Cochlear Nerve Anatomy and Size
Miyanohara et al (2011) noted that cochlear nerve deficiency (CND) refers to a very small or absent cochlear nerve, as imaged via Magnetic Resonant Imaging ( MRI). They reported that CND may indicate a very small, perhaps non-visible, cochlear nerve and may involve progressive hearing loss.
Kim et al (2013) report that results of parasagittal MRI measurements (data collected from 2010 through 2012) on 68 post-lingually deafened adults (mean age 49 years, range 16 to 77 years) with respect to the mean cross sectional areas (CSA) of their CNs, which was determined to be 0.922 mm2. Kim et al report that CSA was negatively associated with duration of deafness and hearing loss (as duration of deafness increased, CSA decreased, and as hearing loss increased, CSA decreased) and CSA was (weakly) positively correlated with auditory performance with a cochlear implant.
For More Information, References, and Recommendations
Kim BG, Chung HJ, Park JJ, Park S, Kim SH, Chois JY. (2013) Correlation of Cochlear Nerve Size and Auditory Performance After Cochlear Implantation in Postlingually Deaf Patients. JAMA Otolaryngol Head Neck Surg. 2013; 139(6):604-609.
Miyanohara I, Miyashita K, Takumi K, Nakajo M, Kuruno Y. (2011) A Case of Cochlear Nerve Deficiency Without Profound Sensorineural Hearing Loss. Otology & Neurotology. 32(4):529-532.