Evolution of sleep disordered breathing in infants with achondroplasia

PURPOSE: Children with achondroplasia (ACH) are at risk for sudden death in infancy due to sleep disordered breathing (SDB) and foramen magnum stenosis (FMS). Sleep studies and neuroimaging are performed in infants with ACH, but interpretation of infant studies is challenging. We sought to describe baseline data on polysomnography (PSG) indices in infants with achondroplasia as well as effects of age and surgery on these parameters. METHODS: Retrospective data were abstracted from the multisite CLARITY ACH database from years 2008-2017. Both obstructive apnea hypopnea index (OAHI) and central apnea index (CAI) were extracted, and effects of age and surgical intervention (adenoidectomy [AD] or cervicomedullary decompression [CMD]) were analyzed. RESULTS: 172 PSGs from 86 infants were analyzed. In surgically naive children, OAHI decreased over the first year but then increased in the second year, while CAI was mostly stagnant over the first two years. There were no significant differences between age at first PSG or PSG indices for surgically naive infants versus those who underwent AD or CMD. OAHI decreased after AD and CAI decreased after CMD. CONCLUSION: Similar to average stature infants, our results demonstrate the need to interpret sleep study findings of children with ACH in the context of age, particularly for obstructive indices. Neither OAHI nor CAI differentiated those infants who subsequently underwent surgery, suggesting that there were other important clinical factors in the surgical decision-making process. Independent of age, AD resulted in improvement in OSA and CMD with improvement in central sleep apnea.