Our study supports the potential negative impact on vestibular function caused by cochlear implantation, especially for children who receive bilateral implantation. Vestibular impairment or dysfunction after cochlear implantation is clinically significant and should be well addressed preoperatively. Vestibular evaluation such as VOR and VEMP testing can be used in screening vestibular function for children who are candidates for CI. Future improvements in design of CI electrodes and surgical technique may minimize the traumatic impact of cochlear implantation on the inner ear structures and functionality.

In our series of 22 patients with bilateral vocal cord paralysis, 14 had spontaneous recovery of function. Patients managed with tracheostomy were noted to have a high incidence of comorbid factors. In this series, recovery rates were found to be higher in nontracheostomized patients than in tracheostomized patients. Patients can be carefully selected for observation versus tracheostomy at the time of diagnosis based on underlying medical conditions.

Fragile X syndrome is a common form of mental retardation associated with a fragile site on the human X chromosome. Although fragility at this site is usually evident as a nonstaining chromatid gap, it remains unclear whether or not actual chromosomal breakage occurs. By means of somatic cell hybrids containing either a normal human X or a fragile X chromosome and utilizing two genes that flank the fragile site as markers of chromosome integrity, segregation of these markers was shown to be more frequent if they encompass the fragile site under appropriate culture conditions. Hybrid cells that reveal marker segregation were found to contain rearranged X chromosomes involving the region at or near the fragile site, thus demonstrating true chromosomal breakage within this area. Two independent translocation chromosomes were identified involving a rodent chromosome joined to the human X at the location of the fragile site. DNA analysis of closely linked, flanking loci was consistent with the position of the breakpoint being at or very near the fragile X site. Fragility at the translocation junctions was observed in both hybrids, but at significantly lower frequencies than that seen in the intact X of the parental hybrid. This observation suggests that the human portion of the junctional DNA may contain part of a repeated fragility sequence. Since the translocation junctions join heterologous DNA, the molecular cloning of the fragile X sequence should now be possible.

CF patients receiving aminoglycosides are at high risk for developing SNHL.