The use of electro-acoustic impedance measurements in detecting early clinical otosclerosis.

The first evidence that sodium fluoride (NaFl) can stop the otosclerotic process was recently presented. This development has placed new emphasis on the early detection of clinical otosclerosis. Electro-acoustic impedance measurements often detect minute changes in absolute impedance and compliance of the ossicular chain. The most valuable diagnostic information, however, is a negative on-off (biphasic) type of acoustic reflex. These results are often evident prior to the detection of positive clinical signs of otosclerosis. The negative on-off acoustic reflex is reviewed in this paper along with case discussions involving medical/surgical management of early otosclerosis.