Neuromagnetic investigations of mechanisms and effects of STN-DBS and medication in Parkinson's disease

Brief summary

Deep brain stimulation is a therapeutic recourse undertaken to treat motor symptoms in Parkinson's disease (PD) when dopaminergic medication is no longer able to suppress symptoms adequately. Though DBS has been empirically shown to be effective in treating PD symptoms, the effect-mechanisms are still not well understood, which is hindering progress in improving treatment outcomes and reducing side-effects.

To further our understanding of these aspects, we used magnetoencephalograhy (MEG) to study oscillatory dynamics at rest, during movement and during somatosensory processing in PD patients and healthy controls. These measurements were conducted in DBS-treated, untreated (DBS-washout) and dopaminergic-medicated states in the PD patients. 

Based on the results of the three studies, we firstly infer that DBS and dopaminergic medication employ partially different anatomo-functional pathways and functional strategies when improving PD symptoms. Secondly, we suggest that treatments act on pathological oscillatory dynamics differently at cortical and sub-cortical levels and may do so through more sophisticated mechanisms than mere suppression of the pathological spectral power in a particular band. And thirdly, we urge exploring the effect mechanisms of PD treatments beyond the motor system (e.g. for sensory function) to allow for a more integrated view on mechanisms of treatments, which could pave the way for better disease management paradigms.

Opponents

1. Andrea Kühn, Department of Neurology with Chair in Experimental Neurology,
   Charité Universitätsmedizin Berlin, Germany
2. Jyrki Mäkelä, Biomag Laboratory,
   Helsinki University Central Hospital, Finland

ALL ARE WELCOME.