My aim in this article is to present the neurological causes of Focal Dystonia in a way that is easy to understand and which at the same time maintains the precision of the scientific, neurological research that has thus far been undertaken.
This is no mean feat as the brain is enormously complex and so is the language and the scientific explications of the interrelationships between the different areas of the brain. For example it is estimated that there are a minimum of 100 trillion neural connections (synapses), in the human brain. That is at least 1,000 times the number of stars in the Milky Way!
Whilst the physiological changes in the brain that cause Musician´s Focal Dystonia are not completely understood; some clear findings have been made. These include:
Abnormal muscle firing at different levels of the central nervous system
In general, the nervous system has a subtle balance between activation and inhibition in the neural circuits. The balance is especially important in the precise and smooth movements of the hand and embouchure. In patients suffering from Focal Hand Dystonia, electromyographic recordings showed that the muscles fired for longer than normal. At the same time there was a co-contraction of antagonistic muscle pairs and inappropriate muscles were also activated (Cohen LG, 1998).
Some groups of muscles work together and are called antagonistic muscle pairs. One muscle of the pair is called the “prime mover” (or agonist muscle) and it is responsible for generating or controlling a specific movement. The other muscle of the pair is the antagonist muscle and their role is to produce an opposing joint torque to the prime mover muscle. This torque aids in controlling a motion. In most cases they function in the following way, as one muscle contracts, the other relaxes. The loss of muscular coordination that occurs in Focal Dystonia is frequently accompanied by a co-contraction of antagonist muscle groups. For example, in Pianists Focal Hand Dystonia the co-activation of wrist flexor and wrist extensor muscles is frequently observed.
In people suffering from Musician´s Focal Dystonia the subtle balance between activation and inhibition is broken as there is a lack of inhibition which is found at multiple levels of the nervous system, such as at the spinal level and in the sensory-motor system. Curiously it is found in both hemispheres, even in patients who only have symptoms in one side of their body.
Mal-adaptive plasticity, altered sensory perception and alterations in the sensorimotor integration
It has been shown that in the somatosensory cortex of patients with Musicians Focal Dystonia, the structural location of where their brain receives the messages, from individual fingers in the case of Hand FD and from the lips and tongue in Embouchure FD, overlaps more than in healthy musicians. (Elbert T, 1998).
It is believed that the overlapping of the representations of the fingers or lips and tongue in the somatosensory and motor cortices leads to the involuntary motor output which shows up as the involuntary muscle tensions, spasms and torsions of the muscles that the musician experiences. (Konczak J, 2013)
This overlapping also results in them losing tactile sensitivity and acuity when they play their instrument. It addition, it affects their body scheme and their sense of ownership of these parts of their body. Focal Dystonia can lead to dissociation between a person´s body scheme and the sensory information that their brain registers from their body. Clients frequently say to me that it is as if their hand doesn´t belong to them.
Scientists are yet to confirm what causes this overlapping to occur, however, I have observed in all my clients with Musicians Focal Dystonia that they have higher levels than usual of self-demanding and perfectionism that in all cases is a learned behaviour from their family environment and/or their musical education. This level of perfectionism has been confirmed by psychological studies of people who suffer from Musician´s Focal Dystonia (Altenmüller E, 2010). I have been struck by Dr James Coan´s research which indicates that we literally map the body of our early attachment figures in our somatosensory cortex and into our own sense of body (Coan J, 2006). Part of the treatment that I complete with my clients is to enable them to recover their sense of who they are and separate it from the feelings that they absorbed from these early figures. As a result their brain no longer includes self-demanding and perfectionism in their personal identity and they experience an important reduction in their dystonic symptoms.
Abnormal functioning of the basal ganglia
It has long been assumed that Musician´s Focal Dystonia involves abnormal functioning of the basal ganglia that ultimately affects the sensorimotor cortices. The exact link between the observable dystonic symptoms and the neural dysfunction in the basal ganglia is not yet established. However, what emerges from the large body of neurophysiological research on Focal Dystonia is that it is linked to the dysfunction of a complex network comprising basal-ganglia-thalamic-frontal cortex connections but also the inferior parietal cortex and the cerebellum. (Avanzino L, 2012)
As I have already mentioned, in psychological studies, musicians with Focal Dystonia have more anxiety and perfectionist tendencies than healthy musicians (Altenmüller E, 2010). This is also born out in my experience with my clients. Interestingly, the neurological research on Brainspotting, one of the key techniques that I use to cure Musician´s Focal Dystonia, explains how this type of social and emotional pain affects the functioning of the basal ganglia, the sensorimotor cortex and thalamocortical processing (Corrigan F, 2013) . I have described this research in more detail in the article…. This article explains how learned self-demanding and perfectionism can change the brain structure and functioning and how the neuroplasticity techniques that I use, which include Brainspotting, reverse this process and produce healing and physiological changes in the brain.
In my experience, musicians find it very helpful and feel relief when they understand that their Focal Dystonia has a real and physiological cause. It helps them to let go of the idea that they should be able to control the symptoms of their condition or that they have the symptoms because they are doing something wrong. It also helps them to understand exactly how to do the exercises that we complete in the sessions and those that they practice in between sessions in order to maximise their neuroplastic impact. If you are suffering from Musicians Focal Dystonia, I hope that this article has been of use to you in understanding that your symptoms are caused by neurological dysfunctions rather than from problems in the muscles of your body or from an error that you are making whilst you play.
Quoted Research
Altenmüller E, J. H. (2010). Focal Dystonia in musicians: phenomenology, pathophysiology, triggering factors, and treatment. Med Probl Perform Art., 25(1):3-9.
Avanzino L, A. G. (2012). How does the cerebellum contribute to the pathophysiology of dystonia. Basal Ganglia, 2, 231-235.
Coan J, S. H. (2006). Lending a Hand: Social regulation of the neural response to threat. Psychological Science, 17 (12), 1032-1039.
Cohen LG, H. M. (1998). Hand cramps: clinical features and elctromyographic patterns in focal dystonia. Neurology, 38:1005-1012.
Corrigan F, G. D. (2013). Brainspotting: Recruiting the midbrain for accessing and healing sensorimotor memories of traumatic activation. Medical Hypotheses, 759-766.
Elbert T, C. V. (1998). Alteration of digital representations in somatosensory cortex in focal hand dystonia. Neuroreport, 16:3571-3575.
Konczak J, A. G. (2013). Focal dystonia in musicians: linking motor symptoms to somatosensory dysfunction. Frontiers in Human Neuroscience, Vol 7: Article 297.