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Vestibular changes after cochlear implantation in children
Letters to the Editor / International Journal of Pediatric Otorhinolaryngology 74 (2010) 104–106
but this is not related to increased post-operative morbidity and the correspondents appear to confuse these separate issues. Morbidity rates were similar in both groups: of the 10 cases of post-operative morbidity, 6 were organic and 4 inorganic foreign bodies. Dikkers and Plaat also make reference to oesophageal foreign bodies, but as can be deduced from the title of our paper we have confined ourselves to a discussion of the management of inhaled foreign bodies, and so the management of ingested foreign bodies is not addressed. The risk of mis-diagnosing an ingested button battery as an inhaled foreign body is an entirely separate issue, and should be avoided by PA and lateral chest X-rays on admission. Navin Mani*, C.M. Bailey Great Ormond Street Hospital for Children, Otorhinolaryngology-Head and Neck Surgery, Great Ormond Street, London, United Kingdom
105
Reference [1] I. Todt, D. Basta, A. Ernst, Does the surgical approach in cochlear implantation influence the occurrence of postoperative vertigo? Otolaryngol. Head Neck Surg. 138 (January (1)) (2008) 8–12.
Ingo Todt* Arne Ernst Department of Otolaryngology and Head and Neck Surgery, Unfallkrankenhaus Berlin, Berlin, Germany *Tel.: +49 30 5681 4301; fax: +49 30 5681 4303 E-mail addresses: [email protected] (I. Todt) [email protected] ((A. Ernst) 6 April 2009 Available online 24 November 2009 doi:10.1016/j.ijporl.2009.10.016
*Tel.: +44 7811 196957 E-mail address: [email protected] (N. Mani) 12 October 2009 Available online 22 November 2009 doi:10.1016/j.ijporl.2009.10.019
Letter to the Editor Vestibular changes after cochlear implantation in children Dear Sir, We would like to comment on the recently published paper by Jacot, Abbele, Debre and Wiener-Vacher (Int J Paed ORL 2009, 73:209– 217). ‘‘Vestibular impairments pre- and post-cochlear implant in children’’. This excellent paper from the group of Wiener-Vacher (Paris) addresses the issue of vestibular lesions induced by cochlear implantation and highlight possible consequences for bilateral implantation. It attributes a clinically frequently underestimated side-effect of cochlear implantation which – per se – is a tremendous progress in auditory rehab of deaf born children. However, long-term consequences of a – possibly bilateral – vestibular lesion or loss after cochlear implantation have not yet been extensively investigated. It is our primary concern to address in this letter the characteristics and the special attention devoted to the surgical technique applied in cochlear implantation in order to prevent iatrogenic lesions during the implantation. Recently, we could evidence in a series of cochlear implantations with two different surgical techniques encountered that a modified round-window approach which preserves saccular function in particular, can be helpful to preserve vestibular receptor functions, i.e. semicircular canals as well [1]. The data of the French group should therefore be an additional argument to surgeons to carefully consider the site and size of cochleostomy when performing cochlear implantation in order to prevent a bilateral vestibular disorder. Thank you for possibly considering our arguments for publication.
Letter to the Editor Reply to I. Todt, D. Basta, A. Ernst, ‘‘Does the surgical approach in cochlear implantation influence the occurrence of postoperative vertigo?’’ [Otolaryngol. Head Neck Surg. 138(January (1)) (2008) 8–12 and 138(June (6)) (2008) 812–3] Dr. I. Todt and collaborators (published in Otolaryngol Head Neck Surg. 2008 January;138(1):8–12 and June;138(6):812–3; author reply 813. Does the surgical approach in cochlear implantation influence the occurrence of postoperative vertigo? Todt I, Basta D, Ernst A) point out that the surgical approach for introducing the cochlear implant electrode can have an impact on the incidence of iatrogenic vestibular impairment. In their retrospective study they found greater preservation of vestibular function with the round window approach than with anterior cochleostomy. It is important to emphasize that in our department we have always used a surgical approach adapted to children and close to a round window approach. ‘‘True’’ round window electrode insertion in young children is often difficult to perform due to the low pneumatization of the mastoid and the narrowness of the posterior tympanotomy. We try to avoid injuries of the chorda tympani and accidental openings of the external auditory canal as well. In most of the cases, we perform a cochleostomy separated to the round window niche but as inferior as possible and vertical to the round window in order to avoid injuries of the spiral lamina and insertion in the scala vestibuli. With this technique, we obtained a rate of vestibular function impairment about 10%, very close to the rate obtained by Todt et al. for ‘‘true’’ round window insertion in adults, i.e. 13% and much lower than the 50% obtained with anterior window cochleostomies. Futur improvement of the electrode size or composition as well as the surgical approach could further decrease the risk of vestibular impairment due to the implantation, however some risk will remain. For this reason, it must be re-emphasized that ‘‘one step bilateral implantation’’ proposed to very young children without any vestibular evaluation, imposes an unacceptable risk of bilateral vestibular loss. This will have an effect on the rest of the child’s life, in particular at important posturomotor developmental stages for which vestibular information are critical. Bilateral implantations should hence be done in two steps at 2– 3-months intervals in order to verify the absence of vestibular loss
but this is not related to increased post-operative morbidity and the correspondents appear to confuse these separate issues. Morbidity rates were similar in both groups: of the 10 cases of post-operative morbidity, 6 were organic and 4 inorganic foreign bodies. Dikkers and Plaat also make reference to oesophageal foreign bodies, but as can be deduced from the title of our paper we have confined ourselves to a discussion of the management of inhaled foreign bodies, and so the management of ingested foreign bodies is not addressed. The risk of mis-diagnosing an ingested button battery as an inhaled foreign body is an entirely separate issue, and should be avoided by PA and lateral chest X-rays on admission. Navin Mani*, C.M. Bailey Great Ormond Street Hospital for Children, Otorhinolaryngology-Head and Neck Surgery, Great Ormond Street, London, United Kingdom
105
Reference [1] I. Todt, D. Basta, A. Ernst, Does the surgical approach in cochlear implantation influence the occurrence of postoperative vertigo? Otolaryngol. Head Neck Surg. 138 (January (1)) (2008) 8–12.
Ingo Todt* Arne Ernst Department of Otolaryngology and Head and Neck Surgery, Unfallkrankenhaus Berlin, Berlin, Germany *Tel.: +49 30 5681 4301; fax: +49 30 5681 4303 E-mail addresses: [email protected] (I. Todt) [email protected] ((A. Ernst) 6 April 2009 Available online 24 November 2009 doi:10.1016/j.ijporl.2009.10.016
*Tel.: +44 7811 196957 E-mail address: [email protected] (N. Mani) 12 October 2009 Available online 22 November 2009 doi:10.1016/j.ijporl.2009.10.019
Letter to the Editor Vestibular changes after cochlear implantation in children Dear Sir, We would like to comment on the recently published paper by Jacot, Abbele, Debre and Wiener-Vacher (Int J Paed ORL 2009, 73:209– 217). ‘‘Vestibular impairments pre- and post-cochlear implant in children’’. This excellent paper from the group of Wiener-Vacher (Paris) addresses the issue of vestibular lesions induced by cochlear implantation and highlight possible consequences for bilateral implantation. It attributes a clinically frequently underestimated side-effect of cochlear implantation which – per se – is a tremendous progress in auditory rehab of deaf born children. However, long-term consequences of a – possibly bilateral – vestibular lesion or loss after cochlear implantation have not yet been extensively investigated. It is our primary concern to address in this letter the characteristics and the special attention devoted to the surgical technique applied in cochlear implantation in order to prevent iatrogenic lesions during the implantation. Recently, we could evidence in a series of cochlear implantations with two different surgical techniques encountered that a modified round-window approach which preserves saccular function in particular, can be helpful to preserve vestibular receptor functions, i.e. semicircular canals as well [1]. The data of the French group should therefore be an additional argument to surgeons to carefully consider the site and size of cochleostomy when performing cochlear implantation in order to prevent a bilateral vestibular disorder. Thank you for possibly considering our arguments for publication.
Letter to the Editor Reply to I. Todt, D. Basta, A. Ernst, ‘‘Does the surgical approach in cochlear implantation influence the occurrence of postoperative vertigo?’’ [Otolaryngol. Head Neck Surg. 138(January (1)) (2008) 8–12 and 138(June (6)) (2008) 812–3] Dr. I. Todt and collaborators (published in Otolaryngol Head Neck Surg. 2008 January;138(1):8–12 and June;138(6):812–3; author reply 813. Does the surgical approach in cochlear implantation influence the occurrence of postoperative vertigo? Todt I, Basta D, Ernst A) point out that the surgical approach for introducing the cochlear implant electrode can have an impact on the incidence of iatrogenic vestibular impairment. In their retrospective study they found greater preservation of vestibular function with the round window approach than with anterior cochleostomy. It is important to emphasize that in our department we have always used a surgical approach adapted to children and close to a round window approach. ‘‘True’’ round window electrode insertion in young children is often difficult to perform due to the low pneumatization of the mastoid and the narrowness of the posterior tympanotomy. We try to avoid injuries of the chorda tympani and accidental openings of the external auditory canal as well. In most of the cases, we perform a cochleostomy separated to the round window niche but as inferior as possible and vertical to the round window in order to avoid injuries of the spiral lamina and insertion in the scala vestibuli. With this technique, we obtained a rate of vestibular function impairment about 10%, very close to the rate obtained by Todt et al. for ‘‘true’’ round window insertion in adults, i.e. 13% and much lower than the 50% obtained with anterior window cochleostomies. Futur improvement of the electrode size or composition as well as the surgical approach could further decrease the risk of vestibular impairment due to the implantation, however some risk will remain. For this reason, it must be re-emphasized that ‘‘one step bilateral implantation’’ proposed to very young children without any vestibular evaluation, imposes an unacceptable risk of bilateral vestibular loss. This will have an effect on the rest of the child’s life, in particular at important posturomotor developmental stages for which vestibular information are critical. Bilateral implantations should hence be done in two steps at 2– 3-months intervals in order to verify the absence of vestibular loss