Congenital muscular torticollis is an asymmetrical deformity of the head and neck in which the head is tilted toward the side with the shortened muscle and the chin rotated towards the opposite side. Congenital muscular torticollis is caused by unilateral contracture of the sternocleidomastoid muscle.
The term torticollis is derived from two Latin words, tortus, meaning “twisted,” and collum, meaning “neck”.
Wryneck is a lay term is used to describe torticollis arising from any cause.
The condition is more common in girls than in boys.
The right side is involved in about 75 percent of cases of congenital muscular torticollis.
Etiology of Congenital Muscular Torticollis
The immediate cause of the deformity in congenital muscular torticollis is fibrosis within the sternocleidomastoid muscle, which subsequently contracts and shortens.
Sternocleidomastoid is a muscle that arises from clavicle [clavicular head and sternum [sternal head] and attaches at the mastoid process behind the ear. The muscle is shown in the figure in a circle.
The exact pathogenesis of the fibrosis is unknown. Edema, degeneration of muscle fibers and acute inflammation lead to fibrosis. Birth injury, occlusion of arterial supply are postulated as possible causes.
Intrauterine malposition is commonly associated with the deformity and local ischemic process resulting from intrauterine malposition could be a factor too.
Presentation of Congenital Muscular Torticollis
The deformity may be present at birth or it may become evident about the second or third weeks.
The head is tilted towards the side of the affected muscle, and the chin is rotated to the opposite side. Rotation of the neck to the side of the deformity and lateral motion to the opposite side [tilting the neck as to touch shoulder with ear] are limited.
On palpation, a hard, nontender, fusiform swelling, or tumor, in the sternocleidomastoid muscle may be revealed. Usually, both the sternal and clavicular heads are involved. However, occasionally, only the sternal head is affected. The part of the muscle close to its mastoid attachment is rarely involved.
It gradually enlarges during the ensuing two to four weeks, reaching the size of the distal phalanx of the adult thumb. Then it begins to regress and gradually disappears in two to six months.
If the contracture is not treated secondary deformities of the face and head develop. The face on the side of the contracted muscle becomes flattened because of external pressure. The infant usually sleeps in a prone posture.
Spontaneously, as it is more comfortable, the neck is rotated so that the affected side is down. Ipsilaterally, the face is flattened by remodeling to conform to the bed.
With skeletal growth, asymmetry of the face increase. The levels of the eyes and ears change. This is to accommodate tilt and becomes more pronounced when the head and neck are brought straight in the midline.
Different levels of eyes may lead to strain on eyes due to ocular imbalances. Deformity of the cervical spine may develop. Scoliosis with concavity towards the affected side may develop in lower cervical and upper thoracic spine.
If the deformity is not corrected the soft tissues of the affected side undergo adaptive shortening as growth proceeds. The deep cervical fascia becomes thickened and contracted. The scalenus anterior and medius muscles become shortened. Later, the carotid sheath and the enclosed vessels contract.
In rare cases of double torticollis, in which both sternocleidomastoid muscles are affected, the neck is in the midline but appears short, the chin is elevated, and the face is tilted upward.
Diagnosis of Congenital Muscular Torticollis
Recognition of congenital muscular torticollis is not usually difficult because of the characteristic cordlike contracture of the sternocleidomastoid muscle. The early fusiform tumor may escape notice.
Congenital muscular torticollis should not be confused with postural torticollis which is caused by intrauterine malposture, has a lesser deformity, has no true fibrotic replacement of the sternocleidomastoid muscle and responds quickly to passive manipulative stretching.
Differential Diagnosis of Congenital Muscular Torticollis
- Postural torticollis
- Hemivertebra, cervical-superior dorsal spine
- Unilateral atlanto-occipital fusion
- Klippel-Feil syndrome
- Unilateral congenital absence of sternocleidomastoid muscle
- Pterygium colli
Trauma C1, C2
- Rotatory subluxation
- Cervical lymphadenitis
- Spontaneous hyperemic subluxation of the atlas
- Rheumatoid arthritis
- Visual disturbances
- Cervical spinal cord tumor
- Brain tumor, posterior fossa
Torticollis may be caused by contracture muscles other than the sternocleidomastoid, such as the scalenus anterior and the omohyoid.
Though not required for diagnosis, every patient should have radiograms of the cervical spine made to exclude congenital anomalies of the vertebrae, such as hemivertebrae, unilateral atlanto-occipital fusion, and the Klippel-Feil syndrome
Treatment of Congenital Muscular Torticollis
Treatment of congenital muscular torticollis should be begun as soon as the diagnosis is made. Manipulations consisting of passive stretching of the contracted sternocleidomastoid muscle should be performed by the parents after adequate instruction.
For manipulation, the head is bent laterally so that the ear on the side opposite the shortened muscle approaches the shoulder, then the head is rotated so that the chin approaches the shoulder of the affected side.
During these manipulations, in order to obtain maximum stretching of the sternocleidomastoid muscle, the neck should be in comfortable hyperextended position and counter traction should be applied by holding the ipsilateral shoulder and chest.
An additional method of stretching the sternocleidomastoid muscle is to make use of gravity by placing the infant supine on the mother’s lap with the head hanging into hyperextension. One hand stabilizes the shoulders and chest, and the other hand tilts the head laterally away from the contracted muscle so that the contralateral ear touches the opposite shoulder. The chin is then rotated toward the contracted muscle.
It is important to hold the muscle stretched to the count of 10.
The exercises should be performed 15 to 20 times in each direction, 4 to 6 times a day.
The crib should be turned so that the infant’s unaffected side is against the wall and he will rotate his head to look toward the involved side when his attention is attracted, actively stretching the muscle when reaching and grasping for toys.
Prone posture during sleep should be avoided, as it will aggravate the facial deformities and the contracture.
If the stretching exercises are begun at a very early age and performed faithfully and correctly every day, the deformity and contracture correct and surgery is not required.
Surgery is indicated when the torticollis does not respond to conservative measures up to one year of age [Fibrous cord that replaces the sternocleidomastoid muscle is unlikely to be stretched by manipulation after the age of one year], or in cases in which the condition is neglected until the child is a year old or poor compliance.
Surgery involves muscle release usually on one end of the muscle, called unipolar release. In severe cases, the release may be required in both upper and lower end of the muscle.
The muscle may be divided at either end or at both ends.
An endoscopic approach has also been described for the release of the muscle.
Recently, bipolar release combined with Z-plasty has reported a high rate of success in cases requiring surgical treatment.