Aetiology of bilateral sensori-neural deafness in children.

The study was carried out in the Department in children born during the four year period 1981-1984 in a well defined geographical areas known as the Greater Manchester County. The children were investigated for possible congenital infections. Perinatal assessment was carried out in conjunction with the Paediatricians for aetiological adverse factors. Family histories were obtained and parents and siblings were examined for any hearing impairment. A total of 155 cases were investigated. Cases with a positive family history with deafness in siblings or parents constituted 18.7% of cases. An even larger group (35.5%) was found to have no known positive cause and negative family history. Adverse perinatal factors accounted for 15.5% of cases while congenital infections were found to be the cause of deafness in 10.3%. Meningitis led to deafness in 6.5% and chromosomal abnormality was the aetiological factor in 3.8% of cases.