Abstract
Introduction Cervical dystonia is the most common form of focal dystonia in adults. Both isolated and segmental forms of cervical dystonia respond to stereotactic neurosurgical intervention with either subthalamic nucleus (STN) or globus pallidus internus (GPi) deep brain stimulation (DBS). Whilst the outcomes relating to the improvement in dystonia severity, disability and pain are comparable between GPi and STN targeting, GPi DBS can be complicated by the development of stimulation-induced bradykinesia with reports of secondary failure in dystonia control.
Case We describe the case of a 67-year-old female with a fourteen-year history of medically refractory segmental dystonia (cervical/facial/oromandibular) who underwent bilateral STN DBS insertion, nine years after initial GPi DBS surgery, due to the development of bradykinesia and partial secondary failure of dystonia control. Following the addition of STN electrodes, there was improvement cervical dystonia at one week maintained through early follow up at six weeks. GPi DBS was continued, but at a lower amplitude, with improved gait and reduced stimulation-induced bradykinesia.
Conclusion Various treatment approaches have been described for the management of secondary failure of GPi DBS in cervical dystonia, including botulinum toxin, additional GPi electrodes and STN DBS with, or without, pallidotomy. This case highlights the safety and efficacy of rescue bilateral STN electrode insertion for the management of bradykinesia and partial secondary failure of GPi DBS in segmental cervical dystonia, with early benefit using combined STN and GPi DBS. Longer follow-up in a larger number of patients is required to ensure the long-term effectiveness of this approach.
