RESUMEN
PURPOSE: Despite the impact of physician-scientists on scientific discovery and translational medicine, several reports have signalled their declining workforce, reduced funding, and insufficient protected research time. Given the paucity of outcome data on Canadian MD/PhD programs, this study presents a national portrait of the sociodemographic characteristics, training trajectories, productivity, and satisfaction in trainees and alumni from Canadian MD/PhD and MD/MSc programs. METHODS: Quantitative data were collected in a national survey launched in 2021. Respondents included 74 MD/PhD alumni and 121 trainees across 12 Canadian MD/PhD and MD/MSc programs. RESULTS: Among MD/PhD alumni, 51% were independent practitioners/researchers while others underwent residency training. Most trainees (88%) were in MD/PhD programs. Significantly more alumni identified as men than did trainees. Significantly more alumni conducted clinical and health services research, while more trainees conducted basic science research. Average time to MD/PhD completion was 8 years, with no correlation to subsequent research outcomes. Self-reported research productivity was highest during MD/PhD training. Concerning training trajectories, most alumni completed residency, pursued additional training, and practised in Canada. Finally, regression models showed that trainees and alumni were satisfied with programs, with significant moderators in trainee models. CONCLUSION: Survey findings showed Canadian MD/PhD and MD/MSc programs recruit more diverse cohorts of trainees than before, provide productive research years, and graduate alumni who pursue training and academic employment in Canada. Both alumni and trainees are largely satisfied with these training programs. The need to collect in-depth longitudinal data on Canadian MD/PhD graduates to monitor diversity and success metrics is discussed.
Asunto(s)
Satisfacción Personal , Canadá , Humanos , Masculino , Encuestas y Cuestionarios , Femenino , Adulto , Investigación Biomédica/estadística & datos numéricosRESUMEN
There is a growing body of literature studying changes in hippocampal subfields in a variety of different neurological conditions, but this work has mainly focused on the hippocampal body given challenges in visualization of hippocampal anatomy in the head and tail when sectioned in the typical coronal image plane. Curved multiplanar reformatting (CMPR) is an image reconstruction method that can improve visualization of complex three-dimensional structures. The objective of this study was to determine whether CMPR could facilitate visualization of the human hippocampal anatomy along the entire caudal-rostral axis. CMPR was applied to high-resolution magnetic resonance imaging acquired ex vivo on four cadaveric hippocampal specimens at 4.7 T (T2-weighted, 0.2 × 0.2 × 0.5 mm3 ). CMPR provided clear visualization of the classic "interlocking C" appearance of the dentate gyrus and cornu ammonis along the entire caudal-rostral axis including the head and tail, which otherwise show complex anatomy on the standard coronal slices. CMPR facilitated visualization of hippocampal anatomy providing the impetus to develop simplified approaches to delineate subfields along the entire hippocampus including the usually neglected head and tail.
Asunto(s)
Hipocampo/diagnóstico por imagen , Procesamiento de Imagen Asistido por Computador/métodos , Imagen por Resonancia Magnética/métodos , HumanosRESUMEN
BACKGROUND: Walking while talking (WWT) is a dual-task (cognitive and motor) performance test that has not yet been validated in older adults with lower-limb amputation (LLA). WWT is composed of two sections: WWT-simple (walking while reciting every letter of the alphabet) and WWT-complex (walking while reciting every other letter of the alphabet). OBJECTIVE: To determine the validity, and provide normative data and a new scoring system for the WWT test in older adults with LLA. STUDY DESIGN: Baseline cross-sectional data were collected from 56 community-living older adults (≥50 years old) with LLA at rehabilitation hospitals in Vancouver, BC, London, ON, and Edmonton, AB, Canada. METHODS: Time and number of recited letters and errors during both sections were recorded. A new score was developed based on all these variables. Correlations of the recorded times with the Activities-specific Balance Confidence (ABC) scale and the 2-Minute Walk Test (2MWT) score were used to evaluate the validity of the WWT test. RESULTS: As hypothesized, the times for both sections of the WWT were negatively correlated with both the ABC and 2MWT scores. Positive correlations were observed between the scores developed for both WWT sections with the 2MWT score. CONCLUSION: Times taken to complete each section of the WWT test were correlated with the 2MWT and the ABC scale scores, providing evidence for the validity of the WWT test. We also provided a scoring method that is more objective and in line with the dual-task nature of the test.
Asunto(s)
Amputación Quirúrgica , Caminata , Anciano , Canadá , Estudios Transversales , Humanos , Persona de Mediana Edad , Prueba de PasoRESUMEN
BACKGROUND: Older adults with lower-limb amputations (LLAs) often experience lack of confidence and poor balance, which limits their mobility. There are few validated measures for assessing these outcomes in the LLA population. OBJECTIVES: To assess the validity of the Life Space Assessment (LSA) and the Physical Activity Scale for the Elderly (PASE) for older adults with LLA. STUDY DESIGN: Secondary analyses of cross-sectional data. METHODS: Sixty-eight older adults with LLA across Canada were recruited to complete the LSA and the PASE. Validity was assessed via correlations with the Activities-specific Balance Confidence (ABC), Four-Square Step Test (FSST), and Two-Minute Walk Test (2-MWT). RESULTS: As hypothesized, the LSA was positively correlated with the ABC (ρ = 0.36, 95% confidence interval [CI] [0.17, 0.62]) and 2-MWT (r = 0.49, 95% CI [0.27, 0.70]) and negatively correlated with FSST (ρ = -0.39, 95% CI [-0.56, -0.10]). The PASE was positively correlated with the ABC (ρ = 0.34, 95% CI [0.10, 0.56]) and 2-MWT (ρ = 0.32, 95% CI [0.05, 0.52]), and negatively correlated with FSST (ρ = -0.36, 95% CI [-0.53, -0.07]). CONCLUSIONS: The LSA has validity in measuring life space mobility. The PASE captures the physical activity with weaker support of validity in older adults with LLA. CLINICAL RELEVANCE: The LSA and PASE are quick low-cost tools for clinicians to assess mobility-related functional health and physical activity, respectively, in older adults with LLA. However, the PASE may contain activities that are not common among older adults with LLA.
Asunto(s)
Amputación Quirúrgica , Equilibrio Postural , Anciano , Estudios Transversales , Ejercicio Físico , Humanos , Reproducibilidad de los Resultados , Prueba de PasoRESUMEN
BACKGROUND: The impact of perihematoma edema in Intracerebral Hemorrhage (ICH) on white matter integrity is uncertain. Fractional Anisotropy (FA), as measured with Diffusion Tensor Imaging (DTI), can be used to assess white matter microstructure. We tested the hypotheses that sections of the Corticospinal Tract (CST) passing through perihematoma edema would 1) have low FA relative to the contralateral CST and 2) would predict NIHSS motor score in ICH patients. METHODS: Patients were prospectively imaged with DTI at 48 h and 7 days after onset. Edema volume/extent was measured on CT at baseline and 24 h. FA, mean, axial and radial diffusivity were measured in the perihematoma edema, contralateral CST and sections of CST passing through the edema ('edematous CST'). RESULTS: Patients (n = 27, mean age 67 ± 13) were scanned with DTI at a median (IQR) of 42.3 (24.5) hours and 7.7 (1.8) days from onset. Median acute ICH volume was 8.8 (22) ml. FA in edematous CST at 72 h was decreased (0.37 ± 0.03) relative to contralateral CST (0.52 ± 0.06; p < 0.0001). Day 7 FA in edematous CST (0.35 ± 0.08) was also decreased compared to contralateral CST (0.54 ± 0.06; p < 0.0001). FA remained stable between 72 h (0.37 ± 0.03) and day 7 (0.35 ± 0.07; p = 0.350). FA at 72 h (ρ = -0.22, p = 0.420) and day 7 (ρ = -0.14, p = 0.624) was unrelated to 90-day motor score. CONCLUSIONS: FA is decreased in the CST where it passes through the edema. Decreased FA in the edematous CST remained stable over time, was unrelated to motor score, and may represent water infiltration into the tracts rather than axonal injury.
Asunto(s)
Imagen de Difusión Tensora , Sustancia Blanca , Anciano , Anciano de 80 o más Años , Anisotropía , Hemorragia Cerebral/complicaciones , Hemorragia Cerebral/diagnóstico por imagen , Hematoma/diagnóstico por imagen , Humanos , Persona de Mediana Edad , Tractos Piramidales/diagnóstico por imagen , Sustancia Blanca/diagnóstico por imagenRESUMEN
OBJECTIVE: Neuropathological studies indicate that hippocampal sclerosis (HS) consists of three subtypes (ILAE types 1-3 HS). However, HS subtypes currently can only be diagnosed by pathological analysis of hippocampal tissue resected during epilepsy surgery or at autopsy. In vivo diagnosis of HS subtypes holds potential to improve our understanding of these variants in the ipsilateral as well as contralateral hippocampus. In this study, we aimed to: i) evaluate the reliability of our histology-derived segmentation protocol when applied to in vivo MRI; and ii) characterize variability of HS subtypes along the hippocampal long axis in patients with epilepsy. METHODS: Eleven subjects with unilateral HS were compared with ten healthy controls. We used 4.7 T MRI to acquire high resolution MR Images of the hippocampus in each subject. In vivo MRI-based diagnoses of HS subtypes were then determined in each patient by two methods: i) hippocampal subfield volumetry of the entire hippocampal body; and ii) subfield area analysis at multiple thin slices throughout the hippocampal body. RESULTS: Hippocampal body subfield segmentation demonstrated excellent reliability and volumetry of the symptomatic hippocampus revealed abnormalities in all eleven patients. Six subjects demonstrated findings consistent with type 1 HS while five subjects had volumetry-defined atypical HS (two with type 2 HS & three with type 3 HS) in the symptomatic hippocampus, while five subjects were found to have type 3 HS in the contralateral hippocampus. Subfield area analyses demonstrated remarkable variability of HS subtypes along the hippocampal long axis, both ipsilateral and contralateral to the seizure focus. SIGNIFICANCE: Our results provide preliminary evidence that determining HS Subtype using in vivo MRI may allow preoperative diagnosis of ILAE HS subtypes. Further studies are essential to determine the pathological correlates of these neuroimaging findings. The heterogeneity of abnormalities observed along the long axis of the hippocampus is consistent with previous autopsy studies and highlights the necessity of studying the entire hippocampus both ipsilateral and contralateral to the seizure focus in these future studies.
Asunto(s)
Epilepsia del Lóbulo Temporal/cirugía , Hipocampo/patología , Esclerosis/patología , Convulsiones/patología , Adulto , Epilepsia del Lóbulo Temporal/patología , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador/métodos , Imagen por Resonancia Magnética/métodos , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados , Adulto JovenRESUMEN
Stuttering is a neurodevelopmental speech disorder with a phenotype characterized by speech sound repetitions, prolongations and silent blocks during speech production. Developmental stuttering affects 1% of the population and 5% of children. Neuroanatomical abnormalities in the major white matter tracts, including the arcuate fasciculus, corpus callosum, corticospinal, and frontal aslant tracts (FAT), are associated with the disorder in adults who stutter but are less well studied in children who stutter (CWS). We used deterministic tractography to assess the structural connectivity of the neural network for speech production in CWS and controls. CWS had higher fractional anisotropy and axial diffusivity in the right FAT than controls. Our findings support the involvement of the corticostriatal network early in persistent developmental stuttering.