Sudden Deafness and Right-to-Left Shunts

<i>Purpose:</i> One of the etiologies for idiopathic sudden deafness is considered to be ischemia of the inner ear. Cryptogenic stroke is caused by a right-to-left shunt (RLS). The present study investigated whether RLS is associated with the occurrence of sudden deafness. <i>Methods:</i> Contrast saline transcranial Doppler ultrasonography was performed to detect RLS. Subjects comprised 23 consecutive sudden deafness patients and 46 age- and gender-matched controls. Clinical characteristics, including vascular risk factors, were compared between sudden deafness and control groups. <i>Results:</i> RLS was more frequent in the sudden deafness group than in controls (48 vs. 17%, p = 0.011). No significant differences in other clinical characteristics were seen between groups. <i>Conclusion:</i> RLS may be a potential cause of sudden deafness.