David Marsden-Award 2005
“Changing the Brain through Practice in Musicians’ Hand Dystonia”
Effective
Behavioral Treatment of Focal Hand Dystonia in Musicians alters Somatosensory
Cortical Organiszation
by Dr.
Victor Candia, Collegium Helveticum, Univ. and ETH Zürich < Dr. Candia’s C.V.
>
Focal
hand dystonia in musicians, is a greatly feared condition that leads to reduced
performance levels, very often resulting in the termination of a musician’s
career. This neurological disorder is characterized by a loss of control over
individual finger movements. The Symptoms usually only occur when patients
perform certain tasks such as playing an instrument (Fig.1A).
Fig.1A & B
It is assumed that focal hand dystonia is caused or at least related to
the excessive performance of repetitive activities. Various approaches to
therapies have been tried, for example physical therapy, prolonged rest,
anticholinergic drugs and Botulinum toxin. Unfortunately these treatments have
not induced long-term improvements even though new reports on Botulinum toxin
injections describe long-term symptoms improvement in some musicians affected
by this Dystonia. (Schuele et al., 2005).
Animal models have shown that repeated and extended use of the hand
results in changes in the functional organization of brain areas related to
sensory processing and motor control. These
changes are not limited to the animals that have been assessed, but can be seen
in healthy human subjects as well. Musicians are a very good example of changes
in brain organization resulting from prolonged and repetitive practice of
specific movement behaviours. Well-known personalities have been identified
including violinists, trumpeters and piano players. Changes in brain organization
in response to practice have been associated with focal hand dystonia as well.
In focal hand dystonia disrupted sensory processing has been repeatedly
demonstrated. It seems likely that these changes might be of relevance for the
outbreak of the disorder. The existence of such sensory anomalies suggests that
focal dystonia cannot be considered to be solely a motor problem. Furthermore, because these abnormalities
can extend far beyond the affected task and have been measured during other
activities unrelated to the symptoms, it is
likely that focal hand dystonia involves abnormalities along an extended
neuronal network within the nervous system.
On the assumption that practice results in brain reorganisation, we
developed a specific behavioural intervention which, assuming that the
movements involve both motor and sensory elements, we named Sensory Motor
Retuning or SMR (Candia et al., 2002; Candia et al., 2003). Briefly, in SMR
therapy, one or more finger(s) are immobilized by means of splints, enabling
the patients to perform different sequences of finger movements on the musical
instrument for short periods of time. Repertoire practice without a splint is
also added in order to achieve the transfer of the improvements gained during
exercises into the normal life process. Under therapist’s supervision, the
treatment is administered for eight consecutive days for 1 ½ to 2 ½
hours per session depending on the patient’s fitness (Candia et al., 2002) (Fig.2).
Fig.2
Pianists and guitarists visibly improved from pre- to post treatment
(Fig.1B). In contrast, the wind players did not improve. Thus, the movements of
the dystonic fingers were smoother after SMR, indicating enhanced motor control
in most of the treated patients. Work in progress including a new series of
eleven patients confirms the long-term effect of SMR. Eight external
evaluators, four neurologists with experience in motor disorders, and four
professional musicians (two pianists and two guitarists) to a great extent
agreed with the opinions of the treated patients that after SMR definite
long-term improvements have been achieved (On the Dystonia Evaluation Scale, 4
is normal) (Fig.3) (Rosset-Llobet et al., 2005b).
Fig.3
To assess whether SMR would also induce alterations in the organization
of the brain cortex of the treated musicians, we studied ten patients pre- and
post treatment by applying Magnetoencephalography (MEG), - a device
measuring biomagnetic signals arising from brain tissue in response to
stimulation of the finger pads. These measurements showed that
a)
prior to treatment, somatosensory relationships of the
individual fingers differed between hands
b)
following treatment, brain representations
corresponding to the dystonic side were similar to the representation of the
less affected side
c)
finger representations were more organized according
to neuronal laws following treatment and
d)
the dystonic area was significantly smaller for the
non-treated hand before treatment, and was similar in both sides of the brain
after treatment. In addition, a truly remarkable discovery was that these
physiologic changes were associated with the behavioural changes (Candia et al., 2003).
Several conclusions can be drawn based on these results. Our data are in
agreement with studies suggesting that cortical organization can be modified
through extensive practice. Therefore, cortical changes together with some
neurological dysfunctions can be redressed by context specific treatment. The
use of SMR, an intervention capable of producing changes in the brain
organisation of sensory areas, emphazises the close relationship between
sensory and motor systems (Candia et al., 2005). Work in progress
suggests that the degree of task similarity and the amount of practice devoted
to such tasks may be critical for the deterioration of symptoms (Rosset-Llobet et al., 2005a). As well,
preliminary data show that improvement of symptoms of wind players and patients
with other forms of focal dystonia, like for example writer’s cramp, can also
be achieved using Sensory Motor Retuning (SMR).
References
Candia V,
Rosset-Llobet J, Elbert T & Pascual-Leone A. (2005). Changing
the brain through therapy for musician's hand dystonia. In The Neurosciences and Music II: From Perception to Performance, ed.
Giuliano Avanzini LL, Stefan Koelsch, and Maria Majno, pp. 1-9. New
York Academy of Sciences, Leipzig.
Candia V, Schafer T, Taub E, Rau H, Altenmuller E,
Rockstroh B & Elbert T. (2002). Sensory motor retuning: a behavioral
treatment for focal hand dystonia of pianists and guitarists. Arch Phys Med Rehabil 83, 1342-1348.
Candia V, Wienbruch C, Elbert T, Rockstroh B & Ray W.
(2003). Effective behavioral treatment of focal hand dystonia in musicians
alters somatosensory cortical organization. Proc
Natl Acad Sci U S A 100, 7942-7946.
Rosset-Llobet J, Candia V, Fàbregas S &
Pascual-Leone A. (2005). Collateral disturbances in 101 cases of musician's
dystonia. (submitted).
Rosset-Llobet J, Pascual-Lone A, Fàbregas S, Elbert T
& Candia V. (2005). Sensory Motor Retuning is a Long-Term Treatment for
Musicians’ Hand Dystonia. (submitted).
Schuele S, Jabusch HC, Lederman RJ & Altenmuller
E. (2005). Botulinum toxin injections in the treatment of musician's dystonia. Neurology 64, 341-343.