Introduction: Microsurgery clipping is one of the most challenging surgical interventions in neurosurgery. The opportunities to train residents are scarce, but the need for accumulating practice is mandatory. New simulating tools are needed for skill learning. Methods: The design, implementation, and assessment of a new hybrid aneurysm clipping simulator are presented. It consists of an ergonomic workstation with a patient head mannequin and a physics-based virtual reality simulation with bimanual haptic feedback. The simulator recreates scenarios of microsurgery from the patient fixation and the exploration of the brain lobes through Sylvian fissure and vascular structures to the aneurysm clipping. Skill metrics were introduced, including monitoring of gestures movements, exerted forces, tissue displacements, and precision in clipping. Results: Two experimental conditions were tested: (1) simple clipping without brain tissue exploration and (2) clipping the aneurysm with brain Sylvian fissure exploration. Differences in the bimanual gestures were observed between both conditions. The quantitative measurements of tissue displacement of the brain lobes exhibited more tissue retrieval for the surgical gestures of neurosurgeons. Appraisal with questionnaires showed positive scores by neurosurgeons in all items evaluating the usability and realism of the simulator. Conclusions: The simulator was well accepted and feasible for training purposes. The analysis of the interactions with virtual tissues offers information to establish differential and common patterns between tested groups and thus useful metrics for skill evaluation of practitioners. Future work can lead to other tasks during the intervention and the inclusion of more clinical cases.

The coronavirus family has tropism for the Central Nervous System (CNS), however, there is no solid evidence demonstrating that the neurological effects of COVID-19 result from direct viral infection or systemic inflammation. The goals of this study were to examine the cytokine profile and the presence of SARS-CoV-2 messenger ribonucleic acid (mRNA) in cerebrospinal fluids (CSF) from two patients with cerebrovascular disease and COVID-19. Although the SARS-CoV-2 mRNA was not detected in CSF of both patients, we found abnormally high levels of numerous proinflammatory cytokines and chemokines, especially IL-8 and MCP-1. Since these chemokines mediate activation and recruitment of neutrophils, monocytes, and macrophages, it is feasible that cerebrovascular disease related-neuroinflammation found in both patients results from an exacerbated inflammatory response instead of SARS-CoV-2 direct invasion to CNS. These results suggest that neuroinflammation plays a key role in cerebrovascular disease and COVID-19.

Transsynaptic transport is the most accepted proposal to explain the SARS-CoV-2 infection of the CNS. Nevertheless, emerging evidence shows that neurons do not express the SARS-CoV-2 receptor ACE2, which highlights the importance of the blood-brain barrier (BBB) in preventing virus entry to the brain. In this study, we examine the presence of SARS-CoV-2 messenger ribonucleic acid (mRNA) and the cytokine profile in cerebrospinal fluids (CSF) from two patients with a brain tumor and COVID-19. To determine the BBB damage, we evaluate the Q-albumin index, which is an indirect parameter to assess the permeability of this structure. The Q-albumin index of the patient with an intraventricular brain tumor suggests that the BBB is undamaged, preventing the passage of SARS-CoV-2 and pro-inflammatory molecules. The development of brain tumors that disrupt the BBB (measured by the Q-albumin index), in this case, a petroclival meningioma (Case 1), allows the free passage of the SARS-CoV-2 virus and probably lets the free transit of pro-inflammatory molecules to the CNS, which leads to a possible activation of the microglia (astrogliosis) and an exacerbated immune response represented by IL-13, IFN-γ, and IL-2 trying to inhibit both the infection and the carcinogenic process.

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Background: Stereotactic brain biopsy (SBB) is used for establishing the histological diagnosis of intracranial lesions that are not amenable for a direct surgical approach. Objective: The objective of the study was to describe our experience having an evaluation of the biopsy sample by a neuropathologist during SBB. Materials and methods: Retrospective analysis of 140 consecutive patients who underwent SBB between 2014 and 2018 in whom trans-operatory analysis of the sample was performed. Results: There were 56% men. The mean age was 45 years. Histological diagnosis was performed in 131 of 140 patients (94% overall diagnostic yield). The presurgical radiological diagnosis was correct in 39%. Neoplastic lesions were reported in 108 cases, and 32 were non-neoplastic. We performed craniotomy and resection after biopsy in 14%. We found complications in 6% of patients. Conclusions: SBB continues to be a safe, useful, and inexpensive procedure. The diagnostic performance of SBB increases when intraoperative cytological evaluation by a neuropathologist is included in the study.