Electrocochleographic findings and the effects of lidocaine on tinnitus in non-hearing ears.

In the preceeding report (Jackson, 1985) the author produced evidence which brought into question the widely held view that, in abolishing tinnitus, lidocaine was acting 'centrally'. This present investigation is another approach to attempt to narrow the site of action of lidocaine in abolishing tinnitus. During a four-year period, patients suffering from strictly unilateral tinnitus which was referred to, and therefore apparently arising from, an ipsilateral 'dead' ear, underwent electrocochleography. Additionally, the subjective effect on the tinnitus of a bolus injection of lidocaine was recorded. Nine patients were available for this study, which appears to show a correlation of the results of the electrocochleogram and the effects of the lidocaine injection, although the numbers are small.