Vascular elasticity and grip strength are associated with bone health of the hemiparetic radius in people with chronic stroke: implications for rehabilitation.

BACKGROUND: People with stroke often have increased bone loss and fracture rate. Increasing evidence has demonstrated a link between cardiovascular health and bone loss in other patient populations. OBJECTIVE: The study objectives were: (1) to compare the bone density and geometry of the radius diaphysis on the left and right sides in people with chronic stroke and people who were matched for age (control participants) and (2) to examine the relationship between the bone strength index at the hemiparetic radius diaphysis and vascular health in people with chronic stroke. DESIGN: This was a case-control study. METHODS: The radius diaphysis on both sides was scanned with peripheral quantitative computed tomography in 65 participants with chronic stroke and 34 control participants. Large-artery and small-artery elasticity indexes were evaluated with a cardiovascular profiling system. RESULTS: The paretic radius diaphysis had significantly lower values for cortical bone mineral density, cortical thickness, cortical area, and the bone strength index but a larger marrow cavity area than the nonparetic radius diaphysis in participants with chronic stroke, whereas no bone measurement showed a significant side-to-side difference in control participants. Multiple regression analyses showed that the large-artery elasticity index and grip strength remained significantly associated with the bone strength index at the hemiparetic radius diaphysis after controlling for age, sex, time since stroke diagnosis, body mass index, and physical activity (R(2)=.790). LIMITATIONS: This study was cross-sectional and could not establish causality. The radius diaphysis is not the most common site of fracture after stroke. CONCLUSIONS: Both the integrity of the vasculature and muscle strength were significantly associated with the bone strength index at the hemiparetic radius diaphysis in participants with chronic stroke. The results may be useful in guiding rehabilitative programs for enhancing bone health in the paretic arm after stroke.

Changes in bone density and geometry of the upper extremities after stroke: a case report.

PURPOSE: The purpose of this study was to examine changes in bone density and geometry of the forearm region and motor function of the paretic upper extremity in a person with subacute stroke. Client Description: The participant was a 48-year-old man with right hemiparesis. INTERVENTION: Not applicable. Measures and Outcomes: The assessment of upper-extremity (UE) function and bone imaging took place at 3 months and 12 months after stroke. The participant had moderate motor impairment and severe disuse of the paretic UE 3 months after stroke. During the follow-up period, no substantial change in paretic UE function was observed. At the 12 month follow-up, the areal bone mineral density (aBMD) of the ultradistal and mid-regions of the paretic forearm, as measured by dual-energy X-ray absorptiometry, sustained a significant reduction of 7.9% and 5.9%, respectively. The non-paretic side, in contrast, had a significant 4.0% increase in aBMD of the mid-forearm and a 2.8% increase in aBMD of the total forearm. Significant findings from peripheral quantitative computed tomography were a reduction in total volumetric bone mineral density (-12.1%) and bone strength index (-20.6%) in the radius distal epiphysis on the paretic side and an increase in cortical bone mineral content (2.0%) and bone strength index (7.6%) in the radius diaphysis on the non-paretic side. IMPLICATIONS: After a stroke that resulted in moderate to severe UE impairment, a significant decline in bone mineral density was identified in various skeletal sites in the forearm region as the participant entered the subacute and chronic stages of recovery. The results point to the potential importance of early rehabilitative intervention in preventing unfavourable bone changes in the paretic upper limb among individuals with stroke.