Severity of obstructive sleep apnea syndrome in relation to hypoglossal nerve dysfunction

BackgroundMany researchers studied treatment of OSAS by hypoglossal nerve (HGN) stimulation with conflicting results, however few studies addressed the role of HGN dysfunction in the pathogenesis of OSAS.AimComparison of HGN conduction findings between patients with OSAS and healthy controls as well as correlation of abnormalities with the severity of OSAS.Methods20 patients with mild and 16 with moderate-severe OSAS, and 12 healthy controls were included. All subjects had undergone sleep study (Apnea-hypopnea index, AHI; lowest oxygen saturation, LOS; Oxygen desaturation index, ODI) and HGN study (Latency and amplitude).ResultsPatients with OSAS had significantly higher values for latency and lower values for amplitude than controls (p < 0.05). There are non-significant differences between right (Rt) and left (Lt) HGN conduction findings in patients’ groups (p > 0.05). There are significant differences between the two patients’ groups regarding AHI, LOS and ODI (p < 0.05). In patients’ groups there is significantly positive correlation for latency and negative correlation for amplitude with the severity of OSAS.ConclusionThere is an evidence of HGN dysfunction even in patients with mild OSAS with significant correlation with the degree of severity. Bilateral assessment of nerve function is essential before treatment with HGN stimulation for proper selection of patients and side to be stimulated.