The contribution of dopamine to regulation of orofacial, limb and trunk control: System or function specific effects? (2007–2009)
Treatment for Parkinson's disease, including dopamine replacement therapy and deep brain stimulation, fail to produce the same beneficial effects on all movement systems. Whereas limb function is the primary beneficiary of these treatments, other functions such as speech and postural control are less responsive. Critical to the research is the postulate that such differences may have arisen due to the fact that previous studies of dopamine and movement control have investigated distinct motor systems via the assessment of distinct movement constructs, making cross system comparisons an impossible task. The proposed research will assess the effect of Parkinson's disease, deep brain stimulation and dopamine on identical muscle functions within the orofacial, trunk and limb muscle systems. To this end, the results generated from this resarch have the potential to reconceptualise working models of brain-muscle relationships. Further the research will provide guidance for future studies that aim to eradicate trade-off effects (e.g. limb function improved but not speech) relating to symptom relief for people with Parkinson's disease.