Saturday, March 13, 2021

Torticollis Case File

Posted By: Medical Group - 3/13/2021 Post Author : Medical Group Post Date : Saturday, March 13, 2021 Post Time : 3/13/2021
Torticollis Case File
Eugene C. Toy, MD, Lawrence M. Ross, MD, PhD, Han Zhang, MD, Cristo Papasakelariou, MD, FACOG

CASE 38
A 3-month-old girl is noted by the pediatrician to have a stiff neck for a 2-month duration. The mother states that the neck seems to be pulled to the right. On examination, the baby’s right ear is tilted toward her right side, but her face is turned toward the left. Palpation of the neck reveals a nontender mass of the right anterior neck region.

 What is the most likely diagnosis?
 What is the anatomical structure affected?


ANSWER TO CASE 38:

Torticollis
Summary: A 3-month-old girl’s head seems to be flexed to the right and rotated to the left. Palpation of the neck reveals a nontender mass of the right anterior neck region.

• Most likely diagnosis: Torticollis

• Anatomical structure affected: Sternocleidomastoid muscle (SCM)


CLINICAL CORRELATION
Torticollis is a deformity usually observed in children as lateral flexion and rotation of the head and neck. Congenital torticollis has an incidence of 3 to 5 per 1000 births. It is thought to be due to a fibrosis of the SCM that develops during infancy and causes shortening of the muscle. A mass can be palpated (about the size of an olive) about 66 percent of the time at the SCM. The etiology is unclear, although it may be associated with breech babies or difficult deliveries. As a result, the baby’s head is flexed laterally toward the affected side and rotated contralaterally. Facial asymmetry may be noted. Physical therapy can help in most cases, and surgery is rarely needed.


APPROACH TO:
The Triangle Neck: Anterior

OBJECTIVES
1. Be able to identify surface landmarks of the anterior neck
2. Be able to describe the actions of the SCM


DEFINITIONS
FIBROSIS: Abnormal growth of fibrous connective tissue in response to trauma or infection.

ANTERIOR NECK: Portion of the neck anterior to the trapezius muscle. Two triangles are found within the anterior neck; the anterior triangle, which contains structures anterior to the SCM, and the posterior triangle, which contains structures posterior to the SCM.


DISCUSSION
An important surface landmark on the anterior surface of the neck is the SCM, which divides the anterior neck into anterior and posterior triangles. The superior head of the muscle attaches to the mastoid process of the temporal bone. Inferiorly,

sternocleidomastoid muscle

Figure 38-1. The sternocleidomastoid muscle and anterior neck: 1 = sternocleidomastoid muscle, 2 = trapezius muscle, 8 = splenius capitis, 9 = levator scapulae, 10 = middle scalene, 11 = anterior scalene, 12 = omohyoid muscle. (Reproduced, with permission, from the University of Texas Health Science Center, Houston Medical School.)

the muscle splits to attach separately to the manubrium of the sternum and the clavicle (Figure 38-1).

Contraction of the SCM has two sequelae: rotation of the head to the opposite side–thus, contraction of the right SCM will rotate the nose toward the left; and lateral flexion–constant contraction of a single SCM will frequently result in lateral flexion to the affected side and rotation to the opposite side, sometimes called “wry neck.” Simultaneous contractions of both SCM muscles may contribute to straight flexion of the neck because the rotational movements cancel each other. However, this is not a strong action unless the neck is flexed against resistance. The SCM is innervated by the spinal accessory nerve (CN XI), which also innervates the trapezius muscle.

Other landmarks of the neck include the laryngeal prominence (Adam’s apple) in the midline. This is formed by the superior border of the thyroid cartilage. The external jugular vein is prominent in some people. The external jugular vein arises

from the posterior auricular and retromandibular veins just inferior to the ear and crosses over the SCM into the posterior triangle. Although variable, its usual course is to drain into the internal jugular before it joins with the subclavian vein. The external jugular vein is also a landmark for the great auricular nerve, which crosses the SCM as it ascends from the muscle’s posterior border. Folds of the platysma muscle are observed when the skin over the neck is tensed (as in shaving). This muscle of facial expression is the most superficial muscle of the neck, and it courses just beneath the superficial fascia underlying the skin.


COMPREHENSION QUESTIONS
38.1 A 2-year-old girl is diagnosed with torticollis involving the right SCM. Which of the following describes the most likely anatomical change?
    A. Head flexed forward in the midline
    B. Head rotated to the right
    C. Head rotated to the left
    D. Head extended in the midline plane

38.2 A 24-year-old football player receives a blow to the left skull, and the team physician finds weakness of the left SCM. Which of the following associated findings is most likely to be seen in this patient?
    A. Weakness of the masseter muscle
    B. Decreased sensation of the ipsilateral face
    C. Decreased tearing from the ipsilateral eye
    D. Weakness of the trapezius muscle

38.3 A clinician is palpating the anterior neck of a patient who has been involved in a motor vehicle accident and notes the laryngeal prominence. Which of the following describes the anatomical structure that corresponds to this prominence?
    A. Thyroid cartilage
    B. Cricoid cartilage
    C. Hyoid bone
    D. First tracheal ring


ANSWERS
38.1 C. With torticollis, the SCM is shortened, leading to rotation of the head toward the contralateral side.
38.2 D. The SCM and the trapezius muscle are innervated by the spinal accessory nerve (CN XI), which is at risk in the posterior triangle of the neck.
38.3 A. The laryngeal prominence is produced by the superior border of the thyroid cartilage.


ANATOMY PEARL
 The anterior neck contains structures that lie anterior to the trapezius muscle.
 The SCM divides the anterior neck into anterior and posterior triangles.
 Contraction of the SCM causes rotation of the head to the opposite side and lateral flexion.
 The laryngeal prominence in the midline is formed by the superior border of the thyroid cartilage

References

Gilroy AM, MacPherson BR, Ross LM. Atlas of Anatomy, 2nd ed. New York, NY: Thieme Medical Publishers; 2012:512, 588−589. 

Moore KL, Dalley AF, Agur AMR. Clinically Oriented Anatomy, 7th ed. Baltimore, MD: Lippincott Williams & Wilkins; 2014:989−992, 1007−1008. 

Netter FH. Atlas of Human Anatomy, 6th ed. Philadelphia, PA: Saunders; 2014: plates 27, 29, 128.

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