The role of the SMA-M1 motor network for upper limb motor learning following active-passive bimanual movement in humans

• Applicant: Dr. Florian Müller-Dahlhaus
• Subject Area: Clinical Neurology; Neurosurgery and Neuroradiology
• Term: from 2012 to 2013
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 230124551

Stroke is one of the most prevalent neurological conditions worldwide and accounts for severe disabilities among those affected. More than 50% of stroke survivors suffer from residual motor impairment, even after completion of standard motor rehabilitation (Hendricks et al., 2002). Motor deficits greatly impair activities of daily living, reduce patient quality of life, and put a large burden on public health systems. Unfortunately, effective therapies for motor rehabilitation after stroke are still limited despite intensive research and numerous clinical trials (Floel and Cohen, 2010). Active-passive bilateral therapy (APBT), in which the paretic hand is driven in a mirror-symmetric pattern by voluntary movement of the contralateral non-paretic hand, has been shown to provide benefits for upper limb motor rehabilitation in chronic stroke patients (Stinear et al., 2008). However, the neural basis of APBT is poorly understood.Together with primary motor cortex (M1) the supplementary motor area (SMA) is crucial for preparation and execution of bimanual tasks and complex sequential finger movements (Nachev et al., 2008). This research project will investigate the role of connectivity and plasticity within the human SMA-M1 motor network for upper limb motor learning following active-passive bimanual movements (APBM) in healthy human subjects. The proposed studies include state-of-the-art techniques in the clinical neurosciences. Specifically, MR-navigated bi-focal transcranial magnetic stimulation (TMS) will be used to study SMA-to-M1 effective connectivity and associative plasticity in the SMA-M1 network. Knowledge gained from these studies will help to understand SMA-M1 network dynamics in the context of upper limb motor learning following APBM and may validate TMS-induced plasticity as a biomarker to predict learning efficacy. Thus, these studies will be of potential relevance to optimize and stratify APBT for upper limb motor rehabilitation post-stroke.

• DFG Programme: Research Fellowships
• International Connection: New Zealand
• Host: Professor Winston Byblow, Ph.D.