Validation of a Measurement Model to Identify Socio-emotional Difficulties in Preschool Children: The Preschool Pediatric Symptom Checklist-Chilean Version.

Identifying issues in early childhood enables timely interventions, potentially mitigating future mental health risks. In this context, this study seeks to validate the model of Preschool Pediatric Symptom Checklist for detecting social and emotional challenges among Chilean preschoolers, as reported by their caregivers. In the first stage, 36 cognitive interviews using the published Spanish version of the PPSC were conducted with caregivers, parents and/or teachers of preschool aged children, so that they could review the questions and be sure that they understood them. In stage 2, 12 experts checked the questions for coherence and consistency. As a result, only one item was slightly modified. Then, 1009 preschool caregivers answered the preliminary version of the Chilean-adapted scale (PPSC-CL). Taking into account the minor changes incorporated in the scale, and using latent variable analysis techniques, it was possible to obtain evidence of validity for the four-factor structure of the PPSC-CL. Additionally, by using the questions about children's difficulties, a robust bifactor model was established, highlighting the presence of a general factor whose items have a specific component that sustain the existence of latent dimensions for internalizing, externalizing, and attentional problems. Thanks to this advancement, it will now be possible to identify and report the occurrence of global mental health challenges in preschool-aged children.

Implementation of a national mental health intervention in educational communities: What do successful teams do differently?

This study aimed to identify the elements that characterize local teams which implement a nationwide preventive mental health intervention in schools and achieve better results. A mixed-methods sequential explanatory design was conducted in two phases: (a) teams were characterized according to their level of achievement in the preventive intervention through latent class analysis; and (b) case studies of three teams with different implementation results were conducted by performing content analysis on interviews, observations, and documents. It was established that the more effective teams have better planning, the more they are familiar with the intervention, and more aware of their strengths and weaknesses. This team also implement culturally pertinent actions aimed at increasing knowledge about the intervention, which causes schools to experience it as part of their community, since they include the intervention in their regular dynamics. Lastly, the importance and relevance of these elements when working in educational communities is discussed.

Gender-transformative school-based sexual health intervention: study protocol for a randomized controlled trial.

BACKGROUND: There is general agreement that sexuality is a central aspect of human development; it is key in sexual health and reproductive education during adolescence. However, in spite of the existing interventions on this topic and the evidence generated, the inclusion of a gender focus in sexuality is relatively recent and there is little evidence available, thus structured and corroborated interventions with a gender-transforming perspective in sexuality are required. METHODS: We will use a mixed method experimental design with a parallel cluster-randomized trial (GRTs) that will evaluate the effectiveness of a comprehensive gender-transformative intervention of sexual education (ENFOCATE -Focus-on-), which will be complemented with qualitative studies to understand the implementation process. The participants will be 609 10th and 11th-grade students. The randomization will be by grade, and the data will be collected at three moments (pre-intervention, post-intervention, and a 3-month follow-up). DISCUSSION: Comprehensive, gender-focused, and culturally pertinent interventions in sexuality are needed for adolescents of countries with high, middle, and low incomes. These produce better results in terms of sexual health, and including a gender-transformative focus contributes to equity in health. Focus-on is unique since it uses a comprehensive gender-transformative intervention in sexual education that will allow putting into practice a program based both on international evidence and that which arises from the object population. It also uses a culturally-sensitive focus, since it is designed based on the characteristics of the object population; it will allow adapting some activities to the needs of the context in which it is developed. TRIAL REGISTRATION: The study was prospectively registered on June 6, 2023, at ClinicalTrials.gov ID: NCT05896540. Protocol version number 1.0. May 22, 2023.

Stereotactic Localization: From Single-Slice to Multi-Slice Registration Including a Novel Solution for Parallel Bipanels.

Frame-based stereotactic localization generally assumes that all required fiducials are present in a single-slice image which can then be used to form targeting coordinates. Previously, we have published the use of novel localizers and mathematics that can improve stereotactic localization. As stereotactic procedures include numerous imaging slices, we sought to investigate, develop, and test techniques that utilize multiple slices for stereotactic localization and provide a solution for a parallel bipanel N-localizer.  Several multi-slice equations were tested. Specifically, multi-slice stereotactic matrices (ms-SM) and multi-slice normal to parallel planes (ms-nPP) were of particular interest. Bipanel (2N) and tripanel (3N) localizer images were explored to test approaches for stereotactic localization. In addition, combination approaches using single-slice stereotactic matrices (ss-SM) and multi-slice methods were tested. Modification of ss-SM to form ms-SM was feasible. Likewise, a method to determine ms-nPP was developed. For the special case of the parallel bipanel N-localizer, single-slice and multi-slice methods fail, but a novel non-linear solution is a robust solution for ms-nPP. Several methods for single-slice and multi-slice stereotactic localization are described and can be adapted for nearly any stereotactic system. It is feasible to determine ms-SM and ms-nPP. In particular, these methods provide an overdetermined means to calculate the vertical z, which is determined for a tripanel system using single-slice methods. In addition, the multi-slice methods can be used for extrapolation outside of the localizer space. Importantly, a novel non-linear solution can be used for parallel bipanel N-localizer systems, where other methods fail. Finally, multi-slice stereotactic localization assumes strict patient and imaging system stability, which should be carefully assessed for each case.

Unilateral C1 split fracture osteosynthesis using a patient-specific three-dimensional-printed guide: Technique report.

Split-type C1 lateral mass fractures have a propensity for progressive fracture displacement. Since almost all cases end up showing progressive fragment diastasis, many authors recommend early surgical treatment. However, placing a C1 lag screw through a C1 split fracture is a challenging task. To overcome this, we designed a patient-custom three-dimensional (3D)-printed guide plate. We present the case of a 57-year-old female patient with a C1 lateral mass split fracture. Considering the amount of fragment translation, primary osteosynthesis was proposed. To purchase both fragments, placement of a lag screw was assisted intraoperatively by a custom 3D-printed composite guide plate, which enabled us to accurately place the screw. After an uneventful procedure, the patient was discharged from hospital after 72 h. Computed tomography scan performed at 12 months showed good fracture consolidation. The use of a patient-specific guide to place a lag screw through a split fracture of the atlas proved to be a safe, accurate, and inexpensive alternative to intraoperative imaging integrated with image-guided surgery.

Monte Carlo Simulation of Errors for N-localizer Systems in Stereotactic Neurosurgery: Novel Proposals for Improvements.

INTRODUCTION:  Frame-based stereotaxis has been widely utilized for precise neurosurgical procedures throughout the world for nearly 40 years. The N-localizer is an integral component of most of the extant systems. Analysis of targeting errors related to the N-localizer has not been carried out in sufficient detail. We highlight these potential errors and develop methods to reduce them.  Methods: N-localizer systems comprising three and four N-localizers of various geometries were analyzed using Monte Carlo (MC) simulations. The simulations included native and altered geometric dimensions (Width [W] x Height [H]). Errors were computed using the MC simulations that included the x- and y-axes of vertically oriented rods, that altered the W/H ratio, and that added a fourth N-localizer to a three N-localizer system.  Results: The inclusion of an overdetermined system of equations and the geometries of the N-localizer systems had significant effects on target errors. Root Mean Square Errors (RMS-e) computed via millions of MC iterations for each study demonstrated that errors were reduced by (1) inclusion of the x- and y-coordinates of the vertically oriented rods, (2) a greater triangular area enclosed by the diagonal fiducials of the N-localizer system (stereotactic triangle), (3) a larger W/H ratio, and (4) an N-localizer system that comprised four N-localizers. CONCLUSION: Monte Carlo simulations of Root Mean Square error (RMS-e) is a useful technique to understand targeting while using N-localizer systems in stereotactic neurosurgery. The application of vertical rod positions enhances computational accuracy and can be performed on any N-localizer system. Keeping the target point within the stereotactic triangle enclosed by the diagonal rods can also reduce errors. Additional optimizations of N-localizer geometry may also reduce potential targeting errors. Further analysis is needed to confirm these findings which may have clinical importance.

Novel Geometries for Stereotactic Localizers.

INTRODUCTION: The N-localizer is generally utilized in a 3-panel or, more rarely, a 4-panel system for computing stereotactic positions. However, a stereotactic frame that incorporates a 2-panel (bipanel) N-localizer system with panels affixed to only the left and right sides of the frame offers several advantages: improved ergonomics to attach the panels, reduced claustrophobia for the patient, mitigation of posterior panel contact with imaging systems, and reduced complexity. A bipanel system that comprises two standard N-localizer panels yields only two three-dimensional (3D) coordinates, which are insufficient to solve for the stereotactic matrix without further information. While additional information to determine the stereotactic positions could include scalar distances from Digital Imaging and Communications in Medicine (DICOM) metadata or 3D regression across the imaging volume, both have risks related to noise and error propagation. Therefore, we sought to develop new stereotactic localizers that comprise only lateral fiducials (bipanel) that leave the front and back regions of the patient accessible but that contain enough information to solve for the stereotactic matrix using each image independently.  Methods: To solve the stereotactic matrix, we assumed the need to compute three or more 3D points from a single image. Several localizer options were studied using Monte Carlo simulations to understand the effect of errors on the computed target location. The simulations included millions of possible combinations for computing the stereotactic matrix in the presence of random errors of 1mm magnitude. The matrix then transformed coordinates for a target that was placed 50mm anterior, 50mm posterior, 50mm lateral, or 50mm anterior and 50mm lateral to the centre of the image. Simulated cross-sectional axial images of the novel localizer systems were created and converted into DICOM images representing computed tomography (CT) images.  Results: Three novel models include the M-localizer, F-localizer, and Z-localizer. For each of these localizer systems, optimized results were obtained using an overdetermined system of equations made possible by more than three diagonal bars. In each case, the diagonal bar position was computed using standard N-localizer mathematics. Additionally, the M-localizer allowed adding a computation using the Sturm-Pastyr method. Monte Carlo simulation demonstrated that the Z-localizer provided optimal results. CONCLUSION: The three proposed novel models meet our design objectives. Of the three, the Z-localizer produced the least propagation of error. The M-localizer was simpler and had slightly more error than the Z-localizer. The F-localizer produced more error than either the Z-localizer or M-localizer. Further study is needed to determine optimizations using these novel models.

The V-Localizer for Stereotactic Guidance.

Image-guidance for frame-based stereotaxis is facilitated by incorporating three to four N-localizers or Sturm-Pastyr localizers into a stereotactic frame. An extant frame that incorporates only two N-localizers violates the fundamental principle of the N-localizer, which requires three non-colinear points to define a plane in three-dimensional space. Hence, this two N-localizer configuration is susceptible to error. The present article proposes the V-localizer that comprises multiple diagonal bars to provide four or more non-colinear points to minimize error.

Chilean version of the INECO Frontal Screening (IFS-Ch): psychometric properties and diagnostic accuracy.

OBJECTIVE: This study sought to analyze the psychometric properties and diagnostic accuracy of the Chilean version of the INECO Frontal Screening (IFS-Ch) in a sample of dementia patients and control subjects. METHODS: After adapting the instrument to the Chilean context and obtaining content validity evidence through expert consultation, the IFS-Ch was administered to 31 dementia patients and 30 control subjects together with other executive assessments (Frontal Assessment Battery [FAB], Modified version of the Wisconsin Card Sorting Test [MCST], phonemic verbal fluencies [letters A and P] and semantic verbal fluency [animals]) and global cognitive efficiency tests (Mini mental State Examination [MMSE] and Addenbrooke's Cognitive Examination-Revised [ACE-R]). Caregivers of dementia patients and proxies of control subjects were interviewed with instruments measuring dysexecutive symptoms (Dysexecutive Questionnaire [DEX]), dementia severity (Clinical Dementia Rating Scale [CDR]) and functional status in activities of daily living (Activities of Daily Living Scale [IADL] and Technology-Activities of Daily Living Questionnaire [T-ADLQ]). Convergent and discriminant validity, internal consistency reliability, cut-off points, sensitivity and specificity for the IFS-Ch were estimated. RESULTS: Evidence of content validity was obtained. Evidence of convergent validity was also found showing significant correlations (p<0.05) between the IFS-Ch and the other instruments measuring: executive functions (FAB, r=0.935; categories achieved in the MCST, r=0.791; perseverative errors in the MCST, r= -0.617; animal verbal fluency, r=0.728; "A" verbal fluency, r=0.681; and "P" verbal fluency, r=0.783), dysexecutive symptoms in daily living (DEX, r= -0.494), dementia severity (CDR, r= -0.75) and functional status in activities of daily living (T-ADLQ, r= -0.745; IADL, r=0.717). Regarding reliability, a Cronbach's alpha coefficient of 0.905 was obtained. For diagnostic accuracy, a cut-off point of 18 points (sensitivity=0.903; specificity=0.867) and an area under curve of 0.951 were estimated to distinguish between patients with dementia and control subjects. DISCUSSION: The IFS-Ch showed acceptable psychometric properties, supported by evidence of validity and reliability for its use in the measurement of executive functions in patients with dementia. The diagnostic accuracy of the IFS-Ch for detecting dementia patients was also considered acceptable.

OBJETIVO: Analisar as propriedades psicométricas e utilitário de diagnóstico da versão chilena do rastreio frontal INECO (IFS-Ch) em uma amostra de pacientes com demência e controles. MÉTODOS: Após a adaptação do instrumento para o contexto chileno e obtenção de evidências de validade de conteúdo, o IFS-Ch foi administrado a 31 pacientes com demência e 30 indivíduos do grupo controle, além de outros testes de eficiência cognitiva global e executiva. Cuidadores de pacientes com demência e informantes de indivíduos controles foram entrevistados com instrumentos de medidas de sintomas disexecutivos, gravidade da demência e estado funcional nas atividades da vida diária. Validade convergente e discriminante, consistência interna, pontos de corte, sensibilidade e especificidade para o IFS-Ch foram estimados. RESULTADOS: A evidência de validade de conteúdo foi obtida através de consulta a um especialista. Evidências de validade convergente foram encontrados, bem como, descritas correlações significativas entre o IFS-Ch e outros instrumentos de medidas: de funções executivas (FAB, r=0,935; categorias alcançadas no MCST, r=0,791; erros perseverativos na MCST, r= -0,617; fluência verbal animais, r=0,728; "A" de fluência verbal, r=0,681; gravidade de demência e fluência verbal de "P", r=0,783), sintomas disexecutivos na vida diária (DEX, r= -0,494), (CDR, r= -0,75) e estado funcional nas atividades da vida diária (T-ADLQ, r= -0,745; AIVD, r=0,717). Quanto à confiabilidade, coeficiente alfa de Cronbach de 0,905 foi obtido. Quanto a utilidade de diagnóstico, um ponto de corte de 18 pontos (sensibilidade=0,903, especificidade=0,867) e uma área sob a curva de 0,951 foi estimada para distinguir entre pacientes com demência e sujeitos controles. DISCUSSÃO: O IFS-Ch mostra propriedades psicométricas aceitáveis, apoiadas por evidências de validade e confiabilidade para sua utilização como medida de funções executivas em pacientes com demência. Sua utilidade diagnóstica para detectar pacientes com demência também é considerada aceitável.