Approximately 324,000 people worldwide have received cochlear implants (CI), including children. The recent developments of bimodal electroacoustic devices and lowered age eligibility in children require long-term preservation of a patient's residual hearing and sensitive neural structures post-implantation. Mild therapeutic hypothermia is known to provide neuroprotection following ischemic and traumatic injuries. We have extended the application of localized hypothermia and applied it to the cochlea during electrode insertion. Our preliminary results suggest significant protection of hair cells from damage caused by insertion trauma and subsequent long-term protection of function. Localized hypothermia is beneficial over systemic hypothermia. In acute and chronic experiments, mild hypothermia (2-6C of cooling) achieved with a custom-designed thermoelectric cooling system and applied locally to the middle and basal turns of the cochlea was found to enable conservation of hearing. The overall objectives of the present application are to identify the inflammatory signaling events regulated by mild hypothermia after cochlear implantation and develop a clinical device to improve CI outcomes in patients. Acute and chronic studies in an animal model will guide future applications of therapeutic hypothermia. We will identify molecular pathways and gene networks together with single genes or gene families significant for otoprotection to further exploit benefits of hypothermia and improve its translation to clinica practice. The proposed studies will lead to the development of a clinical device and novel applications in preservation of auditory and vestibular function during neurotologic surgeries. Ensuring the survival of sensitive hair cells and neural structures in the cochlea will enable patients to benefit from future technologies and/or therapies.
The proposed studies will develop and test a localized, therapeutic mild hypothermia device to conserve hearing following traumatic stress to the ear caused by cochlear implant insertion in ears with residual hearing. We will also determine the molecular mechanisms underlying benefits of therapeutic hypothermia in the inner ear that reduce the trauma associated cellular inflammatory response. The proposed studies will lead to new surgical and treatment approaches for conservation of inner ear function following surgical trauma.
| Bennett, Cassie; Samikkannu, Malaroviyam; Mohammed, Farrah et al. (2018) Blood brain barrier (BBB)-disruption in intracortical silicon microelectrode implants. Biomaterials 164:1-10 |
| Tamames, Ilmar; King, Curtis; Huang, Chin-Yuh et al. (2018) Theoretical Evaluation and Experimental Validation of Localized Therapeutic Hypothermia Application to Preserve Residual Hearing After Cochlear Implantation. Ear Hear 39:712-719 |
| Tamames, Ilmar; King, Curtis; Bas, Esperanza et al. (2016) A cool approach to reducing electrode-induced trauma: Localized therapeutic hypothermia conserves residual hearing in cochlear implantation. Hear Res 339:32-9 |
