Disfunção neuromuscular das vias aéreas superiores na patogênese da apneia obstrutiva do sono na doença de Parkinson

Abstract

Sleep disorders are part of the non-motor symptom complex of Parkinson's Disease (PD), with a negative influence in the quality of life of individuals with PD. Obstructive sleep apnea syndrome (OSAS) is one of them, with a high prevalence varying from 27 to 60%, which presents an uncertain relationship with PD. Upper airway dysfunction in PD is well documented and it is believed to be a reflex of the motor involvement of laryngopharyngeal muscles, being potentially involved in the genesis of the obstructive phenomenon of OSAS in PD. Aim: to evaluate the relationship between neuromuscular dysfunction of the upper airway with OSAS in PD patients. Methods: 48 PD patients (41 male and 7 female) submitted to polyssomnography for OSAS diagnosis, and to functional evaluation of the upper airway by spirometry and clinical analysis of the laryngopharyngeal muscles. Variables related to PD evolution (disease duration, Hoehn-Yahr scale, UPDRS III, levodopa equivalent dose, presence of motor phenomena and postural changes in trunk and neck), and variables related to OSAS (obesity, Mallampati index, neck circumference, snoring, excessive diurnal sleepiness, arterial hypertension, depression, diabetes mellitus and nocturia) were also evaluated. Results: 31 out of 48 participants (64.6%) fulfilled the criteria for OSAS according to ICSD-3 (Group PD with OSAS); the other 17 participants constituted the Group PD without OSAS. The average age was 62.8 ±10.1 and 63.3 ±11 years (p=0,98) and the PD duration was 8.4 ±4.1 and 6.5 ±4.3 years ( p=0,096) in each group, respectively. The upper airway obstruction frequency by spirometry was 25% and the laryngopharyngeal muscular dysfunction detected by clinical analysis was 60.4%, with hipophonia (58.3%) being the main compromise, followed by prejudice in tongue protrusion (25%). The presence of laryngopharyngeal muscular dysfunction was correlated to the occurrence of OSAS (RC=3.49-IC 95%:1.01-12.1, p=0.044), but the same was not observed in respect to the upper airway obstruction on spirometry. The laryngopharyngeal muscular dysfunction was also associated to spirometric changes indicating upper airway dysfunction (RC=5.2-IC 95%:1.002-26.9, p=0.037), to higher PD motor compromise, showed by a higher score on UPDRS III (20 vs 15, p=0.0005) and on the Hoehn-Yahr scale (2.5 vs 2.0, p=0.008), and to a higher frequency of postural changes in trunk and neck (51.7% vs 21.1%, p=0.033) and motor phenomena (65.5% vs 31.6%, p=0.021). The characteristics usually associated to a higher risk for OSAS in the general population, like obesity, increased neck circumference, Mallampati index III-IV, snoring, excessive diurnal sleepiness, arterial hipertension, depression, diabetes mellitus, and nocturia, were not correlated with OSAS in PD. We can conclude in this study that the laryngopharyngeal muscular dysfunction should be considered a factor for the occurence of the obstructive phenomenon of the upper airway in patients with OSAS in PD. We found that patients with laryngopharyngeal muscular have worse motor performance with higher UPDRS III scores, greater frequency of motor phenomena and postural changes in neck and trunk.