The efficacy of neurosurgical intervention on sleep-disordered breathing in pediatric patients with Chiari malformation type I

Abstract

OBJECTIVE Chiari malformation type I (CM-I) involves the herniation of the cerebellar tonsils through the foramen magnum. CM-I is associated with both obstructive sleep apnea (OSA) and central sleep apnea (CSA) in children. The primary management of symptomatic CM-I remains surgical decompression. There is, however, a paucity of data evaluating the efficacy of decompression surgery on outcomes related to sleep-disordered breathing (SDB). The objective of this study was to evaluate SDB outcomes, specifically the need for respiratory support following decompression in pediatric patients with CM-I. METHODS This was a retrospective chart review of all children diagnosed with CM-I when younger than 18 years of age who had polysomnography (PSG) studies pre- and postsurgery, between January 2008 and October 2018 at the Hospital for Sick Children in Toronto. Patient demographics, symptoms, PSG data, ongoing respiratory support, and surgical notes were recorded. Differences in PSG studies obtained pre- and postsurgery were compared using the Wilcoxon test for paired samples. RESULTS A total of 15 children with 15 interventions met inclusion criteria with pre- and postsurgery PSG studies and were considered for statistical analysis. Of the 15 subjects included for analysis, preoperative OSA was present in 2 (13.3%), CSA in 5 (33.3%), mixed SDB (both OSA and CSA) in 4 (26.7%), and no significant SDB in 4 (26.7%). Postoperatively, OSA was present in 3 (20.0%), CSA in 4 (26.7%), mixed SDB in 0 (0%), and no significant SDB in 8 (53.3%). The presence of severe OSA decreased from 4/15 (26.7%) to 2/15 (13.3%) postoperatively, and severe CSA decreased from 5/15 (33.3%) to 2/15 (13.3%) postoperatively. Following decompression surgery, 7/15 subjects (46.7%) required positive airway pressure for management of their SDB. Overall, significant improvements were observed in a number of respiratory parameters following decompression including the following: the total apnea-hypopnea index (AHI) (17.5 ± 48.2 vs 6.1 ± 32.7 events/hour; p = 0.001), obstructive AHI (2.1 ± 16.1 vs 1.0 ± 6.6 events/hour; p = 0.005), central AHI (6.3 ± 48.9 vs 2.7 ± 33.0 events/hour; p = 0.005), and the desaturation index (16.7 ± 49.6 vs 3.8 ± 25.3; p = 0.001). CONCLUSIONS Although decompression surgery led to a significant reduction in obstructive and central events, many children continued to have persistent SDB and required additional positive airway pressure therapy. This information is important and relevant for anticipatory guidance around decompression surgery and the necessity for respiratory support for the management of SDB in pediatric patients with CM-I.

Impact of sleep‐disordered breathing on the management of children with Chiari malformation type I

“…Indeed, 8 patients required ENT surgery, among whom 5 patients with CM-Iia, 24 and 2 patients needed CPAP. 25 Follow-up is also necessary in CM-I patients as cerebellar tonsil reherniation is possible, 9 as observed in 2 patients in the present study. Moreover, follow-up PG may be necessary as SAS may develop or worsen over time, with the necessity of ENT surgery, FMD and/or CPAP/NIV, as observed in a few patients in our study.…”

“…On the contrary, all the patients with CSA had a FMD, and MRI findings and/or symptoms of CM‐I together with moderate‐to‐severe SAS best identified patients who needed a FMD. The CAI significantly decreased in the patients following FMD, while the OAHI remained quite unchanged 24,25 . This was mainly due to 1 patient who showed a worsening of severe OSA (OAHI increased from 55 to 84 events/h) and who required CPAP after FMD.…”

“…Indeed, ENT surgery and CPAP/NIV may also be part of the management of CM‐I patients, and therefore a systematic evaluation of upper airways should be proposed, 24,25 particularly in patients having associated co‐morbidities with a potential cranio‐facial impact. Indeed, 8 patients required ENT surgery, among whom 5 patients with CM‐Iia, 24 and 2 patients needed CPAP 25 . Follow‐up is also necessary in CM‐I patients as cerebellar tonsil reherniation is possible, 9 as observed in 2 patients in the present study.…”

“…The CAI significantly decreased in the patients following FMD, while the OAHI remained quite unchanged. 24,25 This was mainly due to 1 patient who showed a worsening of severe OSA (OAHI increased from 55 to 84 events/h) and who required CPAP after FMD.…”

Pediatric Sleep Respiratory Disorders: A Narrative Review of Epidemiology and Risk Factors

“…In 2013, Khatwa et al studied 22 children with CM1 (median age, 10 years old; range, 1–18 years) using PSG and brain-MRI and documented that some MRI variants (i.e., degree of pegged tonsillar structure, dorsal cerebrospinal fluid attenuation, presence of syrinx, and posterior angulation of the dens) were more expressed in patients with SDB compared to children with normal sleep study results [ 82 ]. Recently, Voutsas et al analyzed the efficacy of decompression surgery on SDB outcomes in 15 children with CM1, showing a significant reduction in obstructive and central events with PSG after neurosurgical intervention; however, half of the patients (46.7%) continued to meet criteria for SDB even after the surgical procedure and needed long-term continuous positive pressure therapy [ 86 ].…”