Cogan's syndrome: audiovestibular involvement and prognosis in 18 patients.

The experience at the Mayo Clinic with 18 patients who had Cogan's syndrome is reviewed. Typically, the illness began with systemic symptoms. The ocular and audiovestibular symptoms included ocular discomfort and redness, photophobia, and fluctuating sensorineural deafness with imbalance. Each patient had interstitial keratitis; the ocular symptoms periodically recurred but responded to therapy. Thirteen patients who had fluctuating bilateral sensorineural deafness subsequently suffered total bilateral deafness. Two patients who are unilaterally deaf have good residual hearing. Two other patients regained hearing within normal limits after treatment with corticosteroids. No hearing symptoms were observed in one patient who had severe vertigo and whose condition is stable. Seventeen patients had vertigo: 11 have no labyrinthine function, 1 had absent responses on vestibular testing initially but currently demonstrates good responses, and the 5 others have remained stable with diminished vestibular function. If Cogan's syndrome is diagnosed early and treatment with corticosteroids is initiated promptly, hearing can be stabilized; otherwise, the prognosis for auditory function is poor.