Perilymphatic fistulas: are they exclusive to the round and oval windows?

Eleven patients suspected of having perilymphatic fistulas were evaluated. A perilymphatic fistula was demonstrable in ten of these patients. In six patients, fistulas of one of the windows, or both were found. In two patients, combined fistulas of both the round window and lateral semicircular canal were found. In two other patients, fistulas were found only in the lateral semicircular canal. The patients in whom fistulas were found and repaired improved dramatically. The patient without a demonstrable fistula remained symptomatic. We have shown that perilymphatic fistulas can occur in the lateral semicircular canal, and suggest exploring this area when indicated.