Release: September 9, 2001
Contact: Kenneth Satterfield(703) 519-1563[email protected]303-228-8460 (9/7-9/12)
LONGTERM FOLLOW-UP REVEALS PEDIATRIC COCHLEAR IMPLANTATION TO BE SAFE AND EFFECTIVE
A new study measures speech perception, linguistic and communication performance of a large number of children who have used cochlear implants for five or more years.
Denver, CO -- Multichannel cochlear implants have been surgically implanted in the hearing impaired pediatric population in North America since 1987. Initially, a conservative approach to selecting patients was taken. The criteria included a lower age limit of two years, a bilateral profound sensorineural hearing loss, the family environment, and no measurable benefit from hearing aids or medical contraindications, and realistic expectations on the part of the child (if old enough). It was felt that while post-linguistically deaf children might benefit, pre-linguistically deaf children were less likely to do so. The post-operative outcome goals were equally modest: no mention was made of open-set speech understanding or the development of oral language skills following implantation.
There are concerns that in children, the cochlear implant function might degrade over time, that devices and electrodes might migrate and extrude in the growing child, or that there might even be a deleterious effect of long-term stimulation of the cochlear nerve. Additionally, anecdotal evidence revealed a wide range of performance of the device after pediatric implantation.
A group of experts in cochlear implantation set out to determine the long-term consequences in providing this device to deaf children. They have found the fears regarding device degradation are unfounded and that cochlear implantation results in real benefits to language and communication skills.
The authors of the study, "Long Term Effects of Cochlear Implants in Children" are Susan B. Waltzman, PhD, Noel L. Cohen, MD, Janet Green, and Thomas Roland, Jr., MD, all from the Department of Otolaryngology, New York University, New York, NY. Their findings were presented on Wednesday, September 12, at the American Academy of Otolaryngology--Head and Neck Surgery Foundation Annual Meeting/OTO EXPO, being held September 9-12, 2001, at the Colorado Convention Center, Denver, CO.
Methodology: From 1987-1995, 133 profoundly hearing impaired children received cochlear implants at New York University Medical Center. The mean age at time of implantation was 4.9 years, with a range of 1.8-15 years. 126 children were implanted with the Nucleus 22 device, and seven children received the Clarion cochlear implant. The cause of deafness was unknown in 64 children (48 percent) while 33 (25 percent) were deaf due to meningitis, 25 (19 percent) were genetic, three (two percent) had Congenital Cytomegalovirus (CMV) and three (two percent) had Mondini deformities. Of the remaining five children, two had Waardenberg's Syndrome, one had Leber Syndrome, one had CHARGE syndrome (consisting of specific birth defects) and one was deafened as a result of ototoxic drugs.
The children were followed for a period of five to 13 years. Age appropriate word and sentence recognition tests were used to measure speech perception preoperatively and postoperatively. If a child was too young or too linguistically impaired to understand or perform the necessary auditory perception task, the tests were not administered or were scored as "0". The speech perception evaluation protocol included two closed set tests: The Early Speech Perception test (ESP) and The Northwestern University Children's Perception Test of Speech (NU-CHIPS). Open set word recognition tests included the Glendonald Auditory Screening procedure (GASP) and the Phonetically Balanced Kindergarten (PBK) test. Sentence recognition tests included the Common Phrases and Bamford-Kowal-Bench tests.
Eighty-one of 133 children were followed at NYU Medical Center for a period of five or more years and were included in this analysis. One child was followed for 13 years, two for 12, three for 11, four for 10, 14 for nine, 15 for eight, 13 for seven, 13 for six and 17 children for five years. Of the remaining children, 39 changed location prior to the five-year follow-up point and were followed elsewhere. Nine children were lost to follow-up and four are known non-users. Eight children required re-implantation due to device malfunction; however, all continued to improve following re-implantation with either the same or an upgraded device.
Results: The data revealed a statistically significant difference between pre-implant and post-implant speech perception test scores with a growth in skills that leveled off or reached a ceiling score in testing. Of the children followed, 88 percent use oral speech as their prime or sole mode of communication. Eleven percent required re-implantation with no measured diminishment in their auditory performance.
The authors suggest that cochlear implants in children offer real advantages in hearing, educational and communication abilities, which can be expected to result in improved quality of life and employability without deleterious long term effects.
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