Nasalance scores in snoring children with obstructive symptoms

Snoring and the sleep apnea syndrome (OSAS) in children are usually caused by adenotonsillar hypertrophy, which may affect air escape into the nose and nasal resonance. A microcomputer-based system makes it possible to objectively determine whether the oral passage is adequately separated from the nasal passage during phonation. The score thus obtained is called nasalance. This study was conducted to verify whether there exists differences in nasalance between primary snorers and OSAS-children.

Fifty-three habitually snoring children (31 boys), mean age 6.1 years (range 3.2-10.5 years), were subjected to overnight sleep polygraphy (PG) and nasalance measurements with the Nasometer 6200. The study was successfully repeated 6 months later on 36 children.

Nineteen children had obstructive apnea-h ypopneaindex (OAHI)> 1 on overnight polygraphy (OSAS-children), while 32 were considered primary snorers (PS), (OAHI<1). No statistically significant difference in nasalance scores was found between the OSAS- and PS children. Both groups of children had somewhat higher mean nasalance values both for oral and nasal passage sentences than the normative values for Finnish speech. In general, the most habitual snorers had lower nasalance scores than the less frequently snoring children (P=0.05). Earlier adenoidectomy or palatine tonsillar size did not have a significant influence on the nasalance. Adenotonsillectomy did not affect the nasalance scores of the nine children operated on during the follow-up period.

According to the present study, nasalance measurements cannot be used to predict the incidence of OSAS among snoring children.