Author(s): Katharine Alter, MD, Kevin J Cipriano, MD, Jared D Astrow, DO, Rajit Banerjee, BS
Originally published: May 7, 2021 Last updated: May 7, 2021
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Disease/ Disorder

Definition

Cervical Dystonia (CD) is an adult-onset focal dystonia presenting with pain and involuntary cranio-cervical muscle activation leading to abnormal movements or postures (often twisting nature) affecting the head, neck, and or chin. Common presentations include Torticollis/caput Anterocollis/caput, Laterocollis/caput, Retrocollis/caput or combined postures determined by specific muscles involved.

Etiology

The recently revised recommendations for Classifications of Dystonia is based on two Axes:

  1. Axis I or Clinical features: Age at onset, distribution, temporal pattern, coexistence of other movement disorders or neurological manifestations
  2. Axis II or Etiology: Nervous system pathology, Heritability and idiopathic with several subcategories in each group 1,2

Epidemiology including risk factors and primary prevention

Adult-onset focal dystonia is the most frequent form of isolated or idiopathic dystonia with CD being the most frequently documented type of focal dystonia. Prevalence of CD varies greatly from 2.3/100,000 to 390/100,000. These wide ranges are explained by inclusion of generalized dystonia or regional differences. Numbers are also likely under-reported due to delayed diagnosis. Females are more affected than males (1.4:1), with males having an earlier age of onset (39.2 vs 42.9 years). Risk factors for primary CD include certain genes (GNAL, THAP1, CIZ1, ANO3) and inherited causes such as DYT23.3

Patho-anatomy/physiology

The cause or causes of dystonia are not well established, and in many patients traditional neuroimaging studies are normal. Investigations have suggested potential causes including:

  • Abnormalities in the brain sensori-motor systems potential pathophysiologic mechanisms of dystonia. 
  • Damage to brain regions in the thalamus, brainstem, parietal lobe and cerebellum, with the basal ganglia.
  • Alterations in CNS inhibitory pathways
  • Disruptions in the various steps in dopamine synthesis or nigrostriatal dopamine neuron function ultimately affecting signaling in basal ganglia circuits.4

Advanced In-vivo neuro imaging, such as PET or fMRI have revealed the following abnormalities in the various types of dystonias: basal ganglia volume expansion, altered dopamine D2 levels, increase in gray matter in sensory motor cortex, abnormal levels of activity in the premotor cortices, sensorimotor cortex, and supplemental motor areas during motor tasks.5 These findings suggest abnormalities in structure, integration processing, and loss of inhibition mediated by GABA levels. Despite similar imaging characteristics across various forms of dystonia, differing levels of Dopamine D2 have been demonstrated between types.

CD is the most common idiopathic dystonia. Evidence implicating specific regions of the nervous system involved is lacking and disease progression and trajectory varies.

  1. Age of presentation
    • Adult onset (typically age 40-60 years)
    • When onset is in infancy or childhood, secondary causes should be investigated
  2. Symptoms vary over time and disease progression is poorly understood but;
    • May get worse with stress or excitement
    • May get better with sensory tricks (i.e. touching cheek or back of the head) Figures 1a. 1b.
  3. Small percentage have spontaneous recovery. This recovery is often temporary lasting days to years with < 1% of affected individuals having permanent recovery
  • Figure 1a Right Torticollis
  • Figure 1b Torticollis response to
    sensory trick

Specific Anatomical Considerations Based on Clinical Presentation

 Ipsilateral  Contralateral  Bilateral
Torticollis and/or Torticaput Figure 1a, 2aM. levator scapulae (M) M. splenius cervicis/capitis (M)  M. sternocleidomastoid (M) M. semispinalis cervicis/capitis (S)  N/A
Laterocollis and/or Laterocaput Figure 2a  M. semispinalis cervicis (M) M. levator scapulae (M) M. scalenus medius (S) M. longissimus cervicis (S)  N/AN/A
Anterocollis and/or Anterocaput Figure 2a  N/AN/AM. levator scapulae (M) M. scalenus medius (M) M. Longus colli/capitis (M)  
Retrocollis and/or Retrocaput  N/AN/AM. semispinalis cervicis (M) M. rectus capitis major (S)  
Anterocollis and Retrocaput  N/AN/AM. sternocleidomastoid (M)  
M=Main, S=Secondary muscle(4)

Specific secondary or associated conditions and complications

Many associated conditions can cause acquired or secondary cervical dystonia including:

  1. Infectious: Viral encephalitis
  2. Metabolic: Wilson’s disease, mitochondrial
  3. Neurodegenerative: Parkinson’s, Huntington’s, pantothenate kinase associated neurodegeneration
  4. Toxic: medication exposure (neuroleptics, anticholinergics), mitochondrial encephalopathies
  5. Trauma: cervical injuries, whiplash, concussion

Complications of CD include: cervical spine arthritis, nerve root compression, cervical stenosis and cervical myelopathy.

Essentials of Assessment

History

Important information:

  1. Onset: Acute vs insidious, age of onset
  2. Head or neck position
  3. Presence of pain and, numbness, or tingling
  4. Associated symptoms/signs
    • High ICP: Vomiting, headache, neurological deficits
    • Infection
  5. History
    • Trauma, infection, or fever
    • Positive family of movement disorders
  6. Medication exposure (i.e. anticholinergics)
  7. Prior treatment (benzodiazepines, baclofen, botulinum toxin)

Physical examination

Musculoskeletal: neck/head/chin position or posture including: tilt; rotation, flexion/extension, tremor, asymmetry of face, shoulder positioning, atrophy/hypertrophy or weakness. Evaluation of other regions: upper and lower limbs including; bony or muscular tenderness to palpation; cervical ROM

Neurological: DTR, muscle tone, resistance to movement (rigidity/spasticity), cranial nerves, primitive reflexes, numbness/tingling/weakness (i.e. brachial plexus injury), mirror dystonia, motor control, cognitive assessment.

HEENT: Vision screen (visual field defects or nystagmus), lymph nodes, pharyngeal inflammation

Cardiorespiratory: chest pain, tachypnea, wheezing, symmetrical thoracic cage expansion and coloration

Gastrointestinal: Difficulty swallowing, regurgitation

Integumentary: Signs of pressure or trauma

Clinical functional assessment: mobility,
self-care cognition/behavior/affective state

Detailed assessment of:

  • Cervical Passive and active ROM using an arthrodial protractor
  • Observation of postures and movements with eyes open and closed
  • Presence of a “geste antagoniste” or sensory trick
  • Working capacity and sleep quality
  • Psychiatric comorbidities
    • Depression
    • Anxiety

Laboratory studies

No specific studies are recommended for all patients with CD. Investigation should be based on history and associated findings:

  • CBC along with gram stain or culture if infectious
  • Medication levels 
  • Genetic testing
  • Serum ceruloplasmin and copper levels
  • Histopathologic studies of masses with fine needle aspiration cytology if imaging is inconclusive

Imaging

No specific imaging test confirms the diagnosis of CD. Cervical radiographs an or MRI may be indicated in some patients. Electrodiagnostic testing in some patients based on presentation to rule out potential treatable causes.

Imaging based guidance for botulinum toxin (BoNT) injections is recommended by many clinicians.

  1. Ultrasound is preferred imaging-based guidance method and provides information about:
    • Localized anatomy, muscle depth, size, location, size, and morphology
    • Identifies safe path to target
  2. Ultrasound is often combined with EMG guidance as EMG provides information about
    • A muscle target’s potential contribution to movements or postures
      1. Level of muscle activity or absence of activity
    • Presence of r compensatory activation or tremulous activation

When determining BoNT injection pattern, a muscle or muscles are determined by knowledge of functional anatomy and further by EMG and ultrasound studies. Clinicians must be skilled in interpreting EMG activity to discriminate between dystonic activation and antagonistic or compensatory muscle activation.7,8,9

Supplemental assessment tools

Additional exam tools:

    Physical Exam:

  • Palpation of muscles to identify hypertrophy
  • In the case of suspected infantile onset congenital torticollis (CMT) as a cause of an abnormal neck position in an adult (rather than CD) assessment clues may include
    • Presence of a pseudotumor or “olive” in the SCM muscle
    • SCM muscle atrophy rather than hypertrophy.
    • Asymmetry of the face and head for plagiocephaly
    • History of congenital hip dysplasia which increases the likelihood of CMT10

Early prediction of outcomes

N/A

Environmental

A few case-control studies suggest a relationship between prior neck-trunk trauma and CD. Additional studies report a higher incidence of idiopathic scoliosis in patients with CD compared to controls and that individuals with a history of cervical trauma were more likely to develop adult onset CD.11

Social role and social support system

The physician should inquire about the patient’s function and impact of CD on ADLs, domestic, avocational and vocational responsibilities, and participation in social/family activities. Educating the patient’s family on the impact of CD to enhance their understanding of the condition is important for providing support to the patient.

Professional issues

Some studies have shown higher levels of social isolation/phobia, anxiety, and depression in patients with CD. Further investigation and research is warranted into the etiology of these symptoms and their contribution to the functional limitations and quality of life of patients with CD. 12,13

Rehabilitation Management and Treatments

Available or current treatment guidelines

The treatment of choice for the vast majority of patients with CD, regardless of etiology, is injection of botulinum toxin (BoNT). Other interventions or medications may be offered to patients who fail to respond to BoNT.

  1.  BoNT: Injection of BoNT is considered first-line treatment. Both BoNT serotype-A (abobotulinumtoxinA, incobotulinumtoxinA, onabotulinumtoxinA) and serotype-B (rimabotulinumtoxinB) carry US FDA approval for treatment of CD. FDA approvals for additional products are likely.  BoNT- A is reported to have a slightly better side effect profile compared to B.
  2. Other treatments:
    • Oral medications: For patients with suspected genetic causes of CD a trial of dopamine is indicated. Other than this, the use of oral medications is typically limited to use in patients who remain symptomatic despite optimization of BoNT.  Options include anticholinergics, dopaminergic or dopamine blocking agents. A positive response to oral medications is low and or variable and   often limited by side effects. Oral medications can also be used in between BoNT injections which is typically performed every 3 months.
    • Surgical Procedures
      •  Deep Brain Stimulation (DBS): Stimulation of the globus pallidus internus or subthalamic nucleus is an “off-label” indication for DBS. It may be effective for some patients with intractable CD.  However, while the efficacy and safety profile of DBS is well described for “on label” indications additional studies are required to establish this for CD.
      • Deafferentation surgery which was performed in past decades is now uncommonly recommended.
    • Physiotherapy; The evidence for the efficacy of PT for CD is limited. This may be in part due to limited expertise in treating this condition.
    • Bracing: Soft cervical collars are not helpful because they are rapidly compressed by the involuntary postures. Also, patients often report being “choked” by a collar. Some patients report benefit from part-time use of a rigid collar for specific activities (watching TV, reading, cooking).
  3. Treatment in patients with acquired or secondary CD: Treatment should focus on the underlying cause or causes.14

At different disease stages

  • The vast majority of patients with CD are diagnosed when the condition is chronic, not during the acute or sub-acute phase
  • CD is typically a chronic condition and rarely resolves. However, a patient’s symptom severity and pattern of muscle involvement may vary or change over time. Therefore, frequent reassessments are needed to provide optimal treatment of the patient’s and to assess for secondary problems such as contractures, cervical spine degeneration and new onset neurological problems such as a myelopathy or radiculopathy.

Coordination of care

There is no universal treatment algorithm for all patients or CD subtypes and CD management must be individualized. It is critical that clinicians first establish the correct diagnosis including potential reversible causes. The next step is recognizing the clinical pattern and establishing a treatment plan including BoNT injection pattern and dose.2

Patient & family education

Patients should be reassured that CD is a treatable condition and most patients will have symptomatic improvement with BoNT therapy. They should be referred to the Dystonia Medical Research Foundation and other sites for education and support. They should also be advised that illness, stress, and pain may increase symptoms.15,16

Measurement of Treatment Outcomes including those that are impairment-based, activity participation-based and environmentally-based

  1. The Pain Numeric Rating Scale (PNRS) can be used to monitor pain improvement post treatment. – Single item questionnaire ranking pain 0-10
  2. The Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) is the most widely used evaluation scale for CD. It can be measured at baseline and prior to subsequent toxin injections.17
  3. Unified Dystonia Rating Scale (UDRS)
  4. 24 question Cervical Dystonia Questionnaire (CDQ-24)6

*Develop a practice specific pre/post injection tool with a standardized list of questions to keep consistent evaluation at your clinic.

Translation into Practice:  practice “pearls”/performance improvement in practice (PIPs)/changes in clinical practice behaviors and skills

Clinical Pearls:

  • Recognizing the patient’s clinical pattern is the first step in establishing a treatment plan.
  • Muscles can only move a structure to which it attaches, i.e. muscles that attach to the cervical spine will move the neck, not the head and vise versa. Examples of patterns/muscles;
    • Anterocollis: dystonia in the scalenes, longus capitis, SCM (when acting bilaterally)
    • Anterorcaput: typically caused by dystonia in the longus capitis.
  • Pre and post treatment photos/videos help establish the pattern and response to treatment Figures 2a. 2b.
  • Supplemental guidance with EMG will enhance identification of muscles requiring treatment. The use of US provides useful information including depth and location and safe path to the target. Many expert clinicians recommend combined US+EMG guidance.
  • Figure 2a. R torticaput and
    R laterocollis and anterocollis
  • Figure 2b. 4 weeks post
    botulinum toxin injection

Cutting Edge/ Emerging and Unique Concepts and Practice

  1. Microcurrent Therapy
    • Low-intensity current applied superficially
    • Multiple studies showed efficacy of shorter treatment duration and improved ROM when used in conjunction with therapeutic exercise and ultrasound
  2. Soft tissue mobilization
  3. Kinesiology Taping (KT)
    • Stretchable tape supporting muscles providing sensory feedback
    • Mixed findings on KT efficacy when used as a supplemental intervention. 
  4. Shear wave Elastography as a potential diagnostic aid
  5. Dry Needling/Acupuncture
  6. Other Investigative Injectable Agents
  7. RFA/Laser/ECSWT

Gaps in the Evidence- Based Knowledge

Additional studies are required to establish:

  •  the cause or causes of idiopathic CD
  • Efficacy of DBS and or disease modifying therapies
  • Whole genome sequencing on CD patients may point to more specific mutations related to CD

References

  1. Albanese A, Bhatia K, Bressman SB, Delong MR, Fahn S, Fung VS, Hallett M, Jankovic J, Jinnah HA, Klein C, Lang AE, Mink JW, Teller JK. Phenomenology and classification of dystonia: a consensus update. Mov Disord. 2013 Jun 15;28(7):863-73. doi: 10.1002/mds.25475. Epub 2013 May 6. PMID: 23649720; PMCID: PMC3729880.
  2. Jinnah HA. The Dystonias. Continuum (Minneap Minn). 2019 Aug;25(4):976-1000. doi: 10.1212/CON.0000000000000747. PMID: 31356290.
  3. Norris SA, Jinnah HA, Espay AJ, Klein C, Brüggemann N, Barbano RL, Malaty IA, Rodriguez RL, Vidailhet M, Roze E, Reich SG, Berman BD, LeDoux MS, Richardson SP, Agarwal P, Mari Z, Ondo WG, Shih LC, Fox SH, Berardelli A, Testa CM, Cheng FC, Truong D, Nahab FB, Xie T, Hallett M, Rosen AR, Wright LJ, Perlmutter JS. Clinical and demographic characteristics related to onset site and spread of cervical dystonia. Mov Disord. 2016 Dec;31(12):1874-1882. doi: 10.1002/mds.26817. Epub 2016 Oct 18. PMID: 27753188; PMCID: PMC5154862.
  4. Jinnah, Hyder & Albanese, Alberto. (2014). The New Classification System for the Dystonias: Why Was It Needed and How Was It Developed?. Movement Disorders Clinical Practice. 1. 10.1002/mdc3.12100.
  5. Breakefield, Xandra & Blood, Anne & Li, Yuqing & Hallett, Mark & Hanson, Phyllis & Standaert, David. (2008). The pathophysiological basis of dystonia. Nature reviews. Neuroscience. 9. 222-34. 10.1038/nrn2337.
  6. Tatu L, Jost WH. Anatomy and cervical dystonia : “Dysfunction follows form”. J Neural Transm (Vienna). 2017 Feb;124(2):237-243. doi: 10.1007/s00702-016-1621-7. Epub 2016 Sep 13. PMID: 27624726.
  7. Katschnig-Winter P, Enzinger C, Bohlsen D, Magyar M, Seiler S, Hofer E, Franthal S, Homayoon N, Kögl M, Wenzel K, Deutschmann H, Fazekas F, Schmidt R, Schwingenschuh P. Minor Structural Differences in the Cervical Spine Between Patients With Cervical Dystonia and Age-Matched Healthy Controls. Front Neurol. 2020 May 29;11:472. doi: 10.3389/fneur.2020.00472. PMID: 32547481; PMCID: PMC7272577.
  8. Alter KE, Karp BI. Ultrasound Guidance for Botulinum Neurotoxin Chemodenervation Procedures. Toxins (Basel). 2017 Dec 28;10(1):18. doi: 10.3390/toxins10010018. PMID: 29283397; PMCID: PMC5793105.
  9. Farrell M, Karp BI, Kassavetis P, Berrigan W, Yonter S, Ehrlich D, Alter KE. Management of Anterocapitis and Anterocollis: A Novel Ultrasound Guided Approach Combined with Electromyography for Botulinum Toxin Injection of Longus Colli and Longus Capitis. Toxins (Basel). 2020 Sep 30;12(10):626. doi: 10.3390/toxins12100626. PMID: 33008043; PMCID: PMC7650774.
  10. Sönmez K, Türkyilmaz Z, Demiroğullari B, Ozen IO, Karabulut R, Bağbanci B, Başaklar AC, Kale N. Congenital muscular torticollis in children. ORL J Otorhinolaryngol Relat Spec. 2005;67(6):344-7. doi: 10.1159/000090046. Epub 2005 Dec 1. PMID: 16327275.
  11. Molloy A, Kimmich O, Williams L, Butler JS, Byrne N, Molloy F, Moore H, Healy DG, Lynch T, Edwards MJ, Walsh C, Reilly RB, O’Riordan S, Hutchinson M. An evaluation of the role of environmental factors in the disease penetrance of cervical dystonia. J Neurol Neurosurg Psychiatry. 2015 Mar;86(3):331-5. doi: 10.1136/jnnp-2014-307699. Epub 2014 Jun 24. PMID: 24963124.
  12. Ceylan D, Erer S, Zarifoğlu M, Türkeş N, Özkaya G. Evaluation of anxiety and depression scales and quality of LIFE in cervical dystonia patients on botulinum toxin therapy and their relatives. Neurol Sci. 2019 Apr;40(4):725-731. doi: 10.1007/s10072-019-3719-9. Epub 2019 Jan 18. PMID: 30659417.
  13. Tomic S, Petkovic I, Pucic T, Resan B, Juric S, Rotim T. Cervical dystonia and quality of life. Acta Neurol Belg. 2016 Dec;116(4):589-592. doi: 10.1007/s13760-016-0634-1. Epub 2016 May 2. PMID: 27138215.
  14. Crowner BE. Cervical dystonia: disease profile and clinical management. Phys Ther. 2007 Nov;87(11):1511-26. doi: 10.2522/ptj.20060272. Epub 2007 Sep 18. PMID: 17878433.
  15. Dystonia Medical Research Foundation, 8 Jan. 2021, www.dystonia-foundation.org/.
  16. “Dystonias Fact Sheet.” National Institute of Neurological Disorders and Stroke, U.S. Department of Health and Human Services, www.ninds.nih.gov/disorders/patient-caregiver-education/fact-sheets/dystonias-fact-sheet#3257_1.
  17. Charles, P.D., Manack Adams, A., Davis, T., Bradley, K., Schwartz, M., Brin, M.F. and Patel, A.T. (2016), Neck Pain and Cervical Dystonia: Treatment Outcomes from CD PROBE (Cervical Dystonia Patient Registry for Observation of OnabotulinumtoxinA Efficacy). Pain Pract, 16: 1073-1082. https://doi.org/10.1111/papr.12408

Author Disclosures

Katharine Alter, MD
Nothing to Disclose

Kevin J Cipriano, MD
Nothing to Disclose

Jared D Astrow, DO
Nothing to Disclose

Rajit Banerjee, BS
Nothing to Disclose