Musicians’ Focal Dystonia
Musicians’ Focal Dystonia (MFD) is a neurological motor disorder characterised by the involuntary contraction of muscles involved in playing a musical instrument. It is task-specific, and initially only impairs the voluntary control of highly practised musical motor skills. Musicians are the professional group at highest risk of developing focal dystonia, and it affects around 1% of all professional musicians. The male to female ratio is estimated to be anything from 2:1 to 6:1, and pianists, guitarists, woodwind players and string players are at the highest risk. Brass and wind players can also develop MFD in the hands and in areas relating to the embouchure (mouth, lips, cheeks, jaws or tongue.) Percussionists may develop dystonia of the foot. It is usually diagnosed in players between their 20s and 40s, and often affects players who have practised particularly intensively over the years. MFD is career threatening, and many famous musicians including Glenn Gould, the famous pianist, have been severely affected.
Symptoms only occur when playing, and often show up in fast passages, as irregularity on playing trills or as involuntary flexion of one or more fingers. When MFD affects the embouchure, musicians may have problems pitching or articulating notes correctly, or may experience a tremor in notes that are held. Triggers for the condition are thought to include a sudden increase in playing, a dramatic change in technique, returning to playing after a long break, trauma, nerve injury and a change of instrument. Pianists often find the 4th and 5th fingers of the right hand are affected, guitarists can experience involuntary curling of the 3rd finger of the right hand, the left hand of flautists is often affected, and violinists and clarinettists can experience problems with either hand.
It is thought that the repetitive hand movements used in playing an instrument can lead to remapping of the receptive fields in the cerebral cortex. This results in brain maps becoming less distinct, with scans showing that areas of finger representation in the cerebral cortex become abnormally fused, leading to instructions from the brain going to the wrong muscles and producing the dystonia symptoms. Usually the sufferer finds that the affected part responds normally at other times, and only becomes uncontrollable during the trigger activity.
Affected individuals need timely referral to a neurologist. Unfortunately there is no curative treatment for this potentially career-terminating condition which can be a huge source of distress to musicians, although botulinum injections, anticholinergics, sensory re-education and sensory motor retuning can help.