The side effects of oral devices observed excessive salivati

The side effects of oral devices observed (excessive salivation and transient tooth discomfort) were minor and tolerable, and no major complications were reported [37]. Objective and subjective aspects of the treatment response were evaluated during a longer follow up. The results demonstrated that oral appliance was effective in decreasing sleep fragmentation and objective and subjective daytime sleepiness and was also well tolerated. Other types of oral devices besides the mandibular advancement device were also published as case reports but the study did not report clinical or polysomnographic changes pre- and post-treatment [36]. Nasal obstruction is another cause of flow limitation and can lead to occlusion of the pharyngeal airway. The decrease in nasal resistance might also reduce the inspiratory effort. A double-blind, randomized, controlled trial with a cross-over design study was performed to evaluate the effect of external nasal dilatation in UARS patients [38]. The external nasal dilator significantly increased nasal cross-sectional area, reduced stage 1 sleep and decreased desaturation time when comparing to the placebo treatment. These were the only changes observed after treatment. There were no significant effects on the MSLT, AHI or TAI or on the clinical complaints. The absence of significant clinical changes after treatment, despite the polysomnographic differences, demonstrated that this nonreceptor tyrosine kinase device, currently, cannot be recommended for the treatment of UARS. Future studies with a larger number of patients and with a longer follow-up should be conducted to better analyze this device׳s effects on UARS patients.
Conclusion
Conflict of interest
Acknowledgments The authors would like to thank for the support by grants from Associaçao Fundo de Incentivo a Pesquisa (AFIP), Fundaçao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP), and Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq).
Introduction Narcolepsy is characterized by excessive daytime sleepiness with or without sudden loss of muscular tonus (cataplexy). Associated characteristics include sleep paralysis and hypnagogic and hypnopompic hallucinations. Narcolepsy is strongly associated with the presence of the HLA-DQB1⁎0602 allele, a variant of the HLA-DQB1 gene, located on the short arm of chromosome 64 and its symptoms result in the destruction of the hypocretin-secreting neurons of the hypothalamus [1]. Infections are recognized as having an important role upon the physiopathology of the auto-immune diseases [2]. Among narcolepsy, two types of superior airway infections have been suggested as susceptibility factors: the ones caused by H1N1 influenza A and the ones caused by streptococcus. Picchioni et al., in a case-controlled study, associated inexplicable fevers and flu with increased risk of 3.9 and 1.8 times, respectively, for narcolepsy [3]. The latency, for the beginning of the disease, also showed a highly seasonal characteristic in children, with an incidence 6 times higher in China, in April as relation to December, suggesting a prevalence of 5–6 months after winter [4]. Dauvilliers et al. found an increased risk of narcolepsy in individuals born in March and a reduced risk in patients born in September [5]. Neurological disorders with a hypothesis of auto-immune disease, such as Sydenham chorea and, of a more controversial manner, obsessive-compulsive disorder, nervous twitches and some encephalitis, have been associated with streptococcal infections [6,7]. Watson et al. demonstrated a significant association between birth order and narcolepsy in genetically susceptible patients, or the ones with positivity for the HLA-DQB1⁎0602 allele, a definitive marker, especially, among narcoleptics with cataplexy. In this study, the affection was prevalent among the younger sons of the cases when compared to controls [8]. The association of this disease with birth order generally reflects the influence of environmental factors, specifically the exposition to infections during the initial phases of life and has been observed in some auto-immune diseases [9,10]. The role of environmental factors is strongly implicit, being the agreement rate with narcolepsy between monozygotic twins of only 20–35% [11,12].