Localized alterations in cortical thickness and sulcal depth of the cingulo-opercular network in relation to lower reading fluency skills in children with dyslexia

The traditional models of reading development describe how language processing and word decoding contribute to reading comprehension and how impairments in word decoding, a defining feature of dyslexia, affect reading comprehension outcomes. However, these models do not include word and sentence reading (contextual reading) fluency, both of which engage executive functions, with notably decreased performance in children with dyslexia. In the current study, we compared cortical thickness and sulcal depth (CT/SD) in the cingulo-opercular (CO) executive functions brain network in children with dyslexia and typical readers and examined associations with word vs. contextual reading fluency. Overall, CT was lower in insular regions and higher in parietal and caudal anterior cingulate cortex regions in children with dyslexia. Children with dyslexia showed positive correlations between word reading fluency and CT/SD in insular regions, whereas no significant correlations were observed in typical readers. For sentence reading fluency, negative correlations with CT/SD were found in insular regions in children with dyslexia, while positive correlations with SD were found in insular regions in typical readers. These results demonstrate the differential relations between word and sentence reading fluency and anatomical circuitry supporting executive functions in children with dyslexia vs. typical readers. It also suggests that word and sentence reading fluency, relate to morphology of executive function-related regions in children with dyslexia, whereas in typical readers, only sentence reading fluency relates to morphology of executive function regions. The results also highlight the role of the insula within the CO network in reading fluency. Here we suggest that word and sentence reading fluency are distinct components of reading that should each be included in the Simple View of Reading traditional model.

Neural Signature of Rhyming Ability During Story Listening in Preschool-Age Children

PURPOSE

Rhyming is a phonological skill that typically emerges in the preschool age range. Prosody/rhythm processing involves right-lateralized temporal cortex, yet the neural basis of rhyming ability in young children is unclear. The study objective was to use functional MRI (fMRI) to quantify neural correlates of rhyming abilities in preschool-age children.

METHOD

Healthy pre-kindergarten child-parent dyads were recruited for a study visit including MRI and the Preschool and Primary Inventory of Phonological Awareness (PIPA) rhyme subtest. MRI included a fMRI task where the child listened to a rhymed and unrhymed story without visual stimuli. fMRI data were processed using the CONN functional connectivity (FC) toolbox, with FC computed between 132 regions of interest (ROI) across the brain. Associations between PIPA score and FC during the rhymed vs. unrhymed story were compared accounting for age, sex and maternal education.

RESULTS

45 children completed MRI (age 54+8 months, 37-63; 19M 26F). Median maternal education was college graduate. FC between ROIs in posterior Default Mode (imagery) and right-Fronto-Parietal (executive function) networks was more strongly positively associated with PIPA score during the rhymed compared to the unrhymed story (F(2,39) = 10.95, p-FDR = 0.043), as was FC between ROIs in right-sided language (prosody) and Dorsal Attention networks (F(2,39) = 9.85, p-FDR = 0.044).

CONCLUSIONS

Preschool-age children with better rhyming abilities had stronger FC between ROIs supporting attention and prosody, and also between ROIs supporting executive function and imagery, suggesting rhyme as a catalyst for attention, visualization and comprehension. These represent novel neural biomarkers of nascent phonological skills.

Deep-Learning Models for Abdominal CT Organ Segmentation in Children: Development and Validation in Internal and Heterogeneous Public Datasets

Background: Deep-learning abdominal organ segmentation algorithms have shown excellent results in adults; validation in children is sparse. Objective: To develop and validate deep-learning models for liver, spleen, and pancreas segmentation on pediatric CT examinations. Methods: This retrospective study developed and validated deep-learning models for liver, spleen, and pancreas segmentation using 1731 CT examinations (1504 training, 221 testing), derived from three internal institutional pediatric (age ≤18) datasets (n=483) and three public datasets comprising pediatric and adult examinations with various pathologies (n=1248). Three deep-learning model architectures (SegResNet, DynUNet, and SwinUNETR) from the Medical Open Network for AI (MONAI) framework underwent training using native training (NT), relying solely on institutional datasets, and transfer learning (TL), incorporating pre-training on public datasets. For comparison, TotalSegmentator (TS), a publicly available segmentation model, was applied to test data without further training. Segmentation performance was evaluated using mean Dice similarity coefficient (DSC), with manual segmentations as reference. Results: For internal pediatric data, DSC for normal liver was 0.953 (TS), 0.964-0.965 (NT models), and 0.965-0.966 (TL models); normal spleen, 0.914 (TS), 0.942-0.945 (NT models), and 0.937-0.945 (TL models); normal pancreas, 0.733 (TS), 0.774-0.785 (NT models), and 0.775-0.786 (TL models); pancreas with pancreatitis, 0.703 (TS), 0.590-0.640 (NT models), and 0.667-0.711 (TL models). For public pediatric data, DSC for liver was 0.952 (TS), 0.876-0.908 (NT models), and 0.941-0.946 (TL models); spleen, 0.905 (TS), 0.771-0.827 (NT models), and 0.897-0.926 (TL models); pancreas, 0.700 (TS), 0.577-0.648 (NT models), and 0.693-0.736 (TL models). For public primarily adult data, DSC for liver was 0.991 (TS), 0.633-0.750 (NT models), and 0.926-0.952 (TL models); spleen, 0.983 (TS), 0.569-0.604 (NT models), and 0.923-0.947 (TL models); pancreas, 0.909 (TS), 0.148-0.241 (NT models), and 0.699-0.775 (TL models). DynUNet-TL was selected as the best-performing NT or TL model and was made available as an opensource MONAI bundle (https://github.com/cchmc-dll/pediatric_abdominal_segmentation_bundle.git). Conclusion: TL models trained on heterogeneous public datasets and fine-tuned using institutional pediatric data outperformed internal NT models and TotalSegmentator across internal and external pediatric test data. Segmentation performance was better in liver and spleen than in pancreas. Clinical Impact: The selected model may be used for various volumetry applications in pediatric imaging.

The influence of different cement spaces on the marginal gap of lithium disilicate crowns constructed by two scanner and milling unit combinations

BACKGROUND

This study compared the marginal gaps of CAD/CAM lithium disilicate (LDS) crowns constructed using a contemporary and older scanner/milling unit combination at three different cement spaces.

METHODS

Twenty-four undergraduate students prepared a Columbia model lower left first molar for an LDS crown in a simulated environment. From each crown preparation, one LDS crown was constructed using an E4D scanner/E4D milling unit (E4DS/E4DM) and TRIOS 3 scanner/Sirona inLab MC X5 milling unit (TRIO/MCX5) at cement space settings of 50, 100 and 200 μm. Each LDS crown was positioned onto the original crown preparation, and then a stereomicroscope was used to make three vertical marginal gap measurements at four locations (mid-buccal, mid-lingual, mid-mesial and mid-distal). The mean marginal gap (MMG) was calculated for each crown and each individual tooth surface.

RESULTS

The MMGs of CAD/CAM LDS crowns constructed by TRIO/MCX5 were 72.31 at 50, 63.73 at 100 μm and 46.23 μm at 200 μm, which were smaller than E4DS/E4DM at each cement space.

CONCLUSIONS

Increasing the cement space decreased the MMG in both scanner/milling unit combinations. The smallest MMG was found using the newer scanner/milling unit at the 200 μm cement space. © 2024 Australian Dental Association.

Machine learning to detect the SINEs of cancer

We previously described an approach called RealSeqS to evaluate aneuploidy in plasma cell-free DNA through the amplification of ~350,000 repeated elements with a single primer. We hypothesized that an unbiased evaluation of the large amount of sequencing data obtained with RealSeqS might reveal other differences between plasma samples from patients with and without cancer. This hypothesis was tested through the development of a machine learning approach called Alu Profile Learning Using Sequencing (A-PLUS) and its application to 7615 samples from 5178 individuals, 2073 with solid cancer and the remainder without cancer. Samples from patients with cancer and controls were prespecified into four cohorts used for model training, analyte integration, and threshold determination, validation, and reproducibility. A-PLUS alone provided a sensitivity of 40.5% across 11 different cancer types in the validation cohort, at a specificity of 98.5%. Combining A-PLUS with aneuploidy and eight common protein biomarkers detected 51% of the cancers at 98.9% specificity. We found that part of the power of A-PLUS could be ascribed to a single feature-the global reduction of AluS subfamily elements in the circulating DNA of patients with solid cancer. We confirmed this reduction through the analysis of another independent dataset obtained with a different approach (whole-genome sequencing). The evaluation of Alu elements may therefore have the potential to enhance the performance of several methods designed for the earlier detection of cancer.

The Liquid Biopsy Consortium: Challenges and opportunities for early cancer detection and monitoring

The emerging field of liquid biopsy stands at the forefront of novel diagnostic strategies for cancer and other diseases. Liquid biopsy allows minimally invasive molecular characterization of cancers for diagnosis, patient stratification to therapy, and longitudinal monitoring. Liquid biopsy strategies include detection and monitoring of circulating tumor cells, cell-free DNA, and extracellular vesicles. In this review, we address the current understanding and the role of existing liquid-biopsy-based modalities in cancer diagnostics and monitoring. We specifically focus on the technical and clinical challenges associated with liquid biopsy and biomarker development being addressed by the Liquid Biopsy Consortium, established through the National Cancer Institute. The Liquid Biopsy Consortium has developed new methods/assays and validated existing methods/technologies to capture and characterize tumor-derived circulating cargo, as well as addressed existing challenges and provided recommendations for advancing biomarker assays.

Seq-ing the SINEs of central nervous system tumors in cerebrospinal fluid

It is often challenging to distinguish cancerous from non-cancerous lesions in the brain using conventional diagnostic approaches. We introduce an analytic technique called Real-CSF (repetitive element aneuploidy sequencing in CSF) to detect cancers of the central nervous system from evaluation of DNA in the cerebrospinal fluid (CSF). Short interspersed nuclear elements (SINEs) are PCR amplified with a single primer pair, and the PCR products are evaluated by next-generation sequencing. Real-CSF assesses genome-wide copy-number alterations as well as focal amplifications of selected oncogenes. Real-CSF was applied to 280 CSF samples and correctly identified 67% of 184 cancerous and 96% of 96 non-cancerous brain lesions. CSF analysis was considerably more sensitive than standard-of-care cytology and plasma cell-free DNA analysis in the same patients. Real-CSF therefore has the capacity to be used in combination with other clinical, radiologic, and laboratory-based data to inform the diagnosis and management of patients with suspected cancers of the brain.

Maternal education as an environmental factor related to reading in children with reading difficulties: A functional magnetic resonance imaging study

The expanded simple view of reading (SVR) model suggests that word decoding, language comprehension and executive functions are necessary for reading comprehension. Children with reading difficulties (RDs) often have deficits in critical components of reading established in the expanded SVR model and alterations in brain function of reading-related regions. Maternal education could provide children with advantageous educational opportunities or resources that support reading acquisition. The primary goal of this study was to examine the contributions of maternal education to the behavioural and neurobiological correlates of the expanded SVR model. Seventy-two 8- to 12-year-old children with RDs and typical readers (TRs) completed reading, behavioural and an functional magnetic resonance imaging stories-listening task to determine the functional connectivity of the receptive language network to the whole brain in association with maternal education. Higher maternal education was associated with better vocabulary in children with RDs and positive functional connectivity between the receptive language network and regions related to visual processing in children with RDs versus TRs. These data suggest that maternal education supports the ability to comprehend oral language and engagement of neural networks that support imagination/visualization in children with RDs.

Colorectal cancer in patients of advanced age is associated with increased incidence of BRAF p.V600E mutation and mismatch repair deficiency

Introduction

The highest incidence of colorectal cancer (CRC) is in patients diagnosed at 80 years or older highlighting a need for understanding the clinical and molecular features of these tumors. Methods. In this retrospective cohort study, 544 CRCs underwent next generation sequencing and mismatch repair (MMR) evaluation. Molecular and clinical features were compared between 251 patients with traditional-onset CRC (50-69 years at diagnosis) and 60 with late-onset CRC (>80 years at diagnosis).

Results

Late-onset CRC showed a significantly higher rate of right-sided tumors (82% vs 35%), MMR deficiency (35% vs. 8%) and BRAF p.V600E mutations (35% vs. 8%) and a significantly lower rate of stage IV disease (15% vs 28%) and APC mutations (52% vs. 78%). Association of these features with advanced age was supported by stratifying patients into 6 age groups (<40, 40-49, 50-59, 60-69, 70-79 and >80 years). However, the age-related rise in MMR deficient (dMMR) CRC was only seen in the female patients with an incidence of 48% (vs. 10% in the male patient) in the >80y group. In addition, BRAF p.V600E was significantly enriched in MMR deficient CRC of advanced age (67% in late-onset CRC). Categorizing CRC by mutational profiling, late-onset CRC revealed a significantly higher rate of dMMR/BRAF ⁺ APC ^- (18% vs. 2.0%), dMMR/BRAF ^- APC ^- (8.3% vs. 1.2%) and MMR proficient (pMMR)/BRAF ⁺ APC ^- (12% vs. 4.0%) as compared to traditional-onset CRC.

Discussion

In summary, there was a higher rate of dMMR and BRAF p.V600E in late-onset CRC, independently or in combination. The higher incidence of dMMR in late-onset CRC in females is most likely predominantly driven by BRAF p.V600E induced hypermethylation. Prospective studies with treatment plans designed specifically for these older patients are warranted to improve their outcomes.

The marginal gaps of sequentially milled lithium disilicate crowns using two different milling units

BACKGROUND

The purpose of this study was to compare the marginal gaps of sequentially milled lithium disilicate (LDS) crowns using two different milling units.

METHODS

One lower left first molar typodont tooth prepared for an LDS crown by an undergraduate student in a simulation clinic was selected. The crown preparation was scanned by a TRIOS 3 scanner and twelve LDS crowns milled by an E4D (E4DM) and a Sirona inLab MC X5 (MCX5) milling unit using identical settings. The crowns were seated onto the original crown preparation and three vertical marginal gap measurements were taken at four locations (mid-buccal, mid-lingual, mid-mesial and mid-distal) using a stereomicroscope. The mean marginal gap (MMG) was calculated for each individual tooth surface and each crown.

RESULTS

The MMG for the E4DM (100.40 μm) was not significantly different to the MCX5 (101.08 μm) milling unit (P = 0.8809). In both units, there was a statistically significant trend of increasing MMG with sequentially milled crowns using the same burs (E4DM P = 0.0133; MCX5 P = 0.0240).

CONCLUSIONS

The E4DM and MCX5 milling units produced LDS crowns with similar MMG's and within a clinically acceptable range but with a trend of increasing MMG when analysed sequentially. © 2022 Australian Dental Association.

Tocilizumab for treatment of SARS-CoV-2 infection at home: A case report

SARS-CoV-2 virtual wards have successfully developed to monitor and escalate patients to hospital throughout the pandemic. Here we describe the case of an 84 year old man who received his complete care for severe SARS-CoV-2 pneumonitis at home, including the administration of oxygen, dexamethasone and tocilizumab.

COVID-19 Transmission Under the Public Health Radar: High Prevalence in Young Adults for COVID-19 Pandemic Wave 1

Purpose

Compare reported data on age specific rates of SARS-CoV-2 infections in countries from several continents to identify differences in age specific incidence of reported cases in different countries.

Methods & Materials

Data on age-specific case incidence of SARS-CoV-2 derived from publicly available databases from selected countries in Europe, North America, Australasia, and Asia were collected and analysed to identify and evaluate trends in reported age specific distribution of morbidity from SARS-CoV-2 in countries for which data was available.

Results

Data for laboratory confirmed COVID-19 cases from South Korea, Australia, New Zealand, Japan and the Netherlands exhibited essentially identical profiles, with a bimodal distribution that shows highest rate of confirmed SARS-CoV-2 infections among individuals in the 20-29 years age cohort (21%-27% of total), and a second lower peak for the 50-59 or 60-69 age cohorts (16-18% of total), while preliminary data from China, United States and Sweden exhibited a unimodal distribution with highest rate of positive individuals for the 50-59 age cohort.

Conclusion

There is increasing evidence that individuals < 30 years of age may be playing a highly significant role in the facilitation and amplification of COVID-19 transmission in countries worldwide. Data reported from the first wave of the COVID-19 Pandemic in at least 5 countries (South Korea, Australia, New Zealand, Japan, Netherlands) demonstrated that greater attention should be paid to the frequency and epidemiological importance of COVID-19 infections among young adults in the 20-29 year age cohort, because individuals in this age range comprise a large proportion (21%-27%) of the known laboratory confirmed COVID-19 cases in these countries, and perhaps other countries for which reliable data are not yet available. The epidemiological importance of COVID-19 infections among young adults and adolescents in amplifying and facilitating the proliferation of the COVID-19 Pandemic has been systematically underestimated in many countries, because of low rates of testing among asymptomatic individuals and low rates of severe disease or mortality among individuals <30 years of age. Clarifying and understanding the epidemiological dynamics of SARS-CoV-2 transmission among individuals in younger age cohorts will help in determining control strategies at the individual and population levels.

The effect of subconcussive head impact exposure and jugular vein compression on behavioral and cognitive outcomes after a single season of high-school football: A prospective longitudinal trial

This prospective longitudinal trial aimed to 1) determine the role of head impact exposure on behavioral/cognitive outcomes, and 2) assess the protective effect(s) of a jugular vein compression (JVC) collar on behavioral/cognitive outcomes following one season of high-school football. Participants included 284 male high-school football players aged 13-18 years enrolled from seven midwestern high-schools. Schools were allocated to the JVC collar intervention(four teams, 140 players) or non-collar/no intervention control (three teams, 144 players) condition. Head impact exposure was measured throughout the season using CSx accelerometers. Outcome measures included post season parent and adolescent report on Strengths and Weaknesses of ADHD Symptoms and Normal Behavior Scale (SWAN) and Post-Concussion Symptom Inventory (PCSI), as well as adolescent performance on Attention Network Task (ANT), digital Trail Making Task (dTMT), and Cued Switching task. No significant effect of head impact exposure or JVC collar use on post-season SWAN or PCSI scores or performance on dTMT and Cued Switching task were noted. There was no effect of head impact exposure on ANT performance; however, the JVC collar group had greater post-season Alerting network scores than the non-collar group (p=.026, d=.22). Findings provide preliminary evidence that the JVC collar may provide some protection to the alerting attention system. These findings should be interpreted cautiously as a greater understanding of the long-term sequalae of head impact exposure and the role of cumulative head impact exposure behavioral/cognitive outcomes is required.

The influence of a composite resin adhesive on microleakage into the implant screw access chamber

BACKGROUND

The sealing of implant screw access chambers can influence prosthesis success, peri-implant health and patient comfort. The aim of this study was to compare the microleakage of single implant crown screw access chambers sealed with and without a composite resin adhesive.

METHODS

Twenty milled lithium disilicate crowns were luted to titanium-base abutments, attached to implants and randomly assigned to one of two groups. The first group had the screw access chamber sealed with polytetrafluoroethylene tape, a 10-methacryloyloxydecyl dihydrogen phosphate containing adhesive, and composite resin. The second group used the same procedure but without an adhesive. All samples were sealed at the implant-abutment interface and subjected to thermocycling then immersed in a ferrous sulphate contrast media for 48 h. Infiltration and microleakage was measured using a microcomputed tomography scanner.

RESULTS

All samples demonstrated high resistance to microleakage with no significant contrast media diffusion in either of the two groups.

CONCLUSIONS

Within the limitations of this in vitro study, the use of a composite resin adhesive for sealing the screw access chamber for single implant crowns provided no additional sealing capacity compared with composite resin alone. Composite resin restorations placed in the traditional manner without sealing provided excellent resistance to microleakage.

Higher maternal education is related to negative functional connectivity between attention system networks and reading-related regions in children with reading difficulties compared to typical readers

Ten to 15% of school-age children have reading difficulties (RD, or dyslexia), defined by deficits in phonological processing, fluency, and executive functions (EFs). Although RD is referred to as a genetic disorder, reading ability may also be affected by environmental factors such as inadequate exposure to literacy and a lack of parental involvement. These environmental components are a part of the socioeconomic status (SES) measure, which is defined by parental occupation, educational attainment, and household income and are positively correlated to reading ability. The goal of the current study was to relate maternal education, a construct of SES to executive functions (EFs) that relate to reading in children with RD compared to typical readers (TRs) using behavioral and neurobiological resting-state fMRI data. The results show that higher maternal education is negatively correlated to inhibitory control for TRs and not for children with RD. Higher maternal education was also associated with negative functional connectivity of the frontal-parietal network to the left central opercular cortex and left occipital gyrus for children with RD compared to TRs. These results suggest that higher maternal education has contrasting roles on the behavioral and neurobiological correlates of EFs for children with RD compared to TRs. We conclude that higher education levels for mothers may provide their children with a structured environment and educational resources that may assist their children with RD and TRs with cognitive development based on their reading profile.

Maternal depression is associated with decreased functional connectivity within semantics and phonology networks in preschool children

INTRODUCTION

Maternal depression is characterized by a lack of emotional responsiveness and engagement with their child, which may lead to the child's decreased cognitive, and language outcomes all related to the child's future reading outcomes. The relations between maternal depression and functional connectivity in neural circuits supporting language in the child was explored.

METHODS

Eleven 4-year-old girls completed language abilities assessment and resting-state functional magnetic resonance imaging scan. Their mothers completed the Beck's Depression Inventory (BDI) to examine maternal depression when the child was 12 months old and at the age of 4. Functional connections within the child's resting-state phonology, semantics, language networks were correlated with maternal BDI scores at the age of 4 years.

RESULTS

Higher maternal depression was associated with the child's decreased within the semantic and phonological networks connectivity during rest. Higher maternal depression at 4 years moderated the relationship between early depression scores and functional connectivity within the phonological network.

CONCLUSIONS

Maternal depression in the first year of life is related to functional connections of phonological processing and enhanced by current maternal depression levels. We conclude that after a mother gives birth, resources should be provided to minimize depressive symptoms and interventions should be applied to support their child's language development for future reading acquisition.

Assessment of agreement between manual and automated processing of liver MR elastography for shear stiffness estimation in children and young adults with autoimmune liver disease

PURPOSE

To compare automated versus standard of care manual processing of 2D gradient recalled echo (GRE) liver MR Elastography (MRE) in children and young adults.

MATERIALS AND METHODS

2D GRE liver MRE data from research liver MRI examinations performed as part of an autoimmune liver disease registry between March 2017 and March 2020 were analyzed retrospectively. All liver MRE data were acquired at 1.5 T with 60 Hz mechanical vibration frequency. For manual processing, two independent readers (R1, R2) traced regions of interest on scanner generated shear stiffness maps. Automated processing was performed using MREplus+ (Resoundant Inc.) using 90% (A90) and 95% (A95) confidence masks. Agreement was evaluated using intra-class correlation coefficients (ICC) and Bland-Altman analyses. Classification performance was evaluated using receiver operating characteristic curve (ROC) analyses.

RESULTS

In 65 patients with mean age of 15.5 ± 3.8 years (range 8-23 years; 35 males) median liver shear stiffness was 2.99 kPa (mean 3.55 ± 1.69 kPa). Inter-reader agreement for manual processing was very strong (ICC = 0.99, mean bias = 0.01 kPa [95% limits of agreement (LoA): - 0.41 to 0.44 kPa]). Correlation between manual and A95 automated processing was very strong (R1: ICC = 0.988, mean bias = 0.13 kPa [95% LoA: - 0.40 to 0.68 kPa]; R2: ICC = 0.987, mean bias = 0.13 kPa [95% LoA: - 0.44 to 0.69 kPa]). Automated measurements were perfectly replicable (ICC = 1.0; mean bias = 0 kPa).

CONCLUSION

Liver shear stiffness values obtained using automated processing showed excellent agreement with manual processing. Automated processing of liver MRE was perfectly replicable.

White Matter Alteration Following SWAT Explosive Breaching Training and the Moderating Effect of a Neck Collar Device: A DTI and NODDI Study

INTRODUCTION

Special Weapons and Tactics (SWAT) personnel who practice breaching with blast exposure are at risk for blast-related head trauma. We aimed to investigate the impact of low-level blast exposure on underlying white matter (WM) microstructure based on diffusion tensor imaging (DTI) and neurite orientation and density imaging (NODDI) in SWAT personnel before and after breacher training. Diffusion tensor imaging is an advanced MRI technique sensitive to underlying WM alterations. NODDI is a novel MRI technique emerged recently that acquires diffusion weighted data from multiple shells modeling for different compartments in the microstructural environment in the brain. We also aimed to evaluate the effect of a jugular vein compression collar device in mitigating the alteration of the diffusion properties in the WM as well as its role as a moderator on the association between the diffusion property changes and the blast exposure.

MATERIALS AND METHODS

Twenty-one SWAT personnel (10 non-collar and 11 collar) completed the breacher training and underwent MRI at both baseline and after blast exposure. Diffusion weighted data were acquired with two shells (b = 1,000, 2,000 s/mm2) on 3T Phillips scanners. Diffusion tensor imaging metrices, including fractional anisotropy, mean, axial, and radial diffusivity, and NODDI metrics, including neurite density index (NDI), isotropic volume fraction (fiso), and orientation dispersion index, were calculated. Tract-based spatial statistics was used in the voxel-wise statistical analysis. Post hoc analyses were performed for the quantification of the pre- to post-blast exposure diffusion percentage change in the WM regions with significant group difference and for the assessment of the interaction of the relationship between blast exposure and diffusion alteration.

RESULTS

The non-collar group exhibited significant pre- to post-blast increase in NDI (corrected P < .05) in the WM involving the right internal capsule, the right posterior corona radiation, the right posterior thalamic radiation, and the right sagittal stratum. A subset of these regions showed significantly greater alteration in NDI and fiso in the non-collar group when compared with those in the collar group (corrected P < .05). In addition, collar wearing exhibited a significant moderating effect for the alteration of fiso for its association with average peak pulse pressure.

CONCLUSIONS

Our data provided initial evidence of the impact of blast exposure on WM diffusion alteration based on both DTI and NODDI. The mitigating effect of WM diffusivity changes and the moderating effect of collar wearing suggest that the device may serve as a promising solution to protect WM against blast exposure.

Multiregion whole-exome sequencing of intraductal papillary mucinous neoplasms reveals frequent somatic KLF4 mutations predominantly in low-grade regions

OBJECTIVE

Intraductal papillary mucinous neoplasms (IPMNs) are non-invasive precursor lesions that can progress to invasive pancreatic cancer and are classified as low-grade or high-grade based on the morphology of the neoplastic epithelium. We aimed to compare genetic alterations in low-grade and high-grade regions of the same IPMN in order to identify molecular alterations underlying neoplastic progression.

DESIGN

We performed multiregion whole exome sequencing on tissue samples from 17 IPMNs with both low-grade and high-grade dysplasia (76 IPMN regions, including 49 from low-grade dysplasia and 27 from high-grade dysplasia). We reconstructed the phylogeny for each case, and we assessed mutations in a novel driver gene in an independent cohort of 63 IPMN cyst fluid samples.

RESULTS

Our multiregion whole exome sequencing identified KLF4, a previously unreported genetic driver of IPMN tumorigenesis, with hotspot mutations in one of two codons identified in >50% of the analyzed IPMNs. Mutations in KLF4 were significantly more prevalent in low-grade regions in our sequenced cases. Phylogenetic analyses of whole exome sequencing data demonstrated diverse patterns of IPMN initiation and progression. Hotspot mutations in KLF4 were also identified in an independent cohort of IPMN cyst fluid samples, again with a significantly higher prevalence in low-grade IPMNs.

CONCLUSION

Hotspot mutations in KLF4 occur at high prevalence in IPMNs. Unique among pancreatic driver genes, KLF4 mutations are enriched in low-grade IPMNs. These data highlight distinct molecular features of low-grade and high-grade dysplasia and suggest diverse pathways to high-grade dysplasia via the IPMN pathway.

Validation of The Reading House and Association With Cortical Thickness

BACKGROUND AND OBJECTIVES

The American Academy of Pediatrics recommends literacy and school readiness promotion during well visits. The Reading House (TRH) is a children's book-based screener of emergent literacy skills in preschool-aged children. Vocabulary, rhyming, and rapid naming are core emergent skills, and reading abilities are associated with thicker cortex in the left hemisphere. Our objective was to expand validity of TRH relative to these skills and explore association with cortical thickness.

METHODS

Healthy preschool-aged children completed MRI including a T1-weighted anatomic scan. Before MRI, TRH and assessments of rapid naming (Comprehensive Test of Phonological Processing, Second Edition), rhyming (Pre-Reading Inventory of Phonological Awareness), vocabulary (Expressive Vocabulary Test, Second Edition), and emergent literacy (Get Ready to Read!) were administered. Analyses included Spearman-ρ correlations (r _ρ) accounting for age, sex, and socioeconomic status (SES). MRI analyses involved whole-brain measures of cortical thickness relative to TRH scores, accounting for covariates.

RESULTS

Seventy children completed assessments (36-63 months old; 36 female) and 52 completed MRI (37-63 months; 29 female). TRH scores were positively correlated with Comprehensive Test of Phonological Processing, Second Edition (r _ρ = 0.61), Expressive Vocabulary Test, Second Edition (r _ρ = 0.54), Get Ready to Read! (r _ρ = 0.87), and Pre-Reading Inventory of Phonological Awareness scores (r _ρ = 0.64; all P < .001). These correlations remained statistically significant across age, sex, and SES groups. TRH scores were correlated with greater thickness in left-sided language and visual cortex (P-family-wise error <.05), which were similar for higher SES yet more bilateral and frontal for low SES, reflecting a less mature pattern (P-family-wise error <.10).

CONCLUSIONS

These findings expand validation evidence for TRH as a screening tool for preschool-aged children, including associations with emergent skills and cortical thickness, and suggest important differences related to SES.

Cytomorphologic characteristics of next-generation sequencing-positive bile duct brushing specimens

INTRODUCTION

Cytology of bile duct brushings (BDBs) is a specific, but insensitive, test for malignancy. Next-generation sequencing (NGS) of BDBs has recently been shown to improve sensitivity. We analyzed the cytologic features of NGS-positive (NGS⁺) and NGS-negative (NGS^-) BDBs and correlated the morphology with the presence of mutations.

MATERIALS AND METHODS

A total of 96 BDBs were analyzed for 29 cytologic features by 2 pathologists who were unaware of the original diagnosis and NGS results. Clinicopathologic follow-up was used to determine the patient outcomes (ie, benign, low-grade neoplasm, malignant [carcinoma/high-grade dysplasia]).

RESULTS

We analyzed 74 NGS⁺ BDBs from 66 patients and 22 NGS^- BDBs from 22 patients. During follow-up, 58 of 66 NGS⁺ patients (88%) had malignancy compared with 0% of NGS^- patients (P < 0.001). Fewer than 50% of the malignant cases had been interpreted as malignant on cytology; however, 100% had demonstrated mutations using NGS. Within the NGS⁺ cases, 53% showed late mutations (TP53, SMAD4, and CDKN2A) supportive of a high-risk stricture. Significant morphologic differences were seen in the background appearance, presence of single cells, architectural disarray, nucleomegaly, anisonucleosis, irregular nuclear borders, increased nuclear/cytoplasmic ratio, nuclear hyperchromasia, nucleoli, abnormal groups, clusters, and/or single cells, and overall impression. Naked nuclei, nucleomegaly, anisonucleosis, and coarse chromatin were more common in BDBs with late mutations than in those with KRAS/GNAS (Kirsten rat sarcoma viral oncogene homolog/guanine nucleotide binding protein, α-stimulating complex locus) mutations only. Cytology had a sensitivity of 16% and a specificity of 100% for malignancy. In contrast, NGS had a sensitivity of 100% and a specificity of 73%. Late mutations were 100% specific for malignancy compared with mutations in KRAS/GNAS only, of which 69% were malignant.

CONCLUSIONS

We found significant overlap in the cytomorphologic features between neoplastic and non-neoplastic BDBs, and more than one half of cancer cases had been interpreted as "nonmalignant" on cytology. NGS showing late mutations was 100% specific for malignancy. Adding genetic testing to BDB cytology would be a valuable ancillary test for the detection of malignancy, and reflex testing should be considered.

Associations between home literacy environment, brain white matter integrity and cognitive abilities in preschool-age children

AIM

Caregiver-child reading is advocated by health organisations, citing cognitive and neurobiological benefits. The influence of home literacy environment (HLE) on brain structure prior to kindergarten has not previously been studied.

METHODS

Preschool-age children completed assessments of language (EVT-2, CTOPP-2 Rapid Object Naming) and emergent literacy skills (Get Ready to Read!, The Reading House) followed by diffusion tensor imaging (DTI). Parents completed a survey of HLE (StimQ-P₂ READ), which has four subscales. DTI measures included axial diffusivity (AD), radial diffusivity (RD), mean diffusivity (MD) and fractional anisotropy (FA).

RESULTS

Forty-seven children completed DTI (54 ± 7 months, range 36-63; 27 girls). StimQ-P₂ READ scores correlated with higher EVT-2, GRTR and TRH scores, controlling for age and gender (P < .01), and also with lower AD, RD and MD in tracts supporting language and literacy skills, controlling for age, gender and income (P < .05, family-wise error corrected). Correlations were strongest for the Bookreading Quantity subscale, including with higher scores on all cognitive measures including CTOPP-2, and also with higher FA in left-lateralised literacy-supporting tracts, controlling for age, gender and income.

CONCLUSION

More nurturing home reading environment prior to kindergarten may stimulate brain development supporting language and literacy skills, reinforcing the need for further study.

Electrical stimulation sensorimotor mapping with stereo-EEG

OBJECTIVE

We evaluated stereo-EEG electrical stimulation mapping (ESM) for localization of anatomic sensorimotor parcels in pediatric patients with drug-resistant epilepsy. We also analyzed sensorimotor and after-discharge thresholds, and the somatotopy of sensorimotor responses.

METHODS

ESM was performed with 50 Hz, biphasic, 2-3 s trains, using 1-9 mA current. Pre- and post-implant neuroimaging was co-registered and intersected with Neurosynth reference, to classify each electrode contact as lying within/outside an anatomic sensorimotor parcel. Indices of diagnostic performance were computed. Sensorimotor and after-discharge thresholds were analyzed using multivariable linear mixed models.

RESULTS

In 15 patients (6 females), aged 5.5-21.2 years, ESM showed high accuracy (0.80), high specificity (0.86), and diagnostic odds ratio (11.4, p < 0.0001) for localization of sensorimotor parcels. Mean sensorimotor threshold (3.4 mA) was below mean after-discharge threshold (4.2 mA, p = 0.0004). Sensorimotor and after-discharge thresholds showed a significant decrease with increasing intelligence quotient. Somatotopy of sensorimotor responses was mapped to standardized brain parcels.

CONCLUSIONS

We provide evidence for diagnostic validity and safety of stereo-EEG sensorimotor ESM.

SIGNIFICANCE

The somatotopy of sensorimotor responses elicited with electrical stimulation provide new insights into mechanisms of motor control and sensory perception.

A comparison of the marginal gaps of lithium disilicate crowns fabricated by two different intraoral scanners

BACKGROUND

The purpose of this study was to assess marginal gaps of CAD/CAM lithium disilicate crowns constructed using two different intraoral scanners of different generations.

METHODS

Twenty four Columbia model lower left molars were prepared for lithium disilicate crowns in a simulated environment by undergraduate students. The crown preparations were scanned by E4D and Trios 3 intraoral scanners and CAD/CAM lithium disilicate crowns designed and manufactured. The crowns were seated onto the original crown preparations and three vertical marginal gap measurements taken at four locations (mid-buccal, mid-lingual, mid-mesial and mid-distal) using a stereomicroscope. The mean marginal gap (MMG) was calculated for each crown and each individual tooth surface.

RESULTS

The MMG was not statistically significantly different for the Trios 3 and E4D scanners (P = 0.111). There was no statistically significant effect of measurement location on the tooth on the marginal gap (P = 0.1134).

CONCLUSIONS

There was no difference in the MMGs of CAD/CAM lithium disilicate crowns constructed using two different intraoral scanners of different generations. Within the limitations of this study, the advances in scanning technology have produced small and insignificant improvements in the accuracy of crown margins.

Associations Between Screen-Based Media Use and Brain White Matter Integrity in Preschool-Aged Children

IMPORTANCE

The American Academy of Pediatrics (AAP) recommends limits on screen-based media use, citing its cognitive-behavioral risks. Screen use by young children is prevalent and increasing, although its implications for brain development are unknown.

OBJECTIVE

To explore the associations between screen-based media use and integrity of brain white matter tracts supporting language and literacy skills in preschool-aged children.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional study of healthy children aged 3 to 5 years (n = 47) was conducted from August 2017 to November 2018. Participants were recruited at a US children's hospital and community primary care clinics.

EXPOSURES

Children completed cognitive testing followed by diffusion tensor imaging (DTI), and their parent completed a ScreenQ survey.

MAIN OUTCOMES AND MEASURES

ScreenQ is a 15-item measure of screen-based media use reflecting the domains in the AAP recommendations: access to screens, frequency of use, content viewed, and coviewing. Higher scores reflect greater use. ScreenQ scores were applied as the independent variable in 3 multiple linear regression models, with scores in 3 standardized assessments as the dependent variable, controlling for child age and household income: Comprehensive Test of Phonological Processing, Second Edition (CTOPP-2; Rapid Object Naming subtest); Expressive Vocabulary Test, Second Edition (EVT-2; expressive language); and Get Ready to Read! (GRTR; emergent literacy skills). The DTI measures included fractional anisotropy (FA) and radial diffusivity (RD), which estimated microstructural organization and myelination of white matter tracts. ScreenQ was applied as a factor associated with FA and RD in whole-brain regression analyses, which were then narrowed to 3 left-sided tracts supporting language and emergent literacy abilities.

RESULTS

Of the 69 children recruited, 47 (among whom 27 [57%] were girls, and the mean [SD] age was 54.3 [7.5] months) completed DTI. Mean (SD; range) ScreenQ score was 8.6 (4.8; 1-19) points. Mean (SD; range) CTOPP-2 score was 9.4 (3.3; 2-15) points, EVT-2 score was 113.1 (16.6; 88-144) points, and GRTR score was 19.0 (5.9; 5-25) points. ScreenQ scores were negatively correlated with EVT-2 (F2,43 = 5.14; R2 = 0.19; P < .01), CTOPP-2 (F2,35 = 6.64; R2 = 0.28; P < .01), and GRTR (F2,44 = 17.08; R2 = 0.44; P < .01) scores, controlling for child age. Higher ScreenQ scores were correlated with lower FA and higher RD in tracts involved with language, executive function, and emergent literacy abilities (P < .05, familywise error-corrected), controlling for child age and household income.

CONCLUSIONS AND RELEVANCE

This study found an association between increased screen-based media use, compared with the AAP guidelines, and lower microstructural integrity of brain white matter tracts supporting language and emergent literacy skills in prekindergarten children. The findings suggest further study is needed, particularly during the rapid early stages of brain development.

Electrical stimulation mapping of language with stereo-EEG

OBJECTIVE

We prospectively validated stereo-electroencephalography (EEG) electrical stimulation mapping (ESM) of language against a reference standard of meta-analytic functional magnetic resonance imaging (fMRI) framework (Neurosynth).

METHODS

Language ESM was performed using 50 Hz, biphasic, bipolar, stimulation at 1-8 mA, with a picture naming task. Electrode contacts (ECs) were scored as ESM+ if ESM interfered with speech/language function. For each patient, presurgical MRI was transformed to a standard space and coregistered with computed tomographic (CT) scan to obtain EC locations. After whole-brain parcellation, this fused image data were intersected with three-dimensional language fMRI (Neurosynth), and each EC was classified as lying within/outside the fMRI language parcel. Diagnostic odds ratio (DOR) and other indices were estimated. Current thresholds for language inhibition and after-discharges (ADs) were analyzed using multivariable linear mixed models.

RESULTS

In 10 patients (5 females), aged 5.4-21.2 years, speech/language inhibition was noted with ESM on 87/304 (29%) ECs. Stereo-EEG language ESM was a valid classifier of fMRI (Neurosynth) language sites (DOR: 9.02, p < 0.0001), with high specificity (0.87) but poor sensitivity (0.57). Similar diagnostic indices were seen for ECs in frontal or posterior regions, and gray or white matter. Language threshold (3.1 ± 1.5 mA) was lower than AD threshold (4.0 ± 2.0 mA, p = 0.0001). Language and AD thresholds decreased with age and intelligence quotient. Electrical stimulation mapping triggered seizures/auras represented patients' habitual semiology with 1 Hz stimulation.

CONCLUSIONS

Stereo-EEG ESM can reliably identify cerebral parcels with/without language function but may under detect all language sites. We suggest a 50-Hz stimulation protocol for language ESM with stereo-EEG.

A Novel Approach to Evaluate Brain Activation for Lower Extremity Motor Control

BACKGROUND AND PURPOSE

The purpose of this study was to assess the consistency of a novel MR safe lower extremity motor control neuroimaging paradigm to elicit reliable sensorimotor region brain activity.

METHODS

Participants completed multiple sets of unilateral leg presses combining ankle, knee, and hip extension and flexion movements against resistance at a pace of 1.2 Hz while lying supine in a 3T MRI scanner. Regions of Interest (ROI) consisted of regions primarily involved in lower extremity motor control (right and left primary motor cortex, primary somatosensory cortex, premotor cortex, secondary somatosensory cortex, basal ganglia, and the cerebellum).

RESULTS

The group analysis based on mixed effects paired samples t-test revealed no differences for brain activity between sessions (P > .05). Intraclass correlation coefficients in the sensorimotor regions were good to excellent for average percent signal change (.621 to .918) and Z-score (.697 to .883), with the exception of the left secondary somatosensory cortex percent signal change (.165).

CONCLUSIONS

These results indicate that a loaded lower extremity force production and attenuation task that simulates the range of motion of squatting, stepping, and landing from a jump is reliable for longitudinal neuroimaging applications and support the use of this paradigm in further studies examining therapeutic interventions and changes in dynamic lower extremity motor function.

Functional Connectivity of Attention, Visual, and Language Networks During Audio, Illustrated, and Animated Stories in Preschool-Age Children

The American Academy of Pediatrics recommends that parents read with their children early and often and limits on screen-based media. While book sharing may benefit attention in children, effects of animated content are controversial, and the influence of either on attention networks has not previously been studied. This study involved functional magnetic resonance imaging (fMRI) of three separate active-task scans composed of similar 5-min stories presented in the same order for each child (audio → illustrated → animated), followed by assessment of comprehension. Five functional brain networks were defined a priori through literature review: dorsal attention network (DAN), ventral attention network (VAN), language (L), visual imagery (VI), and visual perception (VP). Analyses involved comparison of functional connectivity (FC) within- and between networks across formats, applying false discovery rate correction. Twenty-seven of 33 children completed fMRI (82%; 15 boys, 12 girls; mean 58 ± 8 months old). Comprehension of audio and illustrated stories was equivalent and lower for animation (p < 0.05). For illustration relative to audio, FC within DAN and VAN and between each of these and all other networks was similar, lower within-L, and higher between VI-VP, suggesting reduced strain on the language network using illustrations and imagery. For animation relative to illustration, FC was lower between DAN-L, VAN-VP, VAN-VI, L-VI, and L-VP, suggesting less focus on narrative, reorienting to imagery, and visual-language integration. These findings suggest that illustrated storybooks may be optimal at this age to encourage integration of attention, visual, and language networks, while animation may bias attention toward VP.

The influence of different cement spaces on the marginal gap of CAD/CAM all-ceramic crowns

BACKGROUND

The purpose of this study was to measure the marginal gaps of CAD/CAM all-ceramic crowns constructed using different cement spaces on crown preparations created by undergraduate students.

METHODS

Twenty-four Columbia model lower left first molars with assessed tapers and reduction volumes (RV) were recruited to receive complete coverage E.max crowns. Three E.max crowns were digitally designed and milled for each crown preparation using three different cement spaces: 50 μm (CS-50), 100 μm (CS-100), 200 μm (CS-200). Each crown was seated onto its original crown preparation and three vertical marginal gap measurements were taken at four locations (mid-buccal, mid-lingual, mid-mesial, mid-distal) using a stereomicroscope. The mean marginal gap (MMG) was calculated for each crown and each individual tooth surface.

RESULTS

The MMG was statistically significantly different for each of the three cement spaces (126 μm for CS-50, 89 μm for CS-100, and 75 μm for CS-200) (P < 0.0001). A taper of between 20 and 30° produced the smallest MMG. Insufficient RV caused significantly larger MMGs. The buccal margin had significantly smaller MMGs than all other measured surfaces.

CONCLUSIONS

The most accurate margins of digitally designed all-ceramic crowns constructed on simulation teeth prepared by undergraduate students were observed when using a 200 μm cement space.

Altered brain microstructure in association with repetitive subconcussive head impacts and the potential protective effect of jugular vein compression: a longitudinal study of female soccer athletes

PURPOSE

To (1) quantify white matter (WM) alterations in female high school athletes during a soccer season and characterise the potential for normalisation during the off-season rest period, (2) determine the association between WM alterations and exposure to repetitive subconcussive head impacts, and (3) evaluate the efficacy of a jugular vein compression collar to prevent WM alterations associated with head impact exposure.

METHODS

Diffusion tensor imaging (DTI) data were prospectively collected from high school female soccer participants (14-18 years) at up to three time points over 9 months. Head impacts were monitored using accelerometers during all practices and games. Participants were assigned to a collar (n=24) or non-collar group (n=22). The Tract-Based Spatial Statistics approach was used in the analysis of within-group longitudinal change and between-group comparisons.

RESULTS

DTI analyses revealed significant pre-season to post-season WM changes in the non-collar group in mean diffusivity (2.83%±2.46%), axial diffusivity (2.58%±2.34%) and radial diffusivity (3.52%±2.60%), but there was no significant change in the collar group despite similar head impact exposure. Significant correlation was found between head impact exposure and pre-season to post-season DTI changes in the non-collar group. WM changes in the non-collar group partially resolved at 3 months off-season follow-up.

DISCUSSION

Microstructural changes in WM occurred during a season of female high school soccer among athletes who did not wear the collar device. In comparison, there were no changes in players who wore the collar, suggesting a potential prophylactic effect of the collar device in preventing changes associated with repetitive head impacts. In those without collar use, the microstructural changes showed a reversal towards normal over time in the off-season follow-up period.

Impact of Low-Level Blast Exposure on Brain Function after a One-Day Tactile Training and the Ameliorating Effect of a Jugular Vein Compression Neck Collar Device

Special Weapons and Tactics (SWAT) personnel who conduct breacher exercises are at risk for blast-related head trauma. We aimed to investigate the potential impact of low-level blast exposure during breacher training on the neural functioning of working memory and auditory network connectivity. We also aimed to evaluate the effects of a jugular vein compression collar, designed to internally mitigate slosh energy absorption, preserving neural functioning and connectivity, following blast exposure. A total of 23 SWAT personnel were recruited and randomly assigned to a non-collar (n = 11) and collar group (n = 12). All participants completed a 1-day breacher training with multiple blast exposure. Prior to and following training, 18 participants (non-collar, n = 8; collar, n = 10) completed functional magnetic resonance imaging (fMRI) of working memory using N-Back task; 20 participants (non-collar, n = 10; collar, n = 12) completed resting-state fMRI. Key findings from the working memory analysis include significantly increased fMRI brain activation in the right insular, right superior temporal pole, right inferior frontal gyrus, and pars orbitalis post-training for the non-collar group (p < 0.05, threshold-free cluster enhancement corrected), but no changes were noted for the collar group. The elevation in fMRI activation in the non-collar group was found to correlate significantly (n = 7, r = 0.943, p = 0.001) with average peak impulse amplitude experienced during the training. In the resting-state fMRI analysis, significant pre- to post-training increase in connectivity between the auditory network and two discrete regions (left middle frontal gyrus and left superior lateral occipital/angular gyri) was found in the non-collar group, while no change was observed in the collar group. These data provided initial evidence of the impact of low-level blast on working memory and auditory network connectivity as well as the protective effect of collar on brain function following blast exposure, and is congruent with previous collar findings in sport-related traumatic brain injury.

A jugular vein compression collar prevents alterations of endogenous electrocortical dynamics following blast exposure during special weapons and tactical (SWAT) breacher training

Exposure to explosive blasts places one at risk for traumatic brain injury, especially for special weapons and tactics (SWAT) and military personnel, who may be repeatedly exposed to blasts. In the current study, the effectiveness of a jugular vein compression collar to prevent alterations in resting-state electrocortical activity following a single-SWAT breacher training session was investigated. SWAT team personnel were randomly assigned to wear a compression collar during breacher training and resting state electroencephalography (EEG) was measured within 2 days prior to and two after breacher training. It was hypothesized that significant changes in brain dynamics-indicative of possible underlying neurodegenerative processes-would follow blast exposure for those who did not wear the collar, with ameliorated changes for the collar-wearing group. Using recurrence quantification analysis (RQA) it was found that participants who did not wear the collar displayed longer periods of laminar electrocortical behavior (as indexed by RQA's vertical max line measure) after breacher training. It is proposed that the blast wave exposure for the no-collar group may have reduced the number of pathways, via axonal disruption-for electrical transmission-resulting in the EEG signals becoming trapped in laminar states for longer periods of time. Longer laminar states have been associated with other electrocortical pathologies, such as seizure, and may be important for understanding head trauma and recovery.

Does brain functional connectivity contribute to musculoskeletal injury? A preliminary prospective analysis of a neural biomarker of ACL injury risk

OBJECTIVES

We aimed to present a unique prospective neurological dataset for participants who experienced an ACL injury.

DESIGN

Prospective longitudinal case-control.

METHODS

High school female soccer athletes were evaluated using functional magnetic resonance imaging to capture resting-state brain connectivity prior to their competitive season. Two of these athletes later experienced an ACL injury (ACLI). We matched these ACLI participants with eight teammates who did not go on to sustain an ACL injury (uninjured controls, Con) based on age, grade, sex, height, and weight to examine differences in preseason connectivity. Knee-motor regions of interest (ROIs) were created based on previously published data from which five specific areas were selected as seeds for analysis. Independent-samples t-tests with a false discovery rate correction for multiple comparisons determined differences in connectivity between the ACLI and Con.

RESULTS

There was significantly greater connectivity between the left primary sensory cortex (a brain region responsible for proprioception) and the right posterior lobe of the cerebellum (a brain region responsible for balance and coordination) for the Con relative to ACLI, t (8)=4.53, p=0.03 (false discovery rate corrected).

CONCLUSIONS

These preliminary data indicate that those who do not later sustain an ACL injury exhibit a stronger functional connection between a cortical sensory-motor region and a cerebellar region responsible for balance and coordination. These findings may help to guide development of brain-driven biofeedback training that optimizes and promotes adaptive neuroplasticity to reduce motor coordination errors and injury risk.

Mild Jugular Compression Collar Ameliorated Changes in Brain Activation of Working Memory after One Soccer Season in Female High School Athletes

Recent neuroimaging studies have suggested that repetitive subconcussive head impacts, even after only one sport season, may lead to pre- to post-season structural and functional alterations in male high school football athletes. However, data on female athletes are limited. In the current investigation, we aimed to (1) assess the longitudinal pre- to post-season changes in functional MRI (fMRI) of working memory and working memory performance, (2) quantify the association between the pre- to post-season change in fMRI of working memory and the exposure to head impact and working memory performance, and (3) assess whether wearing a neck collar designed to reduce intracranial slosh via mild compression of the jugular veins can ameliorate the changes in fMRI brain activation observed in the female high school athletes who did not wear collars after a full soccer season. A total of 48 female high school soccer athletes (age range: 14.00-17.97 years) were included in the study. These athletes were assigned to the non-collar group (n = 21) or to the collar group (n = 27). All athletes undewent MRI at both pre-season and post-season. In each session, a fMRI verbal N-Back task was used to engage working memory. A significant pre- to post-season increase in fMRI blood oxygen level dependent (BOLD) signal was demonstrated when performing the N-back working memory task in the non-collar group but not in the collar group, despite the comparable exposure to head impacts during the season between the two groups. The collar group demonstrated significantly smaller pre- to post-season change in fMRI BOLD signal than the non-collar group, suggesting a potential protective effect from the collar device. Significant correlations were also found between the pre- to post-season increase in fMRI brain activation and the decrease in task accuracy in the non-collar group, indicating an association between the compensatory mechanism in underlying neurophysiology and the alteration in the behavioral outcomes.

Twenty-year analysis of implant treatment in an Australian public dental clinic

BACKGROUND

This retrospective cohort study reviewed dental implant treatment completed at the Adelaide Dental Hospital over a 20-year period.

METHODS

The database of implant treatment completed between 1996 and 2015 was analysed for patient, implant, prosthesis and operator specifics together with known implant status.

RESULTS

Three hundred and twenty patients (mean age, 51.50 years) were treated with 527 implants. One hundred and eighty-four female patients received 296 implants and 136 males received 231 implants. Three hundred implants were restored with single crowns, 147 implants were restored with 63 mandibular implant overdentures, five implants were restored with two maxillary implant overdentures and 67 implants were restored with 20 full-arch fixed prostheses. The overall known implant survival rate was 87.67%. Mandibular implant overdentures had a risk of implant failure four times that of single implant-retained crowns that was statistically significant (P = 0.0100).

CONCLUSIONS

Implant treatment completed in this public sector clinic using finite resources and a defined system of patient and restorative selection criteria demonstrated a high known implant survival rate. Utilizing a structured and maintained patient recall protocol, it would be ideal to investigate further parameters of interest, particularly those that could improve treatment delivery and longevity.

Shared Reading Quality and Brain Activation during Story Listening in Preschool-Age Children

OBJECTIVE

To explore the relationship between maternal shared reading quality (verbal interactivity and engagement) and brain function during story listening in at-risk, preschool-age children, in the context of behavioral evidence and American Academy of Pediatrics, recommendations.

STUDY DESIGN

In this cross-sectional study, 22 healthy, 4-year-old girls from low socioeconomic status households completed functional magnetic resonance imaging using an established story listening task, followed by videotaped observation of uncoached mother-daughter reading of the same, age-appropriate picture book. Shared reading quality was independently scored applying dialogic reading and other evidence-based criteria reflecting interactivity and engagement, and applied as a predictor of neural activation during the functional magnetic resonance imaging task, controlling for income and maternal education.

RESULTS

Shared reading quality scores were generally low and negatively correlated with maternal distraction by smartphones (P < .05). Scores were positively correlated with activation in left-sided brain areas supporting expressive and complex language, social-emotional integration, and working memory (P <.05, false discovery rate corrected).

CONCLUSIONS

Maternal shared reading quality is positively correlated with brain activation supporting complex language, executive function, and social-emotional processing in at-risk, preschool-age children. These findings represent novel neural biomarkers of how this modifiable aspect of home reading environment may influence foundational emergent literacy skills, reinforce behavioral evidence and American Academy of Pediatrics, recommendations, and underscore the potential of dialogic reading interventions to promote healthy brain development, especially in at-risk households.

Prosthodontic management of maxillofacial cases: a case series

Maxillofacial prosthetics is an important and recognized sub-discipline of prosthodontics that forms a key component of postgraduate training programmes. General dentists have a role to play in the management of maxillofacial defect patients even though treatment usually requires a multidisciplinary approach in an institutional environment. Maxillofacial prosthetic cases frequently present with complex histories but simple patient goals. The conservatively managed implant-retained auricular prosthesis, speech aid prosthesis and orbital prosthesis cases described in this report were completed in a postgraduate clinical residency program and highlight the intrinsic complexities, challenges and ultimately satisfaction related to cases of this nature.

Story time turbocharger? Child engagement during shared reading and cerebellar activation and connectivity in preschool-age children listening to stories

Expanding behavioral and neurobiological evidence affirms benefits of shared (especially parent-child) reading on cognitive development during early childhood. However, the majority of this evidence involves factors under caregiver control, the influence of those intrinsic to the child, such as interest or engagement in reading, largely indirect or unclear. The cerebellum is increasingly recognized as playing a "smoothing" role in higher-level cognitive processing and learning, via feedback loops with language, limbic and association cortices. We utilized functional MRI to explore the relationship between child engagement during a mother-child reading observation and neural activation and connectivity during a story listening task, in a sample of 4-year old girls. Children exhibiting greater interest and engagement in the narrative showed increased activation in right-sided cerebellar association areas during the task, and greater functional connectivity between this activation cluster and language and executive function areas. Our findings suggest a potential cerebellar "boost" mechanism responsive to child engagement level that may contribute to emergent literacy development during early childhood, and synergy between caregiver and child factors during story sharing.

All-ceramic crown preparations: An alternative technique

BACKGROUND

The aim of this study was to compare the crown preparation dimensions produced from two different techniques of preparation for posterior all-ceramic crowns.

METHODS

Twenty-four fourth year dental students undertook a course of advanced simulation training involving education in an alternative technique of preparation for a 36 all-ceramic crown. Crown preparations performed using the traditional technique were compared with an alternative technique for total occlusal convergence (TOC) and reduction difference (RD) using digital scanning and comparative software.

RESULTS

Groups that spent the most time performing the alternative technique produced crown preparations with significantly lower buccolingual (BL) TOC. The training resulted in crown preparations that were closer to ideal TOC and RD measurements.

CONCLUSIONS

The alternative technique of crown preparation for a posterior all-ceramic crown showed initial promise in creating a less buccolingually tapered and more ideally occlusally reduced crown preparation.