Cervical spinal cord compression in infants with achondroplasia: should neuroimaging be routine?

Purpose: To examine results of magnetic resonance imaging (MRI), polysomnograms (PSG), and patient outcomes in patients with achondroplasia in light of recent screening recommendations for infants with achondroplasia. Methods: We reviewed medical records of 49 patients with achondroplasia followed at our institution between September 1997 and January 2017, including physical exams, MRIs, PSGs (when available), and surgical histories. Appropriate PSG data were available for 39 of these patients. Results: Twenty-seven of 49 patients had cervical cord compression on MRI, and 20 of those patients required surgery. Central apnea was detected in 2/23 patients with cervical cord compression in whom PSG data was available. Physical exam revealed depressed deep-tendon reflexes in two patients with cord compression and one patient without cord compression. Besides hypotonia in some, the neurological exams of these patients were unremarkable. Conclusions: Cervical cord compression is a common occurrence in infants with achondroplasia and necessitates surgical intervention in some patients. Physical exam and PSG are poor predictors of the presence of cord compression or the need for surgery. All infants with achondroplasia should have MRIs of the craniocervical junction in the first 6 months of life.