Sleep-disordered breathing in children with Chiari type I malformation.

Objective: The objective was to identify clinical and radiological factors associated with sleep-disordered breathing (SDB) in children with Chiari type I malformation (CIM) and to evaluate the efficacy of foramen magnum decompression (FMD) in resolving SDB.

Methods: A retrospective chart review was conducted for all children evaluated for CIM at a single institution from 2002 to 2022, identifying all children who had undergone nocturnal polysomnography (PSG). Apnea-hypopnea index (AHI) score, sleep apnea type (obstructive, central, mixed, and unspecified), clinical manifestations, and radiological measurements were recorded. SDB was considered present when officially diagnosed in the PSG report. Logistic regression was performed to identify factors correlating with the presence of SDB. For children with SDB who underwent FMD, the Wilcoxon signed-rank test was used to assess AHI improvement.

Results: Of the 997 children referred for CIM, 310 completed PSG. SDB was diagnosed in 147 patients (overall prevalence 14.7%, 95% CI 12.7%-17.1%; prevalence among children with PSG 47.4%, 95% CI 41.9%-53%). Specific SDB diagnosis consisted of 33% of patients with central sleep apnea, 27% with obstructive sleep apnea, 9% mixed, and 31% unspecified. Lower cranial nerve (CN) dysfunction (OR 3.891, p = 0.009), tonsillar position (OR 1.049, p = 0.017), Chiari type 1.5 malformation (OR 1.862, p = 0.044), and BMI (OR 1.039, p = 0.036) were significantly associated with presence of SDB. Of the 310 patients who underwent PSG, 47 were originally categorized as asymptomatic: 27 (57%) of these asymptomatic patients were diagnosed with SDB on PSG. Of children diagnosed with SDB, 34 completed PSG before and after FMD. Median AHI score decreased from 6.5 preoperatively to 1.8 postoperatively, with a median (IQR) difference of -2.3 (-11.9 to 0.1) (p = 0.001). Twelve (35%) had resolution of SDB.

Conclusions: The authors' findings suggest that the prevalence of SDB in children with CIM is high (15%-47%). Furthermore, lower CN dysfunction, Chiari type 1.5, lower tonsillar position, and higher BMI may be risk factors. Notably, SDB can be present even in the absence of clinical symptoms. This study also demonstrates that surgical intervention has the potential to reduce the severity of SDB. These results could help clinicians identify CIM patients at risk for SDB and those who may benefit from surgical decompression.