reviewed the anonymized clinical data and image files of 105 patients who had all undergone MRI, myelography, and MCT. They determined their treatment decisions after each of 2 assessment rounds based on the following: (1) MRI and, if available, native CT, and plain radiographs. (2) Additional myelography and MCT. The intraobserver variability was the primary endpoint. Results Myelography and MCT had been performed in multilevel disease, recurrent complaints after surgery, or if MRI had not revealed a clear finding. The intraobserver variability was 26.3% and varied markedly between the 3 investigators (17%-41 %). It was the highest in cases of multilevel disease. If noninvasive imaging included native CT and plain radiographs, the intraobserver variability was significantly reduced to 10.3%. Conclusions In unclear cases of degenerative disorders of the cervical spine, particularly multilevel stenosis, myelography and MCT add relevant information for therapeutic decisions in more than a quarter of the patients in comparison with MRI as the sole diagnostic modality, and changes therapeutic strategies. However, a significant part of the information drawn out of myelography and MCT can be obtained by a completion of noninvasive examinations (native CT and radiographs).

Objective Metabolic exhaustion in ischemic tissue is the basis for a detrimental cascade of cell damage. In the acute stage of subarachnoid hemorrhage (SAH), a sequence of global and focal ischemia occurs, threatening brain tissue to undergo ischemic damage. This study was conducted to investigate whether early therapy with moderate hypothermia can offer neuroprotection after experimental SAH. Methods Twenty male Sprague-Dawley rats were subjected to SAH and treated by active cooling (34°C) or served as controls by continuous maintenance of normothermia (37.0°C). Mean arterial blood pressure, intracranial pressure, and local cerebral blood flow over both hemispheres were continuously measured. Neurologic assessment was performed 24 hours later. Hippocampal damage was assessed by hematoxylin-eosin and caspase-3 staining. Results By a slight increase of mean arterial blood pressure in the cooling phase and a significant reduction of intracranial pressure, hypothermia improved cerebral perfusion pressure in the first 60 minutes after SAH. Accordingly, a trend to increased cerebral blood flow was observed during this period. The rate of injured neurons was significantly reduced in hypothermia-treated animals compared with normothermic controls. Conclusions The results of this series cannot finally answer whether this form of treatment permanently attenuates or only delays ischemic damage. In the latter case, slowing down metabolic exhaustion by hypothermia may still be a valuable treatment during this state of ischemic brain damage and prolong the therapeutic window for possible causal treatments of the acute perfusion deficit. Therefore, it may be useful as a first-tier therapy in suspected SAH.

Object The authors undertook this study to investigate whether the physiological mechanism of cerebral blood flow (CBF) regulation by alteration of the arterial partial pressure of carbon dioxide (PaCO2) can be used to increase CBF after aneurysmal subarachnoid hemorrhage (aSAH). Methods In 6 mechanically ventilated patients with poor-grade aSAH, the PaCO2 was first decreased to 30 mm Hg by modification of the respiratory rate, then gradually increased to 40, 50 and 60 mm Hg for 15 minutes each setting. Thereafter, the respirator settings were returned to baseline parameters. Intracerebral CBF measurement and brain tissue oxygen saturation (StiO2), measured by near-infrared spectroscopy (NIRS), were the primary and secondary end points. Intracranial pressure (ICP) was controlled by external ventricular drainage. Results A total of 60 interventions were performed in 6 patients. CBF decreased to 77% of baseline at a PaCO2 of 30 mm Hg and increased to 98%, 124%, and 143% at PaCO2 values of 40, 50, and 60 mm Hg, respectively. Simultaneously, StiO2 decreased to 94%, then increased to 99%, 105%, and 111% of baseline. A slightly elevated delivery rate of cerebrospinal fluid was noticed under continuous drainage. ICP remained constant. After returning to baseline respirator settings, both CBF and StiO2 remained elevated and only gradually returned to pre-hypercapnia values without a rebound effect. None of the patients developed secondary cerebral infarction. Conclusions Gradual hypercapnia was well tolerated by poor-grade SAH patients. Both CBF and StiO2 reacted with a sustained elevation upon hypercapnia; this elevation outlasted the period of hypercapnia and only slowly returned to normal without a rebound effect. Elevations of ICP were well compensated by continuous CSF drainage. Hypercapnia may yield a therapeutic potential in this state of critical brain perfusion. Clinical trial registration no.: NCT01799525 (ClinicalTrials.gov).

UNLABELLED In an acute respiratory distress syndrome, venovenous extracorporeal membrane oxygenation (vvECMO) can rapidly normalize arterial hypoxemia and carbon dioxide tension (PaCO2). Considering the positive relationship between PaCO2 and cerebral blood flow, the aim of the current study was to evaluate cerebral regional tissue oxygen saturation (rSO2) during the implementation of vvECMO. Fifteen acute respiratory distress syndrome patients with recordings of cerebral rSO2 by near-infrared spectroscopy before vvECMO implementation until the optimization of the ECMO/ventilator settings were retrospectively studied. RESULTS median (interquartile range). The cerebral rSO2 increased significantly (p < 0.05) from 69(61-74) to 75(60-80)% after ECMO was started, concomitant to the arterial oxygenation. Until the end of the observation period after 83(44-132) minutes, cerebral rSO2 decreased significantly to 61(52-71)%. PaCO2 decreased from 70(61-87) to 43(38-54) mm Hg and the pH increased from 7.23(7.14-7.29) to 7.39(7.34-7.43). The baseline arterial oxygen saturation and tension as well as the actual bicarbonate concentration were negatively correlated with the absolute change in cerebral rSO2 (ΔrSO2). In the 11 nonhypoxemic patients (arterial oxygen saturation ≥90%) ΔPaCO2 was significantly correlated with ΔrSO2. Patients receiving vvECMO treatment are at risk for a decrease in cerebral rSO2. This decrease is more distinct in patients with normal baseline arterial oxygenation and high actual bicarbonate.

It was the objective of this report to present a case of recurrent aneurysmal subarachnoid hemorrhage (SAH) and intracerebral hemorrhage (ICH) in which an MCA aneurysm was detected by 3D rotational fluoroscopy in an emergency situation. A 44-year-old woman was admitted from an external department after repeated SAH and temporal ICH. Due to progressive anisocoria and cardiocirculatory instability, she was transferred to the operating room without angiography. After a 3D rotational fluoroscopy baseline scan, another scan with 50 ml of iodine contrast agent was performed. The Digital Imaging and Communications in Medicine (DICOM) data sets were subtracted and reconstructed using the OsiriX® free imaging software. No adverse effect was observed during and after the administration of the contrast agent. The entire procedure from positioning of the fluoroscope to the production of utilizable 3D images was completely integrated into the surgical workflow with an image acquisition time of 2 × 24 s. The configuration of the aneurysm, the aneurysm-carrying vessel, and the distal vessel anatomy were well assessable. This technique quickly supplies images at adequate quality to assess the configuration of an intracranial aneurysm and is a useful diagnostic tool if the patient's critical condition prohibits aneurysm diagnostics by angiography or CT angiography.

A growing number of industrially manufactured implants have been developed in the last years for vertebral replacement in anterior cervical corpectomy and fusion (ACCF). Polyetheretherketone (PEEK)-cages are used in many centers, but outcome reports are scarce. This study assesses the clinical and radiological outcome after one- or two-level ACCF by the use of a PEEK-cage augmented by a plate–screw osteosynthesis. A total of 21 patients received one-level (18 patients) or two-level (3 patients) ACCF by a PEEK-cage and plate–screw osteosynthesis for multilevel degenerative stenosis. The Visual Analogue Scale, Nurick Score, Neck Disability Index and European Myelopathy Score were used for clinical assessment. Radiological outcome—osseous fusion and loss of height—was evaluated by CT. The mean follow-up was 28 ± 12 months. In 19 patients, bony fusion was achieved after the primary operation. Graft failure that required surgical revision occurred in two patients. In these patients, osseous fusion was achieved after the second operation. Myelopathy improved significantly. The loss of height was 2.2 ± 2.3 and 5.3 ± 2.1 mm after one- and two-level ACCF, respectively. Anterior corpectomy and fusion by a PEEK-cage and plate–screw osteosynthesis resulted in clinical improvement in all patients. Bony fusion was achieved in all patients in the long run. PEEK cages are allegedly less rigid than other xenografts. Similar to those, however, their use bears the risk of early cage-dislocation and subsidence. A comparison of industrial xenografts and autologous bone implants is required to challenge the different fusion techniques.

Background Derangement of cerebral metabolism occurs after various insults such as ischemia, traumatic brain injury, and subarachnoid hemorrhage (SAH). Objective To investigate the course of cerebral blood flow and metabolic parameters in the first hours after experimental SAH. Methods Sixteen Sprague-Dawley rats were subjected to SAH using the endovascular filament model or served as controls (8 rats in each group). Local cerebral blood flow and intracranial pressure were measured continuously. Microdialysis samples were acquired in 30-minute intervals for 6 hours after SAH. Concentrations of glucose, lactate, pyruvate, and glutamate were determined. Results After induction of SAH, cerebral perfusion pressure and local cerebral blood flow sharply decreased. The decrease in local cerebral blood flow exceeded the decrease in cerebral perfusion pressure throughout the observation period. Glutamate concentrations in microdialysis samples increased sixfold and recovered to baseline levels. Lactate concentrations immediately increased after SAH, recovered incompletely, and remained above the levels of control animals until the end of the sampling period. Pyruvate concentrations showed a delayed increase starting 2 hours after SAH. Conclusion The course of cerebral blood flow after SAH resembles global ischemia followed by a continuous low-flow state caused by a sudden decrease in cerebral perfusion pressure and acute vasoconstriction. The courses of lactate and pyruvate concentrations indicate a persistently deranged aerobic metabolism.