The Effect of Combining Robotic-Assisted Therapy With Levodopa/Carbidopa in Chronic Post-Stroke Upper-Limb Hemiparesis

Every year, approximately 795,000 people suffer a new or recurrent stroke in the United States, meaning that every 40 seconds someone has a stroke. In the United States, stroke is the third most frequent cause of death and the leading cause of lasting hemiparesis and adult disability. Since the prevalence of stroke increases with age, and since the world population is aging, the incidence of stroke is expected to rise in the coming years. This will become a significant societal burden since the care of stroke survivors is costly, to the individual and to society.

Post-stroke upper extremity (UE) impairment usually implies initial weakness, with subsequent diminished dexterity and limitation or incapacity for reaching, transport and grasping movements since the onset. Survivors may regain partial or, less often, complete muscle strength in the affected UE during the recovery process. However, a persistent degree of weakness and evolution to secondary complications as spasticity (characterized by increased flexor hypertonia), shoulder pain and contractures is frequent. These additional issues are associated with greater impairment, worse function and lower health-related quality of life. Treatment interventions for hemiparesis after stroke usually include stretching, strengthening of antagonist muscles, splinting, oral medications, and focal injections (phenol or botulinum toxin) and intrathecal baclofen. However, the amount, intensity and length of therapies still need further investigation. Despite adequate traditional treatment, a high number of patients are still permanently limited as a consequence of stroke. Based on motor learning theories, recent studies have demonstrated that intensive, repetitive, task-oriented therapies can help the paretic extremity "relearn" how to perform movements that were lost after brain damage.

ROBOTIC-ASSISTED UPPER-LIMB TRAINING WITH ARMEO®

Current evidence has shown that rehabilitation without specific training will not result in measurable outcomes. Factors such as intensity and specificity of motor training are important to achieve recovery of motor function, especially in the chronic phase of the stroke. There is robust evidence that highly-repetitive movement rehabilitation could improve motor and functional ability, based on its role in motor learning processes.Robotic devices have become a very important area of research because of their capacity to achieve high-intensity and specificity therapies.

In this proposed project, we plan to use the Armeo robotic system to deliver motor training therapy. The Armeo system is an adjustable arm orthosis that has received FDA 510k exemption. It passively counterbalances the weight of the arm, thereby reducing the effort required by the paretic arm to overcome gravity. The device is able to augment feedback through a virtual environment (i.e. computer games). The tasks presented in the virtual environment are designed to achieve functional movements, i.e. the subject has to perform tasks such as reaching for objects as part of the game. Gravity compensation, which can reduce the level of difficulty of performing an activity, facilitates active arm movement, especially when it involves training in grasping and reaching. By using the Armeo system, we hope to achieve repetitive training of reach, grasp, and release in an engaging environment that can be adapted to individual capabilities. We also expect to enable stroke survivors whose motor weakness may have excluded them from performing repetitive therapy tasks to participate in this study.