A focal brain-cooling device as an alternative to electrical stimulation for language mapping during awake craniotomy: patient series

Bridging the Gap-Thermofluidic Designs for Precision Bioelectronics

Bioelectronics, the merging of biology and electronics, can monitor and modulate biological behaviors across length and time scales with unprecedented capability. Current bioelectronics research largely focuses on devices' mechanical properties and electronic designs. However, the thermofluidic control is often overlooked, which is noteworthy given the discipline's importance in almost all bioelectronics processes. It is believed that integrating thermofluidic designs into bioelectronics is essential to align device precision with the complexity of biofluids and biological structures. This perspective serves as a mini roadmap for researchers in both fields to introduce key principles, applications, and challenges in both bioelectronics and thermofluids domains. Important interdisciplinary opportunities for the development of future healthcare devices and precise bioelectronics will also be discussed.

An update on tests used for intraoperative monitoring of cognition during awake craniotomy

PURPOSE

Mapping higher-order cognitive functions during awake brain surgery is important for cognitive preservation which is related to postoperative quality of life. A systematic review from 2018 about neuropsychological tests used during awake craniotomy made clear that until 2017 language was most often monitored and that the other cognitive domains were underexposed (Ruis, J Clin Exp Neuropsychol 40(10):1081-1104, 218). The field of awake craniotomy and cognitive monitoring is however developing rapidly. The aim of the current review is therefore, to investigate whether there is a change in the field towards incorporation of new tests and more complete mapping of (higher-order) cognitive functions.

METHODS

We replicated the systematic search of the study from 2018 in PubMed and Embase from February 2017 to November 2023, yielding 5130 potentially relevant articles. We used the artificial machine learning tool ASReview for screening and included 272 papers that gave a detailed description of the neuropsychological tests used during awake craniotomy.

RESULTS

Comparable to the previous study of 2018, the majority of studies (90.4%) reported tests for assessing language functions (Ruis, J Clin Exp Neuropsychol 40(10):1081-1104, 218). Nevertheless, an increasing number of studies now also describe tests for monitoring visuospatial functions, social cognition, and executive functions.

CONCLUSIONS

Language remains the most extensively tested cognitive domain. However, a broader range of tests are now implemented during awake craniotomy and there are (new developed) tests which received more attention. The rapid development in the field is reflected in the included studies in this review. Nevertheless, for some cognitive domains (e.g., executive functions and memory), there is still a need for developing tests that can be used during awake surgery.

Risk and protective factors associated with wound infection after neurosurgical procedures: A meta-analysis

To systematically evaluate the risk factors for wound infection at the surgical site after neurosurgical craniotomy by meta-analysis, and to provide an evidence-based basis for preventing the occurrence of wound infection. A computerised search of PubMed, EMBASE, Cochrane Library, China National Knowledge Infrastructure and Wanfang database was conducted for relevant studies on risk factors for surgical site wound infection after neurosurgical craniotomy published from the database inception to November 2023. Two researchers independently screened the literature, extracted the data and performed quality assessment in strict accordance with the inclusion and exclusion criteria. STATA 17.0 software was applied for data analysis. Overall, 18 papers with 17 608 craniotomy patients were included, of which 905 patients developed wound infections. The analysis showed that underlying diseases [OR = 2.50, 95% CI (1.68, 3.72), p < 0.001] and emergency surgery [OR = 2.47, 95% CI (1.80, 3.38), p < 0.001] were the risk factors for developing wound infections after craniotomy, age < 60 years [OR = 0.72, 95% CI (0.52, 0.98), p = 0.039] was a protective factor for wound infections; whereas sex [OR = 1.11, 95% CI (0.98, 1.27), p = 0.112] and the antimicrobial use [OR = 1.30, 95% CI (0.81 2.09), p = 0.276] were not associated with the presence or absence of wound infection after craniotomy. Underlying disease and emergency surgery are risk factors for developing wound infections after craniotomy, whereas age < 60 years is a protective factor. Clinicians can reduce the occurrence of postoperative wound infections by communicating with patients in advance about the possibility of postoperative wound infections based on these factors, and by doing a good job of preventing postoperative wound infections.

Bidirectional alterations in brain temperature profoundly modulate spatiotemporal neurovascular responses in-vivo

Neurovascular coupling (NVC) is a mechanism that, amongst other known and latent critical functions, ensures activated brain regions are adequately supplied with oxygen and glucose. This biological phenomenon underpins non-invasive perfusion-related neuroimaging techniques and recent reports have implicated NVC impairment in several neurodegenerative disorders. Yet, much remains unknown regarding NVC in health and disease, and only recently has there been burgeoning recognition of a close interplay with brain thermodynamics. Accordingly, we developed a novel multi-modal approach to systematically modulate cortical temperature and interrogate the spatiotemporal dynamics of sensory-evoked NVC. We show that changes in cortical temperature profoundly and intricately modulate NVC, with low temperatures associated with diminished oxygen delivery, and high temperatures inducing a distinct vascular oscillation. These observations provide novel insights into the relationship between NVC and brain thermodynamics, with important implications for brain-temperature related therapies, functional biomarkers of elevated brain temperature, and in-vivo methods to study neurovascular coupling.