2026 Workshop Handout Bundle-W51C - NMUS Anatomy of the Head and Neck for Chemodenervation Procedures

W51C - NMUS Anatomy of the Head and Neck for Chemodenervation Procedures - Alter

Pdf Summary

The presentation reviews functional and ultrasound anatomy relevant to botulinum neurotoxin (BoNT) treatment of cranio-cervical disorders, particularly cervical dystonia. Conditions discussed include focal dystonias, upper motor neuron–related posturing, congenital torticollis, bruxism, and sialorrhea.<br /><br />Safe, effective treatment begins by identifying the patient’s movement pattern and setting individualized goals. Clinicians should distinguish head (“caput”) from neck (“collum”) postures—such as torticaput versus torticollis, or anterocaput versus anterocollis—and consider whether postures are sustained, intermittent, or tremulous. Muscle selection requires understanding prime movers, secondary movers, synergists, and muscles that compensate for dystonia; observed activity alone does not establish that a muscle is the treatment target.<br /><br />The regional anatomy is complex, with layered muscles near vessels, nerves, glands, the airway, and esophagus. Ultrasound can help identify target muscles, assess their size and depth, guide needle placement, and avoid nearby structures. Electromyography may add information about muscle activity. These tools complement—but do not replace—knowledge of anatomy and functional movement patterns.<br /><br />Examples of muscle groups associated with common postures include the sternocleidomastoid, splenius muscles, and obliquus capitis inferior for rotational postures; scalenes, splenius cervicis, and levator scapulae for lateral neck flexion; and longus colli or longus capitis for anterior flexion. Bilateral sternocleidomastoid activity may contribute to anterocollis with retrocaput. Shoulder elevation can involve different muscles depending on scapular position.<br /><br />The recommended process includes assessing dystonia and structural factors such as contractures, selecting targets and dose, planning a safe injection path, and arranging follow-up—typically at four to six weeks.

Keywords

botulinum neurotoxin

cervical dystonia

cranio-cervical disorders

ultrasound anatomy

functional anatomy

dystonia muscle selection

sternocleidomastoid

splenius muscles

EMG guidance

safe injection planning