[Cortical auditory evoked potentials in congenital hearing impaired children with cochlear implants].
OBJECTIVE
By investigating the auditory cortical evoked potential in congenital hearing impaired children with cochlear implants, the association between central auditory development and the age of implantation was studied.


METHODS
P1-N1-P2 were recorded in 110 profound hearing impaired children, aged from 12 to 80 months old and being implanted with cochlear implants before the age of 5 years. Their implant using time ranged from just at the switch-on to 48 months. The stimuli were /m/, /t/, /g/, presented at 65 dB SPL in sound field. The presence rate of each wave was obtained and the relationship between P1 latency and implant age, the time of speech processor switch-on were analyzed.


RESULTS
The presence rate of P1, N1 and P2 was 66.4%, 15.5% and 12.7%, respectively. The presence of P1 was significantly higher than that of N1(χ(2)=228.542, P=0.00)and P2(χ(2)=257.438, P=0.00). There was no significant difference of P1 presence rate elicited by /m/, /t/ and /g/(64.1%, 66.9% and 68.3%, χ(2)=0.589, P=0.75). There existed no significant difference either among P1 latency(P=0.22)or amplitude(P=0.09) elicited by /m/, /t/ and /g/. There was significant difference between the implant age before and after 42-month-old regarding the proportion that entered the age-appropriate normal P1 latency range(P=0.02). No significant difference was found among groups of implant using time of 1, 2, 3 and 4 years in aspect of the proportion that entered the age-appropriate normal P1 latency range(P=1.00).


CONCLUSIONS
Compared with implanted after the age of 42-month-old children with prelingual hearing impairment younger than 5 years old, the ones implanted before 42-month-old have more chance for normal development for central auditory system. Once implanted before 42-month-old, the cortical auditory system restored its normal development as early as 1 year after implantation.
Department of Otology, the First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, China.
W
W
Lu
L L
LL
Chen
Department of Otology, the First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, China.
Q
Q
Lu
Department of Otology, the First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, China.
S P
SP
Sun
Department of Otology, the First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, China.
Y B
YB
Lei
Department of Otorhinolaryngology Head and Neck Surgery, Beijing Tongren Hospital, Capital Medical University, Beijing Institute of Otolaryngology, Key Laboratory of Otolaryngology Head and Neck Surgery (Capital Medical University), Ministry of Education, Beijing 100730, China.
X Q
XQ
Chen
Tongzhou Rehabilitation Center for Cochlear Implants, Beijing 101100, China.
S
S
Mi
Department of Otorhinolaryngology Head and Neck Surgery, Beijing Tongren Hospital, Capital Medical University, Beijing Institute of Otolaryngology, Key Laboratory of Otolaryngology Head and Neck Surgery (Capital Medical University), Ministry of Education, Beijing 100730, China.
L Y
LY
Mo
D000367:Age Factors; D002648:Child; D002675:Child, Preschool; D003054:Cochlear Implants; D003638:Deafness / Q000151:congenital* / Q000503:physiopathology*; D005072:Evoked Potentials, Auditory / Q000502:physiology*; D006801:Humans; D007223:Infant; D012016:Reference Values