Nucleus 22 cochlear implantation results in postmeningitic deafness.

Cochlear implant surgery was performed on 13 patients with postmeningitic deafness (seven adults, six children). Two adults and two children (30.8%) had severe labyrinthitis ossificans requiring radical "drill-out." Five of 13 (38.5%) had some bone growth requiring partial drill-out, and four of 13 (30.8%) had normal insertion with no drill-out. Hearing results for patients with no bone growth were similar to nonmeningitic patients; three of four (75%) had open-set speech recognition. Performance of patients with total drill-out was poor; "auditory only" performance was limited to detection and pattern perception of speech, and no patients had open-set speech recognition. Results for patients with partial drill-out were similar to results in patients with no bone growth. Labyrinthitis ossificans not only presents surgical challenges to cochlear implantation but may also adversely affect hearing outcome.

Early hearing testing of still critically ill neonates.

OBJECTIVE: To use a newly applied hearing screening technique for early measurement in neonatal intensive care unit (NICU) patients to learn more about the high incidence of hearing loss in this population. METHODS: An automated, portable infant hearing screener that measures the auditory brain-stem response at the bedside was used at the NICU of the Hospital Nacional de Niños, San Jose, Costa Rica. Patients were evaluated early, even if they were on a ventilator. The screener tested with a 40-dB hearing level click stimulus to each ear over a bandwidth of 750 to 3000 Hz. RESULTS: During a 15-month period, 92 newborns underwent 226 auditory brain-stem response tests (range, one to six tests; mean, 2 1/2 tests). Before discharge from the NICU or death, each infant was successfully screened. Of 72 infants discharged from the hospital alive, 68 passed bilaterally and four failed bilaterally, a 6% failure rate. Of 20 infants who died, 15 failed bilaterally, a 75% failure rate. Persistent bilateral failure of the test was detectable from each infant's first test and showed an association (chi-square, P<.001) with death. The overall bilateral failure rate was 21%. CONCLUSIONS: Simple bedside auditory brain-stem response screening of all NICU infants was consistently possible regardless of clinical status, the early onset of hearing loss suggests that NICU treatment was not ototoxic and the unexpectedly high overall bilateral test failure rate resulted from the inclusion of patients who would have died untested if conventional testing had been done.

Failure to clinically predict NICU hearing loss.

Neonatal intensive care unit (NICU) survivors demonstrate handicapping sensorineural hearing loss up to 50 times more frequently than normal newborns, yet little is known about the etiology of the hearing loss. Theoretically, accurate identification and triage of a particular infant based on a clinical profile would be useful. Forty NICU graduates of The Massachusetts General Hospital were selected for a detailed retrospective chart review evaluating prenatal, perinatal, and NICU medical conditions and treatment. Twenty-three patients identified with hearing loss and 17 infants with normal hearing were compared clinically. Univariate and multivariate analysis was performed on a subpopulation of patients (20 with hearing loss and 16 with normal hearing). A history of ventilation was associated with hearing loss (P = .0023), but this factor was not absolute. No other clinical parameters were convincingly linked to hearing loss. We conclude that reliance on risk factors is an inadequate clinical method to select a patient for a hearing test and that each NICU survivor deserves audiometric evaluation.

Clinical experience with electroneurography in the pediatric patient.

Electroneurography (ENoG) has demonstrated utility in adults with facial nerve paralysis. We wished to evaluate the possible usefulness of this test in children. Twenty-six patients, aged 3 months through 16 years, were studied. Initial measurements were obtainable in all but two patients; they were successfully tested on a second attempt. All subsequent patient testing efforts were completed, for an overall successful test rate of 95%. Waveform amplitude and morphology were consistent with adult values, except in infants. The most clinically helpful use of this test was to objectively assess facial nerve function, once spontaneous motion was lost in acquired paralysis or if it had never been seen in congenital paralysis. Surprisingly, analysis of the "normal" side of the face proved most informative for three patients. Use of the test as an absolute predictor for return of function is not possible; however, the ENoG results add data that can be incorporated into the clinical information to make such predictions more rational. We conclude that ENoG can be performed on children, and that the measurements, within bounds of interpretation, can offer objective data not usually available in this age population.