Which of the following statement regarding cochlear implant is true: (AIIMS Nov 10)
|A||Cochlear malformation is not a CI to its use|
|B||Contraindicated in children < 5 yrs of age|
|C||Indicated in mild-moderate hearing loss|
|D||Approached through oval window|
Ref. Current Otolaryngology 3rd/ed p 8S6; Dhingra 5th/ed p 739-740
a. As discussed earlier Cochlear implants are useful in B/l severe to profound hearing loss and not in mild-moderate hearing loss :. Option C is incorrect (Dhingra Sth/ed p 139), 6th/ed p 125)
b. Cochlear implants can be implanted in children at 12 months of age, rather early implantation gives better results. (Dhingra 5th/ed p 139), 6th led p 125
c. "The timing of implantation is very important. Earlier implantation in children generally yields more favorable results and many centers roultinely implant children under 12 months of age:'
d. So friends-Option b-C/I in children < 5 years of age is incorrect.
e. Approach for cochlear implants is via facial recess, where a simple cortical mastoidectomy is done first and short process of incus and lateral semicircular canal is identified. The facial recess is operated by performing a posterior tymparotomy. A cochleostomy is then done inferior to round window (Not oval window) with the goal of affording access to scale tympani (where the electrode has to be placed).
f. Thus option d . it is approached through oval window is incorrect. So by exclusion are answer is a cochlear malformation is not a contradiction to its use.