Clinical Significance of Gray to White Matter Ratio after Cardiopulmonary Resuscitation in Children

Cardiopulmonary resuscitation (CPR) successfully restores systemic circulation approximately 50% of the time; however, many successfully restored patients have severe neurologic damage. In adults, the gray matter to white matter attenuation ratio (GWR) in brain computed tomography (CT) correlates with the neurologic outcome. However, in children, the clinical significance of GWR still remains unclear. The aim of this study was to evaluate the clinical characteristics of children who underwent CPR for cardiac arrest according to the survival and to demonstrate the differentiation of grey/white matter by Hounsfield units of brain CT and to characterize the attenuations of grey and white matters. Methods: This is a retrospective single-center study. We enrolled those who underwent brain CT within 24 h after return of spontaneous circulation (ROSC) from January 2005 to June 2018. Brain CTs were taken within 24 h of ROSC. We measured the attenuation of grey and white matter in Hounsfield units and calculated GWR. They were compared with healthy controls. Patients were analyzed as follows: survivors vs. non-survivors and better neurologic outcome vs. worse neurologic outcome. Results: Among 100 pediatric patients who had CPR, 56 met inclusion criteria. There were 24 patients who survived and 32 non-survivors. Our study revealed that the incidence of seizure, duration of CPR, and instances of hypothermia were significantly different between survivors and non-survivors. In both survivors and non-survivors, the attenuation of the caudate nucleus, putamen, GWR-basal ganglia, and average GWR were significantly different from controls. In regression analyses, the medial cortex and average GWR were the significant variables to predict survival, and the receiver operating curves revealed areas under curve of 0.733 and 0.666, respectively. Also, the medial cortex 1 was the only variable that predicted the neurologic outcome. Conclusions: There was some predictive survival value of GWR and medial cortex at the centrum semiovale level in early brain CT within 24 h after cardiac arrest. Although we could not find the predictive value of GWR in the neurologic outcome of pediatric patients, we found that the absolute attenuation of the medial cortex was low in patients with worse neurologic outcomes. Further prospective, multicenter studies are needed to determine the predictive value of GWR and the medial cortex.

Reduction and Fixation of Proximal Humeral Fracture With Severe Medial Instability Using a Small Locking Plate

Background Currently, the reduction and support of comminuted medial cortex of humeral fracture remains a challenge, Therefore, a novel reduction and fixation technique that employs an anteromedial small locking plate was explored in this study, and its viability and the associated complications were assessed. Methods Fifteen cases of proximal humeral fractures with medial instability (five cases were classified as three-part and ten as four-part by Neer classification) were treated by the proposed reduction technique using an anteromedial small locking plate. Subsequently, the radiological and clinical outcomes were evaluated over an average follow-up period of 18.53 months. Results The average operation time was 108 minutes (range, 70–130 minutes), and the mean fracture union time in all patients was 12.13 weeks (range, 8–16 weeks). Complications such as infection and neurovascular injury were not observed. Postoperative X-ray showed avascular necrosis and screw penetration in one patient, while screw penetration, varus malunion, or significant reduction loss was not found in the other cases. The mean Constant score was 79.8 (range, 68–92) during the final visit. Conclusions The use of an anteromedial small locking plate improved the reduction efficiency, reconstructed the medial support, and alleviated the occurrence of complications in proximal humeral fractures with medial instability.

Reduction and fixation of proximal humeral fracture with severe medial instability using a small locking plate

Background Currently, the reduction and support of comminuted medial cortex of humeral fracture remains a challenge, Therefore, a novel reduction and fixation technique that employs an anteromedial small locking plate was explored in this study, and its viability and the associated complications were assessed. Methods Fifteen cases of proximal humeral fractures with medial instability (five cases were classified as three-part and ten as four-part by Neer classification) were treated by the proposed reduction technique using an anteromedial small locking plate. Subsequently, the radiological and clinical outcomes were evaluated over an average follow-up period of 18.53 months. Results The average operation time was 108 min (range, 70–130 min), and the mean fracture union time in all patients was 12.13 weeks (range, 8–16 weeks). Complications such as infection and neurovascular injury were not observed. Postoperative X-ray showed avascular necrosis and screw penetration in one patient, while screw penetration, varus malunion, or significant reduction loss was not found in the other cases. The mean Constant score was 79.8 (range, 68–92) during the final visit. Conclusions The use of an anteromedial small locking plate improved the reduction efficiency, reconstructed the medial support, and alleviated the occurrence of complications in proximal humeral fractures with medial instability.

Neural Mechanisms of Intimate Partner Aggression

People sometimes hurt those they profess to love; yet our understanding of intimate partner aggression (IPA) and its causes remains incomplete. We examined brain activity using functional magnetic resonance imaging (fMRI) in an ethnically and racially diverse sample of 50 female-male, monogamous romantic couples as they completed an aggression task against their intimate partner, a close friend, and a different-sex stranger. Laboratory and real-world IPA were uniquely associated with altered activity within and connectivity between cortical midline structures that subserve social cognition and the computation of value. Men’s IPA most corresponded to lower posterior cingulate reactivity during provocation and women’s IPA most corresponded to lower ventromedial prefrontal cortex activity during IPA itself. Actor-partner independence modeling suggested women’s IPA may correspond to their male partner’s neural reactivity to provocation. Broadly, these findings highlight the importance of self-regulatory functions of the medial cortex and away from effortful inhibition subserved by dorsolateral cortices.

A generalized cortical activity pattern at internally-generated mental context boundaries during unguided narrative recall

Current theory and empirical studies suggest that humans segment continuous experiences into events based on the mismatch between predicted and actual sensory inputs; detection of these “event boundaries” evokes transient neural responses. However, boundaries can also occur at transitions between internal mental states, without relevant external input changes. To what extent do such “internal boundaries” share neural response properties with externally-driven boundaries? We conducted an fMRI experiment where subjects watched a series of short movies and then verbally recalled the movies, unprompted, in the order of their choosing. During recall, transitions between movies thus constituted major boundaries between internal mental contexts, generated purely by subjects’ unguided thoughts. Following the offset of each recalled movie, we observed stereotyped spatial activation patterns in the default mode network, especially the posterior medial cortex, consistent across different movie contents and even across the different tasks of movie watching and recall. Surprisingly, the between-movie boundary patterns were negatively correlated with patterns at boundaries between events within a movie. Thus, major transitions between mental contexts elicit neural phenomena shared across internal and external modes and distinct from within-context event boundary detection, potentially reflecting a cognitive state related to the flushing and reconfiguration of situation models.

Teacher-Student Neural Coupling During Teaching and Learning

Human communication is remarkably versatile, enabling teachers to share highly abstracted and novel information with their students. What neural processes enable such transfer of information across brains during naturalistic teaching and learning? Here, a teacher was scanned in fMRI giving an oral lecture with slides on a scientific topic followed by a review lecture. Students were then scanned watching either the intact lecture and review (N = 20) or a temporally scrambled version of the lecture (N = 20). Using intersubject correlation (ISC), we observed widespread teacher-student neural coupling spanning sensory cortex and language regions along the superior temporal sulcus as well as higher-level regions including posterior medial cortex (PMC), superior parietal lobule (SPL), and dorsolateral and dorsomedial prefrontal cortex. Teacher-student alignment in higher-level areas was not observed when learning was disrupted by temporally scrambling the lecture. Moreover, teacher-student coupling in PMC was significantly correlated with learning: the more closely the student’s brain mirrored the teacher’s brain, the more the student improved their learning score. Together, these results suggest that the alignment of neural responses between teacher and students may reflect effective communication of complex information across brains in classroom settings.

Contextual expectations shape cortical reinstatement of sensory representations

When making a turn at a familiar intersection, we know what items and landmarks will come into view. These perceptual expectations, or predictions, come from our knowledge of the context, however it is unclear how memory and perceptual systems interact to support the prediction and reactivation of sensory details in cortex. To address this, human participants learned the spatial layout of animals positioned in a cross maze. During fMRI, participants navigated between animals to reach a target, and in the process saw a predictable sequence of five animal images. Critically, to isolate activity patterns related to item predictions, rather than bottom-up inputs, one quarter of trials ended early, with a blank screen presented instead. Using multivariate pattern similarity analysis, we reveal that activity patterns in early visual cortex, posterior medial regions, and the posterior hippocampus showed greater similarity when seeing the same item compared to different items. Further, item effects in posterior hippocampus were specific to the sequence context. Critically, activity patterns associated with seeing an item in visual cortex and posterior medial cortex, were also related to activity patterns when an item was expected, but omitted, suggesting sequence predictions were reinstated in these regions. Finally, multivariate connectivity showed that patterns in the posterior hippocampus at one position in the sequence were related to patterns in early visual cortex and posterior medial cortex at a later position. Together, our results support the idea that hippocampal representations facilitate sensory processing by modulating visual cortical activity in anticipation of expected items.

Functional Brain Connectivity During Narrative Processing Relates to Transportation and Story Influence

Engaging with narratives involves a complex array of cognitive and affective processes. These processes make stories persuasive in ways that standard arguments are not, though the underlying reasons for this remain unclear. Transportation theory proposes a potential explanation for this: narratives are processed in a way which makes individuals feel immersed in the world of a story, which in turn leads people to resonate emotionally with the events of the story. Recent fMRI studies have shown that the posterior medial cortex (PMC) and anterior insula (AI) play important roles in understanding the meaning of stories and experiencing the feelings they produce. In this study, we aimed to explore the AI’s and PMC’s role in narrative processing by measuring their functional connectivity with the rest of the brain during story listening, and how connectivity changes as a function of narrative transportation and the persuasiveness of the story. We analyzed data from 36 right-handed subjects who listened to two stories, obtained from podcasts, inside the fMRI scanner. After the scan, subjects were asked a series of questions, including a measure of how transported into the story they felt, how likely they would be to donate to causes related to the messages of the stories. We used searchlight multivariate pattern analysis (MVPA) to classify functional connectivity maps using seeds in both the AI and PMC and to compare these maps between participants who differed in transportation and prosocial intention. We found that connectivity to various regions successfully distinguished between high and low ratings on each of these behavioral measures with accuracies over 75%. However, only one pattern of connectivity was consistent across both stories: PMC-inferior frontal gyrus connectivity successfully distinguished high and low ratings of narrative transportation in both stories. All other findings were not consistent across stories. Instead, we found that patterns of connectivity may relate more to the specific content of the story rather than to a universal way in which narratives are processed.

Analysis on risk factors for neck shortening after internal fixation for Pauwels II femoral neck fracture in young patients

Background Femoral neck shortening can occur in young patients receiving internal fixation for Pauwels type II femoral neck fracture. The risk factors for neck shortening, which can affect hip function, are not clear. This study aimed to retrospectively identify risk factors for neck shortening after internal fixation with parallel partially threaded cannulated cancellous screws (FPTCS) for Pauwels type II femoral neck fracture in relatively young patients. Methods Clinical data from 122 cases with Pauwels type II femoral neck fracture from February 2014 to February 2019 were reviewed and analyzed, and causes of neck shortening were statistically analyzed. And the Chi-squared test or Fisher’s exact test was used to compare indicators. Multivariate analysis was conducted with non-conditional logistic regression analysis. Results Statistically significant differences were found in age, sex, BMD, BMI, fracture type, posterior medial cortex comminution, and reduction quality between patients with femoral neck shortening and those without femoral neck shortening. Logistic regression analysis showed that fracture type, posterior medial cortex comminution, and reduction quality were the main risk factors for neck shortening. Conclusion Fracture type, posterior medial cortex comminution, and reduction quality can be used as important reference indexes to predict the possibility of neck shortening after internal fixation with FPTCS for Pauwels type II femoral neck fracture in young patients. BMD and BMI may be also risk factors.

Willingness to Pay in the Human Brain: A fMRI Activation Likelihood Estimation Meta-analysis

The neural substrate of willingness to pay (WTP) ultimately supports human economic exchange activities and plays a crucial role in daily life. This paper aimed to identify the neural basis of WTP for food and nonfood, as well as the brain regions related to real and hypothetical WTP choices. We found the human brain centers of WTP by performing an activation likelihood estimation (ALE) meta-analysis (27 experiments, 796 subjects) on the existing neuroimaging studies. The conjunction analysis revealed that WTP for food and nonfood engaged a common cluster in the paracingulate and cingulate gyrus, revealing a common reward circuit in the brain. The frontal medial cortex and paracingulate gyrus were particularly activated by WTP for nonfood. Furthermore, the left caudate, left thalamus, angular gyrus and supramarginal gyrus (subregions of inferior parietal lobule) were more convergently activated by hypothetical WTP choice. Our findings support the idea that a common currency representation in the brain and reward-specific neural basis. Results also provide evidence of neural representations of the hypothetical bias.