Preferred muscles in cervical dystonia.

The classification of abnormal posture and the assessment of the affected muscles in cervical dystonia (CD) have changed in recent years. To determine the frequency of injected muscles, we studied 306 patients with CD. The mean age was 55.5 ± 13.1 years (range 21-90), 67% were female. Splenius capitis was the most commonly injected muscle (83%), followed by sternocleidomastoid (79.1%), and trapezius muscles (58.5%). The three next most common were the levator scapulae, semispinalis capitis, and obliquus capitis inferior muscles. The study shows that the most commonly injected muscles have remained unchanged over the past few decades, although the concept has changed. However, several new muscles have been added that were previously never, or hardly ever, considered.