Nevin Manimala

BMJ Open Ophthalmol. 2022 Apr 1;7(1):e000929. doi: 10.1136/bmjophth-2021-000929. eCollection 2022.

ABSTRACT

Myopia is a global healthcare concern and effective analyses of dioptric power are important in evaluating potential treatments involving surgery, orthokeratology, drugs such as low-dose (0.05%) atropine and gene therapy. This paper considers issues of concern when analysing refractive state such as data normality, transformations, outliers and anisometropia. A brief review of methods for analysing and representing dioptric power is included but the emphasis is on the optimal approach to understanding refractive state (and its variation) in addressing pertinent clinical and research questions. Although there have been significant improvements in the analysis of refractive state, areas for critical consideration remain and the use of power matrices as opposed to power vectors is one such area. Another is effective identification of outliers in refractive data. The type of multivariate distribution present with samples of dioptric power is often not considered. Similarly, transformations of samples (of dioptric power) towards normality and the effects of such transformations are not thoroughly explored. These areas (outliers, normality and transformations) need further investigation for greater efficacy and proper inferences regarding refractive error. Although power vectors are better known, power matrices are accentuated herein due to potential advantages for statistical analyses of dioptric power such as greater simplicity, completeness, and improved facility for quantitative and graphical representation of refractive state.

PMID:35452207 | PMC:PMC8977790 | DOI:10.1136/bmjophth-2021-000929

J Clin Neurophysiol. 2021 Oct 12. doi: 10.1097/WNP.0000000000000902. Online ahead of print.

ABSTRACT

PURPOSE: During intraoperative neurophysiological monitoring of motor pathways, two types of transcranial electrical stimulation are available, i.e., constant-current and constant-voltage stimulation. Few previous studies, performed only during spinal surgery, analyzed and compared them during intraoperative neurophysiological monitoring. The aim of our study was to compare these two stimulation techniques for eliciting motor-evoked potentials during intraoperative neurophysiological monitoring in a group of patients affected by supratentorial lesions.

METHODS: Supratentorial lesions from 16 patients were retrospectively collected and analyzed. Motor-evoked potentials were performed only from transcranial electrical stimulation because the inability to place the subdural strip electrodes correctly did not permit to perform direct cortical stimulation. At the beginning of surgery, in each patient, motor-evoked potentials were monitored by using both “fast-charge” constant-voltage and “slow-charge” constant-current stimulation. Several neurophysiological parameters were collected and compared between the two stimulation techniques by means of statistical analysis.

RESULTS: “Fast-charge” constant-voltage stimulation allowed statistically higher efficiency rates for eliciting motor-evoked potentials compared with “slow-charge” constant-current stimulation, both for upper and lower limbs. We also found that threshold and maximal charge as well as charge density were significantly lower during constant-voltage stimulation, thus lowering the potential tissue damage.

CONCLUSIONS: “Fast-charge” constant-voltage transcranial electrical stimulation is feasible and safe during intraoperative neurophysiological monitoring for supratentorial surgery and may be preferable to “slow-charge” constant-current stimulation.

PMID:35452204 | DOI:10.1097/WNP.0000000000000902

Neuroradiology. 2022 Apr 22. doi: 10.1007/s00234-022-02958-1. Online ahead of print.

ABSTRACT

PURPOSE: The aim of the study was to assess the prevalence and characteristics of spinal cord cavernous malformations (SCCM) and intraosseous spinal vascular malformations (ISVM) in a pediatric familial cerebral cavernous malformation (FCCM) cohort and evaluate clinico-radiological differences between children with (SCCM +) and without (SCCM-) SCCM.

METHODS: All patients with a pediatric diagnosis of FCCM evaluated at three tertiary pediatric hospitals between January 2010 and August 2021 with [Formula: see text] 1 whole spine MR available were included. Brain and spine MR studies were retrospectively evaluated, and clinical and genetic data collected. Comparisons between SCCM + and SCCM- groups were performed using student-t/Mann-Whitney or Fisher exact tests, as appropriate.

RESULTS: Thirty-one children (55% boys) were included. Baseline spine MR was performed (mean age = 9.7 years) following clinical manifestations in one subject (3%) and as a screening strategy in the remainder. Six SCCM were detected in five patients (16%), in the cervico-medullary junction (n = 1), cervical (n = 3), and high thoracic (n = 2) regions, with one appearing during follow-up. A tendency towards an older age at first spine MR (P = 0.14) and [Formula: see text] 1 posterior fossa lesion (P = 0.13) was observed in SCCM + patients, lacking statistical significance. No subject demonstrated ISVM.

CONCLUSION: Although rarely symptomatic, SCCM can be detected in up to 16% of pediatric FCCM patients using diverse spine MR protocols and may appear de novo. ISVM were instead absent in our cohort. Given the relative commonality of asymptomatic SCCM, serial screening spine MR should be considered in FCCM starting in childhood.

PMID:35451625 | DOI:10.1007/s00234-022-02958-1

Alzheimers Dement. 2022 Apr 22. doi: 10.1002/alz.12663. Online ahead of print.

ABSTRACT

INTRODUCTION: We examined whether German claims data are suitable for dementia risk prediction, how machine learning (ML) compares to classical regression, and what the important predictors for dementia risk are.

METHODS: We analyzed data from the largest German health insurance company, including 117,895 dementia-free people age 65+. Follow-up was 10 years. Predictors were: 23 age-related diseases, 212 medical prescriptions, 87 surgery codes, as well as age and sex. Statistical methods included logistic regression (LR), gradient boosting (GBM), and random forests (RFs).

RESULTS: Discriminatory power was moderate for LR (C-statistic = 0.714; 95% confidence interval [CI] = 0.708-0.720) and GBM (C-statistic = 0.707; 95% CI = 0.700-0.713) and lower for RF (C-statistic = 0.636; 95% CI = 0.628-0.643). GBM had the best model calibration. We identified antipsychotic medications and cerebrovascular disease but also a less-established specific antibacterial medical prescription as important predictors.

DISCUSSION: Our models from German claims data have acceptable accuracy and may provide cost-effective decision support for early dementia screening.

PMID:35451562 | DOI:10.1002/alz.12663

Hum Brain Mapp. 2022 Apr 22. doi: 10.1002/hbm.25878. Online ahead of print.

ABSTRACT

One important approach to human brain mapping is to define a set of distinct regions that can be linked to unique functions. Numerous brain parcellations have been proposed, using cytoarchitectonic, structural, or functional magnetic resonance imaging (fMRI) data. The intrinsic smoothness of brain data, however, poses a problem for current methods seeking to compare different parcellations. For example, criteria that simply compare within-parcel to between-parcel similarity provide even random parcellations with a high value. Furthermore, the evaluation is biased by the spatial scale of the parcellation. To address this problem, we propose the distance-controlled boundary coefficient (DCBC), an unbiased criterion to evaluate discrete parcellations. We employ this new criterion to evaluate existing parcellations of the human neocortex in their power to predict functional boundaries for an fMRI data set with many different tasks, as well as for resting-state data. We find that common anatomical parcellations do not perform better than chance, suggesting that task-based functional boundaries do not align well with sulcal landmarks. Parcellations based on resting-state fMRI data perform well; in some cases, as well as a parcellation defined on the evaluation data itself. Finally, multi-modal parcellations that combine functional and anatomical criteria perform substantially worse than those based on functional data alone, indicating that functionally homogeneous regions often span major anatomical landmarks. Overall, the DCBC advances the field of functional brain mapping by providing an unbiased metric that compares the predictive ability of different brain parcellations to define brain regions that are functionally maximally distinct.

PMID:35451538 | DOI:10.1002/hbm.25878

Genet Epidemiol. 2022 Apr 22. doi: 10.1002/gepi.22453. Online ahead of print.

ABSTRACT

Genetic association studies of child health outcomes often employ family-based study designs. One of the most popular family-based designs is the case-parent trio design that considers the smallest possible nuclear family consisting of two parents and their affected child. This trio design is particularly advantageous for studying relatively rare disorders because it is less prone to type 1 error inflation due to population stratification compared to population-based study designs (e.g., case-control studies). However, obtaining genetic data from both parents is difficult, from a practical perspective, and many large studies predominantly measure genetic variants in mother-child dyads. While some statistical methods for analyzing parent-child dyad data (most commonly involving mother-child pairs) exist, it is not clear if they provide the same advantage as trio methods in protecting against population stratification, or if a specific dyad design (e.g., case-mother dyads vs. case-mother/control-mother dyads) is more advantageous. In this article, we review existing statistical methods for analyzing genome-wide marker data on dyads and perform extensive simulation experiments to benchmark their type I errors and statistical power under different scenarios. We extend our evaluation to existing methods for analyzing a combination of case-parent trios and dyads together. We apply these methods on genotyped and imputed data from multiethnic mother-child pairs only, case-parent trios only or combinations of both dyads and trios from the Gene, Environment Association Studies consortium (GENEVA), where each family was ascertained through a child affected by nonsyndromic cleft lip with or without cleft palate. Results from the GENEVA study corroborate the findings from our simulation experiments. Finally, we provide recommendations for using statistical genetic association methods for dyads.

PMID:35451532 | DOI:10.1002/gepi.22453

J Adv Nurs. 2022 Apr 22. doi: 10.1111/jan.15239. Online ahead of print.

ABSTRACT

AIMS: This review aims to examine updated evidence to evaluate the effectiveness of caregiver-mediated exercise interventions on basic and extended activities of daily living (ADL), anxiety and depression of post-stroke rehabilitation individuals.

DESIGN: A systematic review and meta-analysis.

DATA SOURCES: Six electronic databases, including CINAHL, CENTRAL, Embase, PubMed, PsycINFO and Scopus, grey literature and trial registry were searched from inception until February 2021.

METHODS: Only randomized controlled trials written in English were included. Meta-analyses were conducted for basic and extended ADL, anxiety and depression outcomes using RevMan software. Overall quality of evidence was assessed using Grading of Recommendations, Assessment, Development and Evaluation framework.

RESULTS: A total of 11 randomized controlled trials comprising 2120 participants were identified, with 10 trials meta-analysed. Meta-analyses indicated statistically significant effects favouring caregiver-mediated exercise interventions for basic ADL. Subgroup analyses revealed significant effects for exercise-only interventions mediated by caregivers for basic ADL. No significant effects were found for extended ADL, anxiety and depression for stroke survivors.

CONCLUSION: Caregiver-mediated exercise interventions appear to have beneficial impacts on basic ADL for stroke survivors, suggesting caregiver-mediated exercise interventions as a potentially feasible way to improve functional independence.

IMPACT: Caregiver-mediated intervention with exercises as a major component could be a promising approach to augment stroke rehabilitation. Future research should include high-quality studies with focus on specific intervention components or to explore caregiver outcomes.

PMID:35451521 | DOI:10.1111/jan.15239

J Periodontol. 2022 Apr 22. doi: 10.1002/JPER.21-0615. Online ahead of print.

ABSTRACT

BACKGROUND: This cross-sectional study assessed the role of gingival landmarks (GLs) and cutting points (CPs) for gingival phenotype (GP) determination.

METHODS: Six maxillary anterior teeth (70 subjects) were evaluated using soft tissue cone-beam computed tomography (ST-CBCT). Gingival thickness was measured at different GLs: (1) tissue zone (gingival margin (GM), 1 and 2 mm apical to GM, cementoenamel junction, above the bone crest); (2) bone zone (buccal bone crest (BBC), 1, 2, and 3 mm apical to BBC). Cutting points of 0.6, 0.8, 1.0, 1.2, and 1.5 mm were used to discriminate between thin and thick GP. The clinical determination of GP was made based on transparency of the periodontal probe (TRAN).

RESULTS: The prevalence of thin and thick GP depended on the GL and CP. Considering the CP (1 mm), thin GP at the tissue zone ranged from 99% at the GM to 10.2% above the bone crest. In the bone zone, thick GP ranged from 28% at the BBC to 6% at 3 mm apical to the BBC. The predictability of a correct assessment of GP by TRAN compared to ST-CBCT was influenced by the GLs and CPs. A slight agreement (kappa < 0.2) and low accuracy (area under the curve < 0.7) were found between methods.

CONCLUSION: The determination of thin and thick gingival phenotypes is related to the gingival landmarks and cutting points. Further studies are required for a well-defined treatment protocol considering different gingival landmarks in tissue and bone zones. An ST-CBCT may be useful for this purpose. This article is protected by copyright. All rights reserved.

PMID:35451505 | DOI:10.1002/JPER.21-0615

Acta Obstet Gynecol Scand. 2022 Apr 22. doi: 10.1111/aogs.14366. Online ahead of print.

ABSTRACT

Traditional null hypothesis significance testing (NHST) incorporating the critical level of significance of 0.05 has become the cornerstone of decision-making in health care, and nowhere less so than in obstetric and gynecological research. However, such practice is controversial. In particular, it was never intended for clinical significance to be inferred from statistical significance. The inference of clinical importance based on statistical significance (p < 0.05), and lack of clinical significance otherwise (p ≥ 0.05) represents misunderstanding of the original purpose of NHST. Furthermore, the limitations of NHST-sensitivity to sample size, plus type I and II errors-are frequently ignored. Therefore, decision-making based on NHST has the potential for recurrent false claims about the effectiveness of interventions or importance of exposure to risk factors, or dismissal of important ones. This commentary presents the history behind NHST along with the limitations that modern-day NHST presents, and suggests that a statistics reform regarding NHST be considered.

PMID:35451497 | DOI:10.1111/aogs.14366

Metallomics. 2022 Apr 22:mfac028. doi: 10.1093/mtomcs/mfac028. Online ahead of print.

ABSTRACT

Hemodialysis (HD) represents a life-sustaining treatment for patients with end stage renal disease. However, it is associated with several complications, including anemia. Erythropoiesis stimulating agents (ESA) are often administered to HD patients with renal anemia, but a relevant proportion of them fail to respond to the therapy. Since trace metals are involved in several biological processes and their blood levels can be altered by hemodialysis, we study the possible association between serum trace metal concentrations and ratios with the administration and response to ESA. For this study, data and sample information of 110 HD patients were downloaded from the UC San-Diego Metabolomics Workbench public repository (PR000565). The blood serum levels (and ratios) of antimony, cadmium, copper, manganese, molybdenum, nickel, selenium, tin and zinc were studied applying an omics statistical approach. The Random Forest model was able to discriminate HD dependent patients treated and not treated with ESA, with an accuracy of 71.7% (95% CI 71.5-71.9%). Logistic regression analysis identifies alterations of Mn, Mo, Cd, Sn, and several of their ratios as characteristic of patients treated with ESA. Moreover, patients with scarce response to ESA showed to be characterized by reduced Mn to Ni and Mn to Sb ratios. In conclusion, our results show that trace metals, in particular manganese, play a role in the mechanisms underlying human response to ESA, and if further confirmed, the re-equilibration of their physiological levels could contribute to a better management of HD patients hopefully reducing their morbidity and mortality.

PMID:35451491 | DOI:10.1093/mtomcs/mfac028