Objectives: Imaging plays an essential role in the preoperative workup for cochlear
implantation. Despite establishing cochlear implant candidacy it allows surgeons to predict
additional difficulties that may be encountered during the surgery. Severe inner ear
malformations are present in 20% of patients with congenital sensorineural hearing loss and
are one of the major difficulties that surgeons must deal with. Several data suggest that apart
from major malformations in a group of profoundly deaf children there is also a significant
numer of small abnormalities. Therefore, the total number of major and minor inner ear
abnormalities can be higher than we expect.
The aim of this study is to present results of inner ear measurements in patients undergoing
cochlear implantation, compare it with values reported in the literature and obtained in control
group and present obtained normative values that should increase the diagnosis of inner ear
malformations
Methods: We reviewed the HRCT scans of 200 ears in 100 patients who underwent cochlear
implantation. Control group included 50 patients without congenital sensorineural hearing
loss. Malformations were classified according to Sennaroglu classification. Additionally
several minor malformations were diagnosed when all parameters of each structure deviated
more than 2 SDs from the mean values.
Results: 20% of patients presented „large” malformations described in Sennaroglu
classification. However, less severe dysplasias and abnormalities of inner ear were far more
frequently diagnosed when standardized measurements of inner ear were applied
Conclusions: Some less severe malformations may be missed by visual inspection of the
radiological images. Some of inner ear malformations may be difficult to assess for
inexperienced clinicians. Standardized inner ear measurements and normative values can aid
the diagnosis of inner ear malformations

**Objectives:** Imaging plays an essential role in the preoperative workup for cochlear
implantation. Despite establishing cochlear implant candidacy it allows surgeons to predict
additional difficulties that may be encountered during the surgery. Severe inner ear
malformations are present in 20% of patients with congenital sensorineural hearing loss and
are one of the major difficulties that surgeons must deal with. Several data suggest that apart
from major malformations in a group of profoundly deaf children there is also a significant
numer of small abnormalities. Therefore, the total number of major and minor inner ear
abnormalities can be higher than we expect.
**The aim of this study is to present results of inner ear measurements in patients undergoing
cochlear implantation, compare it with values reported in the literature and obtained in control
group and present obtained normative values that should increase the diagnosis of inner ear
malformations**
**Methods**: We reviewed the HRCT scans of 200 ears in 100 patients who underwent cochlear
implantation. Control group included 50 patients without congenital sensorineural hearing
loss. Malformations were classified according to Sennaroglu classification. Additionally
several minor malformations were diagnosed when all parameters of each structure deviated
more than 2 SDs from the mean values.
**Results:** 20% of patients presented „large” malformations described in Sennaroglu
classification. However, less severe dysplasias and abnormalities of inner ear were far more
frequently diagnosed when standardized measurements of inner ear were applied
**Conclusions:** Some less severe malformations may be missed by visual inspection of the
radiological images. Some of inner ear malformations may be difficult to assess for
inexperienced clinicians. Standardized inner ear measurements and normative values can aid
the diagnosis of inner ear malformations

Congenital inner ear malformations in profound hearing loss - more than we expected

It is with great pleasure and enthusiasm, that on behalf of the Cochlear Implant centers of the Radboud UMC in Nijmegen and Erasmus MC Sophia Children’s Hospital in Rotterdam to invite you to attend the 16th European Symposium on Pediatric Cochlear Implantation to Rotterdam, the Netherlands in 2023.

Yours sincerely, on behalf of the CI Centers at Radboud UMC and Erasmus MC,