0796 Sleep-Related Hypoventilation in Children with Chiari Malformation

Abstract

Introduction: Chiari malformation (CM) is characterized by the herniation of the cerebellum with variable extension through the foramen magnum and possible alteration of the respiratory control center. Central and obstructive sleep apnea have been described, but data on the prevalence of hypoventilation is lacking. This study was an attempt to determine the prevalence of sleep-related hypoventilation in children with CM referred for polysomnography (PSG). Method(s): We performed a retrospective chart review of children (<18 years of age) with a diagnosis of CM who underwent PSG with capnometry between July 2004 and December 2017. Studies with poor CO2 signals were excluded, as well children with prematurity or tracheobronchomalacia. Demographic and PSG characteristics were collected. All PSGs were scored and interpreted according to AASM version 2.4 and ICSD-3 criteria. Hypoventilation was scored if the end-tidal pCO2 was above 50 torr >;25% of the total sleep time. Patients with sleep-related hypoventilation (HYP) were then compared to the rest of the group (non-HYP). Result(s): Forty patients met the inclusion criteria. The mean age was 7.7 +/- 4.7 (SD) years and 52.5% were male. The mean BMI was 20.5 +/- 5.8 kg/m2, the mean obstructive apnea-hypopnea index (AHI) was 5 +/- 11 with 19 (47.5%) meeting criteria for obstructive sleep apnea (AHI >;1.5). Ten patients (25%) were diagnosed with HYP. Only 2 patients had central sleep apnea (>;3 central apneas/hour) both of which were in the non-HYP group. There were no differences in AHI or BMI between the two groups. There were 7 males (70%) in the HYP vs 16 (53%) in the non-HYP group. Conclusion(s): We found that 25% of children with CM had sleep-related hypoventilation. This may be more frequent in males. Reports have shown hypoventilation as the first manifestation on CM patients. Sleep capnometry is hence particularly important in the PSG of children.