Electrode to modiolus proximity: A fluoroscopic and histologic analysis

A Fine Structure Stimulation Strategy and Related Concepts

“…As a matter of fact, this requirement is difficult to meet in most approaches. Temporal bone studies have shown that modiolushugging electrodes increase the danger of basilar membrane perforations and spiral lamina fractures (Gstoettner et al, 2001;Richter et al, 2002;Roland et al, 2000). Besides, even if the array is closer to the modiolus, the surrounding conductive fluids will still cause broad potential distributions, and it is questionable whether a substantial improvement of channel separation is possible at all.…”

Considerations for design of future cochlear implant electrode arrays: Electrode array stiffness, size,

“…Trauma to the delicate structures of the inner ear frequently occurs during insertion of CI electrodes [16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31]. This damage ranges from relatively minor displacement of the basilar membrane to severe fracture of the osseous spiral lamina, tearing of the basilar membrane or spiral ligament, and deviation of the electrode path from its intended location in the ST to the overlying scala media and/or scala vestibuli.…”

Standardization of CT Depiction of Cochlear Implant Insertion Depth

“…1 It is important to be able to describe the CI tip location because electrode-array insertion depth and location are relevant factors when considering hearing and speech outcomes following CI insertion. [1][2][3][4] Audiologic outcomes are better when the electrode array is inserted into the scala tympani, allowing better stimulation of the spiral ganglion neural elements. Multidetector CT can detect the scala tympani in cadaveric specimens, 5 but application to routine clinical postimplantation imaging is limited.…”

“…Multidetector CT can detect the scala tympani in cadaveric specimens, 5 but application to routine clinical postimplantation imaging is limited. Multiple imaging methods have been used to determine CI electrode depth postoperatively, including conventional radiology, 4 fluoroscopy, 3 conebeam CT, 6 fusion of conventional radiography and CT images, 7 and multidetector CT. 5,8 Lecerf et al 9 showed that midmodiolar reconstructed CT on cadaver temporal bones can be used as an effective method for neuroradiologists to assess the location of CIs in either the scala vestibuli or scala tympani with high sensitivity and specificity. Ideally, the radiology report would routinely include objective measures of the CI tip insertion depth and a scalar chamber assignment so that these can be compared against the clinically desired position of the electrode tip.…”