Olfaction and smell identification tests: A novel test that may correlate with cochlear implant outcomes

A cochlear implant (CI) is a prosthetic implantable device that is available for people who do not benefit from traditional, non-invasive means of amplification. Although many people receive significant improvement in their ability to understand speech with CI, there can be variability in patients' ability to understand open-set speech and some people may not get the expected degree of benefit after CI surgery. Currently, the patient-related factors that appear to correlate with CI outcomes are limited to age and duration of deafness. Recent work has suggested cognition, specifically, cognitive decline, may be an additional patient-related factor that contributes to poor CI outcomes. This work is based on the concept that processing of sound requires intact central processing and neurocognitive function. While the relationship between cognition and hearing is evolving, it is well-established that olfactory dysfunction is an early indicator of cognitive decline. Given this relationship, it stands to reason that olfaction may provide information regarding one's ability to process auditory information, which relies heavily on central functioning and cognition. We hypothesize that olfaction and smell identification scores on the University of Pennsylvania Smell Identification Test (UPSIT) may correlate with CI outcomes. More specifically, we hypothesize that olfactory dysfunction may serve as a potential predictor of poor CI outcomes. Evaluating this relationship has the potential to change the standard evaluation for CI candidates and may offer simple and efficient prognostic information for patients who are considering CI.