Motor observation and imagination in Musician's Dystonia

• Applicant: Dr. Johanna Doll-Lee
• Subject Area: Clinical Neurology; Neurosurgery and Neuroradiology
• Term: since 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 537544040

Musician’s Dystonia (MD), a sub-entity of focal task specific dystonia (TSD), is a hyperkinetic, task specific movement disorder that leads to loss of control of fine motor movements with involuntary cramping of the affected body parts at the instrument, thereby threatening professional Musicians’ careers. The pathophysiology of MD is not yet fully understood and the underlying mechanisms are still a matter of conjecture for which there are neither causal therapies nor reliable prevention strategies. While some symptomatic therapies for MD are available, none of these options provides patients with adequate and reliable symptom control due to limiting side effects and insufficient effectiveness. It is therefore of utmost importance to improve our understanding of pathophysiology, as this forms the basis for developing causal therapies and reliable primary prevention strategies. One method that has contributed crucially to a better understanding of the mechanisms of MD is brain imaging. However, a limiting factor of the imaging studies performed so far is that most of them have used resting state protocols in which it is not clear whether the observed activation changes are the cause or consequence of the disease. Other fMRI studies have investigated brain activity during dystonic task performance, but the observed patterns of activation in somatosensory areas may be influenced by compensatory mechanisms, the dystonic movement itself, or somatosensory input related to the task. Motor imagination and observation tasks during fMRI offer a way to address these limitations. Actually, there are some studies hinting that this kind of protocol might be able to reveal dysfunctional networks in TSD, although some studies may have been limited by small sample and small effect size. It can be assumed that patients with MD, most of whom are professional musicians and have been regularly musically trained since childhood, are an ideal group for further research into this approach. Not only do they form a relatively homogeneous group due to their typical training, but this very training has been shown to lead to significant, measurable changes in their brains, which also lead to a demonstrably special ability to imagine instrument-related movements. Observing instrument-related movements has also been shown to lead to a pronounced mirror activation in their brains. My proposal is therefore to obtain further insights into the underlying pathophysiology of MD from this group of musicians with dystonia using a motor imagination and perception fMRI protocol. This might also allow for insights in other TSDs, as experts agree that the best way to better understand dystonia as a whole is to investigate the individual subentities in groups that are as homogeneous as possible. The knowledge gained could then help to find new therapeutic and primary-preventive strategies.

• DFG Programme: WBP Position