Objective: To audit the management of cervical dystonia patients with secondary poor responsiveness to BoNT in two regional U.K. neuroscience centres against the British Neurotoxin Network (BNN) guidelines.

Background: Botulinum toxin type A (BoNT-A) is an effective first-line treatment for cervical dystonia but 20-30% of patients discontinue treatment. Poor responsiveness to BoNT-A treatment has multiple causes, including suboptimal muscle selection, injection technique and dosing, and antibodies to BoNT-A. In 2016 the British Neurotoxin Network (BNN) published recommendations for the management of cervical dystonia patients with poor response to BoNT-A treatment [1].

Method: We retrospectively analysed, across two tertiary movement disorder centres, 68 patients with cervical dystonia who met criteria for poor responsiveness to BoNT-A treatment. Data were collected relating to the BNN guidelines using a standardised proforma.

Results: In total 30 patients (44%) improved with adjustment to dose, muscle selection and injection technique. 18 patients were switched to BoNT-B, of which 7 patients (39%) following intervention had a good response to this treatment. Eight patients (12%) were shown to have proven resistance to BoNT-A via either frontalis or neurophysiological testing. In this subgroup 5 patients were switched to BoNT-B, 2 patients were switched to different BoNT-A preparations and 1 patient was referred for DBS. Four patients were deemed to have a good eventual outcome. Overall 36 patients (53%) were referred for DBS, 8 (22%) of whom underwent the procedure.

Conclusion: Our audit shows that careful adjustment of dose, muscle, and injection technique helps a substantial proportion of patients with cervical dystonia presenting with poor response to BoNT-A therapy. Resistance to BoNT-A was not the most common reason for poor response. The BNN recommendations provide a useful framework for improving dystonia treatment.

References: [1] Marion MH, Humberstone M, Grunewald R, Wimalaratna S. British Neurotoxin Network recommendations for managing cervical dystonia in patients with a poor response to botulinum toxin. Pract Neurol 2016;16(4):288-295.

« Back to 2019 International Congress

MDS Abstracts - https://www.mdsabstracts.org/abstract/management-of-poor-response-to-botulinum-toxin-in-cervical-dystonia-a-multicentre-audit/