Craig A. Buchman, MD, is actively involved in research in a number of hearing-related topics. Together with a number of co-investigators from UNC and abroad, he is actively studying topics such as cochlear nerve deficiency, auditory neuropathy spectrum disorder (ANSD), CMV-related hearing loss, inner ear malformations, and a number of hearing restorative device-related topics. In the field of cochlear implantation, Dr. Buchman and colleagues continue to study the effects of combining electrical stimulation from a cochlear implant with the natural acoustic signal from patients with preserved residual hearing following implant surgery in an attempt to improve hearing performance for patients. Also, ongoing investigations continue into the safety and efficacy of bilateral cochlear implants as well as the reliability of a variety of cochlear implant devices in both adults and children. Newer areas of study include a clinical trial for auditory brainstem implants (ABI) in adults without NF2 and use of the round window membrane for implantation of the Vibrant MedEl device for conductive and mixed hearing losses.
Investigators at UNC continue to be very interested in the field of ANSD in children. Here at UNC, we have a particularly robust clinical experience with this disorder as we are currently following more than 160 affected children. What is clear from our current research is that the findings of ANSD on hearing testing can be associated with a variety of medical conditions. We have learned that some children with ANSD can occasionally have absent or severely deficient cochlear nerves on MRI and that these children may not benefit from hearing restorative interventions. By contrast, most children with ANSD can benefit from either hearing aids or cochlear implants depending on their native hearing abilities. Identifying which children can benefit from the various intervention strategies is a major area of investigation. We have recently begun to use a variety of electrophysiological test together with imaging studies to try and better characterize which children with ANSD can benefit from amplification and those that require cochlear implantation or no intervention.
Dr. Buchman continues to collaborate with Drs. Adunka and Fitzpatrick in the area of electrophysiological markers of hearing loss and intracochlear trauma. Using a combination of human temporal bone studies and animal model experimentation, these projects seek to further define the cause(s) of surgically induced hearing loss and importantly, identify functional markers of impending irreversible trauma. Early results are very promising and application of these findings will have broad reaching effects on the field of inner ear surgery.
Together with the Office of Technology Development at UNC, Dr. Buchman and Dr. Adunka have applied for a US and International Patent to provide intracochlear measurements of acoustically evoked auditory potentials. This new technology should provide improved means to monitory hearing during hearing preservation cochlear implantation. Also, this method might be helpful in the direct assessment of hair cell function rather than to gather in-direct data via conventional audiometric evaluation. The patent application has recently been published with the US Patent and Trademark Office.