SM ZAKZOUK MD,FRCS-FATMA H ALANAZY MD.KSUF

King Abdulaziz University Hospital

Riyadh, Saudi Arabia.

A study was carried out on 302 children with bilateral SNHL. 66% were boys and 34% were girls; aged ranged from 9 months to 12 years. 64 cases, 21.2% with no known cause could be found and was designated of unknown etiology. This group was followed up and was subjected to more study namely: laboratory, ophthalmological evaluation for retinal pigmentary changes and analysis of audiological finding.(18 children under 4 years of age were found to be positive for Ig M antibodies for toxoplasmosis, CMV and rubella. 8 cases with pigmentary retinal changes and positiveERG, 2 cases with renal tubular acidosis).

Some received treatment and their vision corrected. In this way, 28 of the previously designated as unknown, the causes were identified and the etiology was established. The percentage of unknown cases were then reduced to 12% (36 cases only).