CMV e impianto cocleare: valutazioni elettrofisiologiche sulla funzionalità dell’interfaccia elettrodo-neurale.

The survival of the cochlea’s peripheral neural structures directly influences its ability to accurately encode and process electrical stimuli, thereby affecting the clinical-functional outcomes of cochlear implantation. The electrical stimulus from the cochlear implant induces depolarization of the afferent fibers, culminating in the summation of the compound action potential of the eighth nerve (eCAP). Studying the eCAP allows for the examination of the functional status of the neural periphery by observing response variations related to stimulus changes. One parameter that characterizes the biphasic electrical pulse trains of the implant is the time interval between the cathodic (negative) phase and the anodic (positive) phase, known as the interphase gap (IPG). Several studies, using animal models, have demonstrated the sensitivity of eCAP to changes in the interphase gap (IPG) (referred to as the IPG effect) and have associated this differential sensitivity with the survival rate of spiral ganglion neurons (SGNs), hypothesizing that this principle is applicable to human users. In this investigation, eCAP response variations to different IPGs were compared across two groups of congenitally deaf patients: 10 patients with etiology linked to CMV and 10 patients with non-CMV-related etiologies. All patients have Cochlear Nucleus implants. The study compares quantitative and qualitative differences in the eCAP results obtained from three electrodes located in the basal, middle, and apical sections of the array