Medicine (Austin & Northern Health) - Research Publications
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ItemUpright activity and higher motor function may preserve bone mineral density within 6 months of stroke: a longitudinal study(SPRINGER LONDON LTD, 2018-01-08)PURPOSE: Bone fragility contributes to increased fracture risk, but little is known about the emergence of post-stroke bone loss. We investigated skeletal changes and relationships with physical activity, stroke severity, motor control and lean mass within 6 months of stroke. METHODS: This is a prospective observational study. Participants were non-diabetic but unable to walk within 2 weeks of first stroke. Distal tibial volumetric bone mineral density (vBMD, primary outcome), bone geometry and microstructure (high-resolution peripheral quantitative computed tomography) were assessed at baseline and 6 months, as were secondary outcomes total body bone mineral content and lean mass (dual energy X-ray absorptiometry), bone metabolism (serum osteocalcin, N-terminal propeptide of type 1 procollagen (P1NP), C-terminal telopeptide of type 1 collagen (CTX)), physical activity (PAL2 accelerometer) and motor control (Chedoke McMaster) which were also measured at 1 and 3 months. RESULTS: Thirty-seven participants (69.7 years (SD 11.6), 37.8% females, NIHSS 12.6 (SD 4.7)) were included. The magnitude of difference in vBMD between paretic and non-paretic legs increased within 6 months, with a greater reduction observed in paretic legs (mean difference = 1.5% (95% CI 0.5, 2.6), p = 0.007). At 6 months, better motor control was associated with less bone loss since stroke (r = 0.46, p = 0.02). A trend towards less bone loss was observed in people who regained independent walking compared to those who did not (p = 0.053). Higher baseline daily count of standing up was associated with less change in bone turnover over 6 months: osteocalcin (r = -0.51, p = 0.01), P1NP (r = -0.47, p = 0.01), CTX (r = -0.53, p = 0.01). CONCLUSION: Better motor control and walking recovery were associated with reduced bone loss. Interventions targeting these impairments from early post-stroke are warranted. CLINICAL TRIAL REGISTRATION: URL: http://www.anzctr.org.au . Unique identifier: ACTRN12612000123842.
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ItemRationale for Intervention and Dose Is Lacking in Stroke Recovery Trials: A Systematic Review(HINDAWI LTD, 2018)BACKGROUND: The ineffectiveness of most complex stroke recovery trials may be explained by inadequate intervention design. The primary aim of this review was to explore the rationales given for interventions and dose in stroke rehabilitation randomised controlled trials (RCTs). METHODS: We searched the Cochrane Stroke Group library for RCTs that met the following criteria: (1) training based intervention; (2) >50% participants who were stroke survivors; (3) full peer-reviewed text; (4) English language. We extracted data on 16 quality items covering intervention dose (n= 3), trial design (n= 10), and risk of bias (n= 3) and 18 items related to trial method. Logistic regression analyses were performed to determine whether (1) reporting of trial quality items changed over time; (2) reporting of quality items was associated with the likelihood of a positive trial, adjusted for sample size and number of outcomes. RESULTS: 27 Cochrane reviews were included, containing 9,044 participants from 194 trials. Publication dates were 1979 to 2013, sample size was median 32 (IQR 20,58), and primary outcome was reported in 49 trials (25%). The median total quality score was 4 (IQR 3,6) and improved significantly each year (OR 1.12, 95% CI 1.07, 1.16, p<0.001). Total quality score was not associated with likelihood of a positive trial, but trials containing a biological rationale for the intervention were more likely to find a difference in patient outcome (OR 2.18, 95% CI 1.14, 4.19, p=0.02). CONCLUSION: To develop breakthrough treatments we need to build the rationale for research interventions and testing of intervention dosage. This will be achieved through a collective research agenda to understand the mechanistic principles that drive recovery and identification of clearer targets for clinical trials.
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ItemChanges to volumetric bone mineral density and bone strength after stroke: A prospective study(WILEY-BLACKWELL, 2015-04)RATIONALE AND AIM: Stroke survivors experience accelerated bone loss and increased fracture risk, particularly in paretic weight bearing limbs. Understanding how these changes unfold and their relationship to stroke severity and physical activity could help in the development of targeted interventions to prevent or reduce the severity of these outcomes. The primary aim of this study is to investigate the time course and magnitude of changes in volumetric bone mineral density within the first year after stroke, and to examine relationships with physical activity and motor recovery. DESIGN: This is a prospective, observational study of 43 nondiabetic, nonambulant adults with first ever hemispheric stroke. PRIMARY OUTCOME: The primary outcome was the difference in six-month change of total volumetric bone mineral density between paretic and nonparetic distal tibiae, measured at 7% of bone length site using high-resolution peripheral quantitative computed tomography. SECONDARY OUTCOMES: The secondary outcomes are cortical and trabecular volumetric bone mineral density, cortical thickness, and total and cross-sectional areas of distal tibiae and radii of paretic and nonparetic limbs. Also included are total body and regional bone mineral density derived using dual-energy X-ray absorptiometry, physical activity measured using accelerometry, and motor recovery (Chedoke McMaster Stroke Assessment). DISCUSSION: Measuring the timing and magnitude of changes to volumetric bone mineral density and bone structure from immediately after stroke, and relationships between these changes with physical activity and motor recovery will provide the basis for targeted interventions to reduce fracture risk in stroke survivors.