Mechanisms of Upper-Extremity Motor Recovery in Post-stroke Hemiparesis

Not Applicable

Completed

Conditions: Cerebrovascular Accident

Interventions: Other: Experimental
Other: Control

Registration Number: NCT00125658

Lead Sponsor: VA Office of Research and Development

Brief Summary: The results of this study will provide sound, scientific evidence of physiologic mechanisms responsible for upper-extremity weakness; evidence of the processes involved in neuromuscular adaptation; and will elucidate the relationship between impairment and motor disability in post-stroke hemiparesis.

Detailed Description: This proposal extends the work accomplished in our initial study (project #B2405R, 'Effects of Strength Training on Upper-limb Function in Post-stroke Hemiparesis'). In the present study we will conduct a double-blind, randomized clinical trial of staged rehabilitation for the upper-extremity involving sequential delivery of functional therapy and high intensity resistance training. Therefore, this proposal directly compares the effects of functional and resistance training delivered individually. The researchers' previous work investigated a hybrid therapy of functional and resistance training against functional training alone. All subjects will participate in a 5 week run-in period of no treatment. This no-treatment block will afford multiple baseline measurements and, in addition, will provide information regarding the rate and magnitude of any spontaneous recovery without treatment. Following the second baseline measurement, all subjects will be randomized to upper-extremity rehabilitation in either: Order A - 10 weeks of functional task practice training (FTP) followed by 10 weeks of high-intensity resistance training (Power) or Order B - resistance training (Power) followed by FTP. Re-evaluation will occur following each block of treatment,and retention effects will be evaluated after 6 and 12 months with no additional treatment. Subjects will be evaluated with: outcome measures used broadly in Clinical Neurology and Rehabilitation, a battery of biomechanical performance measures including: strength, muscle activation, reflex modulation, and motor coordination, and with kinematics of free reaching movements. The researchers will investigate persons in the intermediate phase of recovery which they define as between 6 and 18 months post-stroke , having completed all inpatient and outpatient therapies, with remaining residual motor deficits.

Recruitment & Eligibility

Status: COMPLETED

Sex: All

Target Recruitment: 14

Inclusion Criteria

Clinical diagnosis of cerebrovascular accident
Single event
Unilateral hemiplegia
Between 6 months and 18 months post-event
Impairment of upper-extremity function
Ability to produce partial range of motion out of plane of gravity at shoulder, elbow, and wrist
At least 10 degrees of wrist motion (any 10 degrees), and finger flexion/extension in 2 fingers
Cognitive ability to follow 3-step commands

Exclusion Criteria

Unstable or uncontrolled blood pressure
Uncontrolled seizures
Flaccid hemiplegia
Severe cognitive impairment

Study & Design

Study Type: INTERVENTIONAL

Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
Experimental	Experimental	POWER: 30 sessions (90 minute sessions, 3 times per week, 10 weeks) followed by FTP: 30 sessions (90 minute sessions, 3 times per week, 10 weeks)
Control	Control	FTP: 30 sessions (90 minute sessions, 3 times per week, 10 weeks) followed by POWER: 30 sessions (90 minute sessions, 3 times per week, 10 weeks)

Primary Outcome Measures

Name	Time	Method
Change in Trunk Displacement	baseline, 10 weeks, 20 weeks	Distance (in cm) of trunk lean while performing reach-to-grasp. This information is obtained from kinematics/3D motion capture and is used to inform regarding compensatory use of the trunk as compared to active motion of the shoulder, elbow, wrist, and hand, during reach-to-grasp. Change scores are expressed relative to baseline.
Change in Shoulder Flexion	baseline, 10 weeks, 20 weeks	joint range of motion obtained using kinematics / motion capture. Change scores expressed relative to baseline.
Upper-extremity Fugl-Meyer Motor Assessment	baseline, 10 weeks, 20 weeks	The Fugl-Meyer Motor Assessment is a standardized scale used to measure the magnitude of motor impairment (severity) following stroke. There are separate sub-scales for the upper and lower extremities. Here we used the upper-extremity component; the full range of the scale is 0 - 66 points. Higher scores approaching 66 represent better, and lower scores approaching 0 worse, motor function. There is a significant ceiling effect with the FMA, thus a score of 66 points does not mean an individual with stroke has fully recovered. Data are change scores expressed relative to baseline.
Change in Elbow Extension Range of Motion	baseline, 10 weeks, 20 weeks	joint range of motion obtained using kinematics / motion capture. Change scores are expressed relative to baseline.

Secondary Outcome Measures

Name	Time	Method
Movement Speed	baseline, 10 weeks, 20 weeks	peak velocity of movement (cm/s) during reach-to-grasp, obtained using kinematics/motion capture. Data are change scores expressed relative to baseline.
Movement Accuracy (Reach Path Ratio, RPR)	baseline, 10 weeks, 20 weeks	Measure is derived from kinematics/motion analysis. RPR = ratio of actual reach trajectory relative to an idealized straight line. Data are change scores, expressed relative to baseline.
Movement Smoothness	baseline, 10 weeks, 20 weeks	Movement smoothness is determined by assessing the number of sub movements (i.e., starts and stops) that can be identified during performance of a task. Here the task was reach-to-grasp. Sub movement are identified from kinematics/3D motion analysis. Sub-movements represent discontinuities or "jerky" movements. For example, skilled reaching is smooth and may reveal a single movement unit; in contrast, unskilled movements will reveal multiple movement units (i.e., starts and stops). As a performer practices and learns the movement, the number of sub movements is reduced. Sub movements can also present in persons with pathology. The unit of sub movements is whole numbers, or counts, of the sub movements. Data are change scores, expressed relative to baseline.