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.

Cervical disc prostheses need a variable center of rotation for flexion / extension below disc level, plus a separate COR for lateral bending above disc level to more closely replicate in-vivo motion: MRI-based biomechanical in-vivo study.

BACKGROUND: Cervical disc prostheses are used to preserve motion after discectomy, but they should also provide a near-physiological qualitative motion pattern. Nevertheless, they come in many completely different biomechanical concepts. This caused us to perform an in-vivo MR-based biomechanical study to further investigate cervical spine motion with the aim to gain new information for improving the design of future cervical arthroplasty devices. METHODS: Fifteen healthy volunteers underwent MRI-investigation (in order to avoid radiation exposure) of their cervical spines from C3 to C7; for each segment centers of rotation (COR) for flexion / extension were determined from 5 different positions, and CORs for lateral bending from 3 different positions. The motion path of the COR is then described and illustrated in relation to the respective COR for maximum flexion / extension or lateral bending, respectively, and the findings are translated into implications for a better biomechanical prosthesis-design. RESULTS: The COR for flexion / extension does not remain constant during motion. The CORs for the respective motion intervals were always found at different positions than the COR for maximum flexion /extension showing that the COR moves both along the x- and the y-axis throughout flexion / extension. For lateral bending a completely independent COR was found above disc-level. CONCLUSION: Flexion / extension is not a simple circular motion. Disc prostheses need a variable COR for flexion / extension below disc level with the capability to move both along the x- and the y-axis during motion, plus a second completely independent COR for lateral bending above disc level to closely replicate in-vivo motion. These findings are important for improving the biomechanical design of such devices in the future.

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.

Correction to: In cervical arthroplasty, only prosthesis with flexible biomechanical properties should be used for achieving a near-physiological motion pattern.

An amendment to this paper has been published and can be accessed via the original article.

In cervical arthroplasty, only prosthesis with flexible biomechanical properties should be used for achieving a near-physiological motion pattern.

BACKGROUND: In cervical arthroplasty, qualitative motion analysis generally investigates the position of the center of rotation (COR) before and after surgery. But is the pre-op COR suitable as reference? We believe that only a comparison against healthy individuals can answer whether a physiological motion pattern has been achieved. The aim of our study was to examine how the COR for flexion/extension after insertion of 3 biomechanically completely different types of disc prostheses compares to healthy volunteers, and whether and how prosthesis design contributes to a more natural or maybe even worse motion pattern. METHODS: In 15 healthy volunteers, MRI in flexion and in extension was taken, and the coordinates for the CORs (COR-HV) from C3 to C7 were determined. Then pre- and post-op flexion/extension x-rays from 30 patients with a one-level disc prosthesis underwent analysis for determination of COR from C3 to C7; 10 patients who received a Bryan, a Prestige STLP, or a Discover prosthesis were chosen, respectively. Change of post-op COR position was investigated in relation to the COR-HV. RESULTS: The pre-operative COR is not congruent with the COR found in healthy subjects and therefore cannot be used as reference for investigation whether a disc prosthesis resembles natural motion. However, the comparison with healthy individuals shows that prosthesis insertion can change the coordinates of the COR to any direction in all levels from C3/4 to C6/7 regardless of the operated segment. Prostheses with flexible biomechanical properties can contribute to shift the COR toward normal, but devices with unphysiological biomechanical design, like fixed ball socket designs, for instance, can make the motion pattern even worse. CONCLUSIONS: Even if the small cohorts in our study do not allow strong conclusions, it seems that in cervical arthroplasty, the biomechanical concept of the prosthesis has a significant impact whether a near-physiological motion pattern can be achieved or not. As it is a rumor but not scientifically proven that prosthesis design has no influence on clinical outcome, surgeons should only choose devices with flexible biomechanical properties for disc replacement.

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.

A patient severely affected by spinal neurofibromas carries a recurrent splice site mutation in the NF1 gene.

Spinal neurofibromas are found in up to 38% of NF1 patients. However, they cause clinical implications only in about 5% of the patients. In contrast, multiple symptomatic spinal neurofibromas are the main clinical finding in patients with familial spinal neurofibromatosis. Familial spinal neurofibromatosis has been considered to be a distinct clinical form of neurofibromatosis. Linkage analysis in two families and identification of a NF1 gene mutation in a third family strongly associate spinal neurofibromatosis with the NF1 gene. We describe a NF1 patient who satisfies the NIH diagnostic criteria and has severe spinal involvement with bilateral spinal root neurofibromas at every level. A recurrent splice site mutation (IVS19b-3C>G) was identified in the NF1 gene in the patient. We discuss the possibility that the clinical picture of this patient represents an additional example of spinal neurofibromatosis. By comparison of the clinical expression of NF1 in this patient and that in another patient with the identical mutation the hypothesis that spinal neurofibromatosis is associated with a particular mutation is highly unlikely. The involvement of other genes linked to the NF1 gene or modifying genes is currently the most likely explanation for the clinical phenotype of spinal neurofibromatosis.