Characteristics of malfunctioning channels in pediatric cochlear implants

Abstract

Objectives/Hypothesis To examine the characteristics of pediatric cochlear implant channel malfunction preceding device failure. Study Design Retrospective review. Methods All pediatric patients who underwent cochlear implantation at a tertiary academic medical center were reviewed regarding device type, reason for replacement, time to replacement, and timing and pattern of channel faults in failed versus nonfailed devices. Results Between 1993 and 2008, 264 pediatric cochlear implantations were performed. With an average 894-day follow-up, the replacement rate was 9.5% (25/264). Reasons for replacement were device failure (6.4%), medical/surgical failure (2.3%), and obsolescence (0.8%). Replacement rates were comparable among Advanced Bionics (13.3%), Cochlear Corporation (6.3%), and MED-EL (10.3%) devices. Fifty-two cochlear implants developed at least one channel fault, and 13 eventually progressed to failure requiring replacement. MED-EL devices comprised 12 of these 13 failures. At the 12-month follow-up interval, one, three, and five channel faults predicted 40%, 75%, and 100% probabilities of eventual electrode failure, respectively. Channels destined to fail demonstrated small, yet statistically significant, impedance elevations 12 months before failure and large elevations 3 months before failure. Conclusions Replacement of cochlear implants in pediatric patients is common and is due to device malfunction about one half of the time. Earlier initial channel fault, earlier subsequent channel faults, adjacent channel faults, and a greater total number of channel faults were associated with the need for replacement surgery. Elevations in a channel’s impedance should raise the concern for an impending failure. These predictors can help the cochlear implant team when considering surgery to replace the device.

Cortical Activation Patterns Correlate with Speech Understanding After Cochlear Implantation

“…In this way, each participant could serve as his/her own control. In future studies, the spatial patterns of activation could be explored by localizing optode positions using the pre-implant MRI most patients receive as part of their medical evaluation of hearing loss and modeling the light travel paths (Cristobal and Oghalai 2008; Lin et al 2010; Jerry and Oghalai 2011; Lin et al 2011; Oghalai et al 2012). Despite these limitations, fNIRS is a powerful technique that is well-suited for use in an outpatient clinical setting and could be easily implemented in clinical studies of CI function.…”

Neuroimaging with near-infrared spectroscopy demonstrates speech-evoked activity in the auditory cortex of deaf children following cochlear implantation

“…Even though the CI can be placed in very young children (Lin et al, 2010; Oghalai et al, 2009), it can be difficult to perform the necessary behavioral testing to program the CI, especially if there are co-existent developmental delays which are often found in this patient population (Beauchamp et al; Cristobal et al, 2008; Katzenstein et al, 2009; Kushalnagar et al, 2007; Pierson et al, 2007). Therefore, an objective method to measure brain activity would be give valuable additional information.…”

Functional near-infrared spectroscopy for neuroimaging in cochlear implant recipients

“…Such information can supplement behavioral tests, which are often limited in young CI users (Choi and Oghalai, 2005; Katzenstein et al, 2009; Lin et al, 2010; Oghalai et al, 2009; Santa Maria and Oghalai, 2014; Williamson et al, 2009; Ying et al, 2013). However, there are inherent limitations in the use of all of the currently available neuroimaging modalities in CI recipients, as outlined below and summarized in Table 1.…”