Cervical dystonia is a condition that causes the muscles in your neck to tighten or spasm without your control. With cervical dystonia, your head may turn in an unusual way, or it may be forced into an abnormal, uncomfortable position. This condition can be painful and challenging. It is unknown what exactly causes the muscle contractions associated with cervical dystonia. BOTOX® id injected into muscles and used to treat the abnormal head position and neck pain that happens with cervical dystonia.