What is the treatment for cervical dystonia?

Treatment of Cervical Dystonia

Botulinum toxin type A injections are the first-line treatment for cervical dystonia, with recommended doses of 120-240 units for incobotulinumtoxinA (Xeomin) administered every 12 weeks. 1

First-Line Treatment: Botulinum Toxin

Botulinum Toxin Formulations

• OnabotulinumtoxinA (Botox): 135 units recommended, not exceeding 400 units every 84 days 2
• IncobotulinumtoxinA (Xeomin): 120-240 units per treatment 1
• AbobotulinumtoxinA (Dysport): Starting dose of 500 units recommended 2, 3
• RimabotulinumtoxinB (Myobloc): Alternative formulation with similar efficacy 2

Injection Technique

• Target the most affected muscles based on the pattern of dystonia
• Common injection sites include:
  • Sternocleidomastoid (median 25 units of Xeomin)
  • Splenius capitis/semispinalis (median 48 units of Xeomin)
  • Trapezius (median 25 units of Xeomin)
  • Levator scapulae (median 25 units of Xeomin)
  • Scalene muscles (median 20 units of Xeomin) 1
• EMG guidance is recommended for more precise injections and better outcomes 4

Dosing Considerations

• Start with lower doses (e.g., 120 units of Xeomin or 500 units of Dysport) and titrate upward in subsequent sessions if needed 1, 3
• While standard injection intervals are ≥12 weeks, approximately 47% of patients may require reinjection at ≤12 weeks 5
• Use the lowest effective dose at the longest possible interval to maintain responsiveness over time 4

Second-Line and Adjunctive Treatments

Oral Medications

• Nerve-stabilizing agents:
  • Pregabalin
  • Gabapentin
  • Duloxetine 2
• Sodium channel blockers:
  • Carbamazepine (50-200 mg/day)
  • Oxcarbazepine (75-300 mg/day) 2

Rehabilitation Approaches

• Referral to rehabilitation specialists for comprehensive neuromusculoskeletal management
• Manual treatment including mobilization and manipulation of cervical and thoracic spine
• Vestibular rehabilitation if vestibular symptoms are present 2

Follow-up and Monitoring

• Reassess within 1 month after initial treatment to evaluate:
  • Symptom resolution
  • Side effects
  • Need for dose adjustment 2
• Monitor for potential side effects:
  • Dysphagia (difficulty swallowing)
  • Neck weakness
  • Voice changes
  • In rare cases, respiratory difficulties 1

Important Considerations and Precautions

Potential Side Effects

• Dysphagia occurs more frequently with bilateral sternocleidomastoid injections
• Patients with smaller neck muscle mass may be at greater risk for side effects
• Limiting the dose injected into the sternocleidomastoid muscle may decrease dysphagia risk 1

Treatment Failures

• If inadequate response, consider:
  • Adjusting dose
  • Modifying injection sites
  • Switching to another botulinum toxin serotype 2

Contraindications

• Known hypersensitivity to botulinum toxin or excipients
• Caution in patients with pre-existing swallowing or breathing difficulties
• Caution in patients with neuromuscular junction disorders (e.g., myasthenia gravis) 1

Long-Term Efficacy and Safety

• Botulinum toxin remains effective even after 25 years of repeated treatments 6
• Average benefit duration ranges from 88-99 days depending on formulation 6
• Early intervention with botulinum toxin can prevent long-term complications such as contractures and radiculopathy 7