StimTox-CD study

TP1 Team

SP1: A randomized, sham-controlled trial of pallidal neurostimulation versus botulinum toxin treatment for cervical dystonia (StimTox-CD)

Principle Investigator: Jens Volkmann
Study coordinator: Thorsten Odorfer

The StimTox-CD study has a randomized, prospective, multicentre, double-dummy controlled, doubleblind, parallel-group study design to compare DBS and BoNT A treatment.

Deep brain stimulation of the internal globus pallidus is highly effective for various forms of primary dystonia, but is currently considered a last resort
therapy for severe and medication-refractory segmental or generalized dystonia according to treatment guideline.

The first-line treatment for focal dystonia is selective peripheral denervation through repeated injections of botulinum toxin into dystonic muscles. Cervical dystonia, the most frequent focal dystonia, is a chronic condition with profound impact on quality of life.

Our recent multicenter trial has demonstrated the efficacy and safety of pallidal neurostimulation in a large cohort of patients with cervical dystonia, who had failed on botulinum toxin therapy.

The results encourage us to challenge the role of botulinum toxin in the treatment algorithm for cervical dystonia and to establish deep brain stimulation as an alternative earlier in the disease by demonstrating:

  • superior control of dystonia symptoms by deep brain stimulation compared to best practice of botulinum toxin therapy
  • better health-related quality of life with deep brain stimulation compared to best practice of botulinum toxin therapy
  • acceptable safety of deep brain stimulation

Primary efficacy endpoint:

  • Difference in the TWSTRS total score between the baseline assessement and the assessment at 6 months after surgery

Key secondary endpoint(s):

  • Difference in the Craniocervical Dystonia Questionnaire (CDQ-24) between the baseline assessement and the assessment at 6 months after surgery
  • Change in TWSTRS motor
  • Change in TSUI score
  • Change in SF-36
  • Frequency and severity of therapy related adverse events of BoNT A injection+sham Stim or DBS+sham injection