Focal dystonia: Difference between revisions

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== Introduction  ==
== Introduction  ==


Dystonia is defined as an involuntary contraction of the agonistic and antagonistic muscles, which can lead to repetitive involuntary movements and/or abnormal positions, most common in the hand (known as Focal Hand Dystonia). The affected population includes individuals who require repetitive movements in their regular daily life; one of the most affected populations are the musicians and professional writers&nbsp;<ref name="Aranguiz et al. (2011)">Aranguiz, R., Chana-Cuevas, P., Alburquerque, D. Leon, M. (2011). Focal dystonia in musicians. Neurologia, 26(1), 45-52. doi: 10.1016/j.nrl.2010.09.019</ref>. In the European and American populations Focal dystonia varies its prevalence between 3 and 29.5 per 100.000 inhabitants&nbsp;<ref name="Aranguiz et al. (2011)" /><ref name="Defazio et al. (2004)">Defazio, G., Abbruzzese, G., Livrea, P. Berardelli, A. (2004). Epidemiology of primary dystonia. Lancet Neurol, 3(11), 673-678. doi: 10.1016/s1474-4422(04)00907-x</ref>. Inside musicians dystonia it is estimated that of all musicans, 0.5&nbsp;% to 1% suffer from some form of focal dystonia&nbsp;<ref name="Aranguiz et al. (2011)" /><ref name="Jabusch et al. (2005)">Jabusch, H. C., Zschucke, D., Schmidt, A., Schuele, S., Altenmuller, E. (2005). Focal dystonia in musicians: treatment strategies and long-term outcome in 144 patients. Mov Disord, 20(12), 1623-1626. doi: 10.1002/mds.20631</ref>. These figures are highly variable if we individualize each case, depending on the instrument and the effort required on each performance; for instance the difference between a rhythm and a soloist guitar player.  
Dystonia is defined as an involuntary contraction of the agonistic and antagonistic muscles, which can lead to repetitive involuntary movements and/or abnormal positions. This occurs most commonly in the hand and is known as Focal Hand Dystonia.  
 
The affected population includes individuals who require repetitive movements in their regular daily life, with one of the most affected populations being musicians and professional writers.<ref name="Aranguiz et al. (2011)">Aránguiz R, Chana-Cuevas P, Alburquerque D, León M. [https://www.sciencedirect.com/science/article/pii/S2173580811700086 Focal dystonia in musicians]. Neurología (English Edition). 2011 Jan 1;26(1):45-52.</ref> In the European and American populations, Focal Dystonia varies its prevalence between 3 and 29.5 per 100.000 inhabitants.<ref name="Aranguiz et al. (2011)" /><ref name="Defazio et al. (2004)">Defazio G, Abbruzzese G, Livrea P, Berardelli A. [https://www.sciencedirect.com/science/article/pii/S147444220400907X Epidemiology of primary dystonia]. The Lancet Neurology. 2004 Nov 1;3(11):673-8.</ref> With dystonia occurring in musicians, it is estimated that 0.5 -1% of all musicians suffer some form of focal dystonia.<ref name="Aranguiz et al. (2011)" /><ref name="Jabusch et al. (2005)">Jabusch HC, Zschucke D, Schmidt A, Schuele S, Altenmüller E. [https://movementdisorders.onlinelibrary.wiley.com/doi/abs/10.1002/mds.20631 Focal dystonia in musicians: treatment strategies and long‐term outcome in 144 patients]. Movement disorders: official journal of the Movement Disorder Society. 2005 Dec;20(12):1623-6.</ref> These figures are highly variable if we individualize each case, depending on the instrument and the effort required with each performance; For example, the difference between a rhythm and a soloist guitar player.  


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== Mechanism of Injury / Pathological Process<br>  ==
== Mechanism of Injury / Pathological Process   ==


Although the pathological process of Focal Dystonia is still classified as idiopathic, increasing evidence suggested a multifactorial etiology (e.g.&nbsp;<ref name="Byl et al. (2009)">Byl, N. N., Archer, E. S.; McKenzie, A. (2009). Focal hand dystonia: effectiveness of a home program of fitness and learning-based sensorimotor and memory training. J Hand Ther, 22(2), 183-197; quiz 198. doi: 10.1016/j.jht.2008.12.003</ref>&nbsp;interaction between genetic, neuromuscular, auditory, neural adaptative, anatomic, stressful, repetitive, psychosocial, traumatic, among others). An alteration in tactile discrimation was found in dystonic musicians comparing with generalized dystonias and healthy controls; this has been related with the superposition of the areas of representation of the fingers affected in musicians&nbsp;<ref name="Aranguiz et al. (2011)" /><ref name="Byl et al. (2003)">Byl, N. N., Nagajaran, S.McKenzie, A. L. (2003). Effect of sensory discrimination training on structure and function in patients with focal hand dystonia: a case series. Arch Phys Med Rehabil, 84(10), 1505-1514.</ref>.&nbsp;Other etiological mechanisms are also described in further literature, for instance the alteration of inhibitory spinal, trunk, and intracortical &nbsp;and alterations in sensorimotor integration.&nbsp;<ref name="Aranguiz et al. (2011)" /><br>  
Although the pathological process of Focal Dystonia is still classified as idiopathic, increasing evidence suggested a multifactorial etiology<ref name="Byl et al. (2009)">Byl NN, Archer ES, McKenzie A. [https://www.sciencedirect.com/science/article/pii/S0894113008002202 Focal hand dystonia: effectiveness of a home program of fitness and learning-based sensorimotor and memory training.] Journal of Hand Therapy. 2009 Apr 1;22(2):183-98.</ref> (i.e. the interaction between genetic, neuromuscular, auditory, neural adaptative, anatomic, stressful, repetitive, psychosocial, traumatic, among others). An alteration in tactile discrimination was found in dystonic musicians compared to generalized dystonias and healthy controls; this has been related to the superposition of the areas of the cortical representation of the fingers affected in musicians.<ref name="Aranguiz et al. (2011)" /><ref name="Byl et al. (2003)">Byl NN, Nagajaran S, McKenzie AL. [https://www.sciencedirect.com/science/article/pii/S0003999303002764 Effect of sensory discrimination training on structure and function in patients with focal hand dystonia: a case series]. Archives of physical medicine and rehabilitation. 2003 Oct 1;84(10):1505-14.</ref> Other etiological mechanisms are also described in the literature, such as the alteration of inhibitory spinal, trunk, and intracortical as well as alterations in sensorimotor integration.<ref name="Aranguiz et al. (2011)" />  


Many triggering factors have been described in current literature and can be separated into external and internal factors. Extrinsic factors include spatial, temporal and spatial contraints, depending on the workload of the respective body part and the complexity of the movements used. Intrinsic factors include the need of control, the need of perfectionism, anxiety, local pain, trauma, overuse and the deficit in inhibitory mechanisms. Predisposing factors such as genetics and sex are also important. These triggering factors combined can affect the manifestation of Dystonia<ref name="Altenmuller & Jabusch (2010)">Altenmuller, E. Jabusch, H. C. (2010). Focal dystonia in musicians: phenomenology, pathophysiology, triggering factors, and treatment. Med Probl Perform Art, 25(1), 3-9.</ref>.
Many triggering factors have been described in the current literature and can be separated into external and internal factors. Extrinsic factors include spatial, temporal, and spatial constraints, depending on the workload of the respective body part and the complexity of the movements used. Intrinsic factors include the need for control, the need for perfectionism, anxiety, local pain, trauma, overuse and the deficit in inhibitory mechanisms. Predisposing factors such as genetics and sex are also important. These triggering factors combined can affect the manifestation of Dystonia.<ref name="Altenmuller & Jabusch (2010)">Altenmüller E, Jabusch HC. [https://www.ingentaconnect.com/content/scimed/mppa/2010/00000025/00000001/art00002 Focal dystonia in musicians: phenomenology, pathophysiology, triggering factors, and treatment]. Medical Problems of Performing Artists. 2010 Mar 1;25(1):3-9.</ref>  


== Clinical Presentation  ==
== Clinical Presentation  ==


Some examples of Focal dystonia are Cervical Dystonia (AKA spasmodic[[Adult-onset Idiopathic Torticollis|torticollis]]), which causes the neck to twist or tilt, Musician's Dystonia, Writer's Dystonia,&nbsp;Blepharospasm (bilateral, involuntary, synchronous, forceful eye closure) and Spasmodic Dystonia, among others. Musician's and Writer's Dystonia are referenced in this article.
Some examples of Focal Dystonia are Cervical Dystonia (AKA spasmodic&nbsp;[[Adult-onset Idiopathic Torticollis|torticollis]]), which causes the neck to twist or tilt, Musician's Dystonia, Writer's Dystonia, Blepharospasm (bilateral, involuntary, synchronous, forceful eye closure) and Spasmodic Dystonia, among others.


Musician's Dystonia is manifested by a loss of voluntary motor movement in repeatedly trained movements. This is a high disabling pathology that can end a musical career; it can be classified according to the instrument played and the movement extensively performed. Normally it occurs without pain although aching as been described after prolonged spasms.<ref name="Altenmuller & Jabusch (2010)" />&nbsp;This loss of muscle coordination is often accompannied by a co-contraction of antagonist muscles. <ref name="Altenmuller & Jabusch (2010)" /><br>  
The study by Qiyu Chen et al. suggests that the presence of Head Tremors (HT) and its type depend on a patient’s predominant posture (patients with retrocollis were more prone to have HT than patients with anterocollis), age (earlier age of onset compared to patients without HT), and duration (longer disease duration compared to patients without HT)<ref>Chen Q, Vu JP, Cisneros E, Benadof CN, Zhang Z, Barbano RL, Goetz CG, Jankovic J, Jinnah HA, Perlmutter JS, Appelbaum MI. [https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6988138/ Postural directionality and head tremor in cervical dystonia]. Tremor and Other Hyperkinetic Movements. 2020;10.</ref>. 
 
Musician's Dystonia is manifested by a loss of voluntary motor movement in repeatedly trained movements. This is a high disabling pathology that can end a musical career; it can be classified according to the instrument played and the movement extensively performed. Normally it occurs without pain although aching has been described after prolonged spasms.<ref name="Altenmuller & Jabusch (2010)" /> This loss of muscle coordination is often accompanied by a co-contraction of antagonist muscles.<ref name="Altenmuller & Jabusch (2010)" /><br>  


Writer's Dystonia or Writer's cramp can be also be manifested by uncontrollable muscle contractions and abnormal postures of the whole upper limb during writing. Tremor and spasms of the hand can also occur.  
Writer's Dystonia or Writer's cramp can be also be manifested by uncontrollable muscle contractions and abnormal postures of the whole upper limb during writing. Tremor and spasms of the hand can also occur.  
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== Diagnostic Procedures  ==
== Diagnostic Procedures  ==


Magnetic Resonance Imaging (MRI) - to exclude [[Stroke|stroke]]&nbsp;or tumours involving the basal ganglia  
Magnetic Resonance Imaging (MRI) - to exclude [[Stroke|stroke]] or tumours involving the basal ganglia  


Measurement of the blood ceruloplasmin level - to rule out Wilson's disease (a disorder of copper metabolism that can produce dystonia and other movement disorders)<br>
Blood work&nbsp;to assess ceruloplasmin levels - to rule out [[Wilson's Disease|Wilson's disease]] (a disorder of copper metabolism that can produce dystonia and other movement disorders)


== Differential Diagnosis ==
*Paroxysmal dystonia: this presents as discrete episodes of abnormal movements lasting from minutes to hours, with intervening periods of normalcy<ref>Demirkiran M, Jankovic J. [https://onlinelibrary.wiley.com/doi/abs/10.1002/ana.410380405 Paroxysmal dyskinesias: clinical features and classification]. Annals of Neurology: Official Journal of the American Neurological Association and the Child Neurology Society. 1995 Oct;38(4):571-9.</ref>
*Dopa-responsive dystonia: this is characterized by a diurnal variation of dystonic movements, with improvement in the morning and worsening in the afternoon<ref>Ichinose H, Ohye T, Takahashi EI, Seki N, Hori TA, Segawa M, Nomura Y, Endo K, Tanaka H, Tsuji S, Fujita K. [https://www.nature.com/articles/ng1194-236 Hereditary progressive dystonia with marked diurnal fluctuation caused by mutations in the GTP cyclohydrolase I gene]. Nature genetics. 1994 Nov;8(3):236-42.</ref>; it is linked to chromosome 14, which is involved in dopamine synthesis
*Dystonic tics (which may be associated with the obsessive-compulsive disorder): patients with dystonic tics feel an internal, uncomfortable sensation in the affected body part, and this sensation builds up to an overwhelming "urge" to perform a sustained, tonic tic, For example, head-turning; patients often report relief immediately after performing the tic, but this is soon followed by recurrence of the urge to perform the tic again
*Iatrogenic causes: dopamine receptor-blocking medications, For example, neuroleptics and phenothiazine-based antiemetics, can produce an acute dystonic reaction from a single dosage, or tardive dystonia from chronic usage<ref>Miller LG, Jankovic J. [https://europepmc.org/article/med/1971459 Neurologic approach to drug-induced movement disorders: a study of 125 patients.] Southern medical journal. 1990 May 1;83(5):525-32.</ref>
== Outcome Measures  ==
== Outcome Measures  ==


Motor control and ADL scales  
Motor control and ADL scales  


== Management / Interventions<br> ==
== Medical Management  ==
 
The aim of medical management is to manage muscle contractions and limit deformity
*Botulin Toxin&nbsp;<ref name="Ceballos-Baumann et al. (1997)">Ceballos-Baumann, A. O., Sheean, G., Passingham, R. E., Marsden, C. D. Brooks, D. J. (1997). Botulinum toxin does not reverse the cortical dysfunction associated with writer's cramp. A PET study. Brain, 120 ( Pt 4), 571-582.</ref>  
*Drug management targets neurotransmitters that affect muscle movement and include:&nbsp;Anticholinergics<ref>Fahn S, Burke R, Stern Y. [https://www.sciencedirect.com/science/article/pii/S007961230860922X Antimuscarinic drugs in the treatment of movement disorders]. Progress in brain research. 1990 Jan 1;84:389-97.</ref>,&nbsp;Baclofen and benzodiazepines dopamine related medications. <ref>Termsarasab P, Thammongkolchai T, Frucht SJ. [https://clinicalmovementdisorders.biomedcentral.com/articles/10.1186/s40734-016-0047-6 Medical treatment of dystonia.] Journal of clinical movement disorders. 2016 Dec;3(1):1-8.</ref>
*Surgery&nbsp;  
*Injection therapy of Botulin Toxin directly into the muscle can reduce, and in many cases stop muscle contractions that cause abnormal postures.<ref name="Ceballos-Baumann et al. (1997)">Ceballos-Baumann AO, Sheean G, Passingham RE, Marsden CD, Brooks DJ. [https://academic.oup.com/brain/article-abstract/120/4/571/372106 Botulinum toxin does not reverse the cortical dysfunction associated with writer's cramp. A PET study.] Brain: a journal of neurology. 1997 Apr 1;120(4):571-82.</ref> They may have side effects such as dry mouth, voice changes and weakness.
*Ergonomic changes at the instrument (Musician's dystonia)
*Surgery&nbsp;may be indicated if the symptoms are severe and have not responded to other interventions.  Surgery might involve the insertion of electrodes into the brain which are connected to a generator that is placed into the chest.  The generator sends signals to the brain which can control muscle contractions and movement.  Another surgical intervention is to sever the nerves that control muscle spasm, this is known as Selective Denervation Surgery.
*Immobilization&nbsp;<ref name="Priori et al. (2001)">Priori, A., Pesenti, A., Cappellari, A., Scarlato, G. Barbieri, S. (2001). Limb immobilization for the treatment of focal occupational dystonia. Neurology, 57(3), 405-409 (abstract only)</ref>
*Immobilization, in a study by Priori et al,  has been shown to have a positive effects on focal dystonia.  The possible rational for improvement is the plastic changes that occur at cortical level.  Immediately after immobilisation there were signs of weakness, clumsiness and poor limb control, but these symptoms were temporary and in most cases improved within 4 weeks.<ref name="Priori et al. (2001)">Priori A, Pesenti A, Cappellari A, Scarlato G, Barbieri S. [https://n.neurology.org/content/57/3/405.short Limb immobilization for the treatment of focal occupational dystonia]. Neurology. 2001 Aug 14;57(3):405-9.</ref><br>
*Behavioral training&nbsp;<ref name="Berque et al. (2010)">Berque, P., Gray, H., Harkness, C. McFadyen, A. (2010). A combination of constraint-induced therapy and motor control retraining in the treatment of focal hand dystonia in musicians. Med Probl Perform Art, 25(4), 149-161 (abstract only).</ref><ref name="Byl et al. (2009)" /><br>  
*Drug management includes:&nbsp;Anticholinergics<ref>Fahn S, Burke R, Stern Y: Antimuscarinic drugs in the treatment of movement disorders. Progr Brain Res 1990; 84:389-397</ref>,&nbsp;Baclofen and benzodiazepines,&nbsp;
 
=== Physiotherapy  ===


*[[Transcutaneous Electrical Nerve Stimulation (TENS)|TENS]]&nbsp;<ref name="Tinazzi et al. (2006)">Tinazzi, M., Zarattini, S., Valeriani, M., Stanzani, C., Moretto, G., Smania, N., . . . Abbruzzese, G. (2006). Effects of transcutaneous electrical nerve stimulation on motor cortex excitability in writer's cramp: neurophysiological and clinical correlations. Mov Disord, 21(11), 1908-1913. doi: 10.1002/mds.21081</ref>  
== Physiotherapy Management  ==
*Sensomotor Training&nbsp;<ref name="Byl et al. (2003)" />  
The aim of physiotherapy is to ease symptoms and improve function.  There are several approaches and will be dependent on symptoms but the most common interventions are:
*[[Transcutaneous Electrical Nerve Stimulation (TENS)|TENS]]<ref name="Tinazzi et al. (2006)">Tinazzi M, Zarattini S, Valeriani M, Stanzani C, Moretto G, Smania N, Fiaschi A, Abbruzzese G. [https://movementdisorders.onlinelibrary.wiley.com/doi/abs/10.1002/mds.21081 Effects of transcutaneous electrical nerve stimulation on motor cortex excitability in writer's cramp: neurophysiological and clinical correlations]. Movement disorders: official journal of the Movement Disorder Society. 2006 Nov;21(11):1908-13.</ref>
*Sensomotor Training<ref name="Byl et al. (2003)" />  
*Muscle Strengthening  
*Muscle Strengthening  
*Stretching  
*Stretching  
*Relaxation Techniques  
*Relaxation Techniques  
*Home exercises&nbsp;<ref name="Byl et al. (2009)" />
*Home exercises<ref name="Byl et al. (2009)" />
*Ergonomic changes at the instrument (Musician's dystonia)
*Behavioral training<ref name="Berque et al. (2010)">Berque P, Gray H, Harkness C, McFadyen A. [https://www.ingentaconnect.com/content/scimed/mppa/2010/00000025/00000004/art00003 A combination of constraint-induced therapy and motor control retraining in the treatment of focal hand dystonia in musicians]. Medical problems of performing artists. 2010 Dec 1;25(4):149-61.</ref><ref name="Byl et al. (2009)" />


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== Differential Diagnosis<br>  ==
*Paroxysmal dystonia: this presents as discrete episodes of abnormal movements lasting from minutes to hours, with intervening periods of normalcy<ref>Demirkiran M, Jankovic J: Paroxysmal dyskinesias: clinical features and classification. Ann Neurol 1995; 38:571-579</ref>.
*<span>Dopa-responsive dystonia: this is characterized by diurnal variation of dystonic movements, with improvement in the morning and worsening in the afternoon<ref>Ichinose H, Ohye T, Takahashi E, et al: Hereditary progressive dystonia with marked diurnal fluctuation caused by mutations in the GTP cyclohydrolase I gene. Nat Genet 1994; 8:236-242</ref>. It is linked to chromosome 14, which is involved in dopamine synthesis.</span>
*Dystonic tics (which may be associated with obsessive-compulsive disorder):&nbsp;Patients with dystonic tics feel an internal, uncomfortable sensation in the affected body part, and this sensation builds up to an overwhelming "urge" to perform a sustained, tonic tic eg. head turning. Patients often report relief immediately after performing the tic, but this is soon followed by recurrence of the urge to perform the tic again.<br>
*Iatrogenic causes: Dopamine receptor-blocking medications, eg. neuroleptics and phenothiazine-based antiemetics, can produce an acute dystonic reaction from a single dosage, or tardive dystonia from chronic usage<ref>Miller LG, Jankovic J: Neurologic approach to drug-induced movement disorders: a study of 125 patients. South Med J 1990; 83:525-532</ref>.
== Recent Related Research (from [http://www.ncbi.nlm.nih.gov/pubmed/ Pubmed])  ==
<div class="researchbox">
<rss>http://www.ncbi.nlm.nih.gov/entrez/eutils/erss.cgi?rss_guid=1bwpplXhiviTrxvO6gyhlwnc47vOkYmGwcp24prWmdmXTR-QFu|charset=UTF-8|short|max=10</rss>
</div>
== References  ==
== References  ==


<references />  
<references />  


[[Category:Neurological_Conditions]] [[Category:Cerebral_Palsy]]
[[Category:Conditions]]  
[[Category:Neurological - Conditions]]
[[Category:Hand]]
[[Category:Cervical Spine]]
[[Category:Cervical Spine - Conditions]]
[[Category:Hand - Conditions]]
[[Category:Hand - Conditions]]

Latest revision as of 23:52, 10 March 2022

Original Editor - Carlos Areia

Top Contributors - Carlos Areia, Kim Jackson, Laura Ritchie, Evan Thomas, Anas Mohamed, Aminat Abolade, Admin, Wendy Walker, Tarina van der Stockt, WikiSysop, Scott Buxton, Naomi O'Reilly and Vidya Acharya

Introduction[edit | edit source]

Dystonia is defined as an involuntary contraction of the agonistic and antagonistic muscles, which can lead to repetitive involuntary movements and/or abnormal positions. This occurs most commonly in the hand and is known as Focal Hand Dystonia.

The affected population includes individuals who require repetitive movements in their regular daily life, with one of the most affected populations being musicians and professional writers.[1] In the European and American populations, Focal Dystonia varies its prevalence between 3 and 29.5 per 100.000 inhabitants.[1][2] With dystonia occurring in musicians, it is estimated that 0.5 -1% of all musicians suffer some form of focal dystonia.[1][3] These figures are highly variable if we individualize each case, depending on the instrument and the effort required with each performance; For example, the difference between a rhythm and a soloist guitar player.

[4]

Mechanism of Injury / Pathological Process[edit | edit source]

Although the pathological process of Focal Dystonia is still classified as idiopathic, increasing evidence suggested a multifactorial etiology[5] (i.e. the interaction between genetic, neuromuscular, auditory, neural adaptative, anatomic, stressful, repetitive, psychosocial, traumatic, among others). An alteration in tactile discrimination was found in dystonic musicians compared to generalized dystonias and healthy controls; this has been related to the superposition of the areas of the cortical representation of the fingers affected in musicians.[1][6] Other etiological mechanisms are also described in the literature, such as the alteration of inhibitory spinal, trunk, and intracortical as well as alterations in sensorimotor integration.[1]

Many triggering factors have been described in the current literature and can be separated into external and internal factors. Extrinsic factors include spatial, temporal, and spatial constraints, depending on the workload of the respective body part and the complexity of the movements used. Intrinsic factors include the need for control, the need for perfectionism, anxiety, local pain, trauma, overuse and the deficit in inhibitory mechanisms. Predisposing factors such as genetics and sex are also important. These triggering factors combined can affect the manifestation of Dystonia.[7]

Clinical Presentation[edit | edit source]

Some examples of Focal Dystonia are Cervical Dystonia (AKA spasmodic torticollis), which causes the neck to twist or tilt, Musician's Dystonia, Writer's Dystonia, Blepharospasm (bilateral, involuntary, synchronous, forceful eye closure) and Spasmodic Dystonia, among others.

The study by Qiyu Chen et al. suggests that the presence of Head Tremors (HT) and its type depend on a patient’s predominant posture (patients with retrocollis were more prone to have HT than patients with anterocollis), age (earlier age of onset compared to patients without HT), and duration (longer disease duration compared to patients without HT)[8]. 

Musician's Dystonia is manifested by a loss of voluntary motor movement in repeatedly trained movements. This is a high disabling pathology that can end a musical career; it can be classified according to the instrument played and the movement extensively performed. Normally it occurs without pain although aching has been described after prolonged spasms.[7] This loss of muscle coordination is often accompanied by a co-contraction of antagonist muscles.[7]

Writer's Dystonia or Writer's cramp can be also be manifested by uncontrollable muscle contractions and abnormal postures of the whole upper limb during writing. Tremor and spasms of the hand can also occur.

Diagnostic Procedures[edit | edit source]

Magnetic Resonance Imaging (MRI) - to exclude stroke or tumours involving the basal ganglia

Blood work to assess ceruloplasmin levels - to rule out Wilson's disease (a disorder of copper metabolism that can produce dystonia and other movement disorders)

Differential Diagnosis[edit | edit source]

  • Paroxysmal dystonia: this presents as discrete episodes of abnormal movements lasting from minutes to hours, with intervening periods of normalcy[9]
  • Dopa-responsive dystonia: this is characterized by a diurnal variation of dystonic movements, with improvement in the morning and worsening in the afternoon[10]; it is linked to chromosome 14, which is involved in dopamine synthesis
  • Dystonic tics (which may be associated with the obsessive-compulsive disorder): patients with dystonic tics feel an internal, uncomfortable sensation in the affected body part, and this sensation builds up to an overwhelming "urge" to perform a sustained, tonic tic, For example, head-turning; patients often report relief immediately after performing the tic, but this is soon followed by recurrence of the urge to perform the tic again
  • Iatrogenic causes: dopamine receptor-blocking medications, For example, neuroleptics and phenothiazine-based antiemetics, can produce an acute dystonic reaction from a single dosage, or tardive dystonia from chronic usage[11]

Outcome Measures[edit | edit source]

Motor control and ADL scales

Medical Management[edit | edit source]

The aim of medical management is to manage muscle contractions and limit deformity

  • Drug management targets neurotransmitters that affect muscle movement and include: Anticholinergics[12], Baclofen and benzodiazepines dopamine related medications. [13]
  • Injection therapy of Botulin Toxin directly into the muscle can reduce, and in many cases stop muscle contractions that cause abnormal postures.[14] They may have side effects such as dry mouth, voice changes and weakness.
  • Surgery may be indicated if the symptoms are severe and have not responded to other interventions. Surgery might involve the insertion of electrodes into the brain which are connected to a generator that is placed into the chest. The generator sends signals to the brain which can control muscle contractions and movement. Another surgical intervention is to sever the nerves that control muscle spasm, this is known as Selective Denervation Surgery.
  • Immobilization, in a study by Priori et al, has been shown to have a positive effects on focal dystonia. The possible rational for improvement is the plastic changes that occur at cortical level. Immediately after immobilisation there were signs of weakness, clumsiness and poor limb control, but these symptoms were temporary and in most cases improved within 4 weeks.[15]

Physiotherapy Management[edit | edit source]

The aim of physiotherapy is to ease symptoms and improve function. There are several approaches and will be dependent on symptoms but the most common interventions are:

  • TENS[16]
  • Sensomotor Training[6]
  • Muscle Strengthening
  • Stretching
  • Relaxation Techniques
  • Home exercises[5]
  • Ergonomic changes at the instrument (Musician's dystonia)
  • Behavioral training[17][5]
[18]

References[edit | edit source]

  1. ↑ 1.0 1.1 1.2 1.3 1.4 Aránguiz R, Chana-Cuevas P, Alburquerque D, León M. Focal dystonia in musicians. Neurología (English Edition). 2011 Jan 1;26(1):45-52.
  2. ↑ Defazio G, Abbruzzese G, Livrea P, Berardelli A. Epidemiology of primary dystonia. The Lancet Neurology. 2004 Nov 1;3(11):673-8.
  3. ↑ Jabusch HC, Zschucke D, Schmidt A, Schuele S, Altenmüller E. Focal dystonia in musicians: treatment strategies and long‐term outcome in 144 patients. Movement disorders: official journal of the Movement Disorder Society. 2005 Dec;20(12):1623-6.
  4. ↑ Associated Press. Musician Billy McLaughlin Outwits Focal Dystonia. Available from: http://www.youtube.com/watch?v=cNOkvG-15wA [last accessed 29/08/16]
  5. ↑ 5.0 5.1 5.2 Byl NN, Archer ES, McKenzie A. Focal hand dystonia: effectiveness of a home program of fitness and learning-based sensorimotor and memory training. Journal of Hand Therapy. 2009 Apr 1;22(2):183-98.
  6. ↑ 6.0 6.1 Byl NN, Nagajaran S, McKenzie AL. Effect of sensory discrimination training on structure and function in patients with focal hand dystonia: a case series. Archives of physical medicine and rehabilitation. 2003 Oct 1;84(10):1505-14.
  7. ↑ 7.0 7.1 7.2 Altenmüller E, Jabusch HC. Focal dystonia in musicians: phenomenology, pathophysiology, triggering factors, and treatment. Medical Problems of Performing Artists. 2010 Mar 1;25(1):3-9.
  8. ↑ Chen Q, Vu JP, Cisneros E, Benadof CN, Zhang Z, Barbano RL, Goetz CG, Jankovic J, Jinnah HA, Perlmutter JS, Appelbaum MI. Postural directionality and head tremor in cervical dystonia. Tremor and Other Hyperkinetic Movements. 2020;10.
  9. ↑ Demirkiran M, Jankovic J. Paroxysmal dyskinesias: clinical features and classification. Annals of Neurology: Official Journal of the American Neurological Association and the Child Neurology Society. 1995 Oct;38(4):571-9.
  10. ↑ Ichinose H, Ohye T, Takahashi EI, Seki N, Hori TA, Segawa M, Nomura Y, Endo K, Tanaka H, Tsuji S, Fujita K. Hereditary progressive dystonia with marked diurnal fluctuation caused by mutations in the GTP cyclohydrolase I gene. Nature genetics. 1994 Nov;8(3):236-42.
  11. ↑ Miller LG, Jankovic J. Neurologic approach to drug-induced movement disorders: a study of 125 patients. Southern medical journal. 1990 May 1;83(5):525-32.
  12. ↑ Fahn S, Burke R, Stern Y. Antimuscarinic drugs in the treatment of movement disorders. Progress in brain research. 1990 Jan 1;84:389-97.
  13. ↑ Termsarasab P, Thammongkolchai T, Frucht SJ. Medical treatment of dystonia. Journal of clinical movement disorders. 2016 Dec;3(1):1-8.
  14. ↑ Ceballos-Baumann AO, Sheean G, Passingham RE, Marsden CD, Brooks DJ. Botulinum toxin does not reverse the cortical dysfunction associated with writer's cramp. A PET study. Brain: a journal of neurology. 1997 Apr 1;120(4):571-82.
  15. ↑ Priori A, Pesenti A, Cappellari A, Scarlato G, Barbieri S. Limb immobilization for the treatment of focal occupational dystonia. Neurology. 2001 Aug 14;57(3):405-9.
  16. ↑ Tinazzi M, Zarattini S, Valeriani M, Stanzani C, Moretto G, Smania N, Fiaschi A, Abbruzzese G. Effects of transcutaneous electrical nerve stimulation on motor cortex excitability in writer's cramp: neurophysiological and clinical correlations. Movement disorders: official journal of the Movement Disorder Society. 2006 Nov;21(11):1908-13.
  17. ↑ Berque P, Gray H, Harkness C, McFadyen A. A combination of constraint-induced therapy and motor control retraining in the treatment of focal hand dystonia in musicians. Medical problems of performing artists. 2010 Dec 1;25(4):149-61.
  18. ↑ Dr. Larry Santora. Physical therapy for focal hand dystonia. Available from: http://www.youtube.com/watch?v=Ihew0-BAkC8 [last accessed 29/08/16]
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