New Treatments for Induction of Motor Plasticity after Stroke

Recent progress has enabled an improved understanding of how the brain recovers from motor impairment during the first months after stroke. The integrity of fiber tracts connecting movement areas of the brain with spine and muscles (i.e., of the so-called cortico-spinal tract, CST) and repair processes around the damaged brain cortex were found to key factors for motor improvement within the first 3 months. Furthermore, new treatment approaches have become available that can influence neural processes that may be important for recovery. Hence, we can now start to apply treatments which induce specific repair processes in patient subgroups that are likely to benefit. This has the potential to obtain causal and customised treatment of motor handicap.

This project proposes to test two therapy concepts resulting from recent advances in the understanding of motor plasticity in patients with subacute stroke.

In a first component of the project, we will perform non-invasive stimulation by applying a small direct current to the scalp of patients with stroke (a technique called “transcranial direct current stimulation”). This treatment will be tested in patients with light to moderate motor handicap and with at least partial integrity of the CST. We hypothesize that if this treatment is started within 4 weeks after stroke onset, it enhances repair processes in the cortex and leads to improved clinical motor recovery.

In a second part of the project, we will test a treatment in patients with severe motor handicap and severe damage to the CST. A brain-computer interface system will detect when patients activate their movement areas of the brain by trying to move their paralyzed arm. This will trigger an electrical stimulation of the arm muscles and lead to a movement. We hypothesize that, if this treatment is applied within 4 weeks after stroke, it helps restore CST fibers and improve recovery of patients with severe handicap.

We hope that our approach can influence more selectively and efficiently repair processes that are critical for recovery and that it leads to robust effects on motor recovery even in patients with severe motor deficits.