Cerebral Blood Flow Response to Hypercapnia in Children with Obstructive Sleep Apnea Syndrome

Area of Science:

• Pediatric Sleep Medicine
• Neurovascular Physiology
• Respiratory Medicine

Background:

• Obstructive sleep apnea syndrome (OSAS) in children frequently involves hypercapnia during sleep.
• Hypercapnia is a known potent stimulator of cerebral blood flow (CBF).
• The impact of sleep-related hypercapnia on wakeful CBF regulation in pediatric OSAS is not well understood.

Purpose of the Study:

• To investigate whether children with OSAS exhibit altered CBF responses to hypercapnia during wakefulness.
• To compare CBF responses to hypercapnia in children with OSAS, habitual snorers, and healthy controls.

Main Methods:

• Utilized diffuse correlation spectroscopy (DCS) to measure CBF changes during hypercapnic ventilatory response (HCVR).
• Assessed peak CBF changes relative to pre-hypercapnic baseline in three groups: OSAS, snorers, and controls.
• Study conducted at an academic pediatric sleep center.

Main Results:

• Twelve children with OSAS, eight snorers, and ten controls were analyzed.
• The normalized fractional CBF change during hypercapnia was significantly lower in children with OSAS (7.1 ± 1.5 %/mmHg) and snorers (6.7 ± 1.9 %/mmHg) compared to controls (9 ± 1.8 %/mmHg).
• Statistical significance was observed with P = 0.023 for OSAS vs. controls and P = 0.025 for snorers vs. controls.

Conclusions:

• Children diagnosed with OSAS and those who habitually snore demonstrate a blunted cerebral blood flow response to hypercapnia during wakefulness.
• Noninvasive DCS measurements of hypercapnic reactivity provide valuable insights into the pathophysiology of pediatric OSAS.
• Findings may contribute to a better understanding of potential central nervous system complications associated with OSAS in children.