[Diagnosis in infants with hearing loss using auditory steady-state evoked potentials].

OBJECTIVE

To investigate the correlation between the auditory steady-state response (ASSR) thresholds and the vision reinforcement audiometry (VRA) thresholds in infants with auditory neuropathy.

METHODS

Ten cases in control group were measured by the ASSR and VRA. Based upon the ABR, DPOAE, and impedance data, as well as the aetiology (infection of the early pregnancy, defect of oxygen in birth and jaundice after birth), the 16 cases with hearing losses were divided into three groups (I , II and III). ASSR and VRA were examined.

RESULTS

From the analysis of ABR, DPOAE, and impedance data, the patients with the infection of early pregnancy in group I (5 cases/8 ears) had that the DPOAE were absent (5 cases/8 ears), the latency of wave I of ABR was delay and the interpeak latency of wave I - V of ABR was short (4 cases/6 ears), as well as the acoustic reflect thresholds in 500 Hz and 1000 Hz were normal (3 cases/6 ears) and high (2 cases/2 ears). They were deduced in cochlear lesion. The patients of group II with defect of oxygen in birth (5 cases/10 ears) showed that the DPOAEs were absent, the wave I of ABR was absent (3 cases/5 ears), and the interpeak latency of wave I - III of ABR was delay (2 cases/3 ears) They were deduced in auditory neuropathy (lesion from the cochlea to the brain-stem). The patients of group III had that the DPOAEs were present (6 cases/8 ears), the wave I/III/V of ABR and acoustic reflect were absent(4 cases/5 ears), and the interpeak latency of wave I -V of ABR was delay (2 cases/3 ears) who were deduced in auditory neuropathy(from the brain-stem to the subcortical lesion). Our results showed that the correlation coefficient-ranges between the ASSR thresholds and the VRA thresholds were the 0. 95 - 0. 98 in group I, the 0. 72 - 0. 84 in group II, and the 0.43 - 0.64 in group III. Comparison of the mean threshold-differences between the ASSR VRA thresholds for group I, group II, and group III for each frequency revealed significant difference (F test, P < 0.05, P < 0.01, P < 0.01, P < 0.05, P < 0.05).

CONCLUSIONS

The correlation technique between the ASSR thresholds and the VRA thresholds could provide the auditory neuropathy diagnosis and differential diagnosis in infants.