The study involves the use of a novel, non-invasive, monitoring device to measure the response to treatment with botulinum toxin injections in 24 (16 Intervention and 8 control) patients with cervical dystonia. A baseline assessment, prior to botulinum treatment,will be structured around validated clinical rating scales for cervical dystonia and questionnaires and the performance of simple neck movements, and will be undertaken while the patient wears a movement sensor attached to the head with an elastic strap. The same assessments will be undertaken at 0, 3, 6, 9 and 12 weeks following treatment to assess response. The patients' treatment will not be affected by their participation in the research. The device readings will then be compared with the clinical ratings to establish whether it might be used as a more sensitive measure of treatment response than clinical assessment alone. This will help clinicians to plan and execute botulinum injections more effectively in future

Inclusion Criteria:

• Male or female participants aged 18 years or older (no upper age limit) and willing and able to provide informed consent.
• Participant is able and willing to comply with the follow-up schedule and protocol.
• Participants diagnosed with cervical dystonia.
• Participant has previously received botulinum toxin therapy for cervical dystonia without adverse side effects OR is naïve to botulinum toxin therapy but is suitable to participate in the investigator's opinion

Exclusion Criteria:

• -Participated in another clinical investigation within 30 days.
• Allergy to device components or botulinum toxin.
• Medical co-morbidities that preclude botulinum toxin therapy.
• Patient is incapable of understanding or responding to the study