Post-Stroke Optimization of Walking Using Explosive Resistance

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.

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