Transforaminal versus posterior lumbar interbody fusion for symptomatic single-level spondylolisthesis (LIFT): a multicentre controlled, patient blinded, randomised non-inferiority trial.

Background: The effectiveness of transforaminal lumbar interbody fusion (TLIF) compared to posterior lumbar interbody fusion (PLIF) in patients with single-level spondylolisthesis has not been substantiated. To address the evidence gap, a well-powered randomized controlled non-inferiority trial comparing the effectiveness of TLIF with PLIF, entitled the Lumbar Interbody Fusion Trial (LIFT), was conducted. Methods: In a multicenter randomized controlled non-inferiority trial among five Dutch hospitals, 161 patients were randomly allocated to either TLIF or PLIF (1:1), stratified according to study site. Patients and statisticians were blinded for group assignment. All patients were over 18 years old with symptomatic single-level degenerative, isthmic or iatrogenic lumbar spondylolisthesis, and eligible for lumbar interbody fusion surgery through a posterior approach. The primary outcome was change in disability measured with the Oswestry Disability Index (ODI) from preoperative to one year postoperative. The non-inferiority limit was set to 7.0 points based on the MCID of ODI. Secondary outcomes were change in quality-adjusted life years (QALY) assessed with EuroQol 5 Dimensions, 5 Levels (EQ-5D-5L) and Short Form Health Survey (SF-36), as well as back and leg pain (Numerical rating scale, NRS), anxiety and depression (Hospital Anxiety Depression Scale; HADS), perioperative blood loss, duration of surgery, duration of hospitalization, and complications. Trial registration: Netherlands Trial Registry, number 5722 (registration date March 30, 2016), Lumbar Interbody Fusion Trial (LIFT): A randomized controlled multicenter trial for surgical treatment of lumbar spondylolisthesis. Findings: Patients were included between August 2017 and November 2020. The total study population was 161 patients. Total loss-to-follow-up after one year was 16 patients. Per-protocol analysis included 66 patients in each group. In the TLIF group (mean age 61.6, 36 females), ODI improved from 46.7 to 20.7, whereas in the PLIF group (mean age 61.9, 41 females), it improved from 46.0 to 24.9. This difference (-4.9, 90% CI -12.2 to +2.4) did not reach the non-inferiority limit of 7.0 points in ODI. A significant difference in the secondary outcome measurement, QALY (SF-36), was observed in favor of TLIF (P < 0.05). However, this was not clinically relevant. No difference was found for all other secondary outcome measurements; PROMs (EQ-5D, NRS leg/back, HADS), perioperative blood loss, duration of surgery, duration of hospitalization, and perioperative and postoperative complications. Interpretation: For patients with single-level spondylolisthesis, TLIF is non-inferior to PLIF in terms of clinical effectiveness. Disability (measured with ODI) did not differ over time between groups. Funding: No funding was received for this trial.

Dynamic Computed Tomography Angiography for capturing vessel wall motion: A phantom study for optimal image reconstruction.

BACKGROUND: Reliably capturing sub-millimeter vessel wall motion over time, using dynamic Computed Tomography Angiography (4D CTA), might provide insight in biomechanical properties of these vessels. This may improve diagnosis, prognosis, and treatment decision making in vascular pathologies. PURPOSE: The aim of this study is to determine the most suitable image reconstruction method for 4D CTA to accurately assess harmonic diameter changes of vessels. METHODS: An elastic tube (inner diameter 6 mm, wall thickness 2 mm) was exposed to sinusoidal pressure waves with a frequency of 70 beats-per-minute. Five flow amplitudes were set, resulting in increasing sinusoidal diameter changes of the elastic tube, measured during three simulated pulsation cycles, using ECG-gated 4D CTA on a 320-detector row CT system. Tomographic images were reconstructed using one of the following three reconstruction methods: hybrid iterative (Hybrid-IR), model-based iterative (MBIR) and deep-learning based (DLR) reconstruction. The three reconstruction methods where based on 180 degrees (half reconstruction mode) and 360 degrees (full reconstruction mode) raw data. The diameter change, captured by 4D CTA, was computed based on image registration. As a reference metric for diameter change measurement, a 9 MHz linear ultrasound transducer was used. The sum of relative absolute differences (SRAD) between the ultrasound and 4D CTA measurements was calculated for each reconstruction method. The standard deviation was computed across the three pulsation cycles. RESULTS: MBIR and DLR resulted in a decreased SRAD and standard deviation compared to Hybrid-IR. Full reconstruction mode resulted in a decreased SRAD and standard deviations, compared to half reconstruction mode. CONCLUSIONS: 4D CTA can capture a diameter change pattern comparable to the pattern captured by US. DLR and MBIR algorithms show more accurate results than Hybrid-IR. Reconstruction with DLR is >3 times faster, compared to reconstruction with MBIR. Full reconstruction mode is more accurate than half reconstruction mode.

Adverse effects of frailty on the outcomes of surgery for degenerative cervical myelopathy: results from a prospective multicenter international data set of 757 patients.

OBJECTIVE: The goal of this study was to determine the effect of the degree of frailty on long-term neurological and functional outcomes after surgery for degenerative cervical myelopathy (DCM). METHODS: A combined database of patients enrolled in the Cervical Spondylotic Myelopathy-North America and Cervical Spondylotic Myelopathy-International prospective international multicenter observational studies who underwent surgery for DCM was used as the source data. All patients underwent baseline and follow-up assessment at 2 years after surgery for functional, disability, and quality of life measurements (modified Japanese Orthopaedic Association [mJOA] scale, Neck Disability Index, SF-36 physical and mental component summary scores). Patients were separated into 4 groups according to their baseline modified frailty index 5-point scale score: not frail, pre-frail, frail, and severely frail. Differences among groups were analyzed at baseline and at 2 years after surgery, including change in scores (delta values) and the odds ratio of achieving the minimum clinically important difference (MCID) through univariate and multivariable logistic regression adjusting for age, approach, number of levels treated, and sex. RESULTS: A total of 757 patients (63% male) with a mean age of 56 (95% CI 55.5-57.2) years were included: 470 patients underwent an anterior approach, 310 had a posterior approach, and 23 had a combined anterior/posterior approach. A total of 50% (n = 378) of patients were classified as not frail, with 33% (n = 250) pre-frail, 13% (n = 101) frail, and 4% (n = 28) severely frail. The baseline mJOA score was significantly lower with increasing frailty (14.00 [95% CI 13.75-14.19] for not frail vs 9.71 [95% CI 9.01-10.42] for severely frail patients; p < 0.05), but the change at 2 years was not significantly different among all groups (2.43 [95% CI 2.16-2.71] for not frail vs 2.56 [95% CI 1.10-4.02] for severely frail). The SF-36 delta values were also not different among groups, but significantly worse at baseline with increasing frailty. The odds ratio of achieving MCID for mJOA was significantly higher in the not frail group (1.89 [95% CI 1.36-2.61]; p < 0.05) compared to the other frailty cohorts, which remained after adjusting for age, approach, levels treated, and sex. The odds ratio of achieving MCID for the SF-36 domains was similar among all frailty groups. CONCLUSIONS: Increasing frailty is associated with worse baseline functional and quality of life measures in patients undergoing surgery for DCM. Frailty does not affect the magnitude of improvement in outcome measures after surgery, but reduces the chance of achieving the MCID for functional impairment significantly. Preoperative frailty assessment can therefore help guide clinicians in managing expectations after surgery for DCM. Potentially modifiable factors should be optimized in frail patients preoperatively to enhance functional outcomes.

Augmented reality-The way forward in patient education for intracranial aneurysms? A qualitative exploration of views, expectations and preferences of patients suffering from an unruptured intracranial aneurysm regarding augmented reality in patient education.

Objectives: The goal of this project is to explore the views, expectations and preferences of patients with an unruptured intracranial aneurysm regarding the use of AR in patient education. Methods: To gain an in-depth understanding of the patients' perspective, a face-to-face interview study was conducted using an interview protocol with a predefined topic list. All interviews were audio-recorded and transcribed verbatim afterwards. Transcripts were analyzed using thematic content analyses. Coding was performed using Atlas.ti software. Results: Seventeen interviews were conducted. The views, expectations and preferences of patients regarding patient education with AR could be subdivided into 15 categories, which could be grouped into 4 general themes: 1) experiences with current patient education, 2) expectations of AR in patient education, 3) opportunities and limitations of AR, and 4) out-of-hospital use of an AR application. Patients' expectations were predominantly positive regarding improving patients' understanding of their medical situation and doctor-patient communication. Discusssion: This study suggests that patients with unruptured intracranial aneurysms are open to receive patient education regarding their disease with AR. Patients expect that AR models can help patients with intra-cranial aneurysms better understand their disease, treatment options and risks. Additionally, patients expect AR could improve doctor-patient communication.

Does spinal cord stimulation improve gait in Parkinson's disease: A comprehensive review.

INTRODUCTION: Axial disability, including gait disturbances, is common in Parkinson's disease (PD), especially in advanced stages. Epidural spinal cord stimulation (SCS) has been investigated as a treatment option for gait disorders in PD. Here, we review the literature on SCS in PD and evaluate its efficacy, optimal stimulation parameters, optimal electrode locations, possible effects of concurrent deep brain stimulation, and possible working mechanisms on gait. METHODS: Databases were searched for human studies involving PD patients who received an epidural SCS intervention and who had at least one gait-related outcome measure. The included reports were reviewed with respect to design and outcomes. Additionally, the possible mechanisms of action underlying SCS were reviewed. RESULTS: Out of 433 records identified, 25 unique studies with in total 103 participants were included. Most studies included only a few participants. The gait disorders of most PD patients with concurrent pain complaints, mostly low back pain, improved with SCS in almost all cases, regardless of stimulation parameters or electrode location. Higher-frequency stimulation (>200 Hz) seemed to be more effective in pain-free PD patients, but the results were inconsistent. Heterogeneity in outcome measures and follow-up times hindered comparability. CONCLUSIONS: SCS may improve gait in PD patients with neuropathic pain, but its efficacy in pain-free patients remains uncertain due to a lack of thorough double-blind studies. Apart from a well-powered, controlled, double-blind study design, future studies could further explore the initial hints that higher-frequency stimulation (>200 Hz) might be the best approach to improve gait outcomes in pain-free patients.

Conservative Treatment of Ulnar Nerve Compression at the Elbow: A Systematic Review and Meta-Analysis.

Background The clinical results of conservative treatment options for ulnar compression at the elbow have not been clearly determined. The aim of this review was to evaluate available conservative treatment options and their effectiveness for ulnar nerve compression at the elbow. Methods In accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) recommendations, a systematic review and meta-analysis of studies was performed. Literature search was performed using Ovid MEDLINE, Embase, and Cochrane Central Register of Controlled Trials (CENTRAL). Results Of the 1,079 retrieved studies, 20 were eligible for analysis and included 687 cases of ulnar neuropathy at the elbow. Improvement of symptoms was reported in 54% of the cases receiving a steroid/lidocaine injection (95% confidence interval [CI], 41-67) and in 89% of the cases using a splint device (95% CI, 69-99). Conclusions Conservative management seems to be effective. Both lidocaine/steroid injections and splint devices gave a statistically significant improvement of symptoms and are suitable options for patients who refuse an operative procedure or need a bridge to their surgery. Splinting is preferred over injections, as it shows a higher rate of improvement.

Design recommendations for exoskeletons: Perspectives of individuals with spinal cord injury.

OBJECTIVE: This study investigated the expectations of individuals with spinal cord injury (SCI) regarding exoskeletons. DESIGN: The survey consisted out of questions regarding multiple aspects of exoskeleton technology. SETTING: An online survey was distributed via the monthly newsletter of the Dutch Patient Association for Spinal Cord Injury (SCI). PARTICIPANTS: Individuals with SCI who are members of the Dutch Patient Association for SCI. OUTCOME MEASURES: General impression of exoskeleton technology, expectations regarding capabilities and user-friendliness, training expectations and experiences, future perspectives and points of improvement. RESULTS: The survey was filled out by 95 individuals with SCI, exoskeletons were considered positive and desirable by 74.7%. About 11 percent (10.5%) thought one could ambulate faster, or just as fast, while wearing an exoskeleton as able-bodied people. Furthermore, 18.9% expected not to use a wheelchair or walking aids while ambulating with the exoskeleton. Twenty-five percent believed that exoskeletons could replace wheelchairs. Some main points of improvement included being able to wear the exoskeleton in a wheelchair and while driving a car, not needing crutches while ambulating, and being able to put the exoskeleton on by oneself. CONCLUSION: Individuals with SCI considered exoskeletons as a positive and desirable innovation. But based on the findings from the surveys, major points of improvement are necessary for exoskeletons to replace wheelchairs in the future. For future exoskeleton development, we recommend involvement of individuals with SCI to meet user expectations and improve in functionality, usability and quality of exoskeletons.

Outcomes After Lumbar Disk Herniation Surgery in the Dutch Population.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: There is only limited data on the outcome of primary surgery of lumbar disk herniation (LDH) in Dutch patients. The objective of this study is to describe undesirable outcomes after primary LDH. METHODS: The National Claims Database (Vektis) was searched for primary LDH operations performed from July 2015 until June 2016, for reoperations within 18 months, prescription of opioids between 6 to 12 months and nerve root block within 1 year. A combined outcome measure was also made. Group comparisons were analyzed with the Student's t-test. RESULTS: Primary LDH surgery was performed in 6895 patients in 70 hospitals. Weighted mean of reoperations was 7.3%, nerve root block 6.7% and opioid use 15.6%. In total, 23.0% of patients had one or more undesirable outcomes after surgery. The 95% CI interval exceeded the 50% incidence line for 14 out of 26 hospitals with less than 50 surgical interventions per year. Although the data suggested a volume effect on undesired outcomes, the t-tests between hospitals with volume thresholds of 100, 150 and 200 interventions per year did not support this (P values 0.078, 0.129, 0.114). CONCLUSION: This unique nationwide claims-based study provides insight into patient-relevant undesirable outcomes such as reoperation, nerve root block and opioid use after LDH surgery. About a quarter of the patients had a serious complication in the first follow up year that prompted further medical treatment. There is a wide variation in complication rates between hospitals with a trend that supports concentration of LDH care.

Safety and efficacy of the eCLIPs bifurcation remodelling system for the treatment of wide necked bifurcation aneurysms: 1 year results from the European eCLIPs Safety, Feasibility, and Efficacy Study (EESIS).

BACKGROUND: The eCLIPs bifurcation remodelling system is a non-circumferential implant that bridges the neck from outside of a bifurcation aneurysm. The goal of the multicenter, post-marketing European eCLIPs Safety, FeasIbility, and Efficacy Study (EESIS), was to present the efficacy and safety results of the eCLIPs device after 365 days of follow-up. METHODS: All patients were to receive an eCLIPs in conjunction with coils. The study was conducted according to good clinical practices and included independent adjudication of safety and efficacy outcomes. RESULTS: Twenty patients were enrolled at four European centers. Mean age was 60 years (range 41-74) and aneurysms were located at the basilar tip (n=19) and carotid tip (n=1). Average aneurysm dome height was 6.0 mm (range 2.0-15.0). Mean neck length was 5.1 mm (range 2.6-8.5). The technical success rate was 90% (18 of 20). No major territorial strokes or deaths occurred between the index procedure and after 365 days of follow-up. Complete occlusion was achieved in 60% of patients (12 of 20 patients) and 67% of patients with an eCLIPs device (12 of 18) after 365 days of follow-up. Adequate occlusion (complete occlusion and neck remnant) was achieved in 80% of patients (16 of 20 patients) and 89% of patients with an eCLIPs device (16 of 18 patients) after 365 days of follow-up. CONCLUSION: In this small series, treatment with eCLIPs was feasible, safe, and efficacious, considering the challenging nature of the aneurysms. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov NCT02607501.

Noninferiority of Posterior Cervical Foraminotomy vs Anterior Cervical Discectomy With Fusion for Procedural Success and Reduction in Arm Pain Among Patients With Cervical Radiculopathy at 1 Year: The FACET Randomized Clinical Trial.

Importance: The choice between posterior cervical foraminotomy (posterior surgery) and anterior cervical discectomy with fusion (anterior surgery) for cervical foraminal radiculopathy remains controversial. Objective: To investigate the noninferiority of posterior vs anterior surgery in patients with cervical foraminal radiculopathy with regard to clinical outcomes after 1 year. Design, Setting, and Participants: This multicenter investigator-blinded noninferiority randomized clinical trial was conducted from January 2016 to May 2020 with a total follow-up of 2 years. Patients were included from 9 hospitals in the Netherlands. Of 389 adult patients with 1-sided single-level cervical foraminal radiculopathy screened for eligibility, 124 declined to participate or did not meet eligibility criteria. Patients with pure axial neck pain without radicular pain were not eligible. Of 265 patients randomized (132 to posterior and 133 to anterior), 15 were lost to follow-up and 228 were included in the 1-year analysis (110 in posterior and 118 in anterior). Interventions: Patients were randomly assigned 1:1 to posterior foraminotomy or anterior cervical discectomy with fusion. Main Outcomes and Measures: Primary outcomes were proportion of success using Odom criteria and decrease in arm pain using a visual analogue scale from 0 to 100 with a noninferiority margin of 10% (assuming advantages with posterior surgery over anterior surgery that would justify a tolerable loss of efficacy of 10%). Secondary outcomes were neck pain, disability, quality of life, work status, treatment satisfaction, reoperations, and complications. Analyses were performed with 2-proportion z tests at 1-sided .05 significance levels with Bonferroni corrections. Results: Among 265 included patients, the mean (SD) age was 51.2 (8.3) years; 133 patients (50%) were female and 132 (50%) were male. Patients were randomly assigned to posterior (132) or anterior (133) surgery. The proportion of success was 0.88 (86 of 98) in the posterior surgery group and 0.76 (81 of 106) in the anterior surgery group (difference, -0.11 percentage points; 1-sided 95% CI, -0.01) and the between-group difference in arm pain was -2.8 (1-sided 95% CI, -9.4) at 1-year follow-up, indicating noninferiority of posterior surgery. Decrease in arm pain had a between-group difference of 3.4 (1-sided 95% CI, 11.8), crossing the noninferiority margin with 1.8 points. All secondary outcomes had 2-sided 95% CIs clustered around 0 with small between-group differences. Conclusions and Relevance: In this randomized clinical trial, posterior surgery was noninferior to anterior surgery for patients with cervical radiculopathy regarding success rate and arm pain at 1 year. Decrease in arm pain and secondary outcomes had small between-group differences. These results may be used to enhance shared decision-making. Trial Registration: Netherlands Trial Register Identifier: NTR5536.

The type of cervical disc herniation on MRI does not correlate to clinical outcomes.

AIMS: The aim of this study was to investigate whether the type of cervical disc herniation influences the severity of symptoms at the time of presentation, and the outcome after surgical treatment. METHODS: The type and extent of disc herniation at the time of presentation in 108 patients who underwent anterior discectomy for cervical radiculopathy were analyzed on MRI, using a four-point scale. These were dichotomized into disc bulge and disc herniation groups. Clinical outcomes were evaluated using the Neck Disability Index (NDI), 36-Item Short Form Survey (SF-36), and a visual analogue scale (VAS) for pain in the neck and arm at baseline and two years postoperatively. The perceived recovery was also assessed at this time. RESULTS: At baseline, 46 patients had a disc bulge and 62 had a herniation. There was no significant difference in the mean NDI and SF-36 between the two groups at baseline. Those in the disc bulge group had a mean NDI of 44.6 (SD 15.2) compared with 43.8 (SD 16.0) in the herniation group (p = 0.799), and a mean SF-36 of 59.2 (SD 6.9) compared with 59.4 (SD 7.7) (p = 0.895). Likewise, there was no significant difference in the incidence of disabling arm pain in the disc bulge and herniation groups (84% vs 73%; p = 0.163), and no significant difference in the incidence of disabling neck pain in the two groups (70.5% (n = 31) vs 63% (n = 39); p = 0.491). At two years after surgery, no significant difference was found in any of the clinical parameters between the two groups. CONCLUSION: In patients with cervical radiculopathy, the type and extent of disc herniation measured on MRI prior to surgery correlated neither to the severity of the symptoms at presentation, nor to clinical outcomes at two years postoperatively.Cite this article: Bone Joint J 2022;104-B(11):1242-1248.

Non-adjustable gravitational valves or adjustable valves in the treatment of hydrocephalus after aneurysmal subarachnoid hemorrhage patients?

PURPOSE: Hydrocephalus requiring permanent CSF shunting after aneurysmal subarachnoid hemorrhage (aSAH) is frequent. It is unknown which type of valve is optimal. This study evaluates if the revision rate of gravitational differential pressure valves (G-DPVs, GAV® system (B Braun)) (G-DPV) is comparable to adjustable pressure valves (Codman Medos Hakim) (APV) in the treatment of post-aSAH hydrocephalus. METHODS: The use of a gravitational differential pressure valve is placed in direct comparison with an adjustable pressure valve system. A retrospective chart review is performed to compare the revision rates for the two valve systems. RESULTS: Within the registry from Radboud University Medical Center, 641 patients with a SAH could be identified from 1 January 2013 until 1 January 2019, whereas at the Heinrich Heine University, 617 patients were identified, totaling 1258 patients who suffered from aSAH. At Radboud University Medical Center, a gravitational differential pressure valve is used, whereas at the Heinrich Heine University, an adjustable pressure valve system is used. One hundred sixty-six (13%) patients required permanent ventricular peritoneal or atrial shunting. Shunt dysfunction occurred in 36 patients: 13 patients of the 53 (25%) of the gravitational shunt cohort, and in 23 of the 113 (20%) patients with an adjustable shunt (p = 0.54). Revision was performed at a mean time of 3.2 months after implantation with the gravitational system and 8.2 months with the adjustable shunt system. Combined rates of over- and underdrainage leading to revision were 7.5% (4/53) for the gravitational and 3.5% (4/113) for the adjustable valve system (p = 0 .27). CONCLUSION: The current study does not show a benefit of a gravitational pressure valve (GAV® system) over an adjustable pressure valve (CODMAN ® HAKIM®) in the treatment of post-aSAH hydrocephalus. The overall need for revision is high and warrants further improvements in care.

The Role of Microelectrode Recording in Deep Brain Stimulation Surgery for Parkinson's Disease: A Systematic Review and Meta-Analysis.

BACKGROUND: STN-DBS is a cornerstone in the treatment of advanced Parkinson's disease (PD). The traditional approach is to use an awake operative technique with microelectrode recording (MER). However, more centers start using an asleep MRI-guided technique without MER. OBJECTIVE: We systematically reviewed the literature to compare STN-DBS surgery with and without MER for differences in clinical outcome. METHODS: We systematically searched PubMed, Embase, MEDLINE, and Web of Science databases for randomized clinical trials and consecutive cohort studies published between 01-01-2000 and 26-08-2021, that included at least 10 PD patients who had received bilateral STN-DBS. RESULTS: 2,129 articles were identified. After abstract screening and full-text review, 26 studies were included in the final analysis, comprising a total of 34 study groups (29 MER and 5 non-MER). The standardized mean difference (SMD) in change in motor symptoms between baseline (OFF medication) and 6-24 months follow-up (OFF medication and ON stimulation) was 1.64 for the MER group and 1.87 for non-MER group (p = 0.59). SMD in change in levodopa equivalent daily dose (LEDD) was 1.14 for the MER group and 0.65 for non-MER group (p < 0.01). Insufficient data were available for comparative analysis of PDQ-39 and complications. CONCLUSION: The change in motor symptoms from baseline to follow-up did not differ between studies that used MER and those that did not. The postoperative reduction in LEDD from baseline to follow-up was greater in the MER-group. In the absence of high-quality studies comparing both methods, there is a clear need for a well-designed comparative trial.

Gender Distribution in Deep Brain Stimulation for Parkinson's Disease: The Effect of Awake versus Asleep Surgery.

There is evidence that men are more likely to undergo deep brain stimulation (DBS) for Parkinson's disease (PD), suggesting that women are relatively undertreated. 121 consecutive PD patients undergoing awake DBS with microelectrode recording and intraoperative clinical testing (30 patients, 5 women) or asleep MRI-guided and CT-verified (91 patients, 38 women) bilateral subthalamic nucleus DBS were included in this study. The results showed an increase in the proportion of female patients from 16.7% to 41.8% after changing our operative technique (OR = 5.61; 95% CI: 1.52-20.78; p = 0.010) from awake to asleep, suggesting that women are more likely to undergo DBS when operated asleep.

Evaluation of the Use of P Values in Neurosurgical Literature: from Statistical Significance to Clinical Irrelevance.

The application and interpretation of P values have caused debate for several decades, and this debate has become particularly relevant in the past few years. The P value represents the probability of seeing results as extreme or more extreme than those observed in a data analysis, were the null hypothesis and other underlying assumptions to be true. While P values are useful in pointing out where an effect may be present, they have often been misused in an attempt to oversell "statistically significant" findings. As P values rely on the spread and number of measurements, a smaller P value does not necessarily imply a larger effect size, which is better assessed via an effect estimate and confidence interval interpreted in the context of the study. The clinical relevance of a computed P value is context dependent. We investigated the current use of P values in a small sample of recent neurosurgical literature. Only a minority of manuscripts that reported statistical significance described confounder adjustment, or effect sizes. A common, incorrect assumption often observed was that statistical significance equals clinical relevance. To enable correct interpretation of clinical significance, it is crucial that authors describe the clinical implications of their findings.

Influence of Industry in Hydrocephalus and Vertebral Augmentation Literature.

OBJECTIVE: To investigate whether financial bias exists in hydrocephalus and vertebral augmentation literature. METHODS: A systematic literature search was performed in PubMed of studies concerning vertebral augmentation and cerebrospinal fluid valves. The relationship between reported conflicts of interest and the nature of the conclusion (positive vs. neutral and negative) was analyzed. RESULTS: Having a conflict of interest was significantly associated with reporting a positive conclusion in studies investigating valves for hydrocephalus (92.3% positive conclusion vs. 36.4%; P = 0.001), but not for cement augmentation studies (80.5% positive conclusion vs. 65.7%; P = 0.087). As studies concerning vertebral augmentation implants had only positive conclusions, no analysis could be performed. CONCLUSIONS: Our findings suggest a positive relationship between reported conflict of interest and positive outcome in neurosurgical literature concerning cerebrospinal fluid valves.

The Role of Microelectrode Recording and Stereotactic Computed Tomography in Verifying Lead Placement During Awake MRI-Guided Subthalamic Nucleus Deep Brain Stimulation for Parkinson's Disease.

BACKGROUND: Bilateral deep brain stimulation of the subthalamic nucleus (STN-DBS) has become a cornerstone in the advanced treatment of Parkinson's disease (PD). Despite its well-established clinical benefit, there is a significant variation in the way surgery is performed. Most centers operate with the patient awake to allow for microelectrode recording (MER) and intraoperative clinical testing. However, technical advances in MR imaging and MRI-guided surgery raise the question whether MER and intraoperative clinical testing still have added value in DBS-surgery. OBJECTIVE: To evaluate the added value of MER and intraoperative clinical testing to determine final lead position in awake MRI-guided and stereotactic CT-verified STN-DBS surgery for PD. METHODS: 29 consecutive patients were analyzed retrospectively. Patients underwent awake bilateral STN-DBS with MER and intraoperative clinical testing. The role of MER and clinical testing in determining final lead position was evaluated. Furthermore, interobserver variability in determining the MRI-defined STN along the planned trajectory was investigated. Clinical improvement was evaluated at 12 months follow-up and adverse events were recorded. RESULTS: 98% of final leads were placed in the central MER-track with an accuracy of 0.88±0.45 mm. Interobserver variability of the MRI-defined STN was 0.84±0.09. Compared to baseline, mean improvement in MDS-UPDRS-III, PDQ-39 and LEDD were 26.7±16.0 points (54%) (p < 0.001), 9.0±20.0 points (19%) (p = 0.025), and 794±434 mg/day (59%) (p < 0.001) respectively. There were 19 adverse events in 11 patients, one of which (lead malposition requiring immediate postoperative revision) was a serious adverse event. CONCLUSION: MER and intraoperative clinical testing had no additional value in determining final lead position. These results changed our daily clinical practice to an asleep MRI-guided and stereotactic CT-verified approach.

Correction: Protocol of the Healthy Brain Study: An accessible resource for understanding the human brain and how it dynamically and individually operates in its bio-social context.

[This corrects the article DOI: 10.1371/journal.pone.0260952.].

Time trends in the risk of delayed cerebral ischemia after subarachnoid hemorrhage: a meta-analysis of randomized controlled trials.

OBJECTIVE: Delayed cerebral ischemia (DCI) contributes to morbidity and mortality after aneurysmal subarachnoid hemorrhage (aSAH). Continuous improvement in the management of these patients, such as neurocritical care and aneurysm repair, may decrease the prevalence of DCI. In this study, the authors aimed to investigate potential time trends in the prevalence of DCI in clinical studies of DCI within the last 20 years. METHODS: PubMed, Embase, and the Cochrane library were searched from 2000 to 2020. Randomized controlled trials that reported clinical (and radiological) DCI in patients with aSAH who were randomized to a control group receiving standard care were included. DCI prevalence was estimated by means of random-effects meta-analysis, and subgroup analyses were performed for the DCI sum score, Fisher grade, clinical grade on admission, and aneurysm treatment method. Time trends were evaluated by meta-regression. RESULTS: The search strategy yielded 5931 records, of which 58 randomized controlled trials were included. A total of 4424 patients in the control arm were included. The overall prevalence of DCI was 0.29 (95% CI 0.26-0.32). The event rate for prevalence of DCI among the high-quality studies was 0.30 (95% CI 0.25-0.34) and did not decrease over time (0.25% decline per year; 95% CI -2.49% to 1.99%, p = 0.819). DCI prevalence was higher in studies that included only higher clinical or Fisher grades, and in studies that included only clipping as the treatment modality. CONCLUSIONS: Overall DCI prevalence in patients with aSAH was 0.29 (95% CI 0.26-0.32) and did not decrease over time in the control groups of the included randomized controlled trials.

Outcomes after Flow Diverter Treatment in Subarachnoid Hemorrhage: A Meta-Analysis and Development of a Clinical Prediction Model (OUTFLOW).

BACKGROUND: patients with a subarachnoid hemorrhage (SAH) might need a flow diverter (FD) placement for complex acutely ruptured intracranial aneurysms (IAs). We conducted a meta-analysis and developed a prediction model to estimate the favorable clinical outcome after the FD treatment in acutely ruptured IAs. METHODS: a systematic literature search was performed from 2010 to January 2021 in PubMed and Embase databases. Studies with more than five patients treated with FDs within fifteen days were included. In total, 1157 studies were identified. The primary outcome measure was the favorable clinical outcome (mRS 0-2). Secondary outcome measures were complete occlusion rates, aneurysm rebleeding, permanent neurologic deficit caused by procedure-related complications, and all-cause mortality. A prediction model was constructed using individual patient-level data. RESULTS: 26 retrospective studies with 357 patients and 368 aneurysms were included. The pooled rates of the favorable clinical outcome, mortality, and complete aneurysm occlusion were 73.7% (95% CI 64.7-81.0), 17.1% (95% CI 13.3-21.8), and 85.6% (95% CI 80.4-89.6), respectively. Rebleeding occurred in 3% of aneurysms (11/368). The c-statistic of the final model was 0.83 (95% CI 0.76-0.89). All the studies provided a very low quality of evidence. CONCLUSIONS: FD treatment can be considered for complex ruptured IAs. Despite high complication rates, the pooled clinical outcomes seem favorable. The prediction model needs to be validated by larger prospective studies before clinical application.