Congenital Muscular Torticollis

Congenital muscular torticollis is a postural deformity of the neck caused by shortening or fibrosis of one sternocleidomastoid muscle, producing head tilt towards the affected side and chin rotation to the opposite side. It is the commonest cause of torticollis in infants.

Reported prevalence is 0.3 to 2% of newborns. The right side is slightly more often involved. Associated factors are first pregnancy, breech or difficult delivery, intrauterine crowding and male sex.

Associated conditions include positional plagiocephaly, which develops in many, and developmental dysplasia of the hip in a minority.

Pathophysiology.

The exact cause is uncertain. Intrauterine malposition or birth trauma may cause compartment syndrome or ischaemia of the sternocleidomastoid, followed by fibrosis, with a firm mass (fibromatosis colli) in the first weeks.

Persistent shortening restricts rotation and lateral flexion, and asymmetric head position then causes cranial and facial asymmetry.

• Head tilt to the affected side and chin turned to the other side, noted in the first 2 months, with restricted passive neck rotation and lateral flexion.
• A firm, painless sternocleidomastoid mass (pseudotumour) in about a third, often at 2 to 4 weeks of age.
• Positional plagiocephaly, facial asymmetry, preferred feeding side, and asymmetric hip examination.

Red flags.

• Torticollis present at birth with other neurological signs, or beginning after 6 months of age.
• Painful neck, fever, or recent infection or trauma.
• Abnormal eye movements, ptosis, vomiting, or developmental delay.
• Abnormal examination of the hips.

• Clinical diagnosis by history, passive range of movement, palpation and examination of the whole spine, head shape and hips.
• Ultrasound of the neck for the muscle mass and fibrosis if the diagnosis is uncertain.
• Hip ultrasound for infants under 4 to 6 months, or radiograph for older infants, if the examination is abnormal or other risk factors exist.
• Cervical spine radiographs or MRI for atypical presentations, persistent torticollis, or neurological signs.

Differential diagnosis. Klippel-Feil syndrome and other vertebral anomalies, atlantoaxial rotatory subluxation, ocular torticollis (fourth nerve palsy), posterior fossa tumour, cervical infection or lymphadenitis, clavicle fracture, Sandifer syndrome and neuromuscular disease.

• Early physiotherapy with parent taught stretching of the sternocleidomastoid several times daily (passive neck rotation towards the affected side and lateral flexion away from it), positioning, tummy time and handling changes. More than 90% resolve when started in the first 3 months.
• Positional plagiocephaly: reposition, with a moulding helmet for selected moderate to severe cases.
• Botulinum toxin injection into the affected muscle is an option for resistant cases under specialist direction.
• Surgical release (unipolar or bipolar release of the sternocleidomastoid) for persistent restriction after 6 to 12 months of age despite stretching, with good results when done before 4 years.
• After surgery, physiotherapy continues for several months to avoid recurrence.

Monitoring. Range of movement and head shape every 4 to 6 weeks at first, and then every 3 months. Review the hips.

Referral and escalation. Refer to physiotherapy at diagnosis, and to paediatric orthopaedics or neurosurgery for lack of improvement by 6 months, atypical features or a persistent mass.