What is the recommended evaluation and treatment approach for an infant with torticollis, including indications for imaging, botulinum toxin injections, and surgical release?

Evaluation and Management of Infant Torticollis

For infants with congenital muscular torticollis (CMT), begin with physical therapy immediately upon diagnosis, reserve ultrasound for cases where diagnosis is uncertain or to guide prognosis, avoid routine MRI imaging, and consider botulinum toxin injection for cases failing conservative therapy before proceeding to surgical release after 12 months of age.

Initial Diagnostic Approach

Clinical Examination Essentials

• Assess for the classic presentation: head tilted toward the affected side with chin rotated to the opposite side 1, 2
• Palpate the sternocleidomastoid muscle (SCM) for a firm fibrous mass (pseudotumor of infancy), which typically appears at 2-3 weeks of age 2
• Evaluate range of motion limitations, particularly lateral neck flexion and rotation 3
• Document any associated plagiocephaly or facial asymmetry, which commonly coexist with positional torticollis 4

Critical Red Flags Requiring Urgent Evaluation

• Rule out ocular causes first: Eye muscle weakness can present as compensatory torticollis 5
• Evaluate for neurological symptoms suggesting spinal cord pathology 5
• Consider inflammatory, orthopedic (cervical spine abnormalities), or neurologic etiologies in the differential diagnosis 1
• Obtain cervical spine radiographs as part of the systematic work-up to exclude bony abnormalities 1

Imaging Strategy

• Ultrasound is the preferred imaging modality when diagnosis is uncertain or to assess prognosis 6
• Ultrasound reveals homogeneous or heterogeneous hyperechoic lesions within the SCM that are diagnostic 6
• The lesion-to-muscle ratio (L/M ratio) on ultrasound predicts surgical need: ratios >62.7% at 1 year correlate with higher surgical rates 6
• Whole-length muscle involvement on longitudinal ultrasound views indicates 34.7% surgical rate versus 6.3% when only middle/lower thirds are involved 6
• MRI of brain and neck is no longer considered cost-effective or necessary in CMT 1

Treatment Algorithm

First-Line Conservative Management (Birth to 12 Months)

• Initiate physical therapy immediately, ideally within the first year of life for optimal outcomes 1, 3
• Implement regular muscle stretching exercises with caregiver education about proper technique 3
• Modify environmental positioning and the child's posture during sleep and activities 3
• Consider molding helmets for associated positional plagiocephaly 4
• The extent of fibrosis naturally decreases from 83.6% at 2 months to 40% beyond 1 year as normal muscle regenerates 6

Intermediate Management: Botulinum Toxin

• For recalcitrant cases failing 6-12 months of intensive physical therapy, botulinum toxin injection into the affected SCM is safe and effective 1, 4
• This approach achieved sufficient improvement in 14 of 15 children (93%) with recalcitrant idiopathic muscular torticollis, avoiding surgical release 4
• Botulinum toxin is particularly valuable for tight but non-fibrotic SCM muscles 4
• Continue physical therapy after injection to maximize benefit 4
• Important caveat: While botulinum toxin is mentioned in ophthalmologic contexts for strabismus-related torticollis 7, one case report documented quadriplegia following spinal manipulation in an infant with torticollis, highlighting the need for careful patient selection and technique 8

Surgical Intervention

• Reserve surgical release for patients presenting after 1 year of age or those failing conservative therapy including botulinum toxin 1, 3
• Unilateral SCM release via bipolar tenotomy is the standard surgical approach 3
• Surgical rates: 16.2% overall in one large series, with higher rates (34.7%) when entire muscle length is involved 6
• Surgery improves range of motion but may not fully correct plagiocephaly, facial asymmetry, or cranial molding, especially in late presentations 1
• Timing is critical: Early detection and physiotherapy minimize surgical risk, but neglected cases require operative intervention to improve quality of life 3

Prognostic Factors

Favorable Indicators (Conservative Management Success)

• Fibrotic lesion limited to lower third of SCM only: 100% resolution without surgery 6
• Treatment initiated within first year of life 1
• L/M ratio <54.5% at 1 year of age 6

Unfavorable Indicators (Higher Surgical Risk)

• Whole-length muscle involvement: 34.7% surgical rate 6
• L/M ratio >62.7% at 1 year of age 6
• Presentation after 1 year of age with persistent head tilt, chin deviation, and limited neck motion 6
• Fibrotic change extending to middle and upper thirds of muscle 6

Key Clinical Pitfalls

The most critical error is missing non-muscular torticollis, which could be life-threatening if inflammatory, neurologic, or orthopedic causes are overlooked 1. Always maintain a broad differential diagnosis and obtain cervical spine imaging when the clinical picture is atypical 1. Conversely, avoid over-imaging with MRI in straightforward CMT cases, as this is not cost-effective 1.