@article{BieniussaKahramanSkornickaetal.2022, author = {Bieniussa, Linda and Kahraman, Baran and Skornicka, Johannes and Schulte, Annemarie and Voelker, Johannes and Jablonka, Sibylle and Hagen, Rudolf and Rak, Kristen}, title = {Pegylated insulin-like growth factor 1 attenuates hair cell loss and promotes presynaptic maintenance of medial olivocochlear cholinergic fibers in the cochlea of the progressive motor neuropathy mouse}, series = {Frontiers in Neurology}, volume = {13}, journal = {Frontiers in Neurology}, issn = {1664-2295}, doi = {10.3389/fneur.2022.885026}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-276669}, year = {2022}, abstract = {The progressive motor neuropathy (PMN) mouse is a model of an inherited motor neuropathy disease with progressive neurodegeneration. Axon degeneration associates with homozygous mutations of the TBCE gene encoding the tubulin chaperone E protein. TBCE is responsible for the correct dimerization of alpha and beta-tubulin. Strikingly, the PMN mouse also develops a progressive hearing loss after normal hearing onset, characterized by degeneration of the auditory nerve and outer hair cell (OHC) loss. However, the development of this neuronal and cochlear pathology is not fully understood yet. Previous studies with pegylated insulin-like growth factor 1 (peg-IGF-1) treatment in this mouse model have been shown to expand lifespan, weight, muscle strength, and motor coordination. Accordingly, peg-IGF-1 was evaluated for an otoprotective effect. We investigated the effect of peg-IGF-1 on the auditory system by treatment starting at postnatal day 15 (p15). Histological analysis revealed positive effects on OHC synapses of medial olivocochlear (MOC) neuronal fibers and a short-term attenuation of OHC loss. Peg-IGF-1 was able to conditionally restore the disorganization of OHC synapses and maintain the provision of cholinergic acetyltransferase in presynapses. To assess auditory function, frequency-specific auditory brainstem responses and distortion product otoacoustic emissions were recorded in animals on p21 and p28. However, despite the positive effect on MOC fibers and OHC, no restoration of hearing could be achieved. The present work demonstrates that the synaptic pathology of efferent MOC fibers in PMN mice represents a particular form of "efferent auditory neuropathy." Peg-IGF-1 showed an otoprotective effect by preventing the degeneration of OHCs and efferent synapses. However, enhanced efforts are needed to optimize the treatment to obtain detectable improvements in hearing performances.}, language = {en} } @article{MuellerGraffIlgenSchendzielorzetal.2022, author = {M{\"u}ller-Graff, Franz-Tassilo and Ilgen, Lukas and Schendzielorz, Philipp and Voelker, Johannes and Taeger, Johannes and Kurz, Anja and Hagen, Rudolf and Neun, Tilmann and Rak, Kristen}, title = {Implementation of secondary reconstructions of flat-panel volume computed tomography (fpVCT) and otological planning software for anatomically based cochlear implantation}, series = {European Archives of Oto-Rhino-Laryngology}, volume = {279}, journal = {European Archives of Oto-Rhino-Laryngology}, number = {5}, issn = {1434-4726}, doi = {10.1007/s00405-021-06924-0}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-266798}, pages = {2309-2319}, year = {2022}, abstract = {Purpose For further improvements in cochlear implantation, the measurement of the cochlear duct length (CDL) and the determination of the electrode contact position (ECP) are increasingly in the focus of clinical research. Usually, these items were investigated by multislice computed tomography (MSCT). The determination of ECP was only possible by research programs so far. Flat-panel volume computed tomography (fpVCT) and its secondary reconstructions (fpVCT\(_{SECO}\)) allow for high spatial resolution for the visualization of the temporal bone structures. Using a newly developed surgical planning software that enables the evaluation of CDL and the determination of postoperative ECP, this study aimed to investigate the combination of fpVCT and otological planning software to improve the implementation of an anatomically based cochlear implantation. Methods Cochlear measurements were performed utilizing surgical planning software in imaging data (MSCT, fpVCT and fpVCT\(_{SECO}\)) of patients with and without implanted electrodes. Results Measurement of the CDL by the use of an otological planning software was highly reliable using fpVCT\(_{SECO}\) with a lower variance between the respective measurements compared to MSCT. The determination of the inter-electrode-distance (IED) between the ECP was improved in fpVCT\(_{SECO}\) compared to MSCT. Conclusion The combination of fpVCT\(_{SECO}\) and otological planning software permits a simplified and more reliable analysis of the cochlea in the pre- and postoperative setting. The combination of both systems will enable further progress in the development of an anatomically based cochlear implantation.}, language = {en} }