Outcomes in Patients with Long Time of Hearing Deprivation
Introduction: Patients with longer duration of deafness may have worse prognosis due to possible ganglion cell survival and deafferentation. Is the presence of intraoperative electrical evoked compound action potentials (ECAP) a positive prognosis predictor in these cases?
Objectives: To identify differences between intraoperative ECAP in patients with more than 10 years and less than 5 years of durations of deafness.
Methods: Adults, post lingually, were randomly selected. Exclusion criteria included bilateral implanted, incomplete electrode insertion, neural etiologies, meningitis, and malformed cochleae. They were divided into two groups according to deafness duration: GI: more than 10 years and GII: less than 5 years. Intraoperative ECAP in at least three electrodes and speech perception performance after 1 year of device use were compared.
Results: The sample was 54 patients, 26 patients implanted with Nucleus 24RE (Cochlear) and 28 implanted with Sonata TI100 (Medel) devices. In all, 47 patients (89%) showed present intraoperative ECAP. Among the Nucleus-implanted patients with present intraoperative ECAP (GI = 12, GII = 11), 58% of GI and 79% of GII showed more than 80% of open set recognition. Among the Sonata-implanted patients with present intraoperative ECAP (GI = 9 and GII = 15), 63.6% of GI and 81.3% of GII presented more than 80% of open set recognition.
Discussion and Conclusions: Patients over 10 years of deprivation showed present intraoperative ECAP, suggesting ganglion cell survival. However, their performance in speech recognition after 1 year of CI use was lower than those who had shorter time of auditory deprivation, suggesting auditory central nervous system deprivation.