•Post-operative paediatric cerebellar mutism syndrome is a well-recognised complication of posterior fossa tumour surgery.•Diffusion tractography shows damage to cerebellar outflow pathways are ...implicated in the development of pCMS.•Perfusion imaging has shown widespread bloodflow deficits in patients with pCMS, which reverses when symptoms improve.•Timely application of diffusion and perfusion MRI studies may help us to answer several remaining questions in pCMS.
Post-operative paediatric cerebellar mutism syndrome (pCMS) occurs in around 25% of children undergoing surgery for cerebellar and fourth ventricular tumours. Reversible mutism is the hallmark of a syndrome which comprises severe motor, cognitive and linguistic deficits. Recent evidence from advanced neuroimaging studies has led to the current theoretical understanding of the condition as a form of diaschisis contingent on damage to efferent cerebellar circuitry. Tractography data derived from diffusion MRI studies have shown disruption of the dentato-rubro-thalamo-cortical tract in patients with pCMS, and perfusion studies have indicated widespread supratentorial regions which may give rise to the florid signs and symptoms of pCMS. Given the difficulties in predicting pCMS from standard structural MRI, this review discusses findings from quantitative MRI modalities which have contributed to our understanding of this debilitating syndrome, and considers the goals and challenges which lie ahead in the field.
Background
Virtual mindfulness may be helpful for individuals with intellectual disabilities in the context of COVID‐related disruptions of in‐person programming, such as Special Olympics (SO). This ...study examined the feasibility of a virtual mindfulness intervention for SO athletes and their caregivers.
Method
SO athletes (n = 44) and their caregivers (n = 29) participated in a 6‐week adapted virtual mindfulness intervention. Athletes completed mindfulness and well‐being questionnaires prior to, immediately following, and 3‐months post‐intervention. Caregivers completed questionnaires assessing their own stress, mindfulness, and well‐being, as well as athlete mental health. Exit interviews were conducted immediately following the intervention.
Results
The intervention was feasible in terms of demand, implementation, acceptability, and limited testing efficacy. There were significant improvements in athlete well‐being and mental health, and caregiver stress and mindfulness post‐intervention.
Conclusions
Adapted virtual mindfulness groups may be an effective intervention in improving the well‐being of adults with intellectual disabilities and their caregivers.
Huntington's disease can be predicted many years before symptom onset, and thus makes an ideal model for studying the earliest mechanisms of neurodegeneration. Diffuse patterns of structural ...connectivity loss occur in the basal ganglia and cortex early in the disease. However, the organizational principles that underlie these changes are unclear. By understanding such principles we can gain insight into the link between the cellular pathology caused by mutant huntingtin and its downstream effect at the macroscopic level. The 'rich club' is a pattern of organization established in healthy human brains, where specific hub 'rich club' brain regions are more highly connected to each other than other brain regions. We hypothesized that selective loss of rich club connectivity might represent an organizing principle underlying the distributed pattern of structural connectivity loss seen in Huntington's disease. To test this hypothesis we performed diffusion tractography and graph theoretical analysis in a pseudo-longitudinal study of 50 premanifest and 38 manifest Huntington's disease participants compared with 47 healthy controls. Consistent with our hypothesis we found that structural connectivity loss selectively affected rich club brain regions in premanifest and manifest Huntington's disease participants compared with controls. We found progressive network changes across controls, premanifest Huntington's disease and manifest Huntington's disease characterized by increased network segregation in the premanifest stage and loss of network integration in manifest disease. These regional and whole brain network differences were highly correlated with cognitive and motor deficits suggesting they have pathophysiological relevance. We also observed greater reductions in the connectivity of brain regions that have higher network traffic and lower clustering of neighbouring regions. This provides a potential mechanism that results in a characteristic pattern of structural connectivity loss targeting highly connected brain regions with high network traffic and low clustering of neighbouring regions. Our findings highlight the role of the rich club as a substrate for the structural connectivity loss seen in Huntington's disease and have broader implications for understanding the connection between molecular and systems level pathology in neurodegenerative disease.
Abstract
Evidence that supports the explicit need to develop leadership skills at all levels of clinical practice is prevalent,1–8 yet intentional development of “self-leadership” within health care, ...and particularly within physical therapy, remains slow, fragmented, and inconsistent. Delineation and standardization of the definition of leadership, and the approach to developing leadership skills in individuals practicing within health care continues to be debated, producing several key dilemmas. Moreover, there is a lingering misperception that developing leadership capacity is reserved for physical therapists who assume positional or formal roles as “leaders” within communities, health care organizations, practices, or teams. This misperception focuses leadership development on “leading others” rather than “leading self.” Similarly, challenges exist between balancing the leadership development needs of the leader as a positional role and the act of “leading” as physical therapists practice and engage within all levels of care and within different communities—as individuals and within teams. This tension further complicates when and how best to prepare physical therapists to meet this essential skill set in clinical practice. The purpose of this perspective is to describe nonpositional self-leadership and its importance to physical therapy practice, to propose common or contemporary leadership-related terminology, and to suggest a framework for leadership development. Through accomplishing these purposes, readers may be encouraged to change and adopt recommendations.
Structural brain networks may be reconstructed from diffusion MRI tractography data and have great potential to further our understanding of the topological organisation of brain structure in health ...and disease. Network reconstruction is complex and involves a series of processesing methods including anatomical parcellation, registration, fiber orientation estimation and whole-brain fiber tractography. Methodological choices at each stage can affect the anatomical accuracy and graph theoretical properties of the reconstructed networks, meaning applying different combinations in a network reconstruction pipeline may produce substantially different networks. Furthermore, the choice of which connections are considered important is unclear. In this study, we assessed the similarity between structural networks obtained using two independent state-of-the-art reconstruction pipelines. We aimed to quantify network similarity and identify the core connections emerging most robustly in both pipelines. Similarity of network connections was compared between pipelines employing different atlases by merging parcels to a common and equivalent node scale. We found a high agreement between the networks across a range of fiber density thresholds. In addition, we identified a robust core of highly connected regions coinciding with a peak in similarity across network density thresholds, and replicated these results with atlases at different node scales. The binary network properties of these core connections were similar between pipelines but showed some differences in atlases across node scales. This study demonstrates the utility of applying multiple structural network reconstrution pipelines to diffusion data in order to identify the most important connections for further study.
The white matter of the brain undergoes a range of structural changes throughout development; from conception to birth, in infancy, and onwards through childhood and adolescence. Several studies have ...used diffusion magnetic resonance imaging (dMRI) to investigate these changes, but a consensus has not yet emerged on which white matter tracts undergo changes in the later stages of development or what the most important driving factors are behind these changes. In this study of typically developing 8- to 16-year-old children, we use a comprehensive data-driven approach based on principal components analysis to identify effects of age, gender, and brain volume on dMRI parameters, as well as their relative importance. We also show that secondary components of these parameters predict full-scale IQ, independently of the age- and gender-related effects. This overarching assessment of the common factors and gender differences in normal white matter tract development will help to advance understanding of this process in late childhood and adolescence.
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