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Introduction: In reverse shoulder arthroplasty (RSA) new designs enable greater amounts of lateralization to prevent instability and scapular notching and increase range of motion, however, excessive lateralization leads to stress upon the acromion that can result in scapular spine fatigue fractures. Aim of this study was to gender- and size-specifically assess the influence of glenosphere size and different humeral designs on lateralization, distalization, and bony impingement-free range of motion (ROM) in patients undergoing RSA. Methods: Computed tomography scans from 30 osteoarthritic patients (f:15, m:15) and 20 cuff tear arthropathy patients (f:10, m:10) were used to virtually simulate RSA implantation. The efficacy of an inlay Grammont-type system vs. an onlay lateralizing system combined with different glenosphere sizes (36 mm vs. 42 mm) in achieving ROM, lateralization, and distalization was evaluated. Moreover, gender and patient's constitution were correlated to humeral size by radiologically measuring the best-fit circle of the humeral head. Results: A different amount of relative lateralization was achieved in both genders using large glenospheres and onlay designs. Latter yielded a higher ROM in all planes for men and women with a 42 mm glenosphere; with the 36 mm glenosphere, an increased ROM was observed only in men. The 155° inlay design led to joint medialization only in men, whereas all designs led to lateralization in women. When adjusting the absolute amount of lateralization to humerus' size (or patient's height), regardless of implant type, women received greater relative lateralization using 36 mm glenosphere (inlay: 1%; onlay 12%) than men with 42 mm glenosphere (inlay: -3%; onlay: 8%). Conclusion: The relative lateralization achieved using onlay design is much higher in women than men. Small glenospheres yield greater relative lateralization in women compared to large glenospheres in men. Humeral lateralization using onlay designs should be used cautiously in women, as they lead to great relative lateralization increasing stress onto the acromion. Level of evidence: Basic Science Study, Computer Modeling. [ABSTRACT FROM AUTHOR]

Background: This study assessed the topography and lateralization of lymph node (LN) metastases in muscle-invasive bladder cancer (MIBC) patients using super-extended pelvic lymph node dissection (sePLND) with sentinel lymph node dissection (SLND). Methods: We analyzed 54 MIBC patients who underwent cystectomy with sePLND and SLND. Tumor location was classified using cystoscopy. Nanocolloid-Tc-99m was injected peritumorally. Preoperative SPECT/CT lymphoscintigraphy and an intraoperative gamma probe were used for SLN detection. Results: A total of 1414 LNs, including 192 SLNs, were resected from 54 patients. Metastases were found in 72 LNs from 22 patients (41%). The obturator fossa was the primary site for LN metastases (37.5%). SLNs were most common in the external iliac region (34.4%). In 36% of the patients with positive LNs, metastases were identified only through sePLND. In 9% of the patients, metastases were found solely in the pararectal region, identified through SLND. Tumor lateralization correlated with ipsilateral positive LNs, but 20% of the patients had contralateral metastases. Conclusions: The pararectal region may be the exclusive site for positive LNs in MIBC. The obturator fossa is the most prevalent region for LN metastases. Unilateral PLND should be avoided due to the risk of contralateral metastases. Combining sePLND with SLND improves staging. [ABSTRACT FROM AUTHOR]

Lateralization Shoulder Angle (LSA) and Distalization Shoulder Angle (DSA) have been proposed to estimate the appropriateness of reverse shoulder arthroplasty (RSA) positioning. The purpose of this study was to evaluate the predictive value of DSA and LSA over clinical outcomes in a group of patients treated by the same surgeon with the same clinical and radiographic follow-up. A retrospective analysis of a consecutive series of RSAs performed between 2017 and 2021 was carried out. Inclusion criteria were primary RSA as a treatment for Cuff Tear Arthropathy, Massive Irreparable rotator cuff tear, Osteoarthritis or Rheumatoid arthritis, a true anteroposterior radiograph of the affected shoulder in neutral rotation at final follow-up, a minimum follow-up of 12 months, radiograph used to measure the angles, and clinical evaluation with the same follow-up. Outcome measures were shoulder range of motion (ROM), visual analog scale (VAS) for pain and Constant-Murley score (CS). A total of 83 patients were included in the study. Patients achieved on average, 130 ± 14.14° of flexion, 97.5 ± 17.67° of abduction, 62.5 ± 3.53° and 72.5 ± 10.60° of external rotation, respectively, at 0° and 90° of abduction, and 5.13° of internal rotation. The mean VAS and CS were, respectively, 2.5 ± 3.5 mm and 69 ± 2.82 points at last follow-up. The mean DSA and LSA were 45 ± 2.72 and 92.99 ± 9.17, respectively. Neither the linear nor the quadratic regression fit for DSA or LSA revealed relevant associations with any of individual ROM measures, except for the quadratic fit correlating LSA and forward flexion (beta = 0.029, P =.027). Linear fit showed a low reverse, but significant, association between DSA and VAS (beta = −0.56, P =.036) and an association of LSA with both CS (beta = −0.344, P =.009) and VAS (beta = 0.091, P =.01). Quadratic models showed higher R squared for all associations, but correlation was significant only between VAS and LSA (beta = 0.006, P =.011) We present the first evaluation of the predictive value of both DSA and LSA in a group of patients treated by the same surgeon with the same clinical and radiographic follow-up. DSA and LSA play only a marginal to no role in the prediction of RSA postoperative ROM and might have a role in predicting VAS and CS. [ABSTRACT FROM AUTHOR]

Restoration of an anatomic joint line after anatomic total shoulder arthroplasty and of the optimal lateral offset after reverse total shoulder arthroplasty may be relatively straightforward when the glenoid does not present with severe erosion. However, in cases of severe glenoid bone loss, the surgeon is left with no preoperative landmark to restore these parameters. The objective of this study was to use statistical shape modeling, to predict the premorbid morphology of the glenoid. We hypothesized that this would allow us to accurately determine premorbid glenoid version and inclination, in addition to accurately quantifying bone loss and medialization. Fifty-six bilateral computed tomography scans of the shoulders of patients scheduled for shoulder arthroplasty and determined to have unilateral osteoarthritis (primary osteoarthritis or cuff tear arthropathy with a healthy contralateral side) were obtained. A statistical shape model was automatically applied on the pathologic arthritic side to predict its premorbid anatomy. Glenoid version, inclination, height, width, and glenoid and scapula lateral offset were measured automatically. These measurements were obtained on the pathological arthritic cases, on the contralateral control healthy cases, and on the premorbid predictions of the pathological arthritic cases and were compared pair by pair. The mean difference between the pathological arthritic side and the contralateral healthy side was 9.1° ± 7.3° for version, 4.8° ± 4.8° for inclination, 4.9 ± 4.5 mm for height, 4.7 ± 5.3 mm for width, 2.4 ± 1.9 mm for scapula lateral offset, and the glenoid lateral offset was 1.5 ± 1.5 mm. The mean difference between the premorbid prediction of the pathological side and the contralateral healthy side was reduced to 3.3° ± 2.4° for version, 3.4° ± 2.6° for inclination, 3.0 ± 1.9 mm for height, 2.3 ± 1.4 mm for width, 2.2 ± 1.7 mm for scapula lateral offset, and the glenoid lateral offset was 0.9 ± 0.8 mm. This study shows that statistical shape modeling can allow accurate prediction of the premorbid morphology of the glenoid. This could help optimize implant selection and positioning after anatomic total shoulder arthroplasty and reverse total shoulder arthroplasty to restore optimal soft-tissue tension. [ABSTRACT FROM AUTHOR]

The design of reverse shoulder arthroplasty (RSA) implants has evolved significantly over the past 50 years. Today there are many options available that differ in design of the glenoid and humeral components, fixation methods, sizes, and modularity. With respect to the humeral component, the literature has generally focused on the differences between inlay and onlay designs and the potential impact on outcomes. However, inlay and onlay design represents only one factor of many. It is our hypothesis that separating onlay and inlay designs into 2 distinct entities is an oversimplification as there can be a wide overlap of the 2 designs, depending on surgical technique and the implant selected. As such, the differences between inlay and onlay designs should be measured in absolute terms—meaning combined distalization and lateralization. By reviewing the many factors that can contribute to the glenosphere–humerus relationship, the role of inlay and onlay humeral designs as an important distinguishing feature is shown to be limited. Preliminary studies suggest that the amount of distalization and lateralization of the construct may be the most accurate method of describing the differences in the constructs. Inlay and onlay humeral component design represents only one factor of many that may impact outcomes. A more accurate method of defining specific design and technique factors in RSA is the degree of lateralization and distalization. [ABSTRACT FROM AUTHOR]

Context The role of hormone parameters at adrenal venous sampling (AVS) in predicting clinical and biochemical outcomes remains controversial. Objective To investigate the impact of hormone parameters at AVS under cosyntropin stimulation on lateralization and on complete biochemical and clinical outcomes. Methods We retrospectively evaluated 150 sequential AVS under cosyntropin infusion. The bilateral successful cannulation rate was 83.3% (n = 140), 47.9% bilateral and 52.1% unilateral. The lateralization index, aldosterone/cortisol ratio (A/C) in the dominant adrenal vein (AV), and relative aldosterone secretion index (RASI = A/C in AV divided by A/C in inferior vena cava) were assessed. The contralateral suppression (CS) percentage was defined by (1 − nondominant RASI) * 100. Results A nondominant RASI <0.5 (CS >50%) had 86.84% sensitivity and 92.96% specificity to predict contralateral lateralization. An A/C ratio in dominant AV >5.9 (74.67% sensitivity and 80% specificity) and dominant RASI >4.7 (35.21% sensitivity and 88.06% specificity) had the worst performance to predict ipsilateral lateralization. Complete biochemical and clinical cure was significantly more frequent in the patients with CS >50% [98.41% vs 42.86% (P <.001) and 41.94% vs 0% (P <.001)]. CS correlated with high aldosterone at diagnosis (P <.001) and low postoperative aldosterone levels at 1 month (P =.019). Postoperative biochemical hypoaldosteronism was more frequent in patients with CS >50% (70% vs 16.67%, P =.014). In multivariable analysis, a CS >50% was associated with complete biochemical cure [odds ratio (OR) 125, 95% confidence interval (CI) 11.904-5000; P =.001] and hypertension remission (OR 12.19, 95% CI 2.074-250; P =.023). Conclusion A CS >50% was an independent predictor of complete clinical and biochemical cure. Moreover, it can predict unilateral primary aldosteronism and postoperative biochemical hypoaldosteronism. Our findings underscore the usefulness of CS for clinical decision-making. [ABSTRACT FROM AUTHOR]

Several previous studies reported reduced leftward lateralization in blind participants’ samples compared to the sighted population. The origins of this difference remain unknown. Here, we tested whether functional lateralization is connected with the structural characteristics of white matter tracts [corpus callosum (CC), uncinate fasciculus (UF), and superior longitudinal fasciculus (SLF)], as suggested by previous studies conducted in the typical sighted population. Twenty-three blind and 21 sighted adult participants were tested during fMRI with a semantic decision paradigm presented both auditorily and in the modality appropriate for reading (tactually for the blind and visually for the sighted). Lateralization indices (LI) were calculated based on the activations. The fractional anisotropy (FA) measure was extracted from the white matter tracts of interest. Correlation analyses testing the relationship between FA and LI were conducted. The reduced leftward lateralization of both speech processing and reading-related activations was replicated. Nevertheless, the relationship between the structural integrity of the CC and LI and between the asymmetry of the intrahemispheric tracts and LI was not confirmed, possibly due to the lack of power. The sources of the reduced lateralization of the language network in the sensory-deprived population remain unknown. Further studies should account for environmental variables (e.g., the frequency of contact with written language) and the complexity of the factors that may influence the functional lateralization of the human brain. [ABSTRACT FROM AUTHOR]

Background Objectives Methods Results Conclusions A randomized trial suggested that reducing left‐sided subthalamic stimulation amplitude could improve axial dysfunction.To explore open‐label tolerability and associations between trial outcomes and asymmetry data.We collected adverse events in trial participants treated with open‐label lateralized settings for ≥3 months. We explored associations between trial outcomes, location of stimulation and motor asymmetry.14/17 participants tolerated unilateral amplitude reduction (left‐sided = 10, right‐sided = 4). Two hundred eighty‐four left‐sided and 1113 right‐sided stimulated voxels were associated with faster gait velocity, 81 left‐sided and 22 right‐sided stimulated voxels were associated with slower gait velocity. Amplitude reduction contralateral to shorter step length was associated with 2.4‐point reduction in axial MDS‐UPDRS. Reduction contralateral to longer step length was associated with 10‐point increase in MDS‐UPDRS.Left‐sided amplitude reduction is potentially more tolerable than right‐sided amplitude reduction. Right‐sided more than left‐sided stimulation could be associated with faster gait velocity. Shortened step length might reflect contralateral overstimulation. [ABSTRACT FROM AUTHOR]

Background/Aims: Within the scope of this research, we aimed to elucidate the relationship between carpal tunnel syndrome and migraine to explore both the pain intensity and the localization of carpal tunnel syndrome (CTS) in concomitant migraine. The primary outcome variable was elaborated as the pain lateralization, and the secondary outcome variable was the pain intensity. Method: This is a cross-sectional, observational prospective study of 500 patients with preliminary carpal tunnel syndrome diagnosis at our institution. After patients with missing data were excluded from the study, 413 remained, 365 (88.4%) women and 48 (11.6%) men. After recording the demographic characteristics, the patient’s migraine pain year of onset, pain characteristics, localization, frequency, duration, severity, triggering factors, symptoms, and findings accompanying the pain were recorded. Results: The lateralization of migraine was on the right side (only on the right or mostly on the right) in 25.9% and on the left side (only on the left or mostly on the left) in 26.4% of the patients. Almost half of the patients (47.7%) experienced bilateral migraine headaches. Carpal tunnel syndrome was in the right hand in 13.3%, in the left hand in 11.6%, and bilateral in 75.1%. Of 197 patients with bilateral pain, 68 (34.5%) had mild, 116 (58.9%) had moderate, and 13 (6.6%) had severe CTS. The VAS level of migraine pain was higher only in patients with CTS in the left hand and in those with moderate CTS. Conclusion: It has been determined that those with carpal tunnel syndrome on the right side have migraines mostly on the right, those with carpal tunnel syndrome on the left have migraines on the left, and those with carpal tunnel syndrome in both directions have migraines predominantly in both directions. [ABSTRACT FROM AUTHOR]

While domestic horses can be trained to choose the highest numerosity, spontaneous choice tests led to contrasting results, which in part might have depended upon the adopted experimental protocols. To bring further evidence, we carried out two experiments based on binary choice tests (1:4, 1:2, 2:3, 4:6 apple halves). We tested both horses used for schooling (N = 25) and semi-wild bred horses (N = 10), using two different arenas. In both experiments, horses did not choose the highest quantity, irrespective of test difficulty. Horses preferentially chose the stimulus located at their left, while no other tested variable affected their choice. The consistency between the results suggests that the lack of discrimination did not depend on test protocols. The strong preference for a given side and high within-individual repeatability indicate that lateralization may affect the results of spontaneous tests. [ABSTRACT FROM AUTHOR]

Elephants are known for strongly lateralized trunk behaviors, but the mechanisms driving elephant lateralization are poorly understood. Here, we investigate features of elephant mouth organization that presumably promote lateralization. We find the lower jaw of elephants is of narrow width, but is rostrally strongly elongated even beyond the jaw bone. Elephant lip vibrissae become progressively longer rostrally. Thus, elephants have two lateral dense, short microvibrissae arrays and central, less dense long macrovibrissae. This is an inversion of the ancestral mammalian facial vibrissae pattern, where central, dense short microvibrissae are flanked by two lateral macrovibrissae arrays. Elephant microvibrissae have smaller follicles than macrovibrissae. Similar to trunk‐tip vibrissae, elephant lip microvibrissae show laterally asymmetric abrasion. Observations on Asian zoo elephants indicate lateralized abrasion results from lateralized feeding. It appears that the ancestral mammalian mouth (upper and lower lips, incisors, frontal microvibrissae) is shaped by oral food apprehension. The elephant mouth organization radically changed, however, because trunk‐mediated feeding replaced oral apprehension. Such elephant mouth changes include the upper lip–nose fusion to the trunk, the super‐flexible elongated lower jaw, the loss of incisors, and lateral rather than frontal microvibrissae. Elephants' specialization for lateral food insertion is reflected by the reduction in the centering effects of oral food apprehension and lip vibrissae patterns. [ABSTRACT FROM AUTHOR]

Background: The volumes of the hippocampal subfields are related to poststroke cognitive dysfunctions. However, it remains unclear whether contralesional hippocampal subfield volume contributes to cognitive impairment. This study aimed to investigate the volumetric differences in the contralesional hippocampal subfields between patients with left and right hemisphere strokes (LHS/RHS). Additionally, correlations between contralesional hippocampal subfield volumes and clinical outcomes were explored. Methods: Fourteen LHS (13 males, 52.57 ± 7.10 years), 13 RHS (11 males, 51.23 ± 15.23 years), and 18 healthy controls (11 males, 46.94 ± 12.74 years) were enrolled. Contralesional global and regional hippocampal volumes were obtained with T1‐weighted images. Correlations between contralesional hippocampal subfield volumes and clinical outcomes, including the Montreal Cognitive Assessment (MoCA) and Mini‐Mental State Examination (MMSE), were analyzed. Bonferroni correction was applied for multiple comparisons. Results: Significant reductions were found in contralesional hippocampal as a whole (adjusted p =.011) and its subfield volumes, including the hippocampal tail (adjusted p =.005), cornu ammonis 1 (CA1) (adjusted p =.002), molecular layer (ML) (adjusted p =.004), granule cell and ML of the dentate gyrus (GC‐ML‐DG) (adjusted p =.015), CA3 (adjusted p =.009), and CA4 (adjusted p =.014) in the RHS group compared to the LHS group. MoCA and MMSE had positive correlations with volumes of contralesional hippocampal tail (p =.015, r =.771; p =.017, r =.763) and fimbria (p =.020, r =.750; p =.019, r =.753) in the LHS group, and CA3 (p =.007, r =.857; p =.009, r =.838) in the RHS group, respectively. Conclusion: Unilateral stroke caused volumetric differences in different hippocampal subfields contralesionally, which correlated to cognitive impairment. RHS leads to greater volumetric reduction in the whole contralesional hippocampus and specific subfields (hippocampal tail, CA1, ML, GC‐ML‐DG, CA3, and CA4) compared to LHS. These changes are correlated with cognitive impairments, potentially due to disrupted neural pathways and interhemispheric communication. [ABSTRACT FROM AUTHOR]

Background: The laterality of motor symptoms is considered a key feature of Parkinson's disease (PD). Here, we investigated whether gait and turning asymmetry coincided with symptom laterality as determined by the MDS-UPRDS part III and whether it was increased compared to healthy controls (HC). Methods: We analyzed the asymmetry of gait and turning with and without a cognitive dual task (DT) using motion capture systems and wearable sensors in 97 PD patients mostly from Hoehn & Yahr stage II and III and 36 age-matched HC. We also assessed motor symptom asymmetry using the bilateral sub-items of the MDS-UPDRS-III. Finally, we examined the strength of the association between gait asymmetry and symptom laterality. Results: Participants with PD had increased gait but not more turning asymmetry compared to HC (p < 0.05). Only 53.7% of patients had a shorter step length on the more affected body side as determined by the MDS-UPDRS-III. Also, 54% took more time and 29% more steps during turns toward the more affected side. The degree of asymmetry in the different domains did not correlate with each other and was not influenced by DT-load. Conclusions: We found a striking mismatch between the side and the degree of asymmetry in different motor domains, i.e., in gait, turning, and distal symptom severity in individuals with PD. We speculate that motor execution in different body parts relies on different neural control mechanisms. Our findings warrant further investigation to understand the complexity of gait asymmetry in PD. [ABSTRACT FROM AUTHOR]

Focal damage due to stroke causes widespread abnormal changes in brain function and hemispheric asymmetry. In this study, functional near‐infrared spectroscopy (fNIRS) was used to collect resting‐state hemoglobin data from 85 patients with subacute stroke and 26 healthy controls, to comparatively analyze the characteristics of lateralization after stroke in terms of cortical activity, functional networks, and hemodynamic lags. Higher intensity of motor cortical activity, lower hemispheric autonomy, and more abnormal hemodynamic leads or lags were found in the affected hemisphere. Lateralization metrics of the three aspects were all associated with the Fugl‐Meyer score. The results of this study prove that three lateralization metrics may provide clinical reference for stroke rehabilitation. Meanwhile, the present study piloted the use of resting‐state fNIRS for analyzing hemodynamic lag, demonstrating the potential of fNIRS to assess hemodynamic abnormalities in addition to the study of cortical neurological function after stroke. [ABSTRACT FROM AUTHOR]

The purpose of this study was to understand the different forces exerted between the side kick and turning kick in taekwon-do, which would add knowledge to the field, as well as help inform future research. Eighty kicks performed by four elite ITF (International Taekwon-do Federation) athletes (age: 28.5 ± 7.2 years; body mass: 77.5 ± 6.7 kg; height: 180.0 ± 1.6 cm) were analysed. Participants performed a series of turning and side kicks with the right and left leg to the target. The impact-force-measuring apparatus was a training shield mounted on a force plate manufactured by AMTI, model MC12-2K. The mean resultant impact force for the turning kick was significantly lower than the mean resultant impact force for the side kick. There were no significant differences in the impact force between turning kicks performed with either the right or left leg. With regard to the correlations for the turning kick performed by both legs, there was almost a full correlation between FZ and the resultant impact force (r = 0.988 for the right leg and r = 0.994 for the left leg). The side kicks' significantly higher resultant force (4429.77 ± 1361.25 N) than that of a turning kick (2648.98 ± 441.41 N) could be due to more effective mass being used. The turning kick peaked in a shorter time; this indicates that a turning kick has a shorter contact time with the target. The strong correlations between Fz and the resultant impact force in both kicks could be due to the direction of the kicks, suggesting that the force in the Z axis was the most important direction. [ABSTRACT FROM AUTHOR]

Abstract Introduction In reverse shoulder arthroplasty (RSA) new designs enable greater amounts of lateralization to prevent instability and scapular notching and increase range of motion, however, excessive lateralization leads to stress upon the acromion that can result in scapular spine fatigue fractures. Aim of this study was to gender- and size-specifically assess the influence of glenosphere size and different humeral designs on lateralization, distalization, and bony impingement-free range of motion (ROM) in patients undergoing RSA. Methods Computed tomography scans from 30 osteoarthritic patients (f:15, m:15) and 20 cuff tear arthropathy patients (f:10, m:10) were used to virtually simulate RSA implantation. The efficacy of an inlay Grammont-type system vs. an onlay lateralizing system combined with different glenosphere sizes (36 mm vs. 42 mm) in achieving ROM, lateralization, and distalization was evaluated. Moreover, gender and patient’s constitution were correlated to humeral size by radiologically measuring the best-fit circle of the humeral head. Results A different amount of relative lateralization was achieved in both genders using large glenospheres and onlay designs. Latter yielded a higher ROM in all planes for men and women with a 42 mm glenosphere; with the 36 mm glenosphere, an increased ROM was observed only in men. The 155° inlay design led to joint medialization only in men, whereas all designs led to lateralization in women. When adjusting the absolute amount of lateralization to humerus’ size (or patient’s height), regardless of implant type, women received greater relative lateralization using 36 mm glenosphere (inlay: 1%; onlay 12%) than men with 42 mm glenosphere (inlay: -3%; onlay: 8%). Conclusion The relative lateralization achieved using onlay design is much higher in women than men. Small glenospheres yield greater relative lateralization in women compared to large glenospheres in men. Humeral lateralization using onlay designs should be used cautiously in women, as they lead to great relative lateralization increasing stress onto the acromion. Level of evidence Basic Science Study, Computer Modeling.

Dominant lateralization refers to the phenomenon of having a leading extremity or leading sense during the execution of complex psychomotor activities. Writing represents a complex human ability and simultaneously the most complex form of linguistic activity, which includes knowledge, skills, and the art of proper letter formation. This study explores the relationship between lateralization and handwriting quality with the aim of identifying children with dysgraphic handwriting. The sample consisted of 90 younger elementary school students (third, fourth, and fifth grade), aged 8 to 11 years (AS = 9.93; SD = 0.84), of both genders (46 boys and 44 girls). The Handwriting Dysgraphia Assessment Test was used to assess handwriting quality. Dominant upper extremity lateralization was assessed using tests from the Sovak Test Battery (1979), while visual lateralization was assessed using a test from the General Defectology Diagnostics Practicum. The research was conducted at an elementary school in Trebinje, during February and March 2024. Research results show that a significant percentage of younger elementary school children have dysgraphic (21.1%) or severely dysgraphichandwriting (35.6%). Among the majority of participants, right-handed upper extremity dominance was observed (86.7%) along with right visual dominance (82.2%), with coordinated visual and upper extremity lateralization present in 88.9% of children. The results of investigation of the impact of uncoordinated upper extremity and visual lateralization on dysgraphic handwriting did not demonstrate statistical significance. Although our results did not confirm a link between lateralization and handwriting quality, for younger elementary school children with uncoordinated upper extremity and visual lateralization, exercises focusing on directing, practicing, and stabilizing lateralization are recommended

Background: Higher bone or metal glenoid offset in reverse shoulder arthroplasty (RSA) reduces scapular notching, improves range of motion (ROM), and reduces postoperative instability. This retrospective multicenter study compared two implant designs to evaluate the short-term clinical and radiologic results of bone increased offset RSA (BIO-RSA) and metal increased offset RSA (MIO-RSA) in reverse shoulder. We hypothesized no difference between groups. Methods: This study analyzed n = 62 BIO-RSA and n = 90 MIO-RSA cases with a mean follow-up of 29.7 ± 6.0 months (BIO-RSA, range 24-49 months) and 24.0 ± 1.1 months (MIO-RSA, range 22-28 months). A 145°-onlay humeral stem was utilized in BIO-RSA cases, while a 135°-semi-inlay humeral stem was implanted in all MIO-RSA cases. Preoperative and postoperative radiologic imaging was reviewed to identify signs of scapular notching. Additionally, lateralization was evaluated according to Erickson et al. The constant score, subjective shoulder value, and ROM were evaluated during the baseline and follow-up consultations, and the findings of both groups were subsequently compared. Results: Scapular notching was observed in 7.0% (n = 8) of MIO-RSA cases and 8.1% (n = 5) of BIO-RSA cases (P = .801). MIO-group had a higher lateralization angle (P = .020) and the BIO-group had a higher distalization angle (P = .005). At baseline, mean constant score in the MIO-RSA group was higher than in the BIO-RSA group (P

AbstractThe ability to hold objects relies on neural processes underlying grip force control during grasping. Brain activity lateralized to contralateral hemisphere averaged over trials is associated with grip force applied on an object. However, the involvement of neural variability within-trial during grip force control remains unclear. We examined dependence of neural variability over frontal, central, and parietal regions of interest (ROI) on grip force magnitude using noninvasive electroencephalography (EEG). We utilized our existing EEG dataset comprised of healthy young adults performing an isometric force control task, cued to exert 5, 10, or 15% of their maximum voluntary contraction (MVC) across trials and received visual feedback of their grip force. We quantified variability in EEG signal via sample entropy (sequence-dependent) and standard deviation (sequence-independent measure) over ROI. We found lateralized modulation in EEG sample entropy with force magnitude over central electrodes but not over frontal or parietal electrodes. However, modulation was not observed for standard deviation in the EEG activity. These findings highlight lateralized and spatially constrained modulation in sequence-dependent, but not sequence-independent component of EEG variability. We contextualize these findings in applications requiring finer precision (e.g., prosthesis), and propose directions for future studies investigating role of neural entropy in behavior. [ABSTRACT FROM AUTHOR]

Auditory spatial cues contribute to two distinct functions, of which one leads to explicit localization of sound sources and the other provides a location-linked representation of sound objects. Behavioral and imaging studies demonstrated right-hemispheric dominance for explicit sound localization. An early clinical case study documented the dissociation between the explicit sound localizations, which was heavily impaired, and fully preserved use of spatial cues for sound object segregation. The latter involves location-linked encoding of sound objects. We review here evidence pertaining to brain regions involved in location-linked representation of sound objects. Auditory evoked potential (AEP) and functional magnetic resonance imaging (fMRI) studies investigated this aspect by comparing encoding of individual sound objects, which changed their locations or remained stationary. Systematic search identified 1 AEP and 12 fMRI studies. Together with studies of anatomical correlates of impaired of spatial-cue-based sound object segregation after focal brain lesions, the present evidence indicates that the location-linked representation of sound objects involves strongly the left hemisphere and to a lesser degree the right hemisphere. Location-linked encoding of sound objects is present in several early-stage auditory areas and in the specialized temporal voice area. In these regions, emotional valence benefits from location-linked encoding as well. [ABSTRACT FROM AUTHOR]

Purpose: Previous studies have demonstrated impaired cerebellar function in patients with obstructive sleep apnea (OSA), which is associated with impaired cognition. However, the effects of OSA on resting-state functional connectivity (FC) in the cerebellum has not been determined. The purpose of this study was to investigate resting-state FC of the cerebellar subregions and its relevance to clinical symptoms in patients with OSA. Methods: Sixty-eight patients with OSA and seventy-two healthy controls (HCs) were included in the study. Eight subregions of the cerebellum were selected as regions of interest, and the FC values were calculated for each subregion with other voxels. A correlation analysis was performed to examine the relationship between clinical and cognitive data. Results: Patients with OSA showed higher FC in specific regions, including the right lobule VI with the right posterior middle temporal gyrus and right angular gyrus, the right Crus I with the bilateral precuneus/left superior parietal lobule, and the right Crus II with the precuneus/right posterior cingulate cortex. Furthermore, the oxygen depletion index was negatively correlated with aberrant FC between the right Crus II and the bilateral precuneus / right posterior cingulate cortex in OSA patients (p = 0.004). Conclusion: The cerebellum is functionally lateralized and closely linked to the posterior default mode network. Higher FC is related to cognition, emotion, language, and sleep in OSA. Abnormal FC may offer new neuroimaging evidence and insights for a deeper comprehension of OSA-related alterations. This study reveals altered resting-state functional connectivity in the cerebellum (8 cerebellar subregions) of obstructive sleep apnea (OSA) patients. These changes correlate with cognitive, emotional, linguistic, and sleep deficits, suggesting functional impairments and compensation in the cerebellum of OSA patients. [ABSTRACT FROM AUTHOR]

Rationale: Chronic stress exposure disrupts the medial prefrontal cortex's (mPFC) ability to regulate impulses, leading to the loss of control over alcohol drinking in rodents, emphasizing the critical role of this forebrain area in regulating alcohol consumption. Moreover, chronic stress exposure causes lateralization of mPFC functions with volumetric and functional changes, resulting in hyperactivity in the right hemisphere and functional decrease in the left. Objectives: This study investigated the inhibitory role of the left prelimbic cortex (LPrL) on ethanol consumption induced by chronic social defeat stress (SDS) in male mice and to examine if inactivation of the LPrL causes disinhibition of the right mPFC, leading to an increase in ethanol consumption. We also investigated the role of lateralization and neurochemical alterations in the mPFC related to ethanol consumption induced by chronic SDS. To this end, we examined the activation patterns of ΔFosB, VGLUT2, and GAD67 in the left and right mPFC. Results: Temporarily blocking the LPrL or right PrL (RPrL) cortices during acute SDS did not affect male mice's voluntary ethanol consumption in male mice. When each cortex was blocked in mice previously exposed to chronic SDS, ethanol consumption also remained unaffected. However, male mice with LPrL lesions during chronic SDS showed an increase in voluntary ethanol consumption, which was associated with enhanced ΔFosB/VGLUT2-positive neurons within the RPrL cortex. Conclusions: The results suggest that the LPrL may play a role in inhibiting ethanol consumption induced by chronic SDS, while the RPrL may be involved in the disinhibition of ethanol consumption. [ABSTRACT FROM AUTHOR]

Humeral implant designs for anatomic total shoulder arthroplasty (aTSA) focus on anatomic reconstruction of the articular segment. Likewise, the pathoanatomy of advanced glenohumeral osteoarthritis often results in humeral head deformity. We hypothesized the anatomic reconstruction of the humeral head in aTSA risks overstuffing the glenohumeral joint. Ninety-seven cases (52 females) of primary glenohumeral osteoarthritis in patients treated with aTSA were evaluated. Preoperative computed tomography scans were used to classify glenoid morphology according to the Walch classification. Coronal plane images in the plane of the humerus were used to determine the anatomic best-fit circle as described by Youderian et al. Humeral head thinning was determined as the distance from the center of rotation of the best-fit circle to the nearest point along the humeral articular surface. aTSA was modeled with a predicted anatomic humeral head and a simulated 4-mm polyethylene glenoid component. The change in the position of the native humerus was determined. Wilcoxon Rank Sum tests were used to evaluate differences in humeral head thinning and humeral lateralization between monoconcave and biconcave glenoid morphologies. Spearman's rank correlation coefficients were used to assess the relationship between humeral head thinning with preoperative active forward elevation and external rotation. The mean radius of the best-fit circle was 25.0 ± 2.1 mm. There was a mean thinning of 2.4 ± 2.0 mm (range −1.7 to 8.3). The mean percent thinning of the humeral head was 9.4% ± 7.7%. The mean humeral lateralization was 6.4 ± 2.0 mm. Humeral head thinning was not significantly associated with active forward elevation (r = −0.15, P =.14) or active external rotation (r = −0.12, P =.25). There were no significant differences in the percentage of humeral head thinning (P =.324) or humeral lateralization (P =.350) between concentric and eccentric glenoid wear patterns. Utilization of the best-fit circle as a guide in aTSA may risk excessive lateralization of the humerus and overstuffing the glenohumeral joint. This may have implications for subscapularis repair and healing, as well as glenoid implant and rotator cuff longevity. These findings call into question whether recreation of normal glenohumeral anatomy in aTSA is appropriate for all patients. Humeral head reconstruction in aTSA should account for glenohumeral joint volume and soft tissue contracture. [ABSTRACT FROM AUTHOR]

Glenoid-sided lateralization in reverse shoulder arthroplasty (RSA) decreases bony impingement and improves rotational range of motion, but has been theorized to increase the risk of acromial or scapular spine fractures (ASFs). The purpose of this study was to assess if glenoid-sided lateralization even up to 8 mm increases the risk for stress fracture following RSA with a 135° inlay humeral component. A retrospective review was performed from a multicenter prospectively collected database on patients who underwent primary RSA from 2015 to 2021. All RSAs were performed with a 135° inlay humeral component. Varying amounts of glenoid lateralization were used from 0 to 8 mm. Preoperative radiographs were reviewed for the presence of acromial thinning, acromiohumeral distance (AHD), and inclination. Postoperative implant position (distalization, lateralization, and inclination) as well as the presence of ASF was evaluated on minimum 1-year postoperative radiographs. Regression analyses were performed on component and clinical variables to assess for factors predictive of ASF. Acromial or scapular spine fractures were identified in 26 of 470 shoulders (5.5%). Glenoid-sided lateralization was not associated with ASF risk (P =.890). Furthermore, the incidence of fracture did not vary based on glenoid-sided lateralization (0-2 mm, 7.4%; 4 mm, 5.6%; 6 mm, 4.4%; 8 mm, 6.0%; P >.05 for all comparisons). RSA on the dominant extremity was predictive of fracture (odds ratio [OR] 2.21, 95% confidence interval [CI] 1.20-5.75; P =.037), but there was no relationship between patient age, sex, preoperative acromial thinning, or diagnosis and risk of fracture. Although there was no difference in mean postoperative AHD between groups (P =.443), the pre- to postoperative delta AHD was higher in the stress fracture group (2.0 ± 0.7 cm vs. 1.7 ± 0.7 cm; P =.015). For every centimeter increase in delta AHD, there was a 121% increased risk for fracture (OR 2.21, 95% CI 1.33-3.68; P =.012). Additionally, for every 1-mm increase in inferior glenosphere overhang, there was a 19% increase in fracture risk (P =.025). Up to 8 mm of glenoid-sided metallic lateralization does not appear to increase the risk of ASF when combined with a 135° inlay humeral implant. Humeral distalization increases the risk of ASF, particularly when there is a larger change between pre- and postoperative AHD or higher inferior glenosphere overhang. In cases of pronounced preoperative superior humeral migration, it may be a consideration to avoid excessive postoperative distalization, but minimizing bony impingement via glenoid-sided lateralization appears to be safe. [ABSTRACT FROM AUTHOR]

Background: Autism spectrum disorder has been linked to a variety of organizational and developmental deviations in the brain. One such organizational difference involves hemispheric lateralization, which may be localized to language-relevant regions of the brain or distributed more broadly. Methods: In the present study, we estimated brain hemispheric lateralization in autism based on each participant's unique functional neuroanatomy rather than relying on group-averaged data. Additionally, we explored potential relationships between the lateralization of the language network and behavioral phenotypes including verbal ability, language delay, and autism symptom severity. We hypothesized that differences in hemispheric asymmetries in autism would be limited to the language network, with the alternative hypothesis of pervasive differences in lateralization. We tested this and other hypotheses by employing a cross-sectional dataset of 118 individuals (48 autistic, 70 neurotypical). Using resting-state fMRI, we generated individual network parcellations and estimated network asymmetries using a surface area-based approach. A series of multiple regressions were then used to compare network asymmetries for eight significantly lateralized networks between groups. Results: We found significant group differences in lateralization for the left-lateralized Language (d = -0.89), right-lateralized Salience/Ventral Attention-A (d = 0.55), and right-lateralized Control-B (d = 0.51) networks, with the direction of these group differences indicating less asymmetry in autistic males. These differences were robust across different datasets from the same participants. Furthermore, we found that language delay stratified language lateralization, with the greatest group differences in language lateralization occurring between autistic males with language delay and neurotypical individuals. Conclusions: These findings evidence a complex pattern of functional lateralization differences in autism, extending beyond the Language network to the Salience/Ventral Attention-A and Control-B networks, yet not encompassing all networks, indicating a selective divergence rather than a pervasive one. Moreover, we observed an association between Language network lateralization and language delay in autistic males. [ABSTRACT FROM AUTHOR]

This study aimed to examine the right-left discrimination of hands, feet and back in individuals with scoliosis. In the study, right-left discrimination performance was evaluated with the mobile application called Recognize, radiographic features of scoliosis were evaluated with X-ray, degree of rotation was evaluated with the mobile application called Scoliodetector, and back pain was evaluated with the Visual Analog Scale. 25 individuals with idiopathic scoliosis were included in the analysis. In the comparison made according to the thoracolumbar and lumbar curve, no difference was found between the groups in the lateralization performances (p>0.05). In the comparison according to the type of curve, no significant difference was observed in the reaction time and accuracy rate between the groups (p>0.05). When comparing the lateralization performance according to the direction of the curve, a significant difference was found between the groups in the left foot and back reaction times (p<0.05). Weak or very weak correlations were shown between Cobb and rotation angle and lateralization measurements of the back, hand and foot. It has been shown that the location and type of the curve (C or S) does not have a significant effect on lateralization performance in individuals with idiopathic scoliosis, however, the direction of the curve may affect the discrimination of right and left. [ABSTRACT FROM AUTHOR]

We analyzed handedness of brown bears (Ursus arctos), which is the tendency to differentially use the right or left forelimb for dexterous actions. Handedness in mammals is hypothesized to be an outcome of lateralization of neocortex function, which serves to increase cognitive capacity by reducing redundancy of function between left and right hemispheres. Handedness in brown bears would give insight into brown bear capacity for cognition and innovative behavior. We tallied brown bear forelimb use from videography of bears foraging on anadromous sockeye salmon (Oncorhynchus nerka) while aggregated at the Brooks River within Katmai National Park, Alaska, USA, during autumn 2022. Brown bears exhibited a significant propensity for handedness, a result driven primarily by brown bears using their right forelimb more often than their left to swat at conspecifics during social interactions. Under the model that neocortex lateralization increases cognitive capacity, the right-handedness we observed in brown bears is consistent with their capacity for problem solving and behavioral innovation. [ABSTRACT FROM AUTHOR]

The human body seems symmetrical but functional asymmetry can be observed for many tasks. One of the tasks observed the functional asymmetry is grip force and rate of grip force development (RGFD). To efficiently accomplish many tasks, it is important to measure those parameters in different ages and special groups. Thus, the purpose of the study was to test asymmetry of max grip force and max RGFD among adolescents with and without intellectual disability. 41 adolescents with (IQ between 50 and 70) and 41 adolescents without intellectual disability voluntarily participated to the study. Max grip force and max RGFD was measured using a force transducer with custom-made software. The statistical analysis displayed that adolescents without intellectual disability had higher max grip force and max RGFD with their both hands compared to adolescent with intellectual disability. Interestingly, whereas adolescent without intellectual disability displayed an asymmetry between the hands both for max grip force and max RGFD, adolescents with intellectual disability had asymmetry only for max grip force but not for max RGFD. Thus, adolescents with intellectual disability may have symmetrical neurological pathways. Individuals with intellectual disability should be provided with more physical activity and/or exercise opportunities including the bimanual movements with fast and ballistic actions. [ABSTRACT FROM AUTHOR]

On the surface, the two hemispheres of vertebrate brains look almost perfectly symmetrical, but several motor, sensory, and cognitive systems show a deeply lateralized organization. Importantly, the two hemispheres are connected by various commissures, white matter tracts that cross the brain's midline and enable cross-hemispheric communication. Cross-hemispheric communication has been suggested to play an important role in the emergence of lateralized brain functions. Here, we review current advances in understanding cross-hemispheric communication that have been made using modern neuroscientific tools in rodents and other model species, such as genetic labeling, large-scale recordings of neuronal activity, spatiotemporally precise perturbation, and quantitative behavior analyses. These findings suggest that the emergence of lateralized brain functions cannot be fully explained by largely static factors such as genetic variation and differences in structural brain asymmetries. In addition, learning-dependent asymmetric interactions between the left and right hemispheres shape lateralized brain functions. Ocklenburg and Guo review the current state of knowledge on cross-hemispheric communication in the vertebrate brain, with a focus on recent research in rodents. They discuss how lateralization in sensory, memory, and motor functions can emerge from asymmetric cross-hemispheric communication. [ABSTRACT FROM AUTHOR]

Introduction: Dysphagia commonly occurs after stroke, yet the mechanisms of post-stroke corticobulbar plasticity are not well understood. While cortical activity associated with swallowing actions is bihemispheric, prior research has suggested that plasticity of the intact cortex may drive recovery of swallowing after unilateral stroke. Age may be an important factor as it is an independent predictor of dysphagia after stroke and neuroplasticity may be reduced with age. Based on previous clinical studies, we hypothesized that cranial muscle activating volumes may be expanded in the intact hemisphere and would contribute to swallowing function. We also hypothesized that older age would be associated with limited map expansion and reduced function. As such, our goal was to determine the impact of stroke and age on corticobulbar plasticity by examining the jaw and tongue muscle activating volumes within the bilateral sensorimotor cortices. Methods: Using the middle cerebral artery occlusion rat stroke model, intracortical microstimulation (ICMS) was used to map regions of sensorimotor cortex that activate tongue and jaw muscles in both hemispheres. Young adult (7 months) and aged (30 months) male F344 x BN rats underwent a stroke or sham-control surgery, followed by ICMS mapping 8 weeks later. Videofluoroscopy was used to assess oral-motor functions. Results: Increased activating volume of the sensorimotor cortex within the intact hemisphere was found only for jaw muscles, whereas significant stroke-related differences in tongue activating cortical volume were limited to the infarcted hemisphere. These stroke-related differences were correlated with infarct size, such that larger infarcts were associated with increased jaw representation in the intact hemisphere and decreased tongue representation in the infarcted hemisphere. We found that both age and stroke were independently associated with swallowing differences, weight loss, and increased corticomotor thresholds. Laterality of tongue and jaw representations in the sham-control group revealed variability between individuals and between muscles within individuals. Conclusion: Our findings suggest the role of the intact and infarcted hemispheres in the recovery of oral motor function may differ between the tongue and jaw muscles, which may have important implications for rehabilitation, especially hemisphere-specific neuromodulatory approaches. This study addressed the natural course of recovery after stroke; future work should expand to focus on rehabilitation. [ABSTRACT FROM AUTHOR]

Sleep disturbance is a recognized risk factor for Alzheimer's disease (AD), but the underlying micro-pathological evidence remains limited. To bridge this gap, we established an amyloid-β oligomers (AβO)-induced rat model of AD and subjected it to intermittent sleep deprivation (SD). Diffusion tensor imaging (DTI) and transmission electron microscopy were employed to assess white matter (WM) integrity and ultrastructural changes in myelin sheaths. Our findings demonstrated that SD exacerbated AβO-induced cognitive decline. Furthermore, we found SD aggravated AβO-induced asymmetrical impairments in WM, presenting with reductions in tract integrity observed in commissural fibers and association fasciculi, particularly the right anterior commissure, right corpus callosum, and left cingulum. Ultrastructural changes in myelin sheaths within the hippocampus and corpus callosum further confirmed a lateralized effect. Moreover, SD worsened AβO-induced lateralized disruption of the brain structural network, with impairments in critical nodes of the left hemisphere strongly correlated with cognitive dysfunction. This work represents the first identification of a lateralized impact of SD on the mesoscopic network and cognitive deficits in an AD rat model. These findings could deepen our understanding of the complex interplay between sleep disturbance and AD pathology, providing valuable insights into the early progression of the disease, as well as the development of neuroimaging biomarkers for screening early AD patients with self-reported sleep disturbances. Enhanced understanding of these mechanisms may pave the way for targeted interventions to alleviate cognitive decline and improve the quality of life for individuals at risk of or affected by AD. a AβO injection and sleep deprivation were conducted on adult rats. b Sleep deprivation and AβO-induced neurotoxicity aggravated cognitive disability with a synergistic effect. c Sleep deprivation and AβO-induced neurotoxicity reduced the integrity of specific association fasciculi and commissural fibers with ultrastructural demyelination. d On the basis of white matter integrity destruction, the structural connection was disrupted. The exacerbated topological properties with lateralized effects were correlated with cognitive decline. [ABSTRACT FROM AUTHOR]

The present study aims to investigate whether begging calls elicit specific auditory responses in non-parenting birds, whether these responses are influenced by the hormonal status of the bird, and whether they reflect biparental care for offspring in the European starling (Sturnus vulgaris). An fMRI experiment was conducted to expose non-parenting male and female European starlings to recordings of conspecific nestling begging calls during both artificially induced breeding and non-breeding seasons. This response was compared with their reaction to conspecific individual warbling song motifs and artificial pure tones, serving as social species-specific and artificial control stimuli, respectively. Our findings reveal that begging calls evoke a response in non-parenting male and female starlings, with significantly higher responsiveness observed in the right Field L and the Caudomedial Nidopallium (NCM), regardless of season or sex. Moreover, a significant seasonal variation in auditory brain responses was elicited in both sexes exclusively by begging calls, not by the applied control stimuli, within a ventral midsagittal region of NCM. This heightened response to begging calls, even in non-parenting birds, in the right primary auditory system (Field L), and the photoperiod induced hormonal neuromodulation of auditory responses to offspring’s begging calls in the secondary auditory system (NCM), bears resemblance to mammalian responses to hunger calls. This suggests a convergent evolution aimed at facilitating swift adult responses to such calls crucial for offspring survival.

Abstract Background The volumes of the hippocampal subfields are related to poststroke cognitive dysfunctions. However, it remains unclear whether contralesional hippocampal subfield volume contributes to cognitive impairment. This study aimed to investigate the volumetric differences in the contralesional hippocampal subfields between patients with left and right hemisphere strokes (LHS/RHS). Additionally, correlations between contralesional hippocampal subfield volumes and clinical outcomes were explored. Methods Fourteen LHS (13 males, 52.57 ± 7.10 years), 13 RHS (11 males, 51.23 ± 15.23 years), and 18 healthy controls (11 males, 46.94 ± 12.74 years) were enrolled. Contralesional global and regional hippocampal volumes were obtained with T1‐weighted images. Correlations between contralesional hippocampal subfield volumes and clinical outcomes, including the Montreal Cognitive Assessment (MoCA) and Mini‐Mental State Examination (MMSE), were analyzed. Bonferroni correction was applied for multiple comparisons. Results Significant reductions were found in contralesional hippocampal as a whole (adjusted p = .011) and its subfield volumes, including the hippocampal tail (adjusted p = .005), cornu ammonis 1 (CA1) (adjusted p = .002), molecular layer (ML) (adjusted p = .004), granule cell and ML of the dentate gyrus (GC‐ML‐DG) (adjusted p = .015), CA3 (adjusted p = .009), and CA4 (adjusted p = .014) in the RHS group compared to the LHS group. MoCA and MMSE had positive correlations with volumes of contralesional hippocampal tail (p = .015, r = .771; p = .017, r = .763) and fimbria (p = .020, r = .750; p = .019, r = .753) in the LHS group, and CA3 (p = .007, r = .857; p = .009, r = .838) in the RHS group, respectively. Conclusion Unilateral stroke caused volumetric differences in different hippocampal subfields contralesionally, which correlated to cognitive impairment. RHS leads to greater volumetric reduction in the whole contralesional hippocampus and specific subfields (hippocampal tail, CA1, ML, GC‐ML‐DG, CA3, and CA4) compared to LHS. These changes are correlated with cognitive impairments, potentially due to disrupted neural pathways and interhemispheric communication.

Several previous studies reported reduced leftward lateralization in blind participants’ samples compared to the sighted population. The origins of this difference remain unknown. Here, we tested whether functional lateralization is connected with the structural characteristics of white matter tracts [corpus callosum (CC), uncinate fasciculus (UF), and superior longitudinal fasciculus (SLF)], as suggested by previous studies conducted in the typical sighted population. Twenty-three blind and 21 sighted adult participants were tested during fMRI with a semantic decision paradigm presented both auditorily and in the modality appropriate for reading (tactually for the blind and visually for the sighted). Lateralization indices (LI) were calculated based on the activations. The fractional anisotropy (FA) measure was extracted from the white matter tracts of interest. Correlation analyses testing the relationship between FA and LI were conducted. The reduced leftward lateralization of both speech processing and reading-related activations was replicated. Nevertheless, the relationship between the structural integrity of the CC and LI and between the asymmetry of the intrahemispheric tracts and LI was not confirmed, possibly due to the lack of power. The sources of the reduced lateralization of the language network in the sensory-deprived population remain unknown. Further studies should account for environmental variables (e.g., the frequency of contact with written language) and the complexity of the factors that may influence the functional lateralization of the human brain.

The asymmetry between the left and right sides seems to be a general principle of organization of the nervous systems in Bilateria, providing the foundations for a plethora of leftward and rightward biases in behaviour as documented in species ranging from Caenorhabditis elegans nematodes to humans. Several theories have been put forward to account for the existence and maintenance in the evolution of the asymmetric organization of the brain at both individual and population levels. However, what is missing in theorizing about the evolution of brain asymmetry is an overarching general hypothesis that may subsume all different aspects of current models. Here, we tried to provide an overarching general framework based on the energy and free-energy minimization principle, which proved so valuable in other areas of neuroscience. We found that at the individual level the antisymmetric singlet configuration realizes the lowest energy state of the system, whereas at the group level, the spontaneous emergence of directional asymmetry arises as a consequence of the minimization of the free energy of the system, which guarantees its stability and equilibrium. We thus argue that the various phenomenological aspects of brain asymmetry that have been captured in biology—e.g. sparing of neural tissue, control of unitary motor responses and, at the population level, evolutionarily stable strategies described by mathematical games theory—may be thought of as the manifestation of a more general principle of energy minimization generating, among others, asymmetry of the brains.

Diffusion tensor imaging (DTI) studies have demonstrated white matter microstructural differences between the left and right hemispheres of the brain. However, the basis of these hemispheric asymmetries is not yet understood in terms of the biophysical properties of white matter microstructure, especially in children. There are reports of altered hemispheric white matter lateralization in ASD; however, this has not been studied in other related neurodevelopmental disorders such as sensory processing disorder (SPD). Firstly, we postulate that biophysical compartment modeling of diffusion MRI (dMRI), such as Neurite Orientation Dispersion and Density Imaging (NODDI), can elucidate the hemispheric microstructural asymmetries observed from DTI in children with neurodevelopmental concerns. Secondly, we hypothesize that sensory over-responsivity (SOR), a common type of SPD, will show altered hemispheric lateralization relative to children without SOR. Eighty-seven children (29 females, 58 males), ages 8-12 years, presenting at a community-based neurodevelopmental clinic were enrolled, 48 with SOR and 39 without. Participants were evaluated using the Sensory Processing 3 Dimensions (SP3D). Whole brain 3 T multi-shell multiband dMRI (b = 0, 1,000, 2,500 s/mm2) was performed. Tract Based Spatial Statistics were used to extract DTI and NODDI metrics from 20 bilateral tracts of the Johns Hopkins University White-Matter Tractography Atlas and the lateralization Index (LI) was calculated for each left-right tract pair. With DTI metrics, 12 of 20 tracts were left lateralized for fractional anisotropy and 17/20 tracts were right lateralized for axial diffusivity. These hemispheric asymmetries could be explained by NODDI metrics, including neurite density index (18/20 tracts left lateralized), orientation dispersion index (15/20 tracts left lateralized) and free water fraction (16/20 tracts lateralized). Children with SOR served as a test case of the utility of studying LI in neurodevelopmental disorders. Our data demonstrated increased lateralization in several tracts for both DTI and NODDI metrics in children with SOR, which were distinct for males versus females, when compared to children without SOR. Biophysical properties from NODDI can explain the hemispheric lateralization of white matter microstructure in children. As a patient-specific ratio, the lateralization index can eliminate scanner-related and inter-individual sources of variability and thus potentially serve as a clinically useful imaging biomarker for neurodevelopmental disorders.

Abstract Background The two major reverse shoulder arthroplasty (RSA) designs are the Grammont design and the lateralized design. Even if the lateralized design is biomechanically favored, the classic Grammont prosthesis continues to be used. Functional and subjective patient scores as well as implant survival described in the literature so far are comparable to the lateralized design. A pure comparison of how the RSA design influences outcome in patients has not yet been determined. The aim of this study was a comparison focused on patients with cuff tear arthropathy (CTA). Methods We analyzed registry data from 696 CTA patients prospectively collected between 2012 and 2020 in two specialized orthopedic centers up to 2 years post-RSA with the same follow-up time points (6,12 24 months). Complete teres minor tears were excluded. Three groups were defined: group 1 (inlay, 155° humeral inclination, 36 + 2 mm eccentric glenosphere (n = 50)), group 2 (inlay, 135° humeral inclination, 36 + 4 mm lateralized glenosphere (n = 141)) and group 3 (onlay, 145° humeral inclination, + 3 mm lateralized base plate, 36 + 2 mm eccentric glenosphere (n = 35)) We compared group differences in clinical outcomes (e.g., active and passive range of motion (ROM), abduction strength, Constant-Murley score (CS)), radiographic evaluations of prosthetic position, scapular anatomy and complications using mixed models adjusted for age and sex. Results The final analysis included 226 patients. The overall adjusted p-value of the CS for all time-points showed no significant difference (p = 0.466). Flexion of group 3 (mean, 155° (SD 13)) was higher than flexion of group 1 (mean, 142° (SD 18) and 2 (mean, 132° (SD 18) (p

Abstract Juvenile male zebra finches (Taeniopygia guttata) must be exposed to an adult tutor during a sensitive period to develop normal adult song. The pre-motor nucleus HVC (acronym used as a proper name), plays a critical role in song learning and production (cf. Broca’s area in humans). In the human brain, left-side hemispheric dominance in some language regions is positively correlated with proficiency in linguistic skills. However, it is unclear whether this pattern depends upon language learning, develops with normal maturation of the brain, or is the result of pre-existing functional asymmetries. In juvenile zebra finches, even though both left and right HVC contribute to song production, baseline molecular activity in HVC is left-dominant. To test if HVC exhibits hemispheric dominance prior to song learning, we raised juvenile males in isolation from adult song and measured neuronal activity in the left and right HVC upon first exposure to an auditory stimulus. Activity in the HVC was measured using the immediate early gene (IEG) zenk (acronym for zif-268, egr-1, NGFI-a, and krox-24) as a marker for neuronal activity. We found that neuronal activity in the HVC of juvenile male zebra finches is not lateralized when raised in the absence of adult song, while normally-reared juvenile birds are left-dominant. These findings show that there is no pre-existing asymmetry in the HVC prior to song exposure, suggesting that lateralization of the song system depends on learning through early exposure to adult song and subsequent song-imitation practice.

This study aims to investigate the impact of application patterns of Korean phonological rules in foreign-accented speech on native speakers’ comprehension. The phonological rules investigated here are lateralization and nasalization, which are considered the most difficult for foreign learners. Lateralization and nasalization are obligatory assimilation rules that frequently occur in spoken Korean. They involve the phoneme at the syllable boundary turning into a lateral or nasal sound during the assimilation process. For example, the words/jʌn + lak/’call’ are pronounced as jʌl.lak, and ‘front door’/ap + mun/as am.mun. A total of 2,340 foreign-accented utterances (39 learners *60 sentences) have been collected and sorted into three categories based on the application pattern of the phonological rule: ‘applied’, ‘misapplied’, and ‘not applied’. Thirteen Korean native speakers have been exposed to thirty utterances, including all application patterns for each phonological rule. Listeners’ comprehension has been measured by intelligibility, comprehensibility and accentedness. The primary argument of this paper is whether we should view the non-application of lateralization and nasalization rules as a pronunciation error that hinders the learner’s communication abilities or simply as an unnatural pronunciation that results in foreign-accented speech. The results showed that the non-application of nasalization rules, especially liquid nasalization and obstruent + liquid nasalization, had a direct impact on listeners’ comprehension. This suggests that learners of Korean need to be aware of these phonological rules and apply them correctly in communicative situations. This study also determined which pronunciation elements need to be taught during a Korean language class.

Face processing dominates the right hemisphere. This lateralization can be affected by co-lateralization within the same system and influence between different systems, such as neural competition from reading acquisition. Yet, how the relationship pattern changes through development remains unknown. This study examined the lateralization of core face processing and word processing in different age groups. By comparing fMRI data from 36 school-aged children and 40 young adults, we investigated whether there are age and regional effects on lateralization, and how relationships between lateralization within and between systems change across development. Our results showed significant right hemispheric lateralization in the core face system and left hemispheric lateralization in reading-related areas for both age groups when viewing faces and texts passively. While all participants showed stronger lateralization in brain regions of higher functional hierarchy when viewing faces, only adults exhibited this lateralization when viewing texts. In both age cohorts, there was intra-system co-lateralization for face processing, whereas an inter-system relationship was only found in adults. Specifically, functional lateralization of Broca’s area during reading negatively predicted functional asymmetry in the FFA during face perception. This study initially provides neuroimaging evidence for the reading-induced neural competition theory from a maturational perspective in Chinese cohorts.

There is considerable debate about whether additional fMRI-measured activity in the right prefrontal cortex readily observed in older adults represents compensatory activation that enhances cognition or whether maintenance of youthful brain activity best supports cognitive function in late adulthood. To investigate this issue, we tested a large lifespan sample of 461 adults (aged 20-89) and treated degree of left-lateralization in ventrolateral and dorsolateral prefrontal cortex during a semantic judgment fMRI task as an individual differences variable to predict cognition. We found that younger adults were highly left-lateralized, but lateralization did not predict better cognition, whereas higher left-lateralization of prefrontal cortex predicted better cognitive performance in middle-aged adults, providing evidence that left-lateralized, youth-like patterns are optimal in middle age. This relationship was reversed in older adults, with lower laterality scores associated with better cognition. The findings suggest that bilaterality in older adults facilitates cognition, but early manifestation of this pattern during middle age is characteristic of low performers. Implications of these findings for current theories of neurocognitive aging are discussed.

Acute ischemic stroke, characterized by a localized reduction in blood flow to specific areas of the brain, has been shown to affect binaural auditory perception. In a previous study conducted during the acute phase of ischemic stroke, two tasks of binaural hearing were performed: binaural tone-in-noise detection, and lateralization of stimuli with interaural time- or level differences. Various lesion-specific, as well as individual, differences in binaural performance between patients in the acute phase of stroke and a control group were demonstrated. For the current study, we re-invited the same group of patients, whereupon a subgroup repeated the experiments during the subacute and chronic phases of stroke. Similar to the initial study, this subgroup consisted of patients with lesions in different locations, including cortical and subcortical areas. At the group level, the results from the tone-in-noise detection experiment remained consistent across the three measurement phases, as did the number of deviations from normal performance in the lateralization task. However, the performance in the lateralization task exhibited variations over time among individual patients. Some patients demonstrated improvements in their lateralization abilities, indicating recovery, whereas others' lateralization performance deteriorated during the later stages of stroke. Notably, our analyses did not reveal consistent patterns for patients with similar lesion locations. These findings suggest that recovery processes are more individual than the acute effects of stroke on binaural perception. Individual impairments in binaural hearing abilities after the acute phase of ischemic stroke have been demonstrated and should therefore also be targeted in rehabilitation programs. [ABSTRACT FROM AUTHOR]

Juvenile male zebra finches (Taeniopygia guttata) must be exposed to an adult tutor during a sensitive period to develop normal adult song. The pre-motor nucleus HVC (acronym used as a proper name), plays a critical role in song learning and production (cf. Broca's area in humans). In the human brain, left-side hemispheric dominance in some language regions is positively correlated with proficiency in linguistic skills. However, it is unclear whether this pattern depends upon language learning, develops with normal maturation of the brain, or is the result of pre-existing functional asymmetries. In juvenile zebra finches, even though both left and right HVC contribute to song production, baseline molecular activity in HVC is left-dominant. To test if HVC exhibits hemispheric dominance prior to song learning, we raised juvenile males in isolation from adult song and measured neuronal activity in the left and right HVC upon first exposure to an auditory stimulus. Activity in the HVC was measured using the immediate early gene (IEG) zenk (acronym for zif-268, egr-1, NGFI-a, and krox-24) as a marker for neuronal activity. We found that neuronal activity in the HVC of juvenile male zebra finches is not lateralized when raised in the absence of adult song, while normally-reared juvenile birds are left-dominant. These findings show that there is no pre-existing asymmetry in the HVC prior to song exposure, suggesting that lateralization of the song system depends on learning through early exposure to adult song and subsequent song-imitation practice. [ABSTRACT FROM AUTHOR]

Background: The two major reverse shoulder arthroplasty (RSA) designs are the Grammont design and the lateralized design. Even if the lateralized design is biomechanically favored, the classic Grammont prosthesis continues to be used. Functional and subjective patient scores as well as implant survival described in the literature so far are comparable to the lateralized design. A pure comparison of how the RSA design influences outcome in patients has not yet been determined. The aim of this study was a comparison focused on patients with cuff tear arthropathy (CTA). Methods: We analyzed registry data from 696 CTA patients prospectively collected between 2012 and 2020 in two specialized orthopedic centers up to 2 years post-RSA with the same follow-up time points (6,12 24 months). Complete teres minor tears were excluded. Three groups were defined: group 1 (inlay, 155° humeral inclination, 36 + 2 mm eccentric glenosphere (n = 50)), group 2 (inlay, 135° humeral inclination, 36 + 4 mm lateralized glenosphere (n = 141)) and group 3 (onlay, 145° humeral inclination, + 3 mm lateralized base plate, 36 + 2 mm eccentric glenosphere (n = 35)) We compared group differences in clinical outcomes (e.g., active and passive range of motion (ROM), abduction strength, Constant-Murley score (CS)), radiographic evaluations of prosthetic position, scapular anatomy and complications using mixed models adjusted for age and sex. Results: The final analysis included 226 patients. The overall adjusted p-value of the CS for all time-points showed no significant difference (p = 0.466). Flexion of group 3 (mean, 155° (SD 13)) was higher than flexion of group 1 (mean, 142° (SD 18) and 2 (mean, 132° (SD 18) (p < 0.001). Values for abduction of group 3 (mean, 145° (SD 23)) were bigger than those of group 1 (mean, 130° (SD 22)) and group 2 (mean, 118° (SD 25)) (p < 0.001). Mean external rotation for group 3 (mean, 41° (SD 23)) and group 2 (mean, 38° (SD 17)) was larger than external rotation of group 1 (mean, 24° (SD 16)) (p < 0.001); a greater proportion of group 2 (78%) and 3 (69%) patients reached L3 level on internal rotation compared to group 1 (44%) (p = 0.003). Prosthesis position measurements were similar, but group 3 had significantly less scapular notching (14%) versus 24% (group 2) and 50% (group 1) (p = 0.001). Conclusions: Outcome scores of different RSA designs for CTA revealed comparable results. However, CTA patients with a lateralized and distalized RSA configuration were associated with achieving better flexion and abduction with less scapular notching. A better rotation was associated with either of the lateralized RSA designs in comparison with the classic Grammont prosthesis. Level of Evidence: Therapeutic study, Level III. [ABSTRACT FROM AUTHOR]