Exoskeleton-assisted Training to Accelerate Walking Recovery Early After Stroke: the TARGET Phase II Study

A Temporal Analysis of the Robustness of Hemiplegic Gait and Standing Balance Early After sTroke - the TARGET Research Project

Phase II: Investigating the effects of additional robot-assisted gait training either initiated early (2 weeks post-stroke) or delayed (8 weeks post-stroke) after stroke onset.

GENERAL:

Pre-clinical research has pointed towards a time window of enhanced responsiveness to therapy early after stroke. For example, training has led to substantial recovery if initiated 5 or 14, but not 30 days post-stroke in a rodent model (Biernaski 2004). It is suggested that this early period is characterized by heightened levels of plasticity and that training can exploit this leading to improved outcome. The typically observed non-linear recovery pattern in stroke survivors (Kwakkel 2004) might suggest that similar mechanisms are induced in the human brain, however clinical research on this is disappointingly sparse.

In two closely inter-related phases, we aim to examine the biomechanical changes related to walking recovery in general (Phase I) and the specific effects of robot-assisted training (Phase II). By that, we aim to detect a time window in stroke survivors which resembles the same characteristics as observed in animal models. To initiate gait training at an early stage, when patients usually present severe weakness and balance deficits, a mobile exoskeleton is used which is developed to provide intensive walking practice.

OBJECTIVES:

(II.a) Are stroke survivors who train with the assistance of a robot at an early stage more likely to achieve independent walking?

(II.b) Does additional robot-assisted training modulate the recovery of standing and walking ability by enhancing behavioral restitution?

Inclusion Criteria:

• First-ever, MRI- or CT-confirmed, ischemic or hemorrhagic, anterior circulation stroke
• Age: 18 - 90 years
• Baseline assessments within the first 14 days after stroke onset
• Unable to walk independently at baseline (FAC <3)
• Moderate to severe weakness of the lower limb at baseline (MI </=75)
• Pre-morbid independence in activities of daily living (mRS </=2) and gait (FAC >3)
• Able to communicate and comprehend
• Sufficient motivation to participate
• Provided a written informed consent

Exclusion Criteria:

• No other neurological condition affecting motor functions of the lower limbs
• Pre-existing musculoskeletal impairment severely affecting the gait pattern
• Body weight > 100 kg
• Severe spasticity or contractures that prevent safe use of the exoskeleton
• Medically unstable to participate in additional therapy sessions