Common variation in NCAN, a risk factor for bipolar disorder and schizophrenia, influences local cortical folding in schizophrenia

Background Recent studies have provided strong evidence that variation in the gene neurocan (NCAN, rs1064395) is a common risk factor for bipolar disorder (BD) and schizophrenia. However, the possible relevance of NCAN variation to disease mechanisms in the human brain has not yet been explored. Thus, to identify a putative pathomechanism, we tested whether the risk allele has an influence on cortical thickness and folding in a well-characterized sample of patients with schizophrenia and healthy controls. Method Sixty-three patients and 65 controls underwent T1-weighted magnetic resonance imaging (MRI) and were genotyped for the single nucleotide polymorphism (SNP) rs1064395. Folding and thickness were analysed on a node-by-node basis using a surface-based approach (FreeSurfer). Results In patients, NCAN risk status (defined by AA and AG carriers) was found to be associated with higher folding in the right lateral occipital region and at a trend level for the left dorsolateral prefrontal cortex. Controls did not show any association (p>0.05). For cortical thickness, there was no significant effect in either patients or controls. Conclusions This study is the first to describe an effect of the NCAN risk variant on brain structure. Our data show that the NCAN risk allele influences cortical folding in the occipital and prefrontal cortex, which may establish disease susceptibility during neurodevelopment. The findings suggest that NCAN is involved in visual processing and top-down cognitive functioning. Both major cognitive processes are known to be disturbed in schizophrenia. Moreover, our study reveals new evidence for a specific genetic influence on local cortical folding in schizophreni

International Consensus Statement on Rhinology and Allergy: Rhinosinusitis

Background: The 5 years since the publication of the first International Consensus Statement on Allergy and Rhinology: Rhinosinusitis (ICAR‐RS) has witnessed foundational progress in our understanding and treatment of rhinologic disease. These advances are reflected within the more than 40 new topics covered within the ICAR‐RS‐2021 as well as updates to the original 140 topics. This executive summary consolidates the evidence‐based findings of the document. Methods: ICAR‐RS presents over 180 topics in the forms of evidence‐based reviews with recommendations (EBRRs), evidence‐based reviews, and literature reviews. The highest grade structured recommendations of the EBRR sections are summarized in this executive summary. Results: ICAR‐RS‐2021 covers 22 topics regarding the medical management of RS, which are grade A/B and are presented in the executive summary. Additionally, 4 topics regarding the surgical management of RS are grade A/B and are presented in the executive summary. Finally, a comprehensive evidence‐based management algorithm is provided. Conclusion: This ICAR‐RS‐2021 executive summary provides a compilation of the evidence‐based recommendations for medical and surgical treatment of the most common forms of RS

Correlation and sex differences between ankle and knee cartilage morphology determined by quantitative magnetic resonance imaging

Objective: To study the correlation between ankle and knee cartilage morphology to test the hypothesis that knee joint cartilage loss in gonarthritis can be estimated retrospectively using quantitative MRI analysis of the knee and ankle and established regression equations; and to test the hypothesis that sex differences in joint surface area are larger in the knee than the ankle, which may explain the greater incidence of knee osteoarthritis in elderly women than in elderly men. Methods: Sagittal MR images (3D FLASH WE) of the knee and hind foot were acquired in 29 healthy subjects (14 women, 15 men; mean (SD) age, 25 (3) years), with no signs joint disease. Cartilage volume, thickness, and joint surface area were determined in the knee, ankle, and subtalar joint. Results: Knee cartilage volumes and joint surface areas showed only moderate correlations with those of the ankle and subtalar joint (r = 0.33 to 0.81). The correlations of cartilage thickness between the two joints were weaker still (r = –0.05 to 0.53). Sex differences in cartilage morphology at the knee and the ankle were similar, with surface areas being –17.5% to –23.5% lower in women than in men. Conclusions: Only moderate correlations in cartilage morphology of healthy subjects were found between knee and ankle. It is therefore impractical to estimate knee joint cartilage loss a posteriori in cross sectional studies by measuring the hind foot and then applying a scaling factor. Sex differences in cartilage morphology do not explain differences in osteoarthritis incidence between men and women in the knee and ankle

Accuracy of 3D fluoro-navigated anterior transpedicular screws in the subaxial cervical spine: an experimental study on human specimens

Pedicle screw stabilization, the standard technique in the thoracic and lumbar spine, is increasingly used in the cervical spine. Initial studies on the use of anterior pedicle screws (ATPS) in the cervical spine have been recently published. ATPS use has theoretical advantages over posterior stabilization. We have already established a 3D-fluoroscopy navigation setup in a study of artificial bones. The aim of the current study was to evaluate the positioning quality/accuracy of ATPS introduced to human specimens. 36 cannulated screws (3.5 mm) were implanted anteriorly into the C3-C7 segments of four spines (unfixed, frozen, cadaveric specimens) using a 3D-fluoroscopy navigation system. Placement accuracy was evaluated using a recently published classification on postoperative CT scans. Grade 1 is perfect position with pedicle wall perforation 4 mm and/or transverse foramen entry. 36 anterior pedicle screws were inserted into four human cervical spine specimens. Of these, seven screws were introduced to C3, five to C4 and eight each to C5, C6, and C7. Classified with the modified G&R, 21 of 36 (58.3%) were grade 1. Ten screws (27.8%) were grade 2. Grade 4 was assessed for two screws and grade 5 for three. Customary good positioning, combining grades 1 and 2, was thus found in 86.1%. Five screws (13.9%) did not meet this criterion (grade ae3). With 86.1% of good positioning (grade 2 or better), a 3D-fluoroscopy navigation of ATPS screws into human c-spine specimens achieved a satisfying results. These are at least comparable to results presented in the literature for posteriorly introduced subaxial pedicle screws