Polysomnographic predictors of abnormal brainstem imaging in children

Area of Science:

• Pediatric Sleep Medicine
• Neuroimaging in Sleep Disorders
• Respiratory Physiology

Background:

• Elevated central apnea-hypopnea index (CAHI) in children often prompts neuroimaging to rule out brainstem pathology.
• Evidence is limited on polysomnography (PSG) thresholds that predict abnormal brainstem imaging.
• This study aimed to identify PSG variables that predict brainstem abnormalities in pediatric patients.

Purpose of the Study:

• To evaluate if specific polysomnography variables can predict brainstem pathology in pediatric patients with central sleep apnea.
• To determine thresholds for CAHI and end-tidal CO₂ that correlate with abnormal brainstem imaging.
• To assess the utility of prolonged central apneas in predicting brainstem abnormalities.

Main Methods:

• Retrospective review of 65 pediatric patients (ages 1-18) who underwent brain MRI for central sleep apnea diagnosis.
• Comparison of demographics, medical history, PSG variables, and MRI results.
• Analysis using receiver operating characteristic (ROC) curves to identify predictive thresholds.

Main Results:

• 69.2% of patients had normal MRIs; 30.8% had abnormal MRIs.
• Seven patients (10.8%) showed brainstem pathology, with a median CAHI of 10.8 events/h and higher rates of hypoventilation.
• A CAHI ≥ 9.5 events/h and ≥ 6.4% of total sleep time with end-tidal CO₂ ≥ 50 mm Hg predicted abnormal brainstem imaging.
• Prolonged central apneas did not predict brainstem abnormalities.

Conclusions:

• Most pediatric central sleep apnea patients do not have brainstem structural abnormalities on MRI.
• Specific CAHI (≥ 9.5 events/h), end-tidal CO₂ (≥ 6.4% TST with ≥ 50 mm Hg), and hypoventilation thresholds may optimize MRI use.
• Clinical history alongside these PSG parameters can aid in judicious MRI utilization for central sleep apnea evaluation.