Right-hemisphere brain regions are strongly implicated in facial emotion processing (FEP), a phenomenon termed right-hemispheric bias (RHB). Variability in FEP hemispheric bias is thought to underpin differences in facial emotion recognition ability. Differences in FEP hemispheric bias have been associated with autistic traits. However, research to date investigating factors affecting FEP hemispheric bias is inconsistent. 427 adults recruited from the general population aged 18-67 years completed the Autism-spectrum Quotient (AQ). We also assessed covariates previously linked with FEP hemispheric bias including age, handedness, and biological sex. FEP hemispheric bias was indexed using laterality quotients (LQs) calculated from a Chimeric Faces Task, where participants indicated which of two identical (but mirrored) half-emotional half-neutral (no emotion) chimeric faces were more emotive. Linear regression models revealed that AQ total score did not significantly predict FEP hemispheric bias. RHB was stronger in right- compared to left-handed participants. These findings indicate that the relationship between autistic traits and FEP hemispheric bias is nuanced. Additionally, handedness influences hemispheric bias effects during FEP. Future research should endeavour to investigate if FEP hemispheric bias is dependent on the emotion being observed and consider use of more direct measures of hemispheric bias.

Facial emotion processing (FEP) tends to be right hemisphere lateralized. This right-hemispheric bias (RHB) for FEP varies within and between individuals. The aim of the present research was to examine evidence pertaining to the prominent theories of FEP hemispheric bias as measured by a half-emotional half-neutral (no emotion) chimeric faces task. FEP hemispheric bias was indexed using laterality quotients (LQs) calculated from a Chimeric Faces Task completed by 427 adults recruited from the general population aged 18-67 years. Participants indicated which of two identical (but mirrored) emotional-neutral chimeric faces were more emotive. While all investigated emotions (fear, anger, and happiness) were right lateralized, fear was significantly more right lateralized than anger and happiness. These results provide evidence for both the right hemisphere hypothesis and the motivational hypothesis of emotion perception.

Theta burst stimulation (TBS) is a non-invasive brain stimulation technique that can modulate neural activity. The effect of TBS on regions beyond the motor cortex remains unclear. With increased interest in applying TBS to non-motor regions for research and clinical purposes, these effects must be understood and characterised. We synthesised the electrophysiological effects of a single session of TBS, as indexed by electroencephalography (EEG) and concurrent transcranial magnetic stimulation and EEG (TMS-EEG), in non-clinical participants. We reviewed 79 studies that administered either continuous TBS (cTBS) or intermittent TBS (iTBS) protocols. Broadly, cTBS suppressed and iTBS facilitated evoked response component amplitudes. Response to TBS as measured by spectral power and connectivity was much more variable. Variability increased in the presence of task stimuli. There was a large degree of heterogeneity in the research methodology across studies. Additionally, the effect of individual differences on TBS response is insufficiently investigated. Future research investigating the effects of TBS as measured by EEG must consider methodological and individual factors that may affect TBS outcomes.

Processes contributing to forming and maintaining the self are matters of longstanding debate and significance, for example regarding disorders manifesting aberrant self-processing, such as borderline personality disorder. One theory proposes a hierarchy of self-referential processes including interoceptive-, exteroceptive-, and mental-self-processing levels. No systematic examination of these levels in relation to borderline personality traits has been conducted. Understanding this relationship may highlight underlying mechanisms contributing to observable borderline personality pathology. The sample of 118 healthy adults (mean age = 36.4 years, SD = 14.6, 80 females) completed an online survey, using instruments indexing self-processing at interoceptive, exteroceptive and mental levels. More atypical embodied sense of self (an exteroceptive index) and lower self -insight (a mental index) were associated with higher self -relevant borderline personality trait levels. There was no evidence of a relationship between interoceptive and self -relevant borderline personality trait measures. These findings support exteroceptive- and mental-self-processing atypicalities in the manifestation of self -relevant borderline personality traits. Specifically targeting these domains behaviourally and narratively may augment existing evidence-based borderline personality disorder interventions.

The restorative and mental state enhancing effects of brief mindfulness-based interventions (MBIs) and restorative environments such as nature has been supported in the research literature. However, regular adoption of these practices is limited by practical constraints and motivational barriers. The current study addressed these challenges by introducing two novel approaches which utilise the immersive and interactive qualities of virtual reality (VR). This included an interactive MBI and an abstract restorative environment using fractal-like imagery. These approaches were explored using a comparative evaluation of two short (6 min) VR interventions: Passive VR (applying principles from restorative interventions) and Interactive VR (implementing a focused attention form of mindfulness meditation). A mixed methods approach revealed increased state mindfulness, reduced mental fatigue, and enhanced aspects of mood (calm/relaxation, anxiety) consistently between conditions. Between group differences revealed additional benefits for cognition (focus), mood (happiness and sadness), and motivational value with the interactive intervention. The abstract environment, used in both interventions, maintained comparable levels of perceived restoration with a nature VR control condition. The results provide preliminary evidence supporting the use of interactive approaches for mindfulness interventions and abstract versions of restorative environments.

Theta burst stimulation (TBS) is associated with the modulation of a range of clinical, cognitive, and behavioural outcomes, but specific neurobiological effects remain somewhat unclear. This systematic literature review investigated resting-state and task-based functional magnetic resonance imaging (fMRI) outcomes post-TBS in healthy human adults. Fifty studies that applied either continuous—or intermittent—(c/i) TBS, and adopted a pretest–posttest or sham-controlled design, were included. For resting-state outcomes following stimulation applied to motor, temporal, parietal, occipital, or cerebellar regions, functional connectivity generally decreased in response to cTBS and increased in response to iTBS, though there were some exceptions to this pattern of response. These findings are mostly consistent with the assumed long-term depression (LTD)/long-term potentiation (LTP)-like plasticity effects of cTBS and iTBS, respectively. Task-related outcomes following TBS were more variable. TBS applied to the prefrontal cortex, irrespective of task or state, also produced more variable responses, with no consistent patterns emerging. Individual participant and methodological factors are likely to contribute to the variability in responses to TBS. Future studies assessing the effects of TBS via fMRI must account for factors known to affect the TBS outcomes, both at the level of individual participants and of research methodology.

While mentally simulated actions activate similar neural structures to overt movement, the role of the primary motor cortex (PMC) in motor imagery remains disputed. The aim of the study was to use continuous theta burst stimulation (cTBS) to modulate corticospinal activity to investigate the putative role of the PMC in implicit motor imagery in young adults with typical and atypical motor ability. A randomized, double blind, sham-controlled, crossover, offline cTBS protocol was applied to 35 young adults. During three separate sessions, adults with typical and low motor ability (developmental coordination disorder [DCD]), received active cTBS to the PMC and supplementary motor area (SMA), and sham stimulation to either the PMC or SMA. Following stimulation, participants completed measures of motor imagery (i.e., hand rotation task) and visual imagery (i.e., letter number rotation task). Although active cTBS significantly reduced corticospinal excitability in adults with typical motor ability, neither task performance was altered following active cTBS to the PMC or SMA, compared to performance after sham cTBS. These results did not differ across motor status (i.e., typical motor ability and DCD). These findings are not consistent with our hypothesis that the PMC (and SMA) is directly involved in motor imagery. Instead, previous motor cortical activation observed during motor imagery may be an epiphenomenon of other neurophysiological processes and/or activity within brain regions involved in motor imagery. This study highlights the need to consider multi-session theta burst stimulation application and its neural effects when probing the putative role of motor cortices in motor imagery.

Hypoglossal nerve palsy is a rare disorder resulting in dysarthria and tongue weakness, usually caused by direct nerve compression or injury. Malignant invasion of the skull base can rarely lead to bilateral hypoglossal nerve compression at the exit of the hypoglossal canals. We report the case of a 40-year-old man with stage IV colorectal cancer who presented with tongue weakness and dysphagia and was discovered to have new metastases to his skull base with invasion of his bilateral hypoglossal canals.

INTRODUCTION:Although intra-articular injections (IAIs) serve as the first-line non-surgical management for severe osteoarthritis (OA), recent analyses have suggested they are associated with an increased infection risk following primary total hip arthroplasty (THA). Therefore, our systematic review and meta-analysis explored the relationship between IAIs and periprosthetic joint infection (PJI) following THA reported in the current literature. METHODS:Five online databases were queried for analyses published from January 1st, 2000-May 1st, 2021 reporting on PJI rates between patients undergoing primary THA who did and did not preoperatively receive an IAI. The overall pooled effect of injection status on PJI incidence was determined using Mantel-Haenszel (M-H) models. This was similarly conducted for segregated preoperative intervals: 0-3 months, > 3-6 months, > 6 + months. RESULTS:A total of 11 articles were included in our analysis reporting on 278,782 THAs (IAI: n = 41,138; no IAI: n = 237,644). Patients receiving pre-operative injections had a significantly higher risk of PJI (OR: 1.31, 95% CI 1.07-1.62; p = 0.009). However, this finding was not robust. IAI receipt within 3-months of THA was associated with significantly higher PJI rates (OR: 1.68, 95% CI 1.48-1.90; p < 0.001). However, no significant difference was demonstrated in the > 3-6 month (OR: 1.19, 95% CI 0.94-1.52; p = 0.16) and > 6 + month sub-analyses (OR: 1.20, 95% CI 0.96-1.50; p = 0.11). The results of all sub-analyses remained were robust. DISCUSSION:Our findings suggest that patients requiring THA should wait at least 3-months following IAI to reduce post-operative infection risk. This information can help inform patients considering OA management options, as well as adult reconstruction surgeons during preoperative optimization.

This systematic review and meta-analysis analyzed the influence of pre-operative intra-articular injections (IAI) on periprosthetic joint infection (PJI) rates after primary total knee arthroplasty (TKA). Studies published between January 1st, 2000 and May 1st, 2021 evaluating PJI rates among TKA patients with and without IAI were identified from PubMed, Cochrane Library, MEDLINE, EBSCO Host, and Google Scholar. The pooled effect of IAI on PJI risk was calculated utilizing Mantel–Haenszel (M–H) models. Sub-analysis comparisons were conducted based on the interval from IAI to TKA: 0–3 months; > 3–6 months; > 6–12 months. The Methodological Index for Non-Randomized Studies (MINORS) and the Risk of Bias in Non-randomized Studies-of Interventions (ROBINS-I) tool were utilized to evaluate the quality of each included study. The present analysis included 12 studies reporting on 349,605 TKAs (IAI: n = 115,122; No IAI: n = 234,483). Patients receiving an IAI at any point prior to TKA (2850/115,122; 2.48

Transcranial magnetic stimulation (TMS) is used to probe inhibitory intracortical neurotransmission and has been used to infer the neurobiological dysfunction that may underly several neurological disorders. One technique, short-interval intracortical inhibition (SICI), indexes gamma-aminobutyric acid (GABA) mediated inhibitory activity and is a promising biomarker. However emerging evidence suggests SICI does not exclusively represent GABAergic activity because it may be influenced by inter-individual differences in the specific excitatory neural populations activated by TMS. Here we used the latency of TMS motor evoked potentials (MEPs) to index these inter-individual differences, and found that a significant proportion of the observed variability in SICI magnitude was accounted for by MEP latency, r = − 0.57, r 2 = 0.33, p = .014. We conclude that SICI is influenced by inter-individual differences in the excitatory neural populations activated by TMS, reducing the precision of this GABAergic probe. Interpreting SICI measures in the context of MEP latency may facilitate a more precise assessment of GABAergic intracortical inhibition. The reduced cortical inhibition observed in some neuropathologies could be influenced by reduced activity in specific excitatory neural populations. Including MEP latency assessment in research investigating SICI in clinical groups could assist in differentiating the cortical circuits impacted by neurological disorders.

Background There is evidence to suggest a disruption of gamma-aminobutyric acid (GABA) in autism spectrum disorder (ASD), but findings are mixed. Concurrent electroencephalography and transcranial magnetic stimulation (TMS-EEG) provides a novel method by which to probe GABA-mediated cortical inhibition. Methods With a particular focus on GABAB-ergic mechanisms, we investigated the N100 peak of the TMS evoked potential (TEP), as well as long interval cortical inhibition (LICI EEG ) in adults with ASD (n = 23; 12 female) without intellectual disability, and a neurotypical comparison group (n =22; 12 female) matched for age, sex, and IQ. Seventy-five single-(spTMS) and 75 paired-(ppTMS; 100 ms inter-stimulus-interval) pulses were applied to the right primary motor cortex (M1), right temporoparietal junction (TPJ), and right dorsolateral prefrontal cortex (DLPFC) while EEG was recorded from 20 scalp electrodes. Additionally, electromyography (EMG) was used to investigate corticospinal inhibition following ppTMS to M1 (LICI EMG ). Results There were no group differences in the N100 amplitude or latency following spTMS. LICI outcomes following ppTMS, as measured by either EEG or EMG, also did not differ between groups. These findings were further supported by Bayesian analyses, which provided weak-moderate support for the null hypothesis. Limitations Data presented here reflect adults without intellectual disability, and the generalisability of these results is therefore limited. Conclusions The findings of this study argue against GABAB-ergic impairment in adults with ASD without intellectual disability, at least at the cortical regions examined. Further research investigating these mechanisms in ASD at various ages, with varying degrees of symptomatology, and at different brain sites is an important factor in understating the role of GABA in the neuropathophysiology of ASD.

During maturation, the ossification centers of the proximal humerus form a characteristic pattern consisting of a metaphyseal peak and corresponding epiphyseal valley. The surface topographies of the metaphyseal peak and epiphyseal valley are not well described and may have variation with age and structural importance to the pathogenesis of proximal humeral epiphysiolysis. High-resolution 3-dimensional surface scans of 24 cadaveric proximal humeral epiphyses and metaphyses in specimens aged 3 to 18 years were obtained. Computer modeling software was used to measure the peak height of the metaphysis and maximal depth of the epiphysis relative to a perpendicular line drawn across the proximal humeral physis. The metaphyseal peak had a mean height of 12.7 ± 1.6 mm while the epiphyseal valley had a mean depth of 13.1 ± 2.1 mm, both consistently positioned in the posterolateral quadrant. Both the absolute metaphyseal peak height (R2 = 0.536; p < 0.001) and absolute epiphyseal valley depth (R2 = 0.524; p < 0.001) increase with advancing age. Multiple linear regression analysis demonstrated that normalized metaphyseal peak height + sex (adjusted R2 = 0.408; p < 0.002) correlated more with age than normalized epiphyseal valley depth + sex (adjusted R2 = 0.128; p < 0.091). Prominence of the metaphyseal peak and epiphyseal valley both increase with advancing age, with a lower correlation between normalized sizes with age as compared to the absolute sizes, suggesting that these structures stay relatively proportional with growth.

Background: Percutaneous epiphysiodesis using transphyseal screws (PETS) is a common procedure to correct lower extremity limb-length discrepancies in the pediatric population. A potential complication of this procedure is development of tibial valgus deformity, which may occur secondary to decreased screw purchase in the thinner medial proximal tibial epiphysis. The thickness of the proximal tibial epiphysis has not yet been well quantified, which was the aim of this study. Methods: Three-dimensional surface scans of 32 cadaveric proximal tibial epiphyses in specimens aged 3 to 17 years old were obtained and computer modeling software was utilized to measure the thickness of the proximal tibial epiphysis at 20 standardized potential screw insertion points according to a generated 5×4 map. Results: When normalized to the total width of the proximal tibial epiphysis, the lateral side is thicker compared with the medial side. The positions with the greatest thickness are located at the midline in the sagittal plane and 33% of the total physeal width away from the medial and lateral edges in the coronal plane (0.265 and 0.261 normalized thickness, respectively). The proximal tibial epiphysis is particularly thin 25% from the medial edge (normalized thickness range: 0.196 to 0.221). Multiple regression analysis revealed a significant relationship between increasing age and female sex with thinner normalized medial and lateral heights. Conclusions: During PETS, areas for greater screw purchase are located centrally in the sagittal plane and 33% of the total width away from the medial and lateral edges of the proximal tibial epiphysis in the coronal plane. Caution should be taken when inserting screws in the medial 25% of the proximal tibial epiphysis as it is thinner relative to the lateral edge, particularly in females. Clinical Relevance: This study provides quantitative, anatomic data on the thickness of the proximal tibial epiphysis, which can direct screw placement during PETS for correcting limb-length discrepancies. These data may help lessen the risk of developing tibial valgus deformity although future clinical studies are necessary to fully evaluate this possibility.

??-Crystallins play a major role in age-related lens trans-parency. Their destabilization by mutations and physical chemical insults are associated with cataract formation. Therefore, drugs that increase their stability should have anticataract properties. To this end, we screened 2560 Federal Drug Agency???approved drugs and natural compounds for their ability to suppress or worsen H2O2 and/or heat-mediated ag-gregation of bovine ??-crystallins. The top two drugs, closantel (C), an antihelminthic drug, and gambogic acid (G), a xan-thonoid, attenuated thermal-induced protein unfolding and aggregation as shown by turbidimetry fluorescence spectros-copy dynamic light scattering and electron microscopy of hu-man or mouse recombinant crystallins. Furthermore, binding studies using fluorescence inhibition and hydrophobic pocket??? binding molecule bis-8-anilino-1-naphthalene sulfonic acid revealed static binding of C and G to hydrophobic sites with medium-to-low affinity. Molecular docking to H??D and other ??-crystallins revealed two binding sites, one in the ???NC pocket??? (residues 50???150) of H??D and one spanning the ???NC tail??? (residues 56???61 to 168???174 in the C-terminal domain). Mul-tiple binding sites overlap with those of the protective mini ??A-crystallin chaperone MAC peptide. Mechanistic studies using bis-8-anilino-1-naphthalene sulfonic acid as a proxy drug showed that it bound to MAC sites, improved Tm of both H2O2 oxidized and native human gamma D, and suppressed turbidity of oxidized H??D, most likely by trapping exposed hydrophobic sites. The extent to which these drugs act as ??-crystallin mimetics and reduce cataract progression remains to be demonstrated. This study provides initial insights into binding properties of C and G to ??-crystallins.

Evidence demonstrates comparable clinical outcomes across the various surgical approaches to primary total hip arthroplasty (THA). However, high-quality contemporary data regarding periprosthetic joint infection (PJI) risk between direct anterior approach (DAA) and other (THA) approaches is lacking. This systematic review and meta-analysis evaluated PJI rates reported in the literature between the DAA and other approaches. Five online databases were queried for all studies published from January 1st, 2000 through February 17th, 2021 that reported PJI rates between DAA and other surgical approaches. Studies reporting on primary THAs for osteoarthritis (OA) and that included PJI rates segregated by surgical approach were included. Articles reporting on revision THA, alternative THA etiologies, or minimally invasive techniques were excluded. Mantel–Haenszel (M–H) models were utilized to evaluate the pooled effect of surgical approach on infection rates. Validated risk of bias and methodological quality assessment tools were applied to each study. Multiple sensitivity analyses were conducted to evaluate the robustness of analyses. 28 articles reporting on 653,633 primary THAs were included. No differences were found between DAA cohorts and combined other approaches (OR: 0.95; 95% CI 0.74–1.21; p = 0.67) as well as segregated anterolateral approach cohorts (OR: 0.82, 95% CI 0.64–1.06; p = 0.13). However, DAA patients had a significantly reduced risk of infection compared to those undergoing posterior (OR: 0.66, 95% CI 0.58–0.74; p < 0.0001) and direct lateral (OR: 0.56, 95% CI 0.48–0.65; p < 0.00001) approaches. The DAA to primary THA had comparable or lower PJI risk when compared to other contemporary approaches. The results of the most up-to-date evidence available serve to encourage adult reconstruction surgeons who have already adopted the DAA. Additionally, orthopaedic surgeons considering adoption or use of the direct anterior approach for other reasons should not be dissuaded over theoretical concern for a general increase in the risk of PJI. Level III.

Percutaneous iliosacral screw fixation and transsacral fixation are challenging procedures requiring extensive knowledge of sacral anatomy to avoid damaging nearby neurovascular structures. Greater knowledge of anatomical screw trajectory and size allowances would be helpful to guide surgical placement. An anatomical study of 40 cadaveric sacra in specimens ages 18–65 was performed. Three‐dimensional surface scans were obtained, and computer modeling software was used to simulate a 7.3 mm diameter screw with 1 mm buffer inserted orthogonal to the sacroiliac joint in the pelvic inlet and outlet views. Transsacral screws were also inserted into S1 and S2 vertebrae. For screws orthogonal to the sacroiliac joint, the overall mean screw insertion angle was 4.1° ± 7.5° (range, −18.3° to 22.0°) in the inlet view in the posterior to anterior direction, and 21.7° ± 5.1° (range, 8.2°–36.3°) in the outlet view in the caudal to cranial direction. Before breaching the sacrum, the range of sacral tunnel lengths was between 31.1 and 70.1 mm with a range of diameters between 9.3 and 13.3 mm. Transsacral screws inserted into either the S1 or S2 vertebrae did not breach the sacrum in 40% (16/40) at each level. 30% (12/40) of sacra could not safely accommodate both S1 and S2 transsacral screws. There is an initial screw insertion angle range of −4° to 12° in the inlet view and 16°–27° in the outlet view. There was always adequate size to accept a 7.3 mm or larger screw.