Central sleep apnea and Chiari 1 malformation in a pediatric patient with Klippel-Feil syndrome.

Klippel-Feil sequence (KFS) is a rare congenital condition that presents with congenital cervical spine fusion, reduced cervical spine flexion, and low posterior hairline. Chiari malformation type 1 and sleep-disordered breathing (SDB) are frequent comorbidities of KFS. The pathologic basis of the connection between Chiari malformation type 1 and SDB in the setting of KFS is not clearly understood. Here we report a pediatric patient with KFS, SDB, and drooling who also had Chiari malformation type 1. Posterior fossa decompression of this patient significantly improved most symptoms including sleep disturbances. Repeat polysomnogram 8 weeks after posterior fossa decompression revealed worsening central sleep apnea despite the patient being clinically asymptomatic. Taken together, this case highlights the point that, although it is critical to recognize the association of SDB in the setting of KFS, decompression alone may not be sufficient to completely alleviate SDB and certain neurologic symptoms.