Causes of bilateral sensorineural hearing loss in school children

ABSTRACT

A study of children in Special schools in Karachi Pakistan, was conducted to find out the factors responsible for hearing impairment. Information was collected through a questionnaire sent to the parents of all the hearing impaired children registered in these schools. In total 657 [60%] completed questionnaires were returned. 100 children were randomly selected for general physical, ear and eye examinations and pure tone audiometry, tympanometry, blood and urine tests, IgG for rubella and a skull X-ray. The causes of hearing impairment was rubella in 2% of the children, jaundice in 4.5% meningitis in 5.2% measles in 11.4%, ototoxicity in 0.7%, prematurity in 0.7%, and genetic factors in 27% of the children investigated. In 80% of the children the mode of inheritance was recessive and in 15% it was domininant.. 5% of these cases were syndromal. The rate of parental consanguinity among hearing impaired children was 58%. Average hearing loss in 94% of the study group was above 80 dBHL. The mean age of diagnosis of hearing loss was 19.1 months in 51% children the hearing impairment was diagnosed by the age of one year. Parents suspected the hearing loss in 61% of cases