Background Idiopathic normal pressure hydrocephalus (iNPH) is a neurodegenerative disease and dementia subtype involving disturbed cerebrospinal fluid (CSF) homeostasis. Patients with iNPH may improve clinically following CSF diversion through shunt surgery, but it remains a challenge to predict which patients respond to shunting. It has been proposed that CSF and blood biomarkers may be used to predict shunt response in iNPH. Objective To conduct a systematic review and meta-analysis to identify which CSF and venous biomarkers predict shunt-responsive iNPH most accurately. Methods Original studies that investigate the use of CSF and venous biomarkers to predict shunt response were searched using the following databases: Embase, MEDLINE, Scopus, PubMed, Google Scholar, and JSTOR. Included studies were assessed using the ROBINS-I tool, and eligible studies were evaluated utilising univariate meta-analyses. Results The study included 13 studies; seven addressed lumbar CSF levels of amyloid-β 1–42, nine studies CSF levels of Total-Tau, six studies CSF levels of Phosphorylated-Tau, and seven studies miscellaneous biomarkers, proteomics, and genotyping. A meta-analysis of six eligible studies conducted for amyloid-β 1–42, Total-Tau, and Phosphorylated-Tau demonstrated significantly increased lumbar CSF Phosphorylated-Tau (− 0.55 SMD, p = 0.04) and Total-Tau (− 0.50 SMD, p = 0.02) in shunt-non-responsive iNPH, though no differences were seen between shunt responders and non-responders for amyloid-β 1–42 (− 0.26 SMD, p = 0.55) or the other included biomarkers. Conclusion This meta-analysis found that lumbar CSF levels of Phosphorylated-Tau and Total-Tau are significantly increased in shunt non-responsive iNPH compared to shunt-responsive iNPH. The other biomarkers, including amyloid-β 1–42, did not significantly differentiate shunt-responsive from shunt-non-responsive iNPH. More studies on the Tau proteins examining sensitivity and specificity at different cut-off levels are needed for a robust analysis of the diagnostic efficiency of the Tau proteins.

Background Patients with the dementia subtype idiopathic normal pressure hydrocephalus (iNPH) may improve clinically following cerebrospinal fluid (CSF) diversion (shunt) surgery, though the predictors of shunt response remain debated. Currently, radiological features play an important role in the diagnosis of iNPH, but it is not well established which radiological markers most precisely predict shunt responsive iNPH. Objective To conduct a systematic review and meta-analysis to identify radiological predictors of shunt responsiveness, evaluate their diagnostic effectiveness, and recommend the most predictive radiological features. Methods Embase, MEDLINE, Scopus, PubMed, Google Scholar, and JSTOR were searched for original studies investigating radiological predictors of shunt response in iNPH patients. Included studies were assessed using the ROBINS-1 tool, and eligible studies were evaluated using a univariate meta-analysis. Results Overall, 301 full-text papers were screened, of which 28 studies were included, and 26 different radiological features were identified, 5 of these met the inclusion criteria for the meta-analysis: disproportionately enlarged subarachnoid space (DESH), callosal angle, periventricular white matter changes, cerebral blood flow (CBF), and computerized tomography cisternography. The meta-analysis showed that only callosal angle and periventricular white matter changes significantly differentiated iNPH shunt responders from non-responders, though both markers had a low diagnostic odds ratio (DOR) of 1.88 and 1.01 respectively. None of the other radiological markers differentiated shunt responsive from shunt non-responsive iNPH. Conclusion Callosal angle and periventricular changes are the only diagnostically effective radiological predictors of shunt responsive iNPH patients. However, due to the DORs approximating 1, they are insufficient as sole predictors and are advised to be used only in combination with other diagnostic tests of shunt response. Future research must evaluate the combined use of multiple radiological predictors, as it may yield beneficial additive effects that may allow for more robust radiological shunt response prediction.

Purpose To determine methods described in the literature to account for patients lost to follow-up (LTFU) in registry studies and whether rates of patient LTFU are within acceptable margins. Methods A scoping review, where a literature search is conducted for studies from 9 arthroscopy registries, was performed on EMBASE, MEDLINE, and the annual reports of each registry. Inclusion criteria included studies with information on patient-reported outcome measures and being based on 9 national registries identified. Exclusion criteria included review articles, conference abstracts, studies not based on registry data, and studies from regional, claims-based, or multicenter registries. Studies were then divided into categories based on method of LTFU analysis used. Results Thirty-six articles were identified for the final analysis. Categories for LTFU analysis included dropout analyses (n = 10), referencing validation studies (n = 12), contacting nonresponders (n = 4), and sensitivity analyses (n = 1). Referencing validation studies was the most common method (n = 12). Majority (n = 35) of the studies exceeded the recommended maximum rates for LTFU. Conclusions Registry studies use inconsistent methods to account for patient LTFU, and rates of patients LTFU are unacceptably high. Clinical Relevance The impact of patients LTFU in studies related to arthroscopic intervention is unknown. A universal method for accounting for patient follow-up is needed.

No abstract

Latif Khan et al 1 have highlighted absenteeism as an important issue amongst medical schools. Although the article originates from Pakistan, the authors state that this is a worldwide issue. The study focusses on lecture attendance. However, worldwide several teaching methods are employed including problem-based learning, team-based learning and video-recorded technologies. As UK medical students, we offer an alternative perspective on the conclusions of the study. We acknowledge several strengths of the study; however, we would like to share a few reflections. Given the range of teaching methods, it would have been appropriate to define the exact parameters of a lecture and therefore disclose the employment of other methods. We feel that this would provide a more holistic overview of student timetables, including total contact hours per week. Consequently, the relative importance of attending lectures compared to attending other teaching sessions for accruing appropriate skills and knowledge is unknown. If teaching occurred outside of lectures, the degree of absenteeism would not be accurate. Conversely, if solely lectures were employed, the conclusions drawn from this study may not be translatable to the rest of the world where other teaching methods are in place. Furthermore, although the study reaffirms the issue of absenteeism and suggests potential reasons, we feel it would have been more beneficial to determine reasons for absenteeism within the sample. This would be of use to identify student motivations and issues. Additionally, absenteeism may be a confounder for an underlying cause, such as mental health which has been shown to affect both academic performance 2 and attendance. 3 Therefore, enforcing mandatory attendance (as implied by the authors to be beneficial) could have a negative impact on these students. Major causes identified can then be addressed and rectified in order to improve both attendance and academic performance. The authors raise an important point of an increasing use of video-captured lectures and online self-learning resources. Alongside alternative teaching methods, we would like to further expand upon their impact on our learning experience. We feel the authors exaggerate the value of lectures, stating that students who do not attend lectures do not "foster a positive learning environment", "[accelerate] teamwork abilities" or increase "self-confidence". We find these claims to be overstated with a lack of supporting literature or poorly related references. From our experience, team-based learning and interactive group work better developed these skills.