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Neurologic sequelae secondary to atlantoaxial instability in Down syndrome. Implications in otolaryngologic surgery.

OBJECTIVE
A comprehensive overview of atlantoaxial instability in Down syndrome as it relates to head and neck surgery and recommendations as derived from a review of the literature.


DATA SOURCES
English-language literature: otolaryngologic problems in Down syndrome and atlantoaxial biomechanics.


DATA SYNTHESIS
Children affected with Down syndrome frequently require otolaryngologic procedures such as myringotomy with ventilation tubes or adenotonsillar surgery. Atlantoaxial instability occurs in 10% to 20% of patients with Down syndrome who are at risk for atlantoaxial subluxation and subsequent complications during anesthetic induction and during positioning and manipulation associated with surgery. To identify patients who are at risk for atlantoaxial subluxation, guidelines have been adapted from the recommendations of the American Academy of Pediatrics and the Special Olympics Inc, which include preoperative neurologic assessments and cervical roentgenograms in the neutral, flexion, and extension positions. Children with an atlantodental interval of greater than 4.5 mm or with peripheral neurologic findings should have further evaluation.


CONCLUSIONS
A small percentage of patients with Down syndrome are at risk for atlantoaxial instability and subluxation. All patients with Down syndrome should have a preoperative neurologic assessment screening by the operating surgeon and/or a cervical roentgenogram in the lateral, extension, and flexion positions. Any abnormality should be investigated before surgery.