title: Histological analysis of palatopharyngeal muscle from children with snoring and obstructive sleep apnea syndrome.
abstract: Obstructive sleep apnea syndrome (OSAS) is an upper airway obstruction that occurs during the sleep. One of the suggested mechanisms involved in this process is a neuromuscular abnormality of the palatal muscles. Whether children with OSAS develop into OSAS adults, or children and adult OSAS are two distinct disorders occurring at different ages are questions to be answered. Here, we made the histological analysis of palatophryngeal muscle in 34 oral-breathing children of both genders, aged 5-12 years old, with hypertrophic tonsils and adenoids. According to the polysomnographic study the participants were divided into children without sleeping disorders (group I) and children with primary snoring (group II) or apnea (group III). The main histological findings were fiber size variability in 70% cases from groups II and III and in 71% from group I; perimysial connective tissue infiltration in 48% children from groups II and III and in 71% from group I; intracytoplasmatic mitochondrial proliferation in 63% cases from groups II and III and in 57% cases from group I. Muscle necrosis was only observed in one case, in association with subglandular inflammation. Others findings observed in all groups included fibers with internal architecture alteration, such as moth-eaten and lobulated fibers, type 2 fiber predominance, and small areas of fiber type grouping. The presence of similar histological findings in the palatopharyngeal muscle in children with primary snoring or apnea but also in children without sleeping disorders indicate that such changes could be a normal histological feature of this muscle rather than a neurogenic or myopathic pathology.
authors.affiliation: Department of Otorhinolaryngology and Head and Neck Surgery, Universidade Federal de São Paulo (UNIFESP), São Paulo, Brazil. ivuono@uol.com.br
authors.forename: Isabela Mattos De
authors.initials: IM
authors.lastname: Vuono
authors.forename: Edmar
authors.initials: E
authors.lastname: Zanoteli
authors.forename: Acary Souza Bulle
authors.initials: AS
authors.lastname: de Oliveira
authors.forename: Reginaldo Raimundo
authors.initials: RR
authors.lastname: Fujita
authors.forename: Shirley Shizue Nagata
authors.initials: SS
authors.lastname: Pignatari
authors.forename: Gilberto Ulson
authors.initials: GU
authors.lastname: Pizarro
authors.forename: Márcia Lurdes
authors.initials: ML
authors.lastname: de Cássia Pradelle-Hallinan
authors.forename: Gustavo Antônio
authors.initials: GA
authors.lastname: Moreira
mesh_terms: D001706:Biopsy; D002648:Child; D002675:Child, Preschool; D003238:Connective Tissue / Q000473:pathology; D005260:Female; D006801:Humans; D008297:Male; D009058:Mouth Breathing; D010156:Palatal Muscles / Q000254:growth & development / Q000473:pathology*; D014066:Palatine Tonsil / Q000254:growth & development; D010609:Pharyngeal Muscles / Q000254:growth & development / Q000473:pathology*; D020181:Sleep Apnea, Obstructive / Q000473:pathology*; D012913:Snoring / Q000473:pathology*