Publication: Koklear implant hastalarında işitme sinirinin elektriksel uyarımlı birleşik aksiyon potansiyelinin ölçümü
Abstract
Bu çalışmada amaç Elektrik uyarımlı Bileşik Aksiyon Potansiyel (EBAP) eşiğinin ve EBAP amplitud artış oranının koklear implantlı hastaların programlanmasında ne ölçüde kullanılabileceğini araştırmaktır. Bu amaçla üç ayrı araştırma planlandı. Birinci araştırmada, operasyon sırasında ve operasyon sonrasındaki EBAP eşiği, ilk programlamada SPEAK moduna göre saptanan T/ C seviyeleri karşılaştırıldı. İkinci araştırmada, operasyon sırasında elde edilen EBAP büyüme eğimi hastaların yaşı, işitme kaybı süresi ve elektrotların yerleşim özelliğine göre incelendi. Üçüncü araştırmada ise implant kullanımının EBAP eşiğine ve EBAP büyüme eğimine etkisi çalışıldı. Çalışmaya toplam 60 hasta dahil edildi. Bu hastalar toplam 108 kez NRT ile test edildi. Bu testlerden 24'ü ameliyat sırasında, 84'ü implant kullanımı sonrasında gerçekleştirildi. Hastalardan 27'si çocuk (15 yaşından küçük), 33'ü yetişkin; 34'ü kadın, 26'sı erkektir. Sonuçta EBAP eşiğinin T ve C seviyesi ile yüksek korelasyon gösterdiği ve koklear implant kullanımının EBAP amplitudunu etkilediği bulundu. Bu bulgular, NRT testinin, koklear implantın takılması, programlanması ve kullanılması aşamalarında operatöre ve odyoloğa hasta özellikleri hakkında önemli bilgiler sağlayan objektif bir araç olduğunu göstermektedir.
The aim of this study is to investigate usefulness of threshold (t-NRT) and amplitude growth function (AGF) of Electrically evoked Compound Action Potential (ECAP) of auditory nerve during the first programming of cochlear implant systems. For this aim, three separate studies were planned. In the first study, intra-operative and post-operative t-NRTs were compared with tune up T and C levels which were obtained according to SPEAK strategy. In the second study, correlation between the intra-operative AGF findings and age & duration of deafness of the patients were examined according to place of the electrodes. And finally, the effect of cochlear implant usage on t-NRT and AGF was studied. Sixty cochlear implant users were involved in these studies. The patients were tested 108 times, as a total. Twenty four of the tests were made intra-operatively, and 84 tests after the first tune-up. Twenty six of the patients were male, and number of children (younger than 15) was 27. Findings showed a good correlation between t-NRT and T/ C levels. However, correlation between AGF and age & duration of deafness were poor due to too many variables which contaminated the results. On the other hand, AGF was effected by CI usage. This finding supports the studies on spiral ganglion cell and chronic electrical stimulation. According to these studies, chronic electrical stimulation causes increase in number or/ and density of spiral ganglion cells. As the result, NRT test is a very important objective tool and in the near future could be used for programming cochlear implant systems.
The aim of this study is to investigate usefulness of threshold (t-NRT) and amplitude growth function (AGF) of Electrically evoked Compound Action Potential (ECAP) of auditory nerve during the first programming of cochlear implant systems. For this aim, three separate studies were planned. In the first study, intra-operative and post-operative t-NRTs were compared with tune up T and C levels which were obtained according to SPEAK strategy. In the second study, correlation between the intra-operative AGF findings and age & duration of deafness of the patients were examined according to place of the electrodes. And finally, the effect of cochlear implant usage on t-NRT and AGF was studied. Sixty cochlear implant users were involved in these studies. The patients were tested 108 times, as a total. Twenty four of the tests were made intra-operatively, and 84 tests after the first tune-up. Twenty six of the patients were male, and number of children (younger than 15) was 27. Findings showed a good correlation between t-NRT and T/ C levels. However, correlation between AGF and age & duration of deafness were poor due to too many variables which contaminated the results. On the other hand, AGF was effected by CI usage. This finding supports the studies on spiral ganglion cell and chronic electrical stimulation. According to these studies, chronic electrical stimulation causes increase in number or/ and density of spiral ganglion cells. As the result, NRT test is a very important objective tool and in the near future could be used for programming cochlear implant systems.