Analysis of hearing loss after shunt placement in patients with normal-pressure hydrocephalus.

OBJECT: Following shunt placement for treatment of normal-pressure hydrocephalus (NPH), several patients suffered hearing loss. The authors undertook a study to analyze this outcome. METHODS: Sixteen patients in whom NPH was diagnosed were treated by placement of a ventriculoperitoneal shunt. Their hearing was assessed pre- and postoperatively by using pure tone audiometry. Two thirds of the ears tested showed a postoperative hearing loss of more than 10 dB. Recovery of the hearing loss occurred 6 to 12 weeks after shunt placement in 75% of the ears examined. CONCLUSIONS: Although shunt insertion for treatment of NPH results in a decrease in hearing, most of the loss can be recovered.

The click-evoked oto-acoustic emission, c-EOAE, in preterm-born infants in the post conceptional age range between 30 and 68 weeks.

Click-evoked otoacoustic emissions (cEOAEs) were repeatedly recorded in an operational sample of 144 very low birth weight (VLBW) infants. A subgroup of 22 was composed of all those babies in which at least 4 recordings were successfully done. The mean birth weight of this group was 1040 g, and the mean duration of assisted ventilation was 17 days. The OAE-recordings were done in the post conceptional age (PCA) range between 30 and 68 weeks. In relation to ear function screening it was shown that the EOAE was present in 95% of the ears at least once at any age, while it was present in all recordings in only 34%. From a longitudinal analysis of the recordings per infant it appeared that: (1) the OAE recorded was already present in one infant at the PCA of 29.4 weeks; (2) in most infants the level of the OAE varies strongly between recordings; (3) in each infant the OAE-level shows an increase with age, on average this growth amounts to 10 dB between the PCAs of 31 and 42 weeks; (4) there is no clearcut difference in the growth of high- and low-frequency components of the EOAE.