Nontraumatic AtlantoAxial Subluxation in Children
Children can have major conditions disguised as relatively minor problems. We often think of Inborn Errors of Metabolism presenting as innocuous vomiting or Late Onset GBS infection presenting as poor feeding. Obviously, conditions like these don’t remain innocuous for long and it is our VIGILANCE that helps us to decipher the clues and prevent poor outcomes. Recently, our friend and PEM expert (and ultrasound expert) Dr. Simone Lawson kindly reminded me of another scary entity that can look like benign Toricollis. Let us take a minute to digest a Morsel on NonTraumatic AtlantoAxial Subluxation in Children:
Atlantoaxial Subluxation: Basics
- Nontraumatic Atlantoaxial Subluxation = Grisel Syndrome [Anania, 2019]
- Named after French otolaryngologist P. Grisel.
- First described by Sir Charles Bell, in 1930. [Ortega-Evangelio, 2011]
- Occurs mostly in children.
- Is rare… but can lead to significant neurologic consequences.
- Most frequently associated with: [Ozalp, 2019; Patel, 2019; Kinon, 2016; Ortega-Evangelio, 2011]
- Grisel Syndrome’s defining characteristics include: [Anania, 2019]
- Some cases have had prolonged duration of torticollis. [Anania, 2019]
- Often cervical pain with neck tilt and limited and painful neck mobility are seen. [Ozalp, 2019]
- Unable to actively counter-rotate past midline.
- Benign torticollis should still have good passive range of motion.
- May have been previously evaluated for torticollis that still persists (delayed diagnosis can increase need for surgery!)
- History of recent HEENT infection or surgery
- Cases have occurred after head and neck surgery.
- Cases have occurred after local ENT infection.
- Cases have also occurred after Kawasaki Syndrome.
- Specific Radiologic Findings based on displacement of atlas:
- Anterior displacement < 3 mm: Type 1
- Anterior displacement 3 – 5 mm: Type 2
- Anterior displacement >5 mm: Type 3
- Posterior displacement: Type 4
Atlantoaxial Subluxation: Mechanism
- The pathogenesis of Grisel syndrome is not completely understood. [Anania, 2019; Ozalp, 2019]
- Children are more predisposed to Grisel syndrome. [Anania, 2019; Kinon, 2016]
- ENT inflammation / infection can affect the paravertebral space. [Anania, 2019]
- Inflammatory processes can spread DIRECTLY to the paravertebral muscles.
- The pharyngovertebral veins and lymphatics drain the adjacent structures and can be a pathway for infection or inflammation to spread.
- Some theories as to why this occurs:
- The combination of the preexisting anatomic laxity seen with children combined with spread of inflammatory/infectious process leads to the subluxation of the atlantoaxial joint. [Anania, 2019]
- An initial muscle spasm from local inflammatory processes lead to torticollis and subsequent rotation deformity, which if left untreated can lead to eventual subluxation. [Ortega-Evangelio, 2011]
Atlantoaxial Subluxation: Evaluation & Management
- Cervical plain films with odontoid views can be a helpful screen. [Ortega-Evangelio, 2011]
- CT imaging is preferred to define degree of subluxation.
- MRI is also useful and some advocate for it to be primary imaging modality. [Ozalp, 2019]
- There is no gold standard for management of Grisel syndrome. [Anania, 2019; Kinon, 2016; Schlierf, 2014; Ortega-Evangelio, 2011; Pilge, 2011]
- Management considerations: [Ortega-Evangelio, 2011]
- Infectious process and control
- Correction of bone deformity
- Prevention of neurological injury.
- Most cases are able to be managed without surgery. [Anania, 2019; Ozalp, 2019; Schlierf, 2014; Ortega-Evangelio, 2011; Pilge, 2011]
- Some cases have been found to spontaneously resolve with only conservative treatments.
- If Type 1, Neck Brace and conservative therapy (ex, antibiotics and anti-inflammatory medications) with close follow-up with spinal surgeons is effective. [Anania, 2019]
- For Types 2-4, the duration of symptoms may suggest different management strategies. [Anania, 2019]
- <1 month: Closed reduction and Philadelphia Brace or Halo Brace
- >1 month: Halo Jacket, Fixation, and Arthrodesis.
- Each case should be treated by a spinal specialist and tailored to the individual.
Moral of the Morsel
- Remain vigilant, but not unreasonable! Torticollis is Common and Grisel is Not.
- Persistent torticollis should turn your head too! Even without trauma, atlantoaxial subluxation can occur… so images may still be warranted!
- Broaden that Ddx! Pain in the neck after recent ENT infection?? Well, that can be a lot of problems… add Grisel to the list!
- Look for the clues! Torticollis + HEENT infection/surgery/inflammatory state = consider Grisel Syndrome.