Current trends and outcomes of non-elective neurosurgical care in Central Europe during the second year of the COVID-19 pandemic.

Reflecting the first wave COVID-19 pandemic in Central Europe (i.e. March 16th-April 15th, 2020) the neurosurgical community witnessed a general diminution in the incidence of emergency neurosurgical cases, which was impelled by a reduced number of traumatic brain injuries (TBI), spine conditions, and chronic subdural hematomas (CSDH). This appeared to be associated with restrictions imposed on mobility within countries but also to possible delayed patient introduction and interdisciplinary medical counseling. In response to one year of COVID-19 experience, also mapping the third wave of COVID-19 in 2021 (i.e. March 16 to April 15, 2021), we aimed to reevaluate the current prevalence and outcomes for emergency non-elective neurosurgical cases in COVID-19-negative patients across Austria and the Czech Republic. The primary analysis was focused on incidence and 30-day mortality in emergency neurosurgical cases compared to four preceding years (2017-2020). A total of 5077 neurosurgical emergency cases were reviewed. The year 2021 compared to the years 2017-2019 was not significantly related to any increased odds of 30 day mortality in Austria or in the Czech Republic. Recently, there was a significant propensity toward increased incidence rates of emergency non-elective neurosurgical cases during the third COVID-19 pandemic wave in Austria, driven by their lower incidence during the first COVID-19 wave in 2020. Selected neurosurgical conditions commonly associated with traumatic etiologies including TBI, and CSDH roughly reverted to similar incidence rates from the previous non-COVID-19 years. Further resisting the major deleterious effects of the continuing COVID-19 pandemic, it is edifying to notice that the neurosurgical community´s demeanor to the recent third pandemic culmination keeps the very high standards of non-elective neurosurgical care alongside with low periprocedural morbidity. This also reflects the current state of health care quality in the Czech Republic and Austria.

Angiosomes of the Ulnar Nerve at the Elbow: A Cadaver Trial Using Contrast-Enhanced Ultrasound.

Three major arteries supplying the ulnar nerve in the cubital tunnel are commonly known. However, their vascular territories (angiosomes) have not been described yet. Contrast-enhanced ultrasound was used to identify the angiosomes of posterior ulnar recurrent artery, inferior ulnar collateral artery and superior ulnar collateral artery in 20 fresh, non-frozen human body donors. The arteries were cannulated, and physiologic blood flow was simulated. Contrast agent was applied in each vessel in a randomized sequence, and the length of the contrast-enhancing ulnar nerve segment was measured by a radiologist blinded to the sequence. The angiosome of the posterior ulnar recurrent artery overlaps both other angiosomes. It fully covers the cubital tunnel in 63.6% of specimens. In addition, collateral flow via nerve and muscle branches of the arterial anastomotic network around the elbow (rete articulare cubiti) partly maintains the intra-neural blood flow in the absence of a vascular pedicle. The posterior ulnar recurrent artery is the dominant nutrient vessel of the ulnar nerve in the cubital tunnel. A potential watershed zone exists proximal to the Osborne ligament. Knowledge of these angiosomes may advance surgery of the ulnar nerve in the cubital tunnel.

Influence of preoperative corticosteroid treatment on rate of diagnostic surgeries in primary central nervous system lymphoma: a multicenter retrospective study.

BACKGROUND: Corticosteroid therapy (CST) prior to biopsy may hinder histopathological diagnosis in primary central nervous system lymphoma (PCNSL). Therefore, preoperative CST in patients with suspected PCNSL should be avoided if clinically possible. The aim of this study was thus to analyze the difference in the rate of diagnostic surgeries in PCNSL patients with and without preoperative CST. METHODS: A multicenter retrospective study including all immunocompetent patients diagnosed with PCNSL between 1/2004 and 9/2018 at four neurosurgical centers in Austria was conducted and the results were compared to literature. RESULTS: A total of 143 patients were included in this study. All patients showed visible contrast enhancement on preoperative MRI. There was no statistically significant difference in the rate of diagnostic surgeries with and without preoperative CST with 97.1% (68/70) and 97.3% (71/73), respectively (p = 1.0). Tapering and pause of CST did not influence the diagnostic rate. Including our study, there are 788 PCNSL patients described in literature with an odds ratio for inconclusive surgeries after CST of 3.3 (CI 1.7-6.4). CONCLUSIONS: Preoperative CST should be avoided as it seems to diminish the diagnostic rate of biopsy in PCNSL patients. Yet, if CST has been administered preoperatively and there is still a contrast enhancing lesion to target for biopsy, surgeons should try to keep the diagnostic delay to a minimum as the likelihood for acquiring diagnostic tissue seems sufficiently high.

Trends and outcomes for non-elective neurosurgical procedures in Central Europe during the COVID-19 pandemic.

The world currently faces the novel severe acute respiratory syndrome coronavirus 2 pandemic. Little is known about the effects of a pandemic on non-elective neurosurgical practices, which have continued under modified conditions to reduce the spread of COVID-19. This knowledge might be critical for the ongoing second coronavirus wave and potential restrictions on health care. We aimed to determine the incidence and 30-day mortality rate of various non-elective neurosurgical procedures during the COVID-19 pandemic. A retrospective, multi-centre observational cohort study among neurosurgical centres within Austria, the Czech Republic, and Switzerland was performed. Incidence of neurosurgical emergencies and related 30-day mortality rates were determined for a period reflecting the peak pandemic of the first wave in all participating countries (i.e. March 16th-April 15th, 2020), and compared to the same period in prior years (2017, 2018, and 2019). A total of 4,752 emergency neurosurgical cases were reviewed over a 4-year period. In 2020, during the COVID-19 pandemic, there was a general decline in the incidence of non-elective neurosurgical cases, which was driven by a reduced number of traumatic brain injuries, spine conditions, and chronic subdural hematomas. Thirty-day mortality did not significantly increase overall or for any of the conditions examined during the peak of the pandemic. The neurosurgical community in these three European countries observed a decrease in the incidence of some neurosurgical emergencies with 30-day mortality rates comparable to previous years (2017-2019). Lower incidence of neurosurgical cases is likely related to restrictions placed on mobility within countries, but may also involve delayed patient presentation.

Vascular endothelial growth factor: the major factor for tumor neovascularization and edema formation in meningioma patients.

BACKGROUND: Peritumoral brain edema (PTBE) may be crucial in the clinical outcome of meningioma patients. The underlying pathogenetic key mechanism has so far not been determined. Sex, age, tumor size, location, involvement of other structures, or the histological appearance was not found to sufficiently explain PTBE formation in meningiomas. OBJECTIVE: As PTBE formation is widely accepted to be vasogenic, we investigated the role of vascular endothelial growth factor (VEGF) and pial supplying vessels in a series of World Health Organization (WHO) grade I meningiomas. METHODS: A total of 79 patients with WHO grade I meningiomas were immunohistochemically studied for VEGF and MIB-1. Pre- and postoperative magnetic resonance imaging including 3-dimensional reconstruction of 1.3-mm thick layers, with calculation of tumor and edema volume, was performed. Intraoperatively, the vascular supply and arachnoidal state were noted by the neurosurgeon. RESULTS: VEGF was found to be exclusively confined to meningioma tumor cells. We identified 4 different patterns. VEGF and supplying pial vessels were found in 14 meningioma patients, pial vascular supply only in 3, VEGF expression only in 46, and neither VEGF expression nor supplying pial vessels in 16. Only the occurrence of both pial vascular supply and tumor VEGF expression was found to be correlated with PTBE formation (P<.002). CONCLUSION: Our data suggest that VEGF may be crucial in angiogenesis and therefore indirectly in PTBE formation in World Health Organization grade I meningiomas.

Using ex vivo proton magnetic resonance spectroscopy to reveal associations between biochemical and biological features of meningiomas.

OBJECT: The goal in this study was to determine if proton ((1)H) MR spectroscopy can differentiate meningioma grade and is associated with interpretations of biological behavior; the study was performed using ex vivo high-resolution spectra indicating metabolic characteristics. METHODS: Sixty-eight resected tissue samples of meningiomas were examined using ex vivo (1)H MR spectroscopy. Of these meningiomas, 46 were WHO Grade I, 14 were WHO Grade II, and 8 were WHO Grade III. Fifty-nine were primary meningiomas and 9 were recurrences. Invasion of adjacent tissue (dura mater, bone, venous sinus, brain) was found in 32 cases. Thirty-nine meningiomas did not rapidly recur (as defined by expansion on MR imaging within a 5-year follow-up period), whereas rapid recurrence was confirmed in 24 meningiomas, and follow-up status was unknown in 5 cases. RESULTS: The absolute concentrations of total alanine and creatine were decreased in high-grade compared with low-grade meningiomas, as was the ratio of glycine to alanine (all p < 0.05). Additionally, alanine and the glycine/alanine ratio distinguished between primary and recurrent meningiomas (all p < 0.05). Finally, the absolute concentrations of alanine and creatine, and the glycine/alanine and choline/glutamate ratios were associated with rapid recurrence (p < 0.05). CONCLUSIONS: These data indicate that meningioma tissue can be characterized by metabolic parameters that are not typically identified by histopathological analysis alone. Creatine, glycine, and alanine may be used as markers of meningioma grade, recurrence, and the likelihood of rapid recurrence. These data validate a previous study of a separate group of Grade I meningiomas.

No association between intraoperative hypothermia or supplemental protective drug and neurologic outcomes in patients undergoing temporary clipping during cerebral aneurysm surgery: findings from the Intraoperative Hypothermia for Aneurysm Surgery Trial.

BACKGROUND: Although hypothermia and barbiturates improve neurologic outcomes in animal temporary focal ischemia models, the clinical efficacy of these interventions during temporary occlusion of the cerebral vasculature during intracranial aneurysm surgery (temporary clipping) is not established. METHODS: A post hoc analysis of patients from the Intraoperative Hypothermia for Aneurysm Surgery Trial who underwent temporary clipping was performed. Univariate and multivariate logistic regression methods were used to test for associations between hypothermia, supplemental protective drug, and short- (24-h) and long-term (3-month) neurologic outcomes. An odds ratio more than 1 denotes better outcome. RESULTS: Patients undergoing temporary clipping (n = 441) were assigned to intraoperative hypothermia (33.3 degrees +/- 0.8 degrees C, n = 208) or normothermia (36.7 degrees +/- 0.5 degrees C, n = 233), with 178 patients also receiving supplemental protective drug (thiopental or etomidate) during temporary clipping. Three months after surgery, 278 patients (63%) had good outcome (Glasgow Outcome Score = 1). Neither hypothermia (P = 0.847; odds ratio = 1.043, 95% CI = 0.678-1.606) nor supplemental protective drug (P = 0.835; odds ratio = 1.048, 95% CI = 0.674-1.631) were associated with 3-month Glasgow Outcome Score. The effect of supplemental protective drug did not significantly vary with temperature. The effects of hypothermia and protective drug did not significantly vary with temporary clip duration. Similar findings were made for 24-h neurologic status and 3-month Neuropsychological Composite Score. CONCLUSION: In the Intraoperative Hypothermia for Aneurysm Surgery Trial, neither systemic hypothermia nor supplemental protective drug affected short- or long-term neurologic outcomes of patients undergoing temporary clipping.

Fiducial versus nonfiducial neuronavigation registration assessment and considerations of accuracy.

OBJECTIVE: For frameless stereotaxy, users can choose between anatomic landmarks (ALs) or surface fiducial markers (FMs) for their match points during registration to define an alignment of the head in the physical and radiographic image space. In this study, we sought to determine the concordance among a point-merged FM registration, a point-merged AL registration, and a combined point-merged anatomic/surface-merged (SM) registration, i.e., to determine the accuracy of registration techniques with and without FMs by examining the extent of agreement between the system-generated predicted value and physical measured values. METHODS: We examined 30 volunteers treated with gamma knife surgery. The frameless stereotactic image-guidance system called the StealthStation (Medtronic Surgical Navigation Technologies, Louisville, CO) was used. Nine FMs were placed on the patient's head and four were placed on a Leksell frame rod-box, which acted as a rigid set to determine the difference in error. For each registration form, we recorded the generated measurement (GM) and the physical measurement (PM) to each of the four checkpoint FMs. Bland and Altman plot difference analyses were used to compare measurement techniques. Correlations and descriptive analyses were completed. RESULTS: The mean of values for GMs were 1.14 mm for FM, 2.3 mm for AL, and 0.96 mm for SM registrations. The mean errors of the checkpoints were 3.49 mm for FM, 3.96 mm for AL, and 3.33 mm for SM registrations. The correlation between GMs and PMs indicated a linear relationship for all three methods. AL registration demonstrated the greatest mean difference, followed by FM registration; SM registration had the smallest difference between GMs and PMs. Differences in the anatomic registration methods, including SM registration, compared with FM registration were within a mean +/- 1.96 (standard deviation) according to the Bland and Altman analysis. CONCLUSION: For our sample of 30 patients, all three registration methods provided comparable distances to the target tissue for surgical procedures. Users may safely choose anatomic registration as a less costly and more time-efficient registration method for frameless stereotaxy.

Implicating chromosomal aberrations with meningioma growth and recurrence: results from FISH and MIB-I analysis of grades I and II meningioma tissue.

The fluorescence in situ hybridization (FISH) technique was used in 111 WHO grades I and II meningioma patients. Clinical, radiological, pathological, and immunohistochemical data were compared to aberrations of chromosomes 1p, 14q, and 22q determined by FISH. Significant differences for MIB-1 labeling were found between grades I and II tumors (p < 0.001), and between grade I tumors that recurred and those that did not recur (p < 0.001). Chromosomal aberrations were detected with FISH analysis in nearly 50% of grade I, and in 93% of grade II meningiomas. The numbers of chromosomal aberrations correlated significantly to MIB-1 (p < 0.001), with signs of grossly invasive tumor growth (p < 0.001), and with tumor recurrence (p < 0.01). The findings suggest that adding FISH analysis may allow better prediction of possible meningioma recurrence and may be a useful adjunct for therapy decisions.

Fluorescent in situ hybridization and ex vivo 1H magnetic resonance spectroscopic examinations of meningioma tumor tissue: is it possible to identify a clinically-aggressive subset of benign meningiomas?

OBJECTIVE: Although histologically benign, Grade I meningiomas can sometimes behave aggressively. The clinically-aggressive subset of Grade I meningiomas is typically indistinguishable from clinically-benign Grade I meningiomas in vivo. We compared molecular genetic and biochemical findings to clinical, pathological, and immunohistochemical information in a series of clinically-aggressive Grade I meningiomas with a series of clinically-benign meningiomas to identify characteristics that may be used to distinguish between these two groups. METHODS: Tumor tissue samples from 30 patients with Grade I meningiomas were harvested. Half of the sample was embedded in paraffin to be used for fluorescent in situ hybridization to examine aberrations of chromosomes 1p, 14q, and 22q; the other half was snap frozen and examined with proton magnetic resonance spectroscopy to identify concentrations of key metabolites in the tissue ex vivo. Clinical and pathological parameters were retrospectively reviewed as part of routine clinical management. These data were evaluated for potential unique associations with diagnostic significance. RESULTS: Molecular genetic and biochemical findings correlated with clinical behavior of the two Grade I meningioma groups. Specific chromosomal abnormalities correlated with the aggressive phenotype: homogeneous loss of 1p, homogeneous loss of 14q, and the presence of any of the examined chromosomal aberrations (P < 0.05). The presence of aberrations also influenced meningioma regrowth after subtotal resection. The ratio of choline to glutamate correlated with histopathological subtype (P < 0.05). The ratio of glutamine to glutamate, and the ratio of glycine to total glutamine and glutamate, and creatine correlated with recurrence. Alanine was decreased in meningiomas with chromosomal aberrations in tumors that recurred. CONCLUSION: Distinct molecular genetic and biochemical alterations differentiated clinically-aggressive Grade I meningiomas from clinically-benign Grade I meningiomas.

Diagnostic and prognostic significance of genetic regional heterogeneity in meningiomas.

We analyzed the frequency and regional distribution of cells with genetic abnormalities of chromosomes 1, 14, and 22 in meningiomas. This data was evaluated for correlation to the clinical outcome of the patients. Eight defined areas of each of 77 paraffin-embedded meningioma samples (59 grade I, 13 grade II, and 5 grade III) were analyzed by fluorescent in situ hybridization using bacterial artificial chromosome probes localized to chromosomes 1p36.32, 1q25.3, 14q13.3, 14q32.12, 22q11.2, and 22q12.1-3. Chromosome deletion was considered to be regionally heterogeneous if 7 regions showed cells with chromosome deletions. Deletion of 1p occurred in 35% of the grade I tumors. Distribution of cells with 1p deletion was regionally heterogeneous in 25% and homogeneous in 10% of grade I tumors. Distribution of cells with deletion of 1p was regionally heterogeneous in 23% and homogeneous in 69% of the grade II tumors. All grade III meningiomas had homogeneous distribution of cells with deletion of chromosome 1p. Distribution of cells with deletion of 14q was regionally heterogeneous in 27% and homogeneous in 2% of the grade I meningiomas, heterogeneous in 31% and homogeneous in 62% of the grade II tumors, and heterogeneous in 40% and homogeneous in 60% of the grade III meningiomas. Distribution of cells with deletion of 22q was regionally heterogeneous in 15% and homogeneous in 3% of the grade I tumors, heterogeneous in 15% and homogeneous in 31% of grade II tumors, and homogeneous in 20% of the grade III meningiomas. Distribution of cells with trisomy 22q was regionally heterogeneous in 10% of grade I tumors, heterogeneous in 23% of grade II, and homogeneous in 80% of grade III meningiomas. The proportion of patients with a deletion of 22q (either homogeneous or heterogeneous) who had recurrence was greater than the proportion of those without 22q deletion who had recurrence, and deletion of 22q was significantly associated with radiologically detected recurrence (P < 0.05). We conclude that the appearance of chromosomal aberrations in different areas of the tumor demonstrates the importance of regional heterogeneity in the biological behavior of meningiomas.

Frequency and risk factors for meningioma in clinically healthy 75-year-old patients: results of the Transdanube Ageing Study (VITA).

BACKGROUND: The prevalence of clinically silent intracranial tumors in specific populations is poorly researched. It is known that, in advanced age groups, the number of clinically manifest meningiomas constitute a small proportion of the actual number of cases. The goals of the current study were to determine the frequency of asymptomatic patients with meningioma in advanced age and to identify risk factors for meningiomas in this population. METHODS: Between May 2000 and November 2002, 532 probands from a specifically defined geographic area of Vienna who were age 75 years underwent a magnetic resonance imaging scan of the brain and were evaluated for the presence of a space-occupying mass. All probands were examined clinically and neurologically as well as by a neuropsychiatrist. The patients' medical histories were carefully documented with regard to previous diseases, medication, and lifestyle, as were their laboratory reports. The collected data were correlated and similarities among subjects with meningioma were determined. RESULTS: Nine meningiomas that were unknown until the time of investigation were observed among the 318 women included in the trial (corresponding to a calculated prevalence of 2800/100,000 clinically silent meningiomas in 75-year-old women). No tumors were found among men. Associated clinical changes or deficits were not observed in any subject. Apart from advanced age and female gender, no other accepted or well known risk factors were observed in the tumor patients. CONCLUSIONS: Clinically quiescent meningiomas in the elderly female population were more common than was believed to be the case to date. Known and influenceable risk factors were found to be less important than age and gender. The high frequency of this lesion should be considered when deciding on the treatment of patients with incidentally discovered, clinically quiescent meningiomas.

Microsurgery for glioblastoma preserves short-term quality of life both in functionally impaired and independent patients.

OBJECTIVE: Considering the short remaining life expectancy with glioblastoma multiforme, numerous patients and their referring physicians are hesitant to use aggressive surgical treatment for fear of greater risk of neurological deterioration. The aim of our study was to determine whether surgical treatment of glioblastoma, utilizing modern microsurgical dissection techniques and tools, interferes with short-term quality of life. METHODS: The functional status before and after 67 microsurgical operations in 65 patients with glioblastomas was studied retrospectively. To evaluate the patients' quality of life, their functional neurological status was correlated with the Karnofsky performance scale (KPS). Post-operative evaluation was done within 7 days of surgery. RESULTS: No significant difference was found between the preoperative and the early postoperative functional status. Neither patient age nor the preoperative functional status determined a significant risk for postoperative functional deterioration. Patients with tumors involving so-called eloquent brain areas statistically worsened (p = 0.018); however, they showed only mild clinical impairment that was represented by a mean KPS status decline of less than -10. After total tumor resection, patients showed functional improvement. CONCLUSION: Microsurgery is safe and effective in order to improve or preserve short-term quality of life in glioblastoma patients. Total tumor resection is not associated with a significantly greater risk for neurological deterioration, either in patients with preoperative functional impairment, or in functionally independent patients.