There is a debilitating movement disorder affecting expert classical musicians and athletes. This disorder is a mysterious breakdown, where through a series of unfortunate events a skilled performer suddenly loses their ability. It is not a typical disease, as their health and ability to perform other skills remains unaffected. Strangely, one of the key factors in its development is too much practice. Somehow, perfecting a skill can become the road to losing it. This mysterious disorder is called task specific dystonia and it is the topic of this PhD.

The cause of task specific dystonia is not well understood, but it is thought to be related to changes in the brain’s ability to control the motor programs that drive complex movements.

To perform a complex skill like playing the violin our brain develops highly specific motor programs, but there is a tradeoff: as a program gains efficiency it loses flexibility. As a result of lower flexibility, these programs are less able to adapt to changes in the outside world. For example, if a violin player starts playing on a new instrument with tighter strings, or a piano player goes from analogue to electric keys, the older more rigid motor programs of experts are confronted with changes they can struggle to adapt to. This can lead to sudden massive problems. For some with particular genetics and neurophysiology, the motor program ‘crashes’ resulting in a complete loss of the ability. Muscles begin to contract randomly and suddenly impeding the expert ability completely ‑ eventually ending careers. Although many sports like golf and baseball are affected by task specific dystonia, classical musicians are especially vulnerable because playing an instrument requires the most extreme complex and precise motor programming.

This PhD focuses on understanding the underlying causes of this strange movement disorder by testing the hypothesis that, along with professional musicians, speedskaters are also affected by task specific dystonia. To do this, cutting edge forms of analysis measuring movements, muscles and the central nervous system were employed.

So far, in addition to the results confirming our hypothesis (1,2), our methods have shown new ways of measuring task specific dystonia that have wider applications. For example, measurements of muscle activity using wavelet-coherence found signs of over-activity in central structures of the brain (3). This efficient, non-invasive, and cost-effective strategy could help in testing for (and measuring improvements in) symptoms of task specific dystonia, also in professional musicians. 

Especially in musicians, better quantitative measurements are useful due to the high prevalence of task specific dystonia (approximately 1% of professional violin and piano players are affected). Famous musicians who have been affected by the disorder include pianists Glenn Gould and Leon Fleischer and violin player Peter Oundjian, all of whom developed dystonia in their hand forcing them to struggle for years, never fully recovering. From his diary entries, it even appears likely that Schumann suffered from task specific dystonia. Through the research of this PhD, new insights are being uncovered into the disorder that will help with earlier diagnosis, whether you are a speedskater or a first chair violinist.