Feature Of Semicircular Canal Function In Obstructive Sleep Apnea-Hypopnea Syndrome

ObjectiveAim of the study was to evaluate the effects of obstructive sleep apnea-hypopnea syndrome(OSAHS) on semicircular canal function and balance characteristics in patients with OSAHS.MethodsBy means of a series prospective study at Otolaryngology Head and Neck Surgery department of our hospital,the study was performed on 77 patients suffering from OSAHS in the period 2012-2014 who underwent polysomnography(PSG) and caloric test. The maximal slow-phase velocity(SPV) and unilateral weakness(UW)were used to measure the vestibular function. Severity of OSAHS was evaluated by the lowest oxygen saturation(LSaO2)and apnea hypopnea index(AHI). Sign the SPV after cool and warm test for each ear and calculate the sum of left ear SPV,then count the SPV of right ear as the same way. Analyze the relationship between LSaO2,AHI,age,BMI and SPV of caloric test.ResultsCaloric vestibular tests in the 77 OSAHS patients demonstrated abnormal findings in 52 patients(67.5%) and normal vestibular functions in the remaining 25patients(32.5%). Of the 52 patients with an abnormal test result, 16(20.8%)patients had unilateral vestibular hyporeflexia and 36( 46.7%) patients revealed a bilateral vestibular hyporeflexia. There is no linear relationship between AHI,age,BMI with SPV of caloric test(P > 0.05).The SPV has significant difference between Lower LSaO2 group(LSaO2<50%) and higher LSaO2 group(LSaO2≥80%)(P<0.05). LSaO2 is lower in patients undertaken bilateral vestibular hyporeflexia.ConclusionsOSAHS patients with long-term intermittent hypoxia can disturb the vestibular organs and reduce semicircular canal function. The heavier hypoxemia will lead to the lower reflex of semicircular canal and with the heavier degree of hypoxemia,bilateral horizontal semicircular canal involvement may also be higher at the same time. Due to the effect of vestibule centre compensatory,OSAHS patients lack ofdizziness and balance disturbances symptoms such as typically acute vestibular damage.That is the character symptoms in patients with OSAHS for a long time.