EARLY HEARING SCREENING FOR BRAIN IMPAIRMENT BABY

CRIB-O GRAM

Abstract

A retrospective investigation by ABR and COG was performed to children with bain impairment determined by neurological follow-up out of children who had hearing screening test, and the relationship with the presence or not of hearing loss was analyzed.
The results obtained are as follows.
1) The failure rate in COG test was 46.3% in the brain impairment group. It was significantly higher than in the hearing loss high-risk group and the low-risk group. However, 20% of 101 children with brain impairment ware cases in which the COG test could not be performed. Presumability, this is due to the special character of COG test.
2) In the brain impairment children group, the rate of true positive, true negative and false negative by COG as to the presence or not of hearing loss stood at 68. 8%, 31. 3%, and 0% respectively. Since, however, 32.4% of the children who failed to pass COG had hearing loss, the usefullness of COG can be said to be high.
3) The incidence of hearing loss was significantly high at 15. 0% in the brain impairment group compared with other groups. In contrast, the rate of true positive was significantly high, the rate of true negative sigsaficantly low and no false negative was noted in the low-risk group. So COG was considered appropriate as a hearing screening device that can be used from the neonatal period.
4) In the brain impairment group, the rate of true positive by ABR was high at 86. 7%, but the rate of true negative was 13%. That is cases that have no hearing loss but do not pass ABR were noted in the brain impairment group.
5) As for the cases that failed inioial ABR and were suspected of hearing loss but eventually diagnosed as having no hearing loss, they all passed COF performed earlier. As for the cases of hearing loss, they all failed to pass COG. So, judgement of "pass" in the preceding COG can be a foundation on which to rule out hearing loss.
6) Eleven out of 13 children in the brain impairment group who failed to pass both COG and ABR had hearing loss. The effciency of hearing loss screening could be raised by combining the tests.