John Ignatius Lane MD, Presenter: Nothing to Disclose

Robert James Witte MD, Abstract Co-Author: Nothing to Disclose

Colin Driscoll MD, Abstract Co-Author: Nothing to Disclose

Jon Shallop PhD, Abstract Co-Author: Nothing to Disclose

Treatment for profound sensorineural hearing loss (SNHL) has been recently advanced with the development of cochlear implantation. The causes of profound SNHL are usually categorized as congenital or acquired. It is commonly assumed that differentiation between the two categories can be determined based on the age of presentation with most congenital causes presenting at birth. We reviewed our cochlear implant database in an attempt to verify this clinical assumption.

65 MR cochlear implant screening examinations of the inner ear performed at 1.5 and 3T were reviewed by two neuroradiologists for the presence of inner ear anomalies. Findings were correlated with the age of onset of profound SNHL as documented in the medical records.

Patients were divided into those with onset of profound SNHL before (n=55) and after the age of forty (n=10) in an effort to exclude acquired presbyacusis as an etiology. 11 incomplete partition anomalies with or without dilated endolymphatic ducts/sacs were identified in the younger cohort. These patients were divided into those with onset prior to speech development (pre-lingual) and those who lost there hearing sometime after speech (post-lingual). The anomaly rate in the post-lingual population (9/27 or 33%) was double that of the pre-lingual group (4/28 or 14%) (Chi square p=.07). 2 patients in the pre-lingual group had findings consistent with labyrinthitis ossificans. Virtually all the patients with anomalies in the post-lingual group developed profound SNHL mid to late first decade or second decade. No anomalies were noted in those patients with onset of SNHL developing after age 40.

All patients with inner ear anomalies had onset of profound SNHL prior to age forty. Unexpectedly, those who presented with SNHL prior to speech development had a lower incidence of anomalies than did those presenting in the first or second decade of life after speech development. Possible explanations for this finding will be discussed. This observation deserves further clinical study.

Lane, J, Witte, R, Driscoll, C, Shallop, J, Inner Ear Anomalies Detected at 1.5 and 3T MR: Correlation with Age of Onset of Sensorineural Hearing Loss (SNHL).  Radiological Society of North America 2004 Scientific Assembly and Annual Meeting, November 28 - December 3, 2004 ,Chicago IL. http://archive.rsna.org/2004/4414855.html