Pilot Project

Principal Investigator: Carolynn Patten, PhD, PT

Project Staff: Heather E. Brown, MSPT; Jody M. Dozono, MPT; B. Jenny Kiratli, PhD; and Christopher R. Jacobs, PhD

Project Category: Bone & Joint and Stroke - 2003

Objective: The goal of this BAJR Center pilot project is to study effects of exercise-based therapeutic interventions on bone remodeling in persons with post-stroke hemiparesis. Stroke is the leading cause of physical disability in western industrialized nations predominantly affecting persons sixty or more years of age. It can be hypothesized that age-related compromise to bone integrity coupled with the profound disabling influence of stroke, would accelerate bone loss and lead to secondary pathologies including osteoporosis and high risk of fractures.

This pilot project seeks to determine the extent to which high-intensity exercise-based therapies intended to restore neuromuscular function in hemiparetic persons affect bone remodeling. The literature reports osteogenic effects of eccentric exercise (e.g., muscle lengthening contractions) in healthy adults. We hypothesize therefore that therapies involving eccentric resistance exercise (i.e., controlling an externally imposed load, gait) will produce physiologically significant osteogenic effects in hemiparetic adults.

Research Plan: Hemiparetic subjects (6-18 months post-stroke) who enroll in the project "Therapeutic Effects on Neuromuscular Function in Post-stroke Hemiparesis" (C. Patten, P.I.) will undergo parallel studies of bone integrity and bone remodeling. Subjects will receive DXA scans (whole body and proximal femur) at baseline, following the two month clinical intervention, and at follow up study one year post-intervention. These studies are conducted in conjunction with Dr. B. Jenny Kiratli in the VA Palo Alto Clinical center. Blood samples will also be obtained at the same time points and analyzed post-hoc for key markers of osteoblastic and osteoclastic activity.

Project Milestones to Date:

1. Due to the protracted continuing resolution in 2003, the start date for the parent project (originally October 1, 2002) did not occur until April 1, 2003.

2. The first class of subjects was enrolled on July 1, 2003 and completed treatment on or around September 1, 2003. All subjects are retained for follow up evaluations at 6 and 12 months post-intervention and thus remain in some stage of project participation.

3. Fourteen subjects have been enrolled to date. All of these subjects have participated in DXA scanning.

4. The IRB protocol to obtain blood samples is currently in review. Once approval has been received we will proceed to conduct this aspect of the study.

Funding Source: VA RR&D Pilot Project

Funding Status: Funded