SLEEP, Vol. 33, No. 7, 2010
Sensory Function in Children—Tapia et al
CHILDREN WITH THE OBSTRUCTIVE SLEEP APNEA
SYNDROME (OSAS) HAVE UPPER AIRWAY COLLAPSE
AND RESULTANT OBSTRUCTIVE APNEA DURING
sleep. This is the consequence of an imbalance between the upper
airway structural load due to factors such as adenotonsillar hy-
pertrophy, and upper airway neuromotor tone.1-3 The pharyngeal
subatmospheric pressure, hypoxemia, and hypercapnia generated
during these apneic episodes4 may activate the dilatory muscles
of the upper airway, resulting in the reopening of the airway and
termination of the obstructive apnea.3,5,6
Upper airway mucosal sensory receptors may have a role in
the termination of an apnea by mediating upper airway tone.7-10
Previous studies in adults have demonstrated that attenuation of
upper airway mucosal sensation by topical anesthesia increases
the tendency to airway collapse.9,11 Furthermore, upper airway
anesthesia also induces apneas and hypopneas during sleep in
normal subjects8 and increases the frequency of obstructive
events in snorers.7,10 The findings of these studies suggest that
impairment of upper airway mucosal sensory function could
contribute to upper airway collapse during sleep. In addition,
previous studies performed in adult subjects have demonstrated
impaired mucosal sensory function in subjects with OSAS.12-16
However, it is unknown whether children with OSAS have im-
paired upper airway sensory function.
Huang et al. recently analyzed cortical processing of afferent
respiratory information by measuring respiratory-related evoked
potentials during sleep in children with OSAS and controls.17
They found blunted respiratory-related evoked potentials re-
sponses in children with OSAS, indicative of impaired afferent
processing. This may be due to impaired upper airway sensation.
Hence, we hypothesized that children with OSAS had dimin-
ished airway mucosal sensation during wakefulness compared
to controls. We therefore studied sensory function in the upper
airway of children with OSAS compared to normal age-, gen-
der-, and BMI-matched controls. Specifically, two-point dis-
crimination during wakefulness was determined in the upper
airway of subjects with OSAS compared to controls.
MATERIAL AND METHODS
Children between 6-16 years of age were included. The
younger age limit was selected to exclude children who could
not understand and cooperate with testing. The older age limit
was chosen to avoid overlap with adult OSAS. Patients with
OSAS were recruited from the Sleep Center at The Children’s
Hospital of Philadelphia following a recent clinical polysom-
nogram. Normal controls were recruited from the general com-
munity by means of advertisements. For screening purposes,
controls completed the validated Pediatric Sleep Questionnaire18
to exclude those with suspected sleep disordered breathing.
Those who passed the screening underwent a polysomnogram
to ensure normalcy. Other exclusion criteria for OSAS and con-
UPPER AIRWAY SENSORY FUNCTION IN CHILDREN WITH OSAS
Upper Airway Sensory Function in Children with Obstructive Sleep Apnea
Ignacio E. Tapia, MD; Preetam Bandla, MD; Joel Traylor, RPSGT; Laurie Karamessinis, CCRC; Jingtao Huang, PhD; Carole L. Marcus, MBBCh
Sleep Center, The Children’s Hospital of Philadelphia, University of Pennsylvania School of Medicine, Philadelphia, PA
Study Objectives: Children with the obstructive sleep apnea syndrome (OSAS) have impaired responses to hypercapnia, subatmospheric pres-
sure, 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.
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 impair-
ment 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.
Keywords: Two-point, discrimination, palate
Citation: Tapia IE; Bandla P; Traylor J; Karamessinis L; Huang J; Marcus CL. Upper airway sensory function in children with obstructive sleep
apnea syndrome. SLEEP 2010;33(7):968-972.
Submitted for publication August, 2009
Submitted in final revised form December, 2009
Accepted for publication January, 2010
Address correspondence to: Carole L. Marcus, MBBCh, The Children’s
Hospital of Philadelphia, Pulmonary Division, 5th floor Wood, 34th & Civic
Center Blvd, Philadelphia, PA 19104; Tel: (267) 426-5842; Fax: (215) 590-
3500; E-mail: firstname.lastname@example.org