[Design and application of a head support frame for prone position ventilation].

Respiratory failure caused by acute respiratory distress syndrome and severe pneumonia is common diseases in intensive care medicine. In recent years, with the continuous updating of treatment methods, prone position ventilation has been found to have a good therapeutic effect on such diseases, and has been widely used in clinical practice. However, prone position ventilation significantly increases the workload of medical staff and the risk of accidental extubation and pressure injuries to patients, seriously affecting the safety of diagnosis and treatment. At present, various devices such as mattresses have been used for prone position ventilation, but there are few devices specifically designed to protect and fix the head and face. Therefore, the medical staff of Affiliated Hospital of Zunyi Medical University designed and developed a head support frame for prone position ventilation, and obtained a National Utility Model Patent of China (patent number: ZL 2018 2 0056891.6). The head support frame for prone position ventilation includes a movable chassis and rollers for easy movement and fixation. The retractable column 1 is vertically fixed on the movable chassis, and its height can be freely adjusted according to the position of the patient. A transverse bridge is fixed at the top of the retractable column 1, the two ends of the bridge are designed a bulge, and the rotating ring is fixed above the transverse bridge, so that the rotating ring can rotate along the bridge at a certain angle. The rotating ring is designed with an inner ring and an inlet and outlet which can pass through the tube is designed on the rotating ring. The inflatable air bag is designed above the rotating ring to improve the comfort of patients and reduce the pressure injury of facial skin. A sliding rod is vertically designed on the upper part of the retractable column 1, and there is a retractable column 2 at the distal end of the slide rod, and the retractable column 2 is connected with the rotating ring, so that the rotating ring adjusts the angle along the cross bridge with the contraction of the collapsible column 2. A retractable column 3 is arranged in the middle of the slide rod, and a catheter clamp is arranged at its far end to facilitate the fixation of the artificial airway and the mechanical ventilation tube. The support frame is practical and convenient, which can protect the patient's head safely in the prone position, and greatly reduce the workload of medical staff.

Clinical efficacy of a head-mounted device for central vision loss.

Central vision loss (CVL) is a major form of low vision that remains inadequately managed worldwide. This study evaluated the clinical efficacy of a novel head-mounted device (HMD), Onyx, designed to enhance visual function and vision-related quality of life for CVL patients. It employs a projection system that enables patients to leverage their residual peripheral vision for environmental awareness. It also integrates artificial intelligence to augment the automatic recognition of text, faces, and objects. In this single-center, prospective cohort study, 41 binocularly low vision patients with CVL were instructed to use Onyx for 4 to 6 h daily over a one-month period. Various metrics were assessed, including near and distance visual acuity (VA), recognition abilities for faces and objects, and the low vision quality-of-life (LVQOL) questionnaire scores, at the start and end of the study. The results showed significant improvements in near VA for 60.98% of the participants, distance VA for 80.49%, and recognition ability for 90.24%. 68.29% of the participants showed significant improvements in the LVQOL scores. Improvement in recognition ability was negatively correlated with baseline recognition ability. Additionally, improvement in the LVQOL scores was correlated with age and the baseline LVQOL score. Overall, the study found that the novel HMD significantly improved visual function and vision-related quality of life for low vision patients with CVL, highlighting the potential benefits and the need for further evaluation of such devices.

Computed Tomography Findings of Patients Presenting With Headache: 4-Year Retrospective Two-Center Study in Central and Western Regions of Ghana.

Objectives: The radiographic assessment of the head is a crucial part of headache care. A computed tomography (CT) scan enables a more detailed analysis of the condition and more focused care. This study examined head CT scans to determine what kinds of anomalies were present in patients with headaches as their primary complaint. Methods: We evaluated 4 years' worth of CT scan data from head exams conducted at two diagnostic facilities in Ghana's western and central regions. We examined data on 477 patients with a headache as their primary complaint between January 2017 and December 2020. We employed chi-square and Fisher's exact tests (where applicable) to compare head CT diagnoses between age groups, gender, headache subtypes, and brain lesion subgroups. Results: There were 53.5% (n = 255) females and 46.5% (n = 222) males in the study. The average age of patients was 38.67 ± 17.23 years, with an annual rate of abnormal CT diagnoses ranging from 35.9% in 2017 to 45.4% in 2022. Abnormal head CT diagnoses are strongly correlated with age groups and patient gender (p = 0.011 and p = 0.009, respectively). Of the 202 patients, 15.3% and 24.3% were classified as intracranial lesions and extracranial lesions, respectively. Maxillary sinusitis affected nearly 60% of the patients, while tumors and hemorrhages affected 25.2% and 11.9%, respectively. Conclusions: A CT scan of the head is essential to detect abnormalities in nearly 50% of patients suffering from various degrees of headache. Sinusitis, brain tumors, and hemorrhage were common lesions detected. It is crucial to create local standard operating procedures to promote better utilization of this type of imaging service, particularly among patients who have been diagnosed with headaches.

Comparing the effects of neck stabilization exercises versus dynamic exercises among patients having nonspecific neck pain with forward head posture: a randomized clinical trial.

BACKGROUND: Nonspecific neck pain (NSNP) is a well-established global burden affecting. It is also a common problem in Pakistan. The burden of neck pain is also increasing day by day due to poor work ergonomics, and increased use of computers and mobiles after the pandemic. An individual's poor posture is often associated with forward head posture (FHP). Limited evidence is available about the effects of neck stabilization (NSE) and dynamic exercises (NDE) for nonspecific neck pain particularly in patients with FHP. This aimed to compare the effects of NSE versus NDE among patients having NSNP with FHP in reducing pain, disability, forward head posture and improving neck range of motion. METHODS: It is a single-blinded randomized clinical trial with 60 patients aged 18-40 years, with moderate intensity NSNP for > 3 weeks and < 6 months along with FHP with a moderate disability on neck disability index (NDI) randomly assigned to the treatment groups. Group 1 was doing NSE and group 2 was doing NDE. Transcutaneous Electical Nerve Stimulation, cold packs, and stretching exercises were given to both groups. A total of 9 sessions (3 sessions/ week) were given to participants. NDI questionnaire, Visual analogue scale (VAS), goniometry, and plumb line measurement tool were used as baseline and assessment at the end of 3rd week. The data was analyzed on SPSS version 21. Descriptive analysis was performed. Independent t-test was used for between group comparison and paired t-test used for within group comparison. A p-value less than 0.05 was considered statistically significant. RESULTS: After treatment within-group analysis of both NSE and NDE showed significant (p < 0.001) improvement in pain on VAS, all ROMs of the neck including flexion, extension, left and right lateral flexion and left rotation, plumb line and NDI score with very large effect size. However, between-group analysis showed non-significant differences (p > 0.05) for post-treatment mean VAS, neck ROM, NDI and plumb line measurement. CONCLUSION: Between NSE and NDE, no one is more beneficial than another. Both are equally effective in alleviating pain, increasing ROM, decreasing functional disability, and improving forward head posture in patients with NSNP. TRIAL REGISTRATION: Registered trial at ClinicalTrials.gov Identifier: NCT05298631, 28/03/2022, prospectively registered.

Evaluating the Usability and Quality of a Clinical Mobile App for Assisting Physicians in Head Computed Tomography Scan Ordering: Mixed Methods Study.

BACKGROUND: Among the numerous factors contributing to health care providers' engagement with mobile apps, including user characteristics (eg, dexterity, anatomy, and attitude) and mobile features (eg, screen and button size), usability and quality of apps have been introduced as the most influential factors. OBJECTIVE: This study aims to investigate the usability and quality of the Head Computed Tomography Scan Appropriateness Criteria (HAC) mobile app for physicians' computed tomography scan ordering. METHODS: Our study design was primarily based on methodological triangulation by using mixed methods research involving quantitative and qualitative think-aloud usability testing, quantitative analysis of the Mobile Apps Rating Scale (MARS) for quality assessment, and debriefing across 3 phases. In total, 16 medical interns participated in quality assessment and testing usability characteristics, including efficiency, effectiveness, learnability, errors, and satisfaction with the HAC app. RESULTS: The efficiency and effectiveness of the HAC app were deemed satisfactory, with ratings of 97.8% and 96.9%, respectively. MARS assessment scale indicated the overall favorable quality score of the HAC app (82 out of 100). Scoring 4 MARS subscales, Information (73.37 out of 100) and Engagement (73.48 out of 100) had the lowest scores, while Aesthetics had the highest score (87.86 out of 100). Analysis of the items in each MARS subscale revealed that in the Engagement subscale, the lowest score of the HAC app was "customization" (63.6 out of 100). In the Functionality subscale, the HAC app's lowest value was "performance" (67.4 out of 100). Qualitative think-aloud usability testing of the HAC app found notable usability issues grouped into 8 main categories: lack of finger-friendly touch targets, poor search capabilities, input problems, inefficient data presentation and information control, unclear control and confirmation, lack of predictive capabilities, poor assistance and support, and unclear navigation logic. CONCLUSIONS: Evaluating the quality and usability of mobile apps using a mixed methods approach provides valuable information about their functionality and disadvantages. It is highly recommended to embrace a more holistic and mixed methods strategy when evaluating mobile apps, because results from a single method imperfectly reflect trustworthy and reliable information regarding the usability and quality of apps.

The effect of safety modifications on head kinematics experienced during common skills in women's artistic gymnastics.

The objective of this study was to evaluate the effect of skill modifications on head motion experienced during women's artistic gymnastics skills. Nine gymnasts (four beginner and five advanced) completed three trials of up to 24 skill progressions, each consisting of a skill and two progressive safety modifications. Gymnasts were instrumented with mouthpiece sensors embedded with an accelerometer and gyroscope collecting motion data at 200, 300, and 500 Hz during each skill performance. Peak-to-peak linear and rotational kinematics during contact phases and peak rotational kinematics during non-contact phases were computed. A mixed-effects model was used to compare differences in modification status nested within skill categories. Timer skills (i.e. drills that simulate performance of a gymnastics skill) resulted in the highest median ΔLA and ΔRA of all skill categories, and 132 skill performances exceeded 10 g ΔLA during a contact phase. Modifications were associated with significant reductions in head kinematics during contact phases of timers, floor skills, bar releases, and vault skills. Gymnasts can be exposed to direct and indirect head accelerations at magnitudes consistent with other youth contact sports, and common safety modifications may be effective at reducing head motion during contact and non-contact phases of gymnastics skills.

[Subcutaneous emphysema in the head and neck region]. / Subcutaan emfyseem in het hoofd-halsgebied.

Subcutaneous emphysema is a relatively harmless finding which is pathognomonic for a mid-facial fracture in most cases. Increasing pressure will cause air to expand beyond the tissues. It is often caused by blowing one's nose, but can also result from intubation in cases of more severe trauma. Crepitus can be heard or felt subcutaneously upon palpitation. Two cases of patients presenting at an oral and maxillofacial unit with extensive emphysema in the head and neck region illustrate both a common and an unusual cause.

Semi-analytic three-shell forward calculation for magnetoencephalography.

In previous studies, the magnetic lead field theorem in the quasi-static approximation was derived and used for the development of a method for the forward problem of MEG. It was applied and tested on a single-shell model of the human head and the question whether one shell is adequate enough for the calculation of the magnetic field is the main reason for this study. This forward method is based on the fundamental concept that one can calculate the lead field for MEG by decomposing it into two parts: the lead field of an arbitrary volume conductor that is already known and the gradient of basis functions that have to be harmonic, here derived from spherical harmonics. The problem then is reduced to evaluating the coefficients found in the basis functions. In this research we aim to improve the accuracy of the forward model, hence improving the localization accuracy in inverse methods by introducing a more detailed realistic head model. We here generalize the algorithm developed for a single-shell volume conductor to a three-shell volume conductor representing the brain, the skull and the skin with homogenous and isotropic conductivities in realistic ratios. The expansion to three shells could be tested as the three-shell algorithm is approaching the single-shell with high accuracy in special cases where three-shell solutions can also be calculated using a single-shell solution, especially for higher levels of expansion. The deviation in the calculation of the lead field is also evaluated when using three shells with realistic conductivities. The magnetic field turned out to differ to an important measurable extend in particular for deeper sources, making the three-shell algorithm substantially more accurate for these dipole locations.

Head and pelvis are the key segments recruited by adult spinal deformity patients during daily life activities.

Functional assessment is a key element in evaluating adult spinal deformity (ASD) patients. The multitude of 3D kinematic parameters provided by movement analysis can be confusing for spine surgeons. The aim was to investigate movement patterns of ASD based on key kinematic parameters. 115 primary ASD and 36 controls underwent biplanar radiographs and 3D movement analysis during walking, sit-to-stand and stair ascent to calculate joint and segment kinematics. Principal component analysis was applied to identify the most relevant kinematic parameters that define movement strategies adopted by ASD. Pelvis and head relative to pelvis kinematics were the most relevant parameters. ASD patients adopted four different movement strategies. Class 1: normative head and pelvis kinematics. Class 2: persistent pelvic backward tilt. Class 3: persistent forward shift of the head. Class 4: both pelvic backward tilt and forward shift of the head. Patients in class 3 and 4 presented sagittal malalignment on static radiographs with increased pelvic tilt, pelvic incidence-lumbar lordosis mismatch and sagittal vertical axis. Surprisingly, patients in class 3 had normal pelvic kinematics during movement, showing the importance of functional evaluation. In addition to being key segments in maintaining static global posture, head and pelvis were found to define movement patterns.

Pictorial Review of Cranial Nerve Denervation in the Head and Neck.

Of the twelve cranial nerves, nine supply motor innervation to the muscles of the head and neck. Loss of this motor nerve supply, or denervation, follows a series of predictable chronologic changes in the affected muscles. Although the length of time between each change is markedly variable, denervation is typically classified into three distinct time points: (a) acute, (b) subacute, and (c) chronic. These muscle changes produce characteristic findings on images, with contrast-enhanced MRI being the preferred modality for assessment. Imaging allows radiologists to not only identify denervation but also evaluate the extent of denervation and localize the potential site of insult. However, these findings may be easily mistaken for other diseases with similar manifestations, such as neoplasm, infection, and inflammatory conditions. As such, it is fundamental for radiologists to be familiar with cranial nerve anatomy and denervation patterns so that they can avoid these potential pitfalls and focus their imaging search on the pathway of the affected nerve. In this article, the anatomy and muscles innervated by motor cranial nerves in the head and neck, denervation, and the associated expected imaging patterns are reviewed, and examples of potential pitfalls and denervation mimics are provided. ©RSNA, 2024.

Evaluating cranial landmarks for yaw orientation in natural head position: a 3D study.

OBJECTIVES: To assess the symmetry of various cranial anthropometric points used as references for yaw orientation in the natural head position (NHP), relative to the mid-sagittal plane. MATERIALS AND METHODS: A prospective analysis using tomography data from 55 patients was conducted. Radiopaque markers, placed on patients in NHP, facilitated head position recording in three planes, with subsequent digital transfer for orientation analysis. Symmetry of eight points (zygomaxillare, zygion, ectoconchion, frontozygomatic suture, stephanion, porion, mastoidale, condylion laterale) was measured against the mid-sagittal plane. RESULTS: Significant asymmetry was observed in the stephanion, frontozygomatic suture, and ectoconchion points (p < 0.05). No significant differences were found in the symmetry of other points (p > 0.05). CONCLUSIONS: Findings suggest that stephanion, frontozygomatic suture, and ectoconchion are unreliable for yaw orientation in NHP. Other points, combined with clinical measurements, may offer better reliability.

Microwave Technique for Linear Skull Fracture Detection-Simulation and Experimental Study Using Realistic Human Head Models.

Microwave (MW) sensing is regarded as a promising technique for various medical monitoring and diagnostic applications due to its numerous advantages and the potential to be developed into a portable device for use outside hospital settings. The detection of skull fractures and the monitoring of their healing process would greatly benefit from a rapidly and frequently usable application that can be employed outside the hospital. This paper presents a simulation- and experiment-based study on skull fracture detection with the MW technique using realistic models for the first time. It also presents assessments on the most promising frequency ranges for skull fracture detection within the Industrial, Scientific and Medical (ISM) and ultrawideband (UWB) ranges. Evaluations are carried out with electromagnetic simulations using different head tissue layer models corresponding to different locations in the human head, as well as an anatomically realistic human head simulation model. The measurements are conducted with a real human skull combined with tissue phantoms developed in our laboratory. The comprehensive evaluations show that fractures cause clear differences in antenna and channel parameters (S11 and S21). The difference in S11 is 0.1-20 dB and in S21 is 0.1-30 dB, depending on the fracture width and location. Skull fractures with a less than 1 mm width can be detected with microwaves at different fracture locations. The detectability is frequency dependent. Power flow representations illustrate how fractures impact on the signal propagation at different frequencies. MW-based detection of skull fractures provides the possibility to (1) detect fractures using a safe and low-cost portable device, (2) monitor the healing-process of fractures, and (3) bring essential information for emerging portable MW-based diagnostic applications that can detect, e.g., strokes.

Dynamics of odor-source localization: Insights from real-time odor plume recordings and head-motion tracking in freely moving mice.

Animals navigating turbulent odor plumes exhibit a rich variety of behaviors, and employ efficient strategies to locate odor sources. A growing body of literature has started to probe this complex task of localizing airborne odor sources in walking mammals to further our understanding of neural encoding and decoding of naturalistic sensory stimuli. However, correlating the intermittent olfactory information with behavior has remained a long-standing challenge due to the stochastic nature of the odor stimulus. We recently reported a method to record real-time olfactory information available to freely moving mice during odor-guided navigation, hence overcoming that challenge. Here we combine our odor-recording method with head-motion tracking to establish correlations between plume encounters and head movements. We show that mice exhibit robust head-pitch motions in the 5-14Hz range during an odor-guided navigation task, and that these head motions are modulated by plume encounters. Furthermore, mice reduce their angles with respect to the source upon plume contact. Head motions may thus be an important part of the sensorimotor behavioral repertoire during naturalistic odor-source localization.

Effect of repetitive transcranial magnetic stimulation on trigeminal-mediated headshaking in 17 horses.

BACKGROUND: Trigeminal-mediated headshaking is a neuropathic facial pain condition in horses. No treatment has been entirely successful. Repetitive transcranial magnetic stimulation (rTMS) is used in human medicine as a treatment for various neuropathic pain conditions, and good results have been achieved in cases of trigeminal neuralgia. OBJECTIVES: Apply rTMS to horses with trigeminal-mediated headshaking (TMHS) and to evaluate tolerability, application of the setting, and success rate. ANIMALS: Seventeen horses with nonseasonal signs of TMHS. METHODS: Other underlying causes of headshaking were ruled out. The rTMS was performed under standing sedation on 5 consecutive days applying 3 sets of 500 stimulations each, with a stimulation strength of 5 Hz. Horses were evaluated on Day 1 (t0) and Day 5 (t1) of the treatment and 2 (t2) and 4 weeks (t3) afterwards using a special scoring system. RESULTS: The rTMS was well tolerated. Headshaking signs during exercise were decreased by 70% (Day 5; t1). Four weeks after rTMS, signs were still decreased (mean reduction of 50%) during exercise. Improvement of mean resting and exercise scores was significant (P < .05) and effect sizes between pretreatment and all time points after treatment (t1, t2, t3) were large (>±0.8). CONCLUSIONS AND CLINICAL IMPORTANCE: Repetitive transcranial magnetic stimulation may be a promising treatment for neuropathic pain and headshaking in affected horses. Pain-free periods after treatment differ individually, and repeated treatment may be necessary. More studies should be performed to determine ideal settings for horses.

Nontraumatic Pediatric Head and Neck Emergencies: Resource for On-Call Radiologists.

The vast array of acute nontraumatic diseases encountered in the head and neck of pediatric patients can be intimidating for radiologists in training in a fast-paced emergency setting. Although there is some overlap of pediatric and adult diseases, congenital lesions and developmental variants are much more common in the pediatric population. Furthermore, the relative incidences of numerous infections and neoplasms differ between pediatric and adult populations. Young patients and/or those with developmental delays may have clinical histories that are difficult to elicit or nonspecific presentations, underscoring the importance of imaging in facilitating accurate and timely diagnoses. It is essential that radiologists caring for children be well versed in pediatric nontraumatic head and neck emergency imaging. The authors provide an on-call resource for radiology trainees, organized by anatomic location and highlighting key points, pearls, pitfalls, and mimics of many acute nontraumatic diseases in the pediatric head and neck. ©RSNA, 2024 Supplemental material is available for this article.

Neuroanatomical photogrammetric models using smartphones: a comparison of apps.

OBJECTIVES: A deep knowledge of the surgical anatomy of the target area is mandatory for a successful operative procedure. For this purpose, over the years, many teaching and learning methods have been described, from the most ancient cadaveric dissection to the most recent virtual reality, each with their respective pros and cons. Photogrammetry, an emergent technique, allows for the creation of three-dimensional (3D) models and reconstructions. Thanks to the spreading of photogrammetry nowadays it is possible to generate these models using professional software or even smartphone apps. This study aims to compare the neuroanatomical photogrammetric models generated by the two most utilized smartphone applications in this domain, Metascan and 3D-Scanner, through quantitative analysis. METHODS: Two human head specimens (four sides) were examined. Anatomical dissection was segmented into five stages to systematically expose well-defined structures. After each stage, a photogrammetric model was generated using two prominent smartphone applications. These models were then subjected to both quantitative and qualitative analysis, with a specific focus on comparing the mesh density as a measure of model resolution and accuracy. Appropriate consent was obtained for the publication of the cadaver's image. RESULTS: The quantitative analysis revealed that the models generated by Metascan app consistently demonstrated superior mesh density compared to those from 3D-Scanner, indicating a higher level of detail and potential for precise anatomical representation. CONCLUSION: Enabling depth perception, capturing high-quality images, offering flexibility in viewpoints: photogrammetry provides researchers with unprecedented opportunities to explore and understand the intricate and magnificent structure of the brain. However, it is of paramount importance to develop and apply rigorous quality control systems to ensure data integrity and reliability of findings in neurological research. This study has demonstrated the superiority of Metascan in processing photogrammetric models for neuroanatomical studies.

On-field Head Acceleration Exposure Measurements Using Instrumented Mouthguards: Multi-stage Screening to Optimize Data Quality.

Instrumented mouthguards (iMGs) are widely applied to measure head acceleration event (HAE) exposure in sports. Despite laboratory validation, on-field factors including potential sensor skull-decoupling and spurious recordings limit data accuracy. Video analysis can provide complementary information to verify sensor data but lacks quantitative kinematics reference information and suffers from subjectivity. The purpose of this study was to develop a rigorous multi-stage screening procedure, combining iMG and video as independent measurements, aimed at improving the quality of on-field HAE exposure measurements. We deployed iMGs and gathered video recordings in a complete university men's ice hockey varsity season. We developed a four-stage process that involves independent video and sensor data collection (Stage I), general screening (Stage II), cross verification (Stage III), and coupling verification (Stage IV). Stage I yielded 24,596 iMG acceleration events (AEs) and 17,098 potential video HAEs from all games. Approximately 2.5% of iMG AEs were categorized as cross-verified and coupled iMG HAEs after Stage IV, and less than 1/5 of confirmed or probable video HAEs were cross-verified with iMG data during stage III. From Stage I to IV, we observed lower peak kinematics (median peak linear acceleration from 36.0 to 10.9 g; median peak angular acceleration from 3922 to 942 rad/s2) and reduced high-frequency signals, indicative of potential reduction in kinematic noise. Our study proposes a rigorous process for on-field data screening and provides quantitative evidence of data quality improvements using this process. Ensuring data quality is critical in further investigation of potential brain injury risk using HAE exposure data.

Immediate and Transient Perturbances in EEG Within Seconds Following Controlled Soccer Head Impact.

Athletes in contact and collision sports can sustain frequent subconcussive head impacts. Although most impacts exhibit low kinematics around or below 10 g of head linear acceleration, there is growing concern regarding the cumulative effects of repetitive sports head impacts. Even mild impacts can lead to brain deformations as shown through neuroimaging and finite element modeling, and thus may result in mild and transient effects on the brain, prompting further investigations of the biomechanical dose-brain response relationship. Here we report findings from a novel laboratory study with continuous monitoring of brain activity through electroencephalography (EEG) during controlled soccer head impacts. Eight healthy participants performed simulated soccer headers at 2 mild levels (6 g, 4 rad/s and 10 g, 8 rad/s) and three directions (frontal, oblique left, oblique right). Participants were instrumented with an inertial measurement unit (IMU) bite bar and EEG electrodes for synchronized head kinematics and brain activity measurements throughout the experiment. After an impact, EEG exhibited statistically significant elevation of relative and absolute delta power that recovered within two seconds from the impact moment. These changes were statistically significantly higher for 10 g impacts compared with 6 g impacts in some topographical regions, and oblique impacts resulted in contralateral delta power increases. Post-session resting state measurements did not indicate any cumulative effects. Our findings suggest that even mild soccer head impacts could lead to immediate, transient neurophysiological changes. This study paves the way for further dose-response studies to investigate the cumulative effects of mild sports head impacts, with implications for long-term athlete brain health.

A deep learning approach to identify the fetal head position using transperineal ultrasound during labor.

OBJECTIVES: To develop a deep learning (DL)-model using convolutional neural networks (CNN) to automatically identify the fetal head position at transperineal ultrasound in the second stage of labor. MATERIAL AND METHODS: Prospective, multicenter study including singleton, term, cephalic pregnancies in the second stage of labor. We assessed the fetal head position using transabdominal ultrasound and subsequently, obtained an image of the fetal head on the axial plane using transperineal ultrasound and labeled it according to the transabdominal ultrasound findings. The ultrasound images were randomly allocated into the three datasets containing a similar proportion of images of each subtype of fetal head position (occiput anterior, posterior, right and left transverse): the training dataset included 70 %, the validation dataset 15 %, and the testing dataset 15 % of the acquired images. The pre-trained ResNet18 model was employed as a foundational framework for feature extraction and classification. CNN1 was trained to differentiate between occiput anterior (OA) and non-OA positions, CNN2 classified fetal head malpositions into occiput posterior (OP) or occiput transverse (OT) position, and CNN3 classified the remaining images as right or left OT. The DL-model was constructed using three convolutional neural networks (CNN) working simultaneously for the classification of fetal head positions. The performance of the algorithm was evaluated in terms of accuracy, sensitivity, specificity, F1-score and Cohen's kappa. RESULTS: Between February 2018 and May 2023, 2154 transperineal images were included from eligible participants across 16 collaborating centers. The overall performance of the model for the classification of the fetal head position in the axial plane at transperineal ultrasound was excellent, with an of 94.5 % (95 % CI 92.0--97.0), a sensitivity of 95.6 % (95 % CI 96.8-100.0), a specificity of 91.2 % (95 % CI 87.3-95.1), a F1-score of 0.92 and a Cohen's kappa of 0.90. The best performance was achieved by the CNN1 - OA position vs fetal head malpositions - with an accuracy of 98.3 % (95 % CI 96.9-99.7), followed by CNN2 - OP vs OT positions - with an accuracy of 93.9 % (95 % CI 89.6-98.2), and finally, CNN3 - right vs left OT position - with an accuracy of 91.3 % (95 % CI 83.5-99.1). CONCLUSIONS: We have developed a DL-model capable of assessing fetal head position using transperineal ultrasound during the second stage of labor with an excellent overall accuracy. Future studies should validate our DL model using larger datasets and real-time patients before introducing it into routine clinical practice.

Apoptosis-dependent head development during metamorphosis of the cnidarian Hydractinia symbiolongicarpus.

Apoptosis is a regulated cell death that depends on caspases. It has mainly been studied as a mechanism for the removal of unwanted cells. However, apoptotic cells can induce fate or behavior changes of their neighbors and thereby participate in development. Here, we address the functions of apoptosis during metamorphosis of the cnidarian Hydractinia symbiolongicarpus. We describe the apoptotic profile during metamorphosis of the larva and identify Caspase3/7a, but no other executioner caspases, as essential for apoptosis in this context. Using pharmacological and genetic approaches, we find that apoptosis is required for normal head development. Inhibition of apoptosis resulted in defects in head morphogenesis. Neurogenesis was compromised in the body column of apoptosis-inhibited animals but there was no effect on the survival or proliferation of stem cells, suggesting that apoptosis is required for cellular commitment rather than for the maintenance of their progenitors. Differential transcriptomic analysis identifies TRAF genes as downregulated in apoptosis-inhibited larvae and functional experiments provide evidence that they are essential for head development. Finally, we find no major role for apoptosis in head regeneration in this animal, in contrast to the significance of apoptosis in Hydra head regeneration.