This clinical trial is focused on studying a condition known as cervical dystonia. This is a disorder where there is abnormal muscle activity in the neck area, leading to unusual head positions such as twisting, tilting, and tremors. The primary treatment for cervical dystonia involves injections of botulinum toxin type A, which helps reduce the abnormal muscle activity by temporarily weakening the targeted muscles.

The purpose of this study is to explore the presence of abnormal muscle activity in the back muscles of individuals with cervical dystonia. In the second phase, the study will investigate the effectiveness and possible side effects of botulinum toxin injections in the back muscles for those who show abnormal activity in this area. The study will use different formulations of botulinum toxin, including Botox and Xeomin, which are administered through intramuscular injections. Some participants may receive a placebo as part of the study design.

Participants will undergo a series of assessments to monitor changes in the severity of their dystonia. The study will take place over a period of several months, with regular follow-up visits to evaluate the treatment’s impact and any side effects. The goal is to better understand how botulinum toxin can be used to manage symptoms in patients with cervical dystonia who also have abnormal back muscle activity.