Laterality Index Research Articles

Modeling the association between functional connectivity and lateralization with the activity flow framework

The human brain is localized and distributed. On the one hand, each cognitive function tends to involve one hemisphere more than the other, also known as the principle of lateralization. On the other hand, interactions among brain regions in the form of functional connectivity (FC) are indispensable for intact function. Recent years have seen growing interest in the association between lateralization and FC. However, FC metrics vary from spurious correlation to causal associations. If lateralization manifests local processing and causal network interactions, more causally valid FC metrics should predict lateralization index (LI) better than FC based on simple correlations. The present study directly investigates this hypothesis within the activity flow framework to compare the association between lateralization and four brain connectivity metrics: correlation-based FC, multiple-regression FC, partial-correlation FC, and combinedFC. We propose two modeling approaches: the one-step approach, which models the relationship between LI and FC directly, and the two-step approach, which predicts the brain activation and calculates the LI. Our results indicated that multiple-regression FC, partial-correlation FC, and combinedFC could significantly improve the model prediction compared to correlation-based FC, which was consistent in a spatial working memory task (typically right-lateralized) and a language task (typically left-lateralized). The one-step and two-step approach yielded similar conclusions. In addition, the finding was replicated in a clinical sample of schizophrenia (SZ), bipolar disorder (BP), and attention deficit hyperactivity disorder (ADHD). The present study suggests that the causal interactions among brain regions help shape the lateralization pattern.

Associations between Verbal Fluency and Asymmetry of White Matter Integrity in the Superior Longitudinal Fasciculus in At-Risk Mental States for Psychosis.

Verbal fluency is one of the most severely impaired components of cognitive function in schizophrenia and is also impaired in at-risk mental states (ARMSs) for psychosis. The aim of this study was to explore the markers of disease progression in subjects with ARMSs by comparing the association between the white matter integrity of the superior longitudinal fasciculus (SLF) and verbal fluency in subjects with ARMSs and healthy control (HC) subjects. The correlations of the fractional anisotropy (FA) values on diffusion tensor imaging (DTI) and the laterality index (LI) values of SLF branches I, II, and III with the verbal fluency performance were analyzed in right-handed subjects with ARMSs (ARMS group; n = 18) and HC subjects (HC group; n = 34) aged 18 to 40 years old. In the HC group compared with the ARMS group, the LI values suggested right lateralization of the SLF II and III. Letter fluency was significantly correlated with the LI of the SLF III in both the ARMS and HC groups. The regression coefficient (β) of this correlation was calculated using the least squares method and yielded a positive number (73.857) in the ARMS group and a negative number (-125.304) in the HC group. The association of the rightward asymmetry of the SLF III with the verbal fluency performance observed in the HC group appeared to be lost in the ARMS group, and this could serve as one of the markers of the pathological progression to psychosis in patients with schizophrenia.

Anodal transcranial direct current stimulation (atDCS) and functional transcranial Doppler sonography (fTCD) in healthy elderly and patients with MCI: modulation of age-related changes in word fluency and language lateralization.

Introduction: In addition to age-related changes in language, hemispheric lateralization of language functions steadily declines with age. Also, performance on word fluency tasks declines and is sensitive to the expression of dementia-related changes. The aim of this study is to evaluate the effect of anodal tDCS combined with a word fluency training on language lateralization and word fluency performance in healthy elderly subjects and in persons with mild cognitive impairment (MCI). Methods: The effect of anodal tDCS over the left inferio frontal gyrus (IFG) was measured in a group of healthy elderly up to the age of 67years (YG, Ø = 63.9 ± 3.02), a group of healthy elderly aged 68years and older (OG, Ø = 78.1, ± 4.85), and a group of patients with MCI (Ø = 81.18, ± 7.35) by comparing performance in phonological and semantic word fluency tasks before and after 3days of tDCS. Half of the experimental participants received sham stimulation. In addition, language lateralization was determined using a lateralization index (LI) measured with functional transcranial Doppler sonography (fTCD) before and after the stimulation period. Results: Anodal tDCS was associated with significantly higher scores in phonological but not semantic word fluency in both YG and OG. In MCI patients, no difference was measured between the tDCS and sham groups in either word fluency task. fTCD showed significantly increased left lateralization in all three groups after the training phase. However, this effect was independent of tDCS and the degree of lateralization could not be predicted by word fluency performance in any of the groups. Discussion: Phonological word fluency can be increased with atDCS in healthy elderly people by stimulating the IFG in a 3-day training. When cognitive decline has reached a certain stage, as is the case with MCI, this paradigm does not seem to be effective enough.

Effect of steam explosion pretreatment on chosen saccharides yield and cellulose structure from fast-growing poplar (Populus deltoides × maximowiczii) wood

The aim of this study was to determine the changes occurring in the wood cellulose of the fast-growing poplar (Populus deltoides × maximowiczii) under the influence of steam explosion (SE) pretreatment. Cellulose from native wood and after pretreatment at 160 and 205 °C was isolated. Cellulose polymerization degree by size exclusion chromatography (SEC) and cellulose crystallinity index by Fourier transform infrared spectroscopy-attenuated total reflectance (FTIR-ATR) were determined. The profiles of sugars in the native wood and in the solid fraction after pretreatment (using the acid hydrolysis method) were also determined. In addition, the profile of monosaccharides in the liquid fraction obtained after steam explosion and in the liquid fraction after acid hydrolysis of the oligosaccharides were investigated using high-performance liquid chromatography (HPLC). This allowed to determine the change in the yield of hexoses and pentoses in the studied material.The behavior of cellulose in wood subjected to steam explosion at 160 and 205 °C and isolated by the Kürschner–Hoffer method was studied by determining the absorption bands of FTIR-ATR spectra. The lateral order index (LOI) of cellulose was calculated from the ratio of the intensity of the corresponding absorption bands A1422/A896 cm−1. Total crystallinity index (TCI) of cellulose was calculated from the ratio of the intensity of absorption bands A1372/A2900 cm−1. TCI of Kürschner-Hoffer cellulose isolated from wood subjected to steam explosion at 160 and 205 °C decreased by 5.6 and 5.0%, respectively, with regard to the applied temperature. LOI increased in cellulose isolated from wood subjected to steam explosion at 160 °C (by 0.7%) and at 205 °C (by 19.2%) in relation to the index of cellulose isolated from native wood. Kürschner–Hoffer cellulose isolated from wood subjected to steam explosion at 160 and 205 °C exhibited, respectively, a reduced degree of polymerization of about 11% and about 8%. Polydispersity index in Kürschner–Hoffer cellulose was 1% lower after both pretreatments than native sample.

Unveiling the Influence of the Menstrual Cycle on Mental Rotation Abilities: A Comparative Analysis of Three-Dimensional vs. Two-Dimensional Tasks

The activational effects of sex hormones on spatial ability have been well documented. It has been suggested that these effects might be related to hormonally induced changes in interhemispheric communication. In this EEG study, we opted to explore menstrual cycle-related changes in the efficacy of solving mental rotation tasks and laterality indices while participants were engaged with the tasks. We compared 2D and 3D mental rotation tasks, as they differ both psychometrically and in terms of lateralization. A group (n = 39) of healthy young women was tested twice, once during the mid-luteal (high estrogen and progesterone) and once during the early follicular (low levels of sex hormones) phase of menstrual cycle. The differences in power within the same frequency band on homologous sites of the left and right hemispheres were then calculated. Participants were faster, more accurate, and showed higher laterality scores when solving 3D mental rotation tasks in the early follicular phase compared to the mid-luteal phase. This indicates a higher lateralization of this specific spatial function when the levels of sex hormones are low. However, for 2D mental rotation tasks, participants showed neither shifts in efficacy nor in hemispheric laterality as a function of the menstrual cycle. This pattern of results provides further support for the notion that fluctuations in sex hormones affect laterality, and consequently, the expression of lateralized cognitive abilities.

Left-sided epileptiform activity influences language lateralization in right mesial temporal sclerosis.

To investigate the association between left epileptiform activity and language laterality indices (LI) in patients with right mesial temporal sclerosis (MTS). Twenty-two patients with right MTS and 22 healthy subjects underwent fMRI scanning while performing a language task. LI was calculated in multiple regions of interest (ROI). Data on the presence of left epileptiform abnormalities were obtained during prolonged video-EEG monitoring. After correction for multiple comparisons, LI was reduced in the middle temporal gyrus in the left interictal epileptiform discharges (IED+) group, compared with the left IED- group (p < 0.05). Using a responsive reading naming fMRI paradigm, right MTS patients who presented left temporal interictal epileptiform abnormalities on video-EEG showed decreased LI in the middle temporal gyrus, indicating decreased left middle temporal gyrus activation, increased right middle temporal gyrus activation or a combination of both, demonstrative of language network reorganization, specially in the MTG, in this patient population. This research studied 22 patients with right mesial temporal sclerosis (a specific type of epilepsy) comparing them to 22 healthy individuals. Participants were asked to perform a language task while undergoing a special brain imaging technique (fMRI). The findings showed that patients with epilepsy displayed a change in the area of the brain typically responsible for language processing. This suggests that their brains may have adapted due to their condition, altering the way language is processed.

Utilizing fNIRS to investigate the impact of Baduanjin training on attentional function in post-stroke cognitive impairment patients: a study protocol for a randomized controlled trial

BackgroundPost-stroke cognitive impairment (PSCI) is a prevalent complication among stroke survivors. It not only directly impacts patients' cognitive abilities but also hampers their capacity to regain independence in daily activities, consequently diminishing their quality of life. Among the various cognitive deficits following stroke, impaired attention is the most frequently observed, influencing not only daily functioning but also higher cognitive functions like working memory, executive functioning, and language.Emerging evidence indicates that Baduanjin, a traditional Chinese exercise, may have a positive impact on enhancing attention in older adults with mild cognitive impairment and stroke survivors. However, the precise mechanisms behind this effect remain unclear. In this study, we employed Baduanjin training as an intervention to address attention decline in post-stroke cognitive impairment patients and to delve into the potential mechanisms through which Baduanjin training may enhance attention in individuals with PSCI.MethodsIn this prospective randomized controlled trial, we plan to recruit 72 participants diagnosed with post-stroke cognitive impairment (PSCI). These participants will be randomly assigned in a 1:1:1 ratio to one of three groups: Baduanjin training(left hemisphere stroke and right hemisphere stroke) and conventional treatment.The conventional treatment group will receive standard rehabilitation sessions. In addition to conventional treatment, participants in the octogenarian training groups will undergo octogenarian training sessions lasting 40 min, five times a week, over a total period of 12 weeks.The primary outcome measures will include the Montreal Cognitive Assessment (MoCA) scale and the Attentional Lateralization Index. These assessments will be conducted by a trained evaluator before the start of the intervention and at weeks 6 and 12 after the intervention begins.Secondary outcome measures will be assessed using the baseline Mandarin version of the Oxford Cognitive Screening (OCS-P) scale, the simplified Fugl-Meyer Motor Function Assessment (FMA) scale, the Pittsburgh Rehabilitation Participation (PRPS) scale, and the Activities of Daily Living (ADL) scale before and after the intervention, respectively.DiscussionThis trial aims to examine the impact of Baduanjin training on attentional lateralization among patients with post-stroke cognitive impairment (PSCI). Functional brain imaging utilizing near-infrared spectroscopy will be employed to investigate how Baduanjin exercise influences the structural and functional connectivity of distinct brain regions or brain networks.Trial registrationChictr.org.cn, ID: ChiCTR2300076533. Registered on 11 October 2023.

Changing handedness after nerve reconstruction in brachial plexus birth palsy.

Right obstetric brachial plexus injuries (OBPI) often lead to left-handedness before limb function is restored post-surgery. A pertinent question arises about promoting a transition from left to right-handedness. We hypothesized that, with the decrease in neuroplasticity, handedness switching is not only difficult, but also reduces handedness-speech lateralization, impaired motor adaptability, and compromised language proficiency. We retrospectively analyzed clinical data from January 1996 to January 2012 at our hospital. Participants were divided into intervention or control groups based on handedness switching. We compared handedness and computed lateral quotient (LQ) and lateralization index (LI) for handedness-speech center. Additionally, we assessed dominant hand's writing speed, language function, and IQ. Associations between absolute LI and LQ values, writing speed, language scores, and IQ were examined. Nineteen extended Erb's palsy participants were enrolled, eight in the intervention group, and 11 in the control. No right-handed individuals were found in either cohort. The intervention group had significantly lower LQ and LI values, and fewer achieved normal writing speed. Yet, no notable disparities in language scores or IQ emerged. Notably, we established correlations between motor finesse, handedness degree, and handedness-speech lateralization. For right extended Erb's palsy, shifting handedness is nearly unfeasible, and such an endeavor could trigger a reduction in handedness-speech lateralization magnitude and diminished motor finesse.

Identifying Spatial Neglect in Chronic Right Hemisphere Stroke Survivors Using the RHDBank Outcomes.

The chronicity of spatial neglect (SN) and the utility of existing diagnostic measures used by speech-language pathologists remain poorly understood. In this retrospective study, we examined how the RHDBank test battery informs the identification of SN after right hemisphere brain damage (RHD) during the chronic phase of recovery. Data from 29 right hemisphere stroke survivors were extracted from the RHDBank, including SN tests, for which we performed laterality index scoring: a 51-item demographic survey, the Apples Test, the Indented Paragraph Test, and the clock drawing task from the Cognitive Linguistic Quick Test (CLQT). Two groups (SN+ and SN-) were identified using the Apples Test. A hierarchical cluster analysis explored CLQT performance clusters in association with SN, and group comparisons of demographic variables and test scores were conducted. Ten patients were identified as having SN+ (34%) using the Apples Test. The Indented Paragraph Test and the CLQT's clock drawing test identified only two of the 20 stroke survivors with SN+. Cluster analyses showed that domain and task scores on the CLQT carried information to classify participants into SN+ and SN- in concordance with performance on the Apples Test. Participants in the SN+ cluster had moderately impaired attention and executive function skills and mildly impaired visuospatial skills. The Apples Test differentiated SN in a group of chronic right hemisphere stroke survivors. Using multiple measures from the CLQT seemed to capture a greater range of problems than clock drawing and paragraph reading tests alone. Therefore, the RHDBank test battery as a whole-and in part the CLQT, Apples Test, and Indented Paragraph Test-can detect certain subtypes of SN in the chronic deficit profile after RHD and is a starting point for diagnostic integration by speech-language pathologists.

Multifocal, Asymmetric Bilateral Primary Aldosteronism Cannot be Excluded by Strong Adrenal Vein Sampling Lateralization: An International Retrospective Cohort Study.

Primary aldosteronism (PA) has been broadly dichotomized into unilateral and bilateral forms. Adrenal vein sampling (AVS) lateralization indices (LI) ≥2 to 4 are the standard-of-care to recommend unilateral adrenalectomy for presumed unilateral PA. We aimed to assess the rates and characteristics of residual PA after AVS-guided adrenalectomy. We conducted an international, retrospective, cohort study of patients with PA from 7 referral centers who underwent unilateral adrenalectomy based on LI≥4 on baseline and/or cosyntropin-stimulated AVS. Aldosterone synthase (CYP11B2) immunohistochemistry and next generation sequencing were performed on available formalin-fixed paraffin-embedded adrenal tissue. The cohort included 283 patients who underwent AVS-guided adrenalectomy, followed for a median of 326 days postoperatively. Lack of PA cure was observed in 16% of consecutive patients, and in 22 patients with lateralized PA on both baseline and cosyntropin-stimulated AVS. Among patients with residual PA postoperatively, 73% had multiple CYP11B2 positive areas within the resected adrenal tissue (versus 23% in those cured), wherein CACNA1D mutations were most prevalent (63% versus 33% in those cured). In adjusted regression models, independent predictors of postoperative residual PA included Black versus White race (odds ratio, 5.10 [95% CI, 1.45-17.86]), AVS lateralization only at baseline (odds ratio, 8.93 [95% CI 3.00-26.32] versus both at baseline and after cosyntropin stimulation), and CT-AVS disagreement (odds ratio, 2.75 [95% CI, 1.20-6.31]). Multifocal, asymmetrical bilateral PA is relatively common, and it cannot be excluded by robust AVS lateralization. Long-term postoperative monitoring should be routinely pursued, to identify residual PA and afford timely initiation of targeted medical therapy.

Nanosecond Laser Fabrication of Novel Micro-/Nanostructured Metal Surfaces: A Dual-Functional Supersurface Combining Antireflectivity and Superhydrophobic Properties.

The research and applications in the field of micro/nano surface manufacturing are progressively shifting their focus toward multifunctional surfaces. In practical applications, objects often need to operate under demanding environmental conditions, and single-function surfaces have inherent limitations in terms of performance, adaptability, and longevity. In this paper, a micro-/nanolayered structural strategy with dual functions of ultrahigh antireflective properties and superhydrophobicity was created on the surface of titanium alloy by using nanosecond pulsed laser processing, and two structural modes of periodic honeycomb and lattice with controllable shapes were designed. In addition, the morphology and formation mechanism of multilevel micro-/nanostructures were investigated in depth, combining laser texturization and silanization of substrate microstructures. The effects of the micro-/nanostructured morphology on the reflection and wettability properties were evaluated with different pulse widths and lateral overlap index. This study also demonstrated that water droplets exhibit excellent bouncing and rolling behavior on superhydrophobic surfaces, further verifying the excellent hydrophobic properties of the prepared samples. Furthermore, in addressing the challenges of susceptibility to dust contamination and performance degradation in extreme environments associated with antireflective surfaces, a series of durability and mechanical stability tests were conducted on controllability periodic micro-/nanostructured surfaces. Successfully meeting this challenge will open up great potential and opportunities for significant improvements in equipment performance and stable operation under extreme operating conditions.

Upper limb motor assessment for stroke with force, muscle activation and interhemispheric balance indices based on sEMG and fNIRS.

Upper limb rehabilitation assessment plays a pivotal role in the recovery process of stroke patients. The current clinical assessment tools often rely on subjective judgments of healthcare professionals. Some existing research studies have utilized physiological signals for quantitative assessments. However, most studies used single index to assess the motor functions of upper limb. The fusion of surface electromyography (sEMG) and functional near-infrared spectroscopy (fNIRS) presents an innovative approach, offering simultaneous insights into the central and peripheral nervous systems. We concurrently collected sEMG signals and brain hemodynamic signals during bilateral elbow flexion in 15 stroke patients with subacute and chronic stages and 15 healthy control subjects. The sEMG signals were analyzed to obtain muscle synergy based indexes including synergy stability index (SSI), closeness of individual vector (CV) and closeness of time profile (CT). The fNIRS signals were calculated to extract laterality index (LI). The primary findings were that CV, SSI and LI in posterior motor cortex (PMC) and primary motor cortex (M1) on the affected hemisphere of stroke patients were significantly lower than those in the control group (p < 0.05). Moreover, CV, SSI and LI in PMC were also significantly different between affected and unaffected upper limb movements (p < 0.05). Furthermore, a linear regression model was used to predict the value of the Fugl-Meyer score of upper limb (FMul) (R2 = 0.860, p < 0.001). This study established a linear regression model using force, CV, and LI features to predict FMul scale values, which suggests that the combination of force, sEMG and fNIRS hold promise as a novel method for assessing stroke rehabilitation.

Uncovering the Neural Mechanisms of Inter-Hemispheric Balance Restoration in Chronic Stroke through EMG-Driven Robot Hand Training: Insights from Dynamic Causal Modeling.

EMG-driven robot hand training can facilitate motor recovery in chronic stroke patients by restoring the interhemispheric balance between motor networks. However, the underlying mechanisms of reorganization between interhemispheric regions remain unclear. This study investigated the effective connectivity (EC) between the ventral premotor cortex (PMv), supplementary motor area (SMA), and primary motor cortex (M1) using Dynamic Causal Modeling (DCM) during motor tasks with the paretic hand. Nineteen chronic stroke subjects underwent 20 sessions of EMG-driven robot hand training, and their Action Reach Arm Test (ARAT) showed significant improvement (β=3.56, p<0.001). The improvement was correlated with the reduction of inhibitory coupling from the contralesional M1 to the ipsilesional M1 (r=0.58, p=0.014). An increase in the laterality index was only observed in homotopic M1, but not in the premotor area. Additionally, we identified an increase in resting-state functional connectivity (FC) between bilateral M1 (β=0.11, p=0.01). Inter-M1 FC demonstrated marginal positive relationships with ARAT scores (r=0.402, p=0.110), but its changes did not correlate with ARAT improvements. These findings suggest that the improvement of hand functions brought about by EMG-driven robot hand training was driven explicitly by task-specific reorganization of motor networks. Particularly, the restoration of interhemispheric balance was induced by a reduction in interhemispheric inhibition from the contralesional M1 during motor tasks of the paretic hand. This finding sheds light on the mechanistic understanding of interhemispheric balance and functional recovery induced by EMG-driven robot training.

Adrenal venous sampling (AVS): Success of catheterization and concordance of imaging lateralization with AVS lateralization

Objective: Primary hyperaldosteronism (PA) is an important cause of secondary hypertension. One of the most crucial steps in the management of patients with PA is the determination of the laterality of aldosterone production (unilateral or bilateral disease). This study aimed to determine the success rate of adrenal venous sampling (AVS) and the concordance between imaging and AVS laterality. Material and Methods: The procedural, radiological, and laboratory data of the patients who underwent AVS were evaluated retrospectively. The Selectivity Index (SI) and Lateralization Index (LI) were used for catheterization success and laterality determination, respectively. The Contralateral Suppression Index (CSI) was used for laterality determination in cases of unilaterally failed AVS. Abdominal CT scans were evaluated for adrenal nodules and hyperplasia. Results: This study included 36 patients for catheterization success and 28 patients for laterality evaluation. The mean age was 56.08±9.01 years. The overall success rate was 88.9% (32 of 36 patients). The bilateral and unilateral successful catheterization rates were 52.8% and 36.2%, respectively. Unilateral disease was present in 15 (53.6%) patients based on AVS, right-sided in 9 (32.1%), and left-sided in 6 (21.4%) patients. Unilateral disease was present in 18 (64.3%) patients based on imaging, right-sided in 11 (39.3%), and left-sided in 7 (25%) patients. The proportion of agreement between imaging and AVS lateralization was 50% (14 of 28 patients). Conclusion: The overall success rate of AVS was high when unilateral success was included. In half of the patients with PA in this study, CT showed discordant disease laterality compared to AVS.

Biomass‐based lateral root morphological parameter models for rapeseed (Brassica napus L.)

AbstractLateral roots, including adventitious roots, are the main component of rapeseed roots with support, absorb, and synthesis functions and their morphological parameters directly affecting the plant's aboveground growth and yield. Root biomass, as a material base for lateral root growth, can be used as a link between plant phenotypes and their physiological processes, as well as to enhance root 3D growth model mechanisms and accuracy. To quantify the relationships between lateral root morphological indices and the corresponding organ biomass for rapeseed, we used two cultivars, NY 22 (conventional) and NZ 1818 (hybrid), and conducted cultivar and fertilizing cylindrical tube experiments during the 2016–2019, with two fertilizer levels, no fertilizer, and 180 kg N ha−1 fertilizer. The lateral root biomass and morphological parameters were determined during the whole growth period. The biomass‐based lateral root morphological parameter models were developed by analyzing the quantitative relationship between the lateral root morphological indices and their corresponding biomass, and the descriptive models were verified with independent experimental data. The results showed that the correlation (r) of simulated and observed values for the lateral root morphological parameters are all greater than 0.9 with significant levels at p &lt; 0.001. The absolute values of the average absolute difference (da) of simulated and observed values for the lateral root length (LLR), lateral root average diameter (ADLR), lateral root surface area (SALR), and lateral root volume (VLR) are −30.408 cm, −0.003 mm, 12.902 cm2, and 0.039 cm3, respectively. The RMSE values are 175.183 cm, 0.010 mm, 59.710 cm2, and 1.513 cm3, respectively. The ratio of da to the average observed values (dap) for the LLR and VLR are all less than 5%, and the ADLR and SALR are all &lt;6%. The models developed in this paper have good performance and reliability for predicting lateral root morphological parameters of rapeseed. The study provides a mechanistic method for linking the rapeseed growth model with the morphological model using corresponding organic biomass and laying a good foundation for establishing a 3D morphological model for rapeseed root system based on biomass.

Correlation of Histopathologic Subtypes of Primary Aldosteronism with Clinical Phenotypes and Postsurgical Outcomes.

Clinical implications of unilateral primary aldosteronism (PA) histopathology remain to be determined in various ethnic populations. We examined the histopathology of unilateral PA using CYP11B2 immunostaining in relation to clinical phenotypes and postsurgical outcomes. Patients consecutively operated for unilateral PA from 2010 to 2020 at 3 tertiary hospitals in South Korea were retrospectively enrolled. Adrenals with solitary aldosterone-producing adenomas and/or dominant aldosterone-producing nodules were classified as the classical and the others as the nonclassical groups. The classical group was subdivided into mixed or solitary group according to whether other aldosterone-producing lesions coexist or not. Of the 240 cases, 124 were solitary, 86 mixed, and 30 nonclassical. Baseline serum potassium concentration was lower in the solitary group than the mixed or nonclassical group. Plasma aldosterone concentration after saline loading was the highest in the solitary group (median 31.65 ng/dL), followed by the mixed group (median 25.40 ng/dL), and the lowest in the nonclassical group (median 14.20 ng/dL). Solitary and mixed groups showed higher lateralization indices and lower contralateral indices than the nonclassical group. The contralateral index was lower in the solitary group than the mixed group. At 6 to 12 months after adrenalectomy, fewer antihypertensive medications were required for the solitary and mixed groups than the nonclassical group. The solitary group, followed by the mixed group, was associated with more severe hyperaldosteronism and more suppressed aldosterone production from the contralateral side than the nonclassical group. Histopathologic phenotypes were related to the clinical manifestations and may suggest postoperative prognosis.

Cephalometric changes in pharyngeal airway dimensions after functional treatment with twin block versus myobrace appliances in developing skeletal class II patients: a randomized clinical trial

BackgroundSeveral appliances have been used for correction of developing skeletal Class II, including different myofunctional appliances as Twin block (TB)as well as the new pre-fabricated Myobrace (MB) appliance. However, the effects of these devices on the pharyngeal airways have not been compared in the literature. Thus, the aim of this study was to compare the effects of two Class II correction appliances; TB and MB on the sagittal pharyngeal airway dimension (SPAD), including the nasopharyngeal airway area (NPAA), the oropharyngeal airway area (OPAA), and the laryngopharyngeal airway area (LPAA).MethodsThis is a two parallel arms randomized comparative clinical trial. Twenty-six children of 9–12 years with Skeletal Class II malocclusion due to mandibular deficiency and normal maxillary growth as confirmed by lateral cephalometric X-ray readings (ANB angle > 4° and SNB angle < 78) and Cervical vertebral maturational index (CVMI) 1 or 2 were randomly assigned into two equal groups. Group I: TB, Group II: MB (prefabricated functional appliance, Myofunctional Research Co., Australia). Lateral cephalograms were taken for all patients in both groups before treatment (T1) and after treatment (6 months later) (T2). The primary aim was to assess pre and post treatment changes in the SPAD in each group, and compare between the two study groups. The secondary aim was to evaluate the sagittal skeletal measurements such as the SNA, SNB, ANB, Wits appraisal, as well as vertical skeletal measurements represented by the Frankfurt-mandibular plane angle (FMA) measured pre- and post-treatment. The independent samples t-test was used to compare the two study groups, and the mean difference and 95% confidence intervals (CI) were computed. The paired samples t-test was used to compare various parameters between T1 and T2 within each group. The cutoff for significance was p-value < 0.05. Data were analyzed using IBM SPSS for Windows (Version 26.0).ResultsBy Comparing changes in airway measurements within each group, it was found that NPAA, OPAA, and LPAA increased significantly after treatment within each group of MB and TB. TB group showed significantly higher mean difference (T2-T1) in both NPAA and OPAA than MB group with 28.39 (± 56.75) and 40.46 (± 52.16) respectively. The increase in LPAA values was not statistically significant at (T2-T1) between both groups. Regarding skeletal changes, there was a significant increase in the SNB values between T1 and T2 within each group with 2.82 (± 3.32) for MB group and 3.79 (± 3.06) for TB group Moreover, there was a significant decrease in the ANB values between T1 and T2 within each group by 2.42 (± 2.70) for MB group and 3.06 (± 1.14) for TB group. Similarly, there was a significant decrease in the ANB values between T1 and T2 within each group by -2.13 (± 0.62) for MB group and − 2.46 (± 0.72) for TB group. No significant differences were found between both groups in SNA, SNB, ANB and Wits appraisal at p = 0.06, p = 0.45, p = 0.43 and p = 0.22 respectively. FMA did not show significant difference between T1 and T2 within each group, nor showed a significant mean difference between both groups at T2-T1.ConclusionsTB was more effective than MB in improving the upper (NPAA) and middle (OPAA) airways, while no difference was found regarding the lower airway (LPAA). Both TB and MB reduced the severity of developing skeletal class II due to mandibular retrognathism by forward posturing of the mandible. Thus, patients with airway problems would benefit more from TB than MB.

Study on Lateral Vibration of Tail Coach for High-Speed Train under Unsteady Aerodynamic Loads

As the speed of high-speed trains increases, the vehicle’s lateral stability steadily deteriorates. There have been observations of abnormal vibrations in the tail car, particularly on certain sections of the railway line. This study built a high-speed train aerodynamic simulation model for a three-car consist, and a multibody dynamics simulation model for an eight-car consist based on numerical simulations of train aerodynamics and multibody dynamics. It investigated both steady and unsteady aerodynamic loads, flow field characteristics, and the dynamic performance of vehicles under varied aerodynamic loads at 400 km/h. The results indicate that the aerodynamic loads generated during high-speed train operation exhibit highly unsteady characteristics. Steady aerodynamic loads have a relatively minor impact on the vehicle’s dynamic performance, whereas unsteady loads exert a more significant influence. Under unsteady aerodynamic forces, the tail car experiences severe lateral vibrations. The lateral stability index, displacement, velocity, and acceleration of the tail car under unsteady conditions were measured at 2.26, 7.54 mm, and 0.53 m/s2, respectively. These values represent increases of over 17.71%, 148.84%, and 111.24%, respectively, compared to the steady loads. Large oscillation amplitudes result in more significant lateral displacements and accelerations of the vehicle. This phenomenon is a crucial factor contributing to the “tail swing” effect observed in high-speed trains. This study emphasizes the importance of considering unsteady aerodynamic effects in assessing the lateral stability of high-speed trains and highlights the significance of mitigating the adverse impacts of such dynamic responses, particularly in the tail car.

Complications following surgical management of Haglund's triad: A retrospective, single-center analysis

BackgroundHaglund's triad consists of Haglund's deformity, insertional Achilles tendinosis, and retrocalcaneal bursitis and is most commonly managed surgically through Haglund's resection, bursectomy, and Achilles tendon detachment-reattachment using a central tendon-splitting approach stabilized with a double row suture construct. This procedure has demonstrated consistently good outcomes; however, we have anecdotally identified a higher complication rate performing this surgery compared with the published literature. Accordingly, we sought to evaluate this further. MethodsWe performed a retrospective electronic medical record review of 44 consecutive patients (10 men, 34 women) who underwent surgical correction of Haglund's triad. Patient age, gender, laterality, body mass index, follow-up duration, complications encountered, and revision surgery performed were analyzed. ResultsSignificant differences were identified for gender and incidence of complications (p = 0.01424), with women having a greater incidence of complications than men and duration of follow-up (p = 0.0432) where women endured a longer follow-up period. No other significant differences for complications were identified for age (p = 0.192), laterality (p = 0.5535), or body mass index (p = 0.9532) irrespective of gender. Complications occurred in 50 % of patients with most complications persisting at the final follow-up. ConclusionWe identified a significantly greater incidence of complications for women compared to men for operative management of Haglund's triad regardless of age, laterality, or body mass index. Further analysis of the effect gender has on operative management of Haglund's triad seems warranted so that measures to mitigate complications can be developed, especially since complications persisted for those patients who encountered them which negatively affected their outcomes. Level of EvidenceIII-Therapeutic study: Retrospective comparative analysis at a single institution CategoryRearfoot and Ankle Reconstruction

The value of plasma metanephrine measurements during adrenal vein sampling.

The assessment of primary aldosteronism incorporates adrenal vein sampling (AVS) to lateralize aldosterone excess. Current adrenal vein sampling protocols rely on concurrent cortisol measurements to assess successful cannulation and lateralization and may be inaccurate in the setting of autonomous cortisol secretion. We aimed to compare the measurement of plasma cortisol and metanephrine concentrations to assess cannulation and lateralization during AVS. This is a diagnostic accuracy study in a tertiary referral endocrinology department. Forty-one consecutive patients with confirmed primary aldosteronism undergoing AVS (49 procedures) were included. None had cortisol autonomy. The use of plasma metanephrine-based ratios were compared with standard cortisol-based ratios to assess cannulation and lateralization during ACTH-stimulated AVS. There was strong agreement between a cortisol selectivity index (SI) ≥5.0 and an adrenal vein (AV) to peripheral vein (PV) plasma metanephrine ratio (AVmet-PVmet) of ≥12.0 to indicate successful cannulation of the AV (n = 117, sensitivity 98%, specificity 89%, positive predictive value (PPV) 95%, negative predictive value (NPV) 94%). There was strong agreement between the standard cortisol-based SI and an AV plasma metanephrine-to-normetanephrine ratio (AVmet-AVnormet) of ≥2.0 to indicate successful cannulation (n = 117, sensitivity 93%, specificity 86%, PPV 94%, NPV 84%). There was strong agreement between the cortisol- or metanephrine-derived lateralization index (LI) > 4.0 for determining lateralization (n = 26, sensitivity 100%, specificity 94.1%, PPV 91.6%, NPV 100%). Ratios incorporating plasma metanephrines provide comparable outcomes to standard cortisol-based measurements for interpretation of AVS. Further studies are required to assess the use of metanephrine-derived ratios in the context of confirmed cortisol autonomy. Primary aldosteronism is a common cause of secondary hypertension, and adrenal vein sampling remains the gold standard test to assess lateralization. Cortisol-derived ratios to assess cannulation and lateralization may be affected by concurrent cortisol dysfunction, which is not uncommon in the context of primary aldosteronism. Our study showed comparable outcomes when using accepted cortisol-derived or metanephrine-derived ratios to determine cannulation and lateralization during adrenal vein sampling. Further research is required to validate these findings and to assess the use of metanephrine-derived ratios in the context of confirmed concurrent cortisol dysfunction.