2007 Volume 50 Issue 2 Pages 144-149
Fasudil, a potent Rho-kinase inhibitor, has been reported to reverse the endothelin-induced vasoconstriction of the spiral modiolar artery in the gerbil cochlea. We previously demonstrated that both endothelin receptors and endothelin-converting enzymes are expressed in the rat cochlea and that the serum endothelin levels in patients with sudden sensorineural hearing loss (SSHL) were significantly increased before steroid treatment. Since one subgroup of SSHL is believed to arise from vasoconstriction and vasospasm of the spiral modiolar artery ultimately causing ischemic stroke of the cochlea, we conducted a clinical investigation of fasudil (Rho-kinase inhibitor) combined with a steroid for the treatment of SSHL by preventing the inner ear ischemia induced by endothelin. Nine out of ten SSHL patients (90%) who received intravenous infusion of fasudil (9 days×30mg twice/day) showed complete or significant recovery in the level of hearing. The average hearing level was 72.7dB (n=10) before fasudil treatment, 44.9dB at the end of fasudil treatment (9 days after), and 31.9dB at the final evaluation. These results indicate that idiopathic SSHL could be caused by endothelin-induced vasoconstriction and vasospasm of the spiral modiolar artery of the cochlea, and that the fasudil administration combined with a steroid may be a novel potent treatment option for SSHL.
