Neuro-otological function in X-linked hearing loss: a multipedigree assessment and correlation with other clinical parameters

Pediatric and adult cochlear implantation

The frequency of cochlear implantation has increased tremendously over the past decade. Cochlear implantation is often performed as an outpatient procedure and is considered an acceptable treatment for severe to profound sensorineural hearing loss in patients who are refractory to conventional hearing augmentation. Imaging plays an important part in the work-up of cochlear implant candidates, and an understanding of imaging evaluation procedures is essential. The radiologist must be familiar with imaging findings that contraindicate implantation (absence of the cochlea or cochlear nerve) and with those that could significantly alter surgery (facial nerve dehiscence, cochlear ossification). It is also imperative to be familiar with the growing number of imaging options (particularly magnetic resonance [MR] imaging pulse sequences) to optimize evaluation of cochlear implant candidates. Imaging choices will be substantially influenced by the manufacturer of the computed tomographic scanner or MR imager. Radiologists will assume an expanding role in evaluating affected patients as the frequency of cochlear implantation continues to increase.

Minimal, progressive, and fluctuating hearing losses in children. Characteristics, identification, and management

Referring to specific types of hearing loss as "minimal" or "mild" seems to imply that their effects are equally mild or negligible. A growing body of literature, however, supports the notion that such losses can have a significant impact on the communicative and educational development of young children. Although OME is considered a common childhood ailment, mounting evidence suggests that it is not always benign and may contribute to significant educational and communicative difficulties in some young children when accompanied by conductive hearing loss. Even very mild bilateral and unilateral SNHL seems to contribute to problems in the areas of social and emotional function, educational achievement, and communication in some children. Because these hearing losses are so mild, they may not be immediately recognized as the source of such difficulties. The purpose of this report is to heighten the general pediatrician's awareness of the significance of even very mild or minimal hearing losses in children. As the gatekeepers for children's health care, pediatricians are typically the primary recipients of parental expressions of concern and the initiators of evaluations or referrals to address such.

Close linkage of a gene for X linked deafness to three microsatellite repeats at Xq21 in radiologically normal and abnormal families

We have used three highly polymorphic microsatellite repeats from Xq21 to type families in whom a gene for X linked deafness with perilymphatic gusher (DFN 3) was segregating. All three markers were tightly linked to the disease in its radiologically normal and abnormal forms, with a maximum lod score of 10.37 with DXS995 and 8.44 with DXS986 at zero recombination, and 14.03 with DXS1002 at theta = 0.01. In an isolated case of deafness of this type, DXS995 indicated either the first recombination observed between the marker and the disease gene or a new mutation in the proband. Southern blotting using a cosmid fragment from the candidate region has confirmed a de novo mutation by showing a deletion in the proband which is not present in his mother as judged by dosage analysis. We also describe a family with a paracentric inversion associated with a microdeletion and discuss how deletion mapping using these and other markers in the region has helped to define a candidate region for the gene.