No abstract

In this study we documented brain connectivity associated with multisensory integration during wrist control in healthy young adults, aged matched controls and stroke survivors. A novel functional MRI task paradigm involving wrist movement was developed to gain insight into the effects of multimodal sensory feedback on brain functional networks in stroke participants. This paradigm consisted of an intermittent position search task using the wrist during fMRI signal acquisition with visual and auditory feedback of proximity to a target position. We enrolled 12 young adults, 10 participants with chronic post-stroke hemiparesis, and nine age-matched controls. Activation maps were obtained, and functional connectivity networks were calculated using an independent component analysis (ICA) approach. Task-based networks were identified using activation maps, and nodes were obtained from the ICA components. These nodes were subsequently used for connectivity analyses. Stroke participants demonstrated significantly greater contralesional activation than controls during the visual feedback condition and less ipsilesional activity than controls during the auditory feedback condition. The sensorimotor component obtained from the ICA differed between rest and task for control and stroke participants: task-related lateralization to the contralateral cortex was observed in controls, but not in stroke participants. Connectivity analyses between the lesioned sensorimotor cortex and the contralesional cerebellum demonstrated decreased functional connectivity in stroke participants (p < 0.005), which was positively correlated the Box and Blocks arm function test (r 2 = 0.59). These results suggest that task-based functional connectivity provides detail on changes in brain networks in stroke survivors. The data also highlight the importance of cerebellar connections for recovery of arm function after stroke.

No abstract

No abstract

No abstract

Background: Tricuspid regurgitation (TR) is linked to poor outcomes and its progression is associated with higher mortality. Left heart disease, age and sex are factors related to TR progression. We assessed echocardiographic (Echo) and demographic predictors of moderate TR progression using Machine Learning Natural Language Processing (ML NLP). Methods: 54,315 patients were retrospectively assessed for moderate TR with an Echo between May 2017 to October 2020 and a follow-up Echo 30 days to 113 months. Exclusion criteria included prior pacemaker/ICD, tricuspid prosthesis or band/ring, history of Ebstein, tetralogy of Fallot and tricuspid endocarditis. Cardiac Intelligence TM (Mpirik, Milwaukee, WI) identified moderate TR, demographic and Echo indices using ML NLP of the Echo report. Our endpoint was progression from moderate to severe TR within 1 or 2 years. Univariate Cox proportional hazard model was used with univariate analysis. Results: Of 3,489 moderate TR patients, 1,564 had a subsequent Echo and 771 met study criteria. Table 1 shows baseline demographic and Echo data. 15% and 24% of moderate TR patients progressed to severe TR within 1 and 2 years, respectively. Black race, left ventricular size, moderate/severe right ventricular (RV) dysfunction and Doppler-based RV systolic pressure were found to be univariate predictors of progression (Figure 1). Conclusion: ML NLP based on input from Echo-derived parameters using a real-world sample can offer insights into risk stratification of moderate TR regarding risk of progression to severe disease. Including further clinical and demographic variables will allow to improve performance of a disease prediction ML model.

No abstract

Background: Botulinum NeuroToxin-A (BoNT-A) relieves muscle spasticity and increases range of motion necessary for stroke rehabilitation. Determining the effects of BoNT-A therapy on brain neuroplasticity could help physicians customize its use and predict its outcome.Objective: The purpose of this study was to investigate the effects of Botulinum Toxin-A therapy for treatment of focal spasticity on brain activation and functional connectivity.Design: We used functional Magnetic Resonance Imaging (fMRI) to track changes in blood oxygen-level dependent (BOLD) activation and functional connectivity associated with BoNT-A therapy in nine chronic stroke participants, and eight age-matched controls. Scans were acquired before BoNT-A injections (W0) and 6 weeks after the injections (W6). The task fMRI scan consisted of a block design of alternating mass finger flexion and extension. The voxel-level changes in BOLD activation, and pairwise changes in functional connectivity were analyzed for BoNT-A treatment (stroke W0 vs. W6).Results: BoNT-A injection therapy resulted in significant increases in brain activation in the contralesional premotor cortex, cingulate gyrus, thalamus, superior cerebellum, and in the ipsilesional sensory integration area. Lastly, cerebellar connectivity correlated with the Fugl-Meyer assessment of motor impairment before injection, while premotor connectivity correlated with the Fugl-Meyer score after injection.Conclusion: BoNT-A therapy for treatment of focal spasticity resulted in increased brain activation in areas associated with motor control, and cerebellar connectivity correlated with motor impairment before injection. These results suggest that neuroplastic effects might take place in response to improvements in focal spasticity.