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Basics ⬇

Author: SaraNeal, MD, MA, CAQSM

Description

  • CCSA can increase risk for myelopathy from cervical stenosis or instability.
  • Specific abnormalities by cervical spine level include craniovertebral junction.
  • Atlantoaxial and lower cervical spine vertebral fusions

Epidemiology

  • Congenital cervical spine abnormalities are rare but can predispose to myelopathy.
  • Often discovered incidentally
  • Frequently associated with other congenital defects such as cardiac, retinal, or renal abnormalities

Prevalence

  • Unknown because many are asymptomatic
  • Prevalence within certain syndromes may be high (e.g., Klippel-Feil, Morquio, and trisomy 21 [Down] syndromes).
  • Estimated incidence of CCSA is 1 in 40,000 to 42,000 live births with slight female predominance (1).
  • Lower cervical spine fusion is associated with some syndromes (most common is Klippel-Feil syndrome).

Etiology and Pathophysiology

  • Abnormalities in the cervical spine cause altered mechanical transfer of axial loading forces, predisposing to neurologic injury.
  • Five patterns of CCSA carry especially high risk for neurologic injury, even with minor trauma: (i) fusion of the occiput to C1, (ii) fusion of C1–C2, (iii) fusion of C2–C3, (iv) long cervical fusion (more than three segments fused) plus abnormal junction of the occiput with C1, and (v) two fused segments with a single open interface (two vertebra fused adjacent to one normal vertebra which is then adjacent to two more fused) (2).

Genetics

Teratologic insults (i.e., maternal smoking, alcohol) and mutations in the homeobox (Hox) genes may play a role.

Risk-Factors

Increased incidence in Klippel-Feil, trisomy 21 (Down), and Morquio syndromes

Commonly Associated Conditions

  • CCSA may be isolated or part of a genetic syndrome.
  • Discovery of a cervical spine abnormality should alert the physician to look for associated pathology.
  • Klippel-Feil syndrome is defined by the congenital fusion of two or more cervical spine vertebral bodies. Associated abnormalities include:
    • Scoliosis/kyphosis/lordosis (>50%).
    • Hearing impairment (30%).
    • Congenital elevation of the scapula (25–35%).
    • Genitourinary anomalies.
    • Cardiovascular anomalies (more common in females), ventricular septal defect most common.
    • Rib abnormalities.
    • Omovertebral bone (3).
  • Lower cervical spine fusion is also seen in fetal alcohol syndrome, Alport syndrome, Crouzon syndrome, and Goldenhar syndrome.
  • C1–C2 instability is common in trisomy 21 (Down), Marfan, and Morquio syndromes; juvenile rheumatoid arthritis; and rickets.
  • Basilar invagination (narrowing of the foramen magnum) is frequent in achondroplasia.
  • Occipitocervical junction anomalies are common in trisomy 21 (Down) syndrome, familial cervical dysplasia, and hyperlaxity syndromes (Ehlers-Danlos and Marfan syndrome).

Diagnosis ⬆ ⬇

History

CCSA may present with an episode of transient paresis after trauma; more commonly, they are asymptomatic or present with nondescript symptoms such as neck pain or stiffness, headaches, syncope, weakness, numbness, and torticollis.

  • Occasionally: symptoms consistent with pyramidal tract or vertebrobasilar insufficiency
  • Rarely: cranial nerve or posterior column disturbance
  • Those with occipitoatlantal fusion may remain asymptomatic throughout life or present with symptoms after mild trauma; common symptoms (in decreasing frequency): pain in occiput/neck, vertigo, weakness, and ataxia in the lower (and occasionally upper) limbs; occasionally: paresis, paresthesias, hoarseness, dysphagia
  • Those with basilar impression and invagination (narrowed foramen magnum) may not have symptoms present until 2nd to 3rd decade.
  • Those with occipitoatlantal instability may be symptomatic even in absence of trauma: neck pain, headache, torticollis, weakness, and vertebrobasilar symptoms.
  • Those with odontoid anomalies: asymptomatic 50% of the time and average age at diagnosis 19 to 30 yr

Physical Exam

  • Loss of range of motion (ROM), especially lateral bending, considered a red flag
  • Syndromic clinical signs that may be associated with CCSA include:
    • Pterygium colli (webbed neck), shortened neck, torticollis, low posterior hairline
    • Other anomalies that can be associated with CCSA include dwarfism, funnel chest, pes cavus, syndactylies, jaw anomalies, cleft palate, congenital ear deformities, hypospadias, other genitourinary tract defects, and scoliosis (present in 60% of Klippel-Feil syndrome patients) (3).
  • Symptoms prompting further evaluation:
    • Radiculopathy: concerning for nerve root irritation from osteophytes at hypermobile segments adjacent to fused vertebrae
    • Upper extremity weakness, numbness, or pain
    • Long-tract signs (spasticity, hyperreflexia, abnormal reflexes) due to pyramidal compression
    • Posterior column signs (altered sensation to deep touch, vibration, and proprioception)
    • Nystagmus, ataxia, and imbalance from cerebellar herniation

Differential Diagnosis

  • Neurologic abnormalities: extensive but include cervical disk disease, congenital spinal stenosis, vascular disease, Arnold-Chiari malformation, and odontoid nonunion
  • Torticollis: congenital muscular torticollis (sternocleidomastoid tumor [SMT], muscular torticollis, postural torticollis without SMT mass or tightness), ocular deficiency, hearing deficit, Grisel and Sandifer syndromes, tumor of posterior fossa, syringomyelia/Arnold-Chiari malformation, Klippel-Feil syndrome, rotatory cervical instability, infection, and cervicothoracic scoliosis
  • Basilar impression:

Diagnostic Tests & Interpretation

Initial Tests (lab, imaging)

  • X-rays: cervical spine anteroposterior (AP) view; open-mouth odontoid view; lateral views in neutral, flexion, and extension ± thoracolumbar posteroanterior and lateral views; abnormalities seen include:
    • AP views: Look for vertebral fusion of facets and spinous processes; AP narrowing of the vertebral bodies (wasp-waist sign); presence of hemivertebrae, omovertebral bone, or spina bifida; condylar dysplasia.
    • On flexion/extension views: Look for decreased movement between fused segments and increased movement between adjacent, nonfused portions.
    • Open-mouth view: odontoid anomalies.
    • Lateral flexion/extension: Evaluate translational instability (anterior or posterior translation >5 mm) or fusion.
    • Basilar impression is difficult to see on x-ray.
    • Computed tomography (CT) scan useful for suspected atlanto-occipital fusion, basilar invagination, canal stenosis, and odontoid abnormalities
  • Magnetic resonance imaging (MRI): indicated in patients with neurologic deficits; excellent for evaluation of canal stenosis, cord compression, disk bulge/herniation, and craniovertebral junction narrowing; evaluates for associated conditions such as myelomalacia, syringohydromyelia, diastematomyelia, diplomyelia, and Chiari I malformation:
    • Obtain for full evaluation of atlantoaxial instability, basilar invagination, and canal stenosis.

Diagnostic Procedures/Other

Arteriography (or magnetic resonance angiography) if surgery planned or if symptoms warrant (basilar impression, occipitoatlantal fusion, atlas aplasia) because there is increased incidence of vertebral artery anomalies with CCSA

Treatment ⬆ ⬇

  • Conservative treatment (e.g., activity modification, bracing, and traction) may reduce symptoms. Indications for and timing of surgical stabilization are not clearly defined; consider for significant pain despite conservative measures.
  • Spinal stabilization recommended in presence of a neurologic lesion or instability
  • If a neurologic process occurs in presence of known canal stenosis, decompression ± stabilization should be considered.

Medication

Analgesics (i.e., acetaminophen, nonsteroidal anti-inflammatory drugs [NSAIDs]) for headache

Issues for Referral

Generally, all congenital cervical disease should be referred to neurosurgeon and/or neurologist for concurrent observation and management.

Surgery/Other Procedures

  • Surgical indication: Posterior column signs and symptoms (most common indication for surgery) require decompression of posterior elements.
  • Procedures:
    • Posterior fusion of occiput-atlas complex in occipitoatlantal fusion
    • Suboccipital decompression with decompressive laminectomies of atlas and axis with posterior fusion in basilar impression
  • Surgical indication: odontoid abnormalities with any of the following coexisting:
    • Myelopathy, instability of ≥10 mm in flexion and extension, progressive instability, or persistent neck pain with C1–C2 instability
    • Procedure: atlantoaxial arthrodesis (± excision os odontoid)
  • Surgical indication: occipitoatlantal instability:
    • Procedure: arthrodesis
  • Surgical indication (rarely required): familial cervical dysplasia; procedure: posterior fusion of C1–C2

Ongoing Care ⬆ ⬇

Follow-up Recommendations

Patient Monitoring

Return to play recommendations are primarily expert opinions:

  • Absolute contraindications to contact/collision sports: odontoid abnormalities, occipitoatlantal fusion, Klippel-Feil syndrome with fusions above C3, and atlantoaxial instability (4,5)[C]
  • Caution but no absolute contraindication for Klippel-Feil syndrome with fusion of one or two interspaces below C3; full cervical ROM; and absence of occipital cervical anomalies, instability, disk disease, or degenerative changes (4)[C]

Patient Education

  • All congenital cervical diseases: Trauma can be catastrophic (more often with translational instability and with stenotic cervical canal).
  • CCSA that carry especially high risk for neurologic injury, even with minor trauma: (i) fusion of the occiput to C1 or C2, (ii) fusion of C2–C3, (iii) long cervical fusion (more than three segments fused) plus abnormal junction of the occiput with C1, and (iv) two fused segments with a single open interface (Two vertebra fused adjacent to one normal vertebra which is then adjacent to two more fused.)

Prognosis

Klippel-Feil syndrome:

  • Hypermobility of upper cervical spine: increased risk for neurologic issues
  • Lower cervical spine involvement: increased risk for degenerative disease
  • Overall prognosis is good, with most patients remaining relatively asymptomatic with occasional mild complaints of headaches, nonradicular weakness, and numbness.

Complications

CCSA may be asymptomatic but can predispose to catastrophic outcomes with minor trauma, including paresis or sudden death.

Additional Reading ⬆ ⬇

  • Davis G, Ugokwe K, Roger EP, et al. Clinics in neurology and neurosurgery of sport: asymptomatic cervical canal stenosis and transient quadriparesis. Br J Sports Med. 2009;43(14):1154–1158.
  • Guille JT, Miller A, Bowen JR, et al. The natural history of Klippel-Feil syndrome: clinical, roentgenographic, and magnetic resonance imaging findings at adulthood. J Pediatr Orthop. 1995;15(5):617–626.
  • Guille JT, Sherk HH. Congenital osseous anomalies of the upper and lower cervical spine in children. J Bone Joint Surg Am. 2002;84-A(2):277–288.
  • Hensinger RN. Congenital scoliosis: etiology and associations. Spine (Phila Pa 1976). 2009;34(17):1745–1750.

See-Also

Congenital Cervical Stenosis

References ⬆ ⬇

  1. Tracy MR, Dormans JP, Kusumi K. Klippel-Feil syndrome: clinical features and current understanding of etiology. Clin Orthop Relat Res. 2004;424:183–190.
  2. Steyaert A. Cervical spine anomalies: a contraindication to sports?J Sports Sci Med. 2012;11(1):184–185.
  3. Klimo P Jr, Rao G, Brockmeyer D. Congenital anomalies of the cervical spine. Neurosurg Clin N Am. 2007;18(3):463–478.
  4. Torg JS, Ramsey-Emrhein JA. Management guidelines for participation in collision activities with congenital, developmental, or postinjury lesions involving the cervical spine. Clin J Sport Med. 1997;7(4):273–291.
  5. Rice SG; for American Academy of Pediatrics Council on Sports Medicine and Fitness. Medical conditions affecting sports participation. Pediatrics. 2008;121(4):841–848.

Clinical Pearls ⬆

  • Absolute contraindications to contact/collision sports: odontoid abnormalities, occipitoatlantal fusion, Klippel-Feil syndrome with fusions above C3, and atlantoaxial instability (4,5)[C]
  • Caution but no absolute contraindication for Klippel-Feil syndrome with fusion of one or two interspaces below C3; full cervical ROM; and absence of occipital cervical anomalies, instability, disk disease, or degenerative changes (4)[C]
  • Discovery of a cervical spine abnormality should alert the physician to look for associated pathology, especially in cardiovascular, renal, and retinal systems.
  • X-rays: basic: cervical spine AP view and open-mouth odontoid view; consider: lateral views in neutral, flexion, and extension ± thoracolumbar posteroanterior and lateral
  • CT scan useful for suspected atlanto-occipital fusion, basilar invagination, and canal stenosis; also used for flexion/extension evaluation of odontoid abnormalities
  • MRI: indicated in patients with neurologic deficits; excellent for evaluation canal stenosis, cord compression, disk bulge/herniation, and craniovertebral junction narrowing; evaluates for associated conditions