Post-Stroke Optimization of Walking Using Explosive Resistance (POWER-D)

Post-Stroke Optimization of Walking Using Explosive Resistance: Concurrent Effects on Depression (POWER-D Trial)

The investigators will study the effects of a 12 week strength training program on individuals who have had a stroke and are depressed to see if this type of exercise training helps treat depression and improves walking function. Our goal is to use the information collected in this study to help design treatments for people who have had a stroke that will help with many of the common consequences of stroke, including depression, muscle weakness and slow walking. Progress toward overcoming some of these issues would be incredibly valuable to any person who has had a stroke and their families.

Depression is the most common neuropsychiatric manifestation following stroke and current treatments are largely ineffective. Depression has both direct and indirect effects on response to rehabilitation, thus subjects with post-stroke depression (PSD) are routinely excluded from clinical trials and treatment options are extremely limited. The investigators propose to determine the impact of a novel, high-intensity resistance training program, Post-stroke Optimization of Walking using Explosive Resistance (POWER) training, on post-stroke depressive symptoms. Further, the investiators will determine if depression limits training-induced improvements in muscular and locomotor function. This project is based on the premise that depression negatively affects the potential for neuroplastic changes to occur in response to treatment such that rehabilitation may not produce the same adaptations that it does in non-depressed individuals. The investigators propose that effective treatment for PSD would result in a virtuous cycle where reducing depression enhances neuroplastic changes, thereby facilitating functional gains. That is, effectively treating depression will make the individual better able to recover from stroke. Furthermore, in addition to its beneficial effects on depression, POWER training is known to improve post-stroke walking, thus providing an attractive option for treating depression as well as an established vehicle to study the effects of PSD on response to rehabilitation. The experiments proposed as part of this project are designed to address critical questions related to 1) the effects of POWER training on depressive symptoms; 2) the potential for PSD to limit improvements following training; and 3) the interaction between improvements in depression and increases in walking function. Successful completion of this project will provide a foundation for larger scale trials to determine dosing parameters as well as establish therapeutic effectiveness of POWER training on post-stroke depression as well as identify the mechanisms that may be responsible for the changes that occur in response to treatment.

The Hamilton Rating Scale for Depression, abbreviated HAM-D, is a multiple item questionnaire used to provide an indication of depression, and as a guide to evaluate recovery. A score of 0-7 is considered to be normal while a score of 20 or higher (indicating at least moderate severity) is usually required for entry into a clinical trial.

Subjects will walk on a 14-ft. long gait mat (GaitRite) to measure self-selected and fastest comfortable walking speed and other spatiotemporal parameters of walking. Subjects will be permitted a practice trial, and then be asked to complete three trials at each speed. For all trials, subjects will wear their own shoes and be asked to walk without an assistive device or ankle-foot orthosis.

Inclusion Criteria: age 50-70 stroke within the past 6 to 60 months residual paresis in the lower extremity (Fugl-Meyer LE motor score <34) ability to walk without assistance and without an AFO during testing and training at speeds ranging from 0.2-0.8 m/s no antidepressant medications or no change in doses of psychotropic medication for at least 4 weeks prior to the study (6 weeks if newly initiated medication) HRSD question #9 regarding suicide <2; and 7) provision of informed consent. Exclusion Criteria: Unable to ambulate at least 150 feet prior to stroke, or experienced intermittent claudication while walking history of congestive heart failure, unstable cardiac arrhythmias, hypertrophic cardiomyopathy, severe aortic stenosis, angina or dyspnea at rest or during ADL's History of COPD or oxygen dependence Preexisting neurological disorders, dementia or previous stroke History of major head trauma Legal blindness or severe visual impairment history of psychosis or other Axis I disorder that is primary Life expectancy <1 yr. Severe arthritis or other problems that limit passive ROM History of DVT or pulmonary embolism within 6 months Uncontrolled diabetes with recent weight loss, diabetic coma, or frequent insulin reactions Severe hypertension with systolic >200 mmHg and diastolic >110 mmHg at rest attempt of suicide in the last 2 years or at suicidal risk assessed by SCID interview History of seizures or currently prescribed anti-seizure medications Current enrollment in a clinical trial to enhance motor recovery Pregnancy