Study objectives: Children with the obstructive sleep apnea syndrome (OSAS) have impaired responses to hypercapnia, subatmospheric pressure, and inspiratory resistive loading during sleep. This may be due, in part, to an impairment in the afferent limb of the upper airway sensory pathway. Therefore, we hypothesized that children with OSAS had diminished upper airway sensation compared to controls.
Design: Case-control.
Setting: Academic hospital.
Participants: Subjects with OSAS aged 6-16 years, and age- and BMI-matched controls.
Interventions: Two-point discrimination (TPD) was measured during wakefulness with modified calipers in the anterior tongue, right interior cheek, and hard palate.
Results: Thirteen children with OSAS and 9 controls were tested. The age (mean +/- SD) for OSAS and controls was 11 +/- 4 vs. 13 +/- 2 years (NS); OSAS BMI Z score 2.4 +/- 0.5, controls 2.2 +/- 0.5 (NS); OSAS apnea hypopnea index 31 +/- 48, controls 0.4 +/- 0.5 events/hour (P < 0.001). Children with OSAS had impaired TPD in the anterior tongue (median [range]) = 9 [3-14] mm, controls 3 [1-7], P = 0.002) and hard palate (OSAS 6 [3-9] mm, controls 3 [1-4], P < 0.001). TPD in the cheek was similar between the groups (P = 0.12).
Conclusion: TPD in the anterior tongue and hard palate was impaired in children with OSAS during wakefulness. We speculate that this impairment might be due to a primary sensory function abnormality or secondary to nerve damage and/or hypoxemia caused by OSAS. Further studies after treatment of OSAS are needed.