[Prevalence of obstructive sleep apnea syndrome (OSA) in patients with sudden hearing loss. A pilot study]

It is estimated that in patients with sleep-related breathing disorders the probability of a cerebral vascular infarction (CVI) is 3.1 times that in patients without sleep apnea and that 25-50% of all patients who have a stroke suffer from sleep apnea (OSA) and have a respiratory disturbance index (RDI) higher than 10. CVI may be caused by variations in intracranial pressure or in intracranial hemodynamics owing to decreasing pO(2) and increasing pCO(2) during cessation of airflow. It is suspected that the most common causes of sudden deafness are vasospasm, thrombosis, embolism, hypercoagulation and sludging. The present study analyzed the prevalence of sleep apnea in patients with sudden hearing loss.

A 7-channel polygraph was used to test 33 subjects with normal hearing and 27 patients suffering from sudden hearing loss. Statistical analyses were performed with a Chi-square test and the Mann-Whitney test.

We found that 29.6% of the patient group and 21.2% of those in the study control group were suffering from OSA and had RDI >10; this difference was not significant ( p=0.554). Sudden hearing loss may also be an indicator of arteriosclerosis secondary to such risk factors as hypertension ( p=0.005), diabetes ( p=0.003), and hyperlipidemia ( p=0.004), which were highly significant for the patient group.

Patients who develop sudden hearing loss tend to have OSA more frequently than those in the control group owing to the similar risk factors for cerebral infarction and sudden hearing loss.