A Neonatal Intensive Care Unit population of 69 infants with prematurity and diverse perinatal complications, such as asphyxia, elevated bilirubin and respiratory distress, were tested for hearing impairment about four weeks after birth using the auditory brainstem response as the basis of a hearing screening procedure. The threshold in premature infants, who had both hyperbilirubinemia and respiratory disorder or asphyxia was elevated more than that in infants with no hyperbilirubinemia not respiratory disorder. The latencies of the various potential components decreased with maturation. A linear latency-intensity function also fitted to each subject's latency because individuals who provided latencies at several levels would contribute more to such an analysis than individuals who provided a single latency.
The usefulness of the 3D-Fast Spin Echo (3D-FSE) method was evaluated in 13 children suffering from severe sensorineural hearing loss. Six out of the 13 children (7 ears) exhibited anomalies of the cochlear nerve: absence of the cochlear nerve was suspected in 3 patients, hypoplasia of the nerve in 2 patients and an abnormal passway in 1 patient. Although sensorineural hearing loss is commonly caused by stricture of the inner auditory meatus, other anomalies of the inner ear, such as hypoplasia and absence of the cochlear nerve, may cause sensorineural hearing loss. The 3D-FSE was demonstrated to be a valuable test for the diagnosis of sensorineural hearing loss.
We reported on the causes of unilateral total deafness in 109 cases as well as their CT-scanning findings and their future problems during the 5 years from 1991 to 1996 at our institute. The causes were mumps infection in 3 cases, cytomegalovirus infection in 1 case, meningitis in 1case and 102 other unknown cases. CT-scanning was conducted on 20 of these 109 cases. Five of these 20 cases. had an abnormal view. CT scanning showed narrowness of the internal auditory meatus and hypoplasia of the cochlea and lateral semicircular ducts. Previous reports have shown that patients have a conservative attitude and a poor understanding. The child's relatives require a careful explanation because they sometimes complain that the child was not diagnosed as unilateral total deafness at the first medical examination.
During the past 23 years,54 children with psychogenic hearing loss have been evauluated clinically and statistically. The results are summarized as follows; 1. The age range of the patients was 6 to 15 years and the male/female ratio was 5 to 2. 2. The patients have been increasing in number and become younger compared with the early 10 year-period. 3. The chief environmental fuctors of the patient were based on not only small physical injury, but also psychogenic problems in their family or school. 4. Thirty of these patients were found by chance during school health examinations, and the other 24 patients were introduced from ENT clinics. 5. Prognoses of these disorders was usually good, except for patients referred to the ENT clinic because of their abnormal attitudes with regard to audiometry.
Deaf children were tested by means of PVT (Picture Vocabulary Test) and WIPPSI or WISC-R, then the relation between speech development and hearing level was discussed. The age of 22 children at the test ranged from 4 years to 13 years. Their average hearing level ranged from 37 dB to 71 dB. Their PIQ (performed IQ) was within the normal range. Results of PVT were almost related to that of VIQ (Verbal IQ), but there was no evident relation between the results of PVT or VIQ and hearing level. Some of the children with mild hearing impairment showed poorer development of their vocabulary and verbalism than expected. We considered that the development of vocabulary and verbalism was affected by several factors besides their hearing level.
From 1990 to 1996,13 children, who sufferd from bilateral moderate hearing impairment, were presented to the section of Pediatric-Otolaryngology of Osaka University Medical School. Most of the cases first appeared at the ages of 3 and 4 years. We evaluated the benefits and problems of using hearing-aids in these cases by analyzing their auditory and behavioral performances and their replies to a questionnaire. Out of 13 cases,7 started to use hearing-aids within 6 months. Once the hearing level was determind, all were recommended to use hearing-aids immediately.