• Placement of the injecting needle [ Time Frame: the day of the inclusion ]
  Assessment of the accurate placement of the injecting needle within the target muscle by ultrasonography in patients injected by the clinical targeting method (number and percent of discordances)
• GCI-I (Clinical Global Impressions - Improvement) patient scale [ Time Frame: 1 month after inclusion ]
  Variation of the GCI-I (Clinical Global Impressions - Improvement) patient scale :

  1. = Very much improved : nearly all better; good level of functioning; minimal symptoms; represents a very substantial change
  2. = Much improved : notably better with significant reduction of symptoms; increase in the level of functioning but some symptoms remain
  3. = Minimally improved : slightly better with little or no clinically meaningful reduction of symptoms. Represents very little change in basic clinical status, level of care, or functional capacity
  4. = No change : symptoms remain essentially unchanged
  5. = Minimally worse : slightly worse but may not be clinically meaningful; may represent very little change in basic clinical status or functional capacity
  6. = Much worse : clinically significant increase in symptoms and diminished functioning
  7. = Very much worse : severe exacerbation of symptoms and loss of functioning
• TWSTRS-2 (Toronto Western Spasmodic Torticollis Rating Scale) : pain scale only [ Time Frame: 1 month after inclusion ]
  Variation of the TWSTRS-2 (Toronto Western Spasmodic Torticollis Rating Scale) : pain scale only Total score = 0 (no pain) to 40 (maximal pain)
• TWSTRS-PSYCH (Toronto Western Spasmodic Torticollis Rating Scale - Psychiatric) scale [ Time Frame: 1 month after inclusion ]
  Variation of the TWSTRS-PSYCH (Toronto Western Spasmodic Torticollis Rating Scale - Psychiatric) scale Total score = 0 (no psychiatric disorders) to 24 (important psychiatric disorders)
• Rate of Adverse Events [ Time Frame: 1 month after inclusion ]
  Adverse events related to the botulinum toxin injection (pain, swallowing disorders, hematoma, muscular weakness, dry mouth)

Botulinum toxin injections are the treatment of choice for cervical dystonia. Even if this treatment is successful for most of the patients, partials or completes failures still remained.

Usually, botulinum toxin injections are realized by clinical localization techniques (observation and palpation of target muscles). The use of Ultrasonography to guide injections of Botulinum toxin has theoretical benefits (as an improved precision, an improved reproducibility, the targeting of deep-seated muscles, and a lower risk of adverse events) but its interest has never been demonstrated.

Open label non-randomised controlled clinical trial comparing clinical localization techniques and ultrasonography to guide injections of Botulinum toxin A.

The primary outcome is to compare both techniques of injection regarding to the health impact of cervical dystonia (CDIP-58) measured 1 month after injection.

The results of this clinical trial will help the clinician to decide which strategy of injection is the most effective in terms of benefit/risk ratio to treat the cervical dystonia.

• Procedure: Clinical targeting
  The intervention consists of the injection of botulinum toxin A into muscles targeted by a clinical localization method (observation and palpation of target muscles)
• Procedure: Ultrasonography targeting
  The intervention consists of the injection of botulinum toxin A into muscles by ultrason-guided method

• Experimental: Clinical targeting
  Clinical localization method (observation and palpation of target muscles)
  Intervention: Procedure: Clinical targeting
• Experimental: Ultrasonography targeting
  Ultrason-guided method
  Intervention: Procedure: Ultrasonography targeting

Inclusion Criteria:

• Patient older than 18 years old
• Focal idiopathic cervical dystonia treated by injections of Botulinum toxin type A (onabotulinumtoxinA, Botox® ; abobotulinumtoxinA, Dysport® ; or incobotulinumtoxinA, Xeomin®).
• Patient who have previously received at least 3 cycles of botulinum toxin A injections in this specific indication
• Injections realized with clinical targeting exclusively or ultrasonography targeting exclusively
• Patient who is not opposed to its participation in this study
• Patient affiliated to the Sécurité Sociale
• Patient able to comply with study procedures and study duration

Exclusion Criteria:

• Woman pregnant, woman of childbearing age not taking effective contraception or breastfeeding

• Contraindication of botulinum toxin injections as :

  • Hypersensivity to the botulinum toxin A or to an excipient of the commercialized treatment (onabotulinumtoxinA, Botox® ; abobotulinumtoxinA, Dysport® ; incobotulinumtoxinA, Xeomin®)
  • Generalized muscular activity disorder (Myasthenia gravis, Lambert-Eaton syndrome)
  • Infection or inflammation of the injection site
• Concomitant treatment that can interact with botulinum toxin A or modify the function of the neuromuscular synapse junction (anticholinergics, curare and other myorelaxing agents, Aminoglycosides, amino-4-quinolines)
• Documented resistance to the botulinum toxin A
• Inability to receive the information, inability to participate to the all study duration, refusal to sign the consent
• EMG-guided botulinum toxin injections