Research Advances in Post-Operative Rehabilitation Following Cochlear Implant

Language profile of children with cochlear implants: comparative study about the effect of age of cochlear implantation and the duration of rehabilitation

PURPOSE

The analysis of different language domains and exploration of variables that affect the outcomes of cochlear implantation would help to document the efficacy of cochlear implantation and intervention programs. The aim of this work was to examine the language profile of children with Cochlear Implants (CI) and to assess the effect of age at the time of cochlear implantation and the impact of duration of rehabilitation on the development of linguistic abilities for cochlear implanted children.

METHODS

The study was conducted on 46 Arabic speaking children using unilateral CI who are receiving regular post-cochlear auditory and language rehabilitation in the phoniatrics unit, Kasr Alaini hospital. A Proficient Preschooler Language Evaluation (APPEL TOOL) was applied for the assessment of different language domains.

RESULTS

Children who received post implant rehabilitation for ≥ 2 years showed significant improvement in all subtests' scores of APPEL tool than children who received same rehabilitation for ≤ 1 year. There was no significant difference of language scores between children who have received CI before age of 3 years and those who have been implanted after age of 3 years.

CONCLUSION

This study showed that the language profile of CI children was beneficially affected by the longer duration of therapy post implantation.

Modeling Intracochlear Magnetic Stimulation: A Finite-Element Analysis

This study models induced electric fields, and their gradient, produced by pulsatile current stimulation of submillimeter inductors for cochlear implantation. Using finite-element analysis, the lower chamber of the cochlea, scala tympani, is modeled as a cylindrical structure filled with perilymph bounded by tissue, bone, and cochlear neural elements. Single inductors as well as an array of inductors are modeled. The coil strength (~100 nH) and excitation parameters (peak current of 1-5 A, voltages of 16-20 V) are based on a formative feasibility study conducted by our group. In that study, intracochlear micromagnetic stimulation achieved auditory activation as measured through the auditory brainstem response in a feline model. With respect to the finite element simulations, axial symmetry of the inductor geometry is exploited to improve computation time. It is verified that the inductor coil orientation greatly affects the strength of the induced electric field and thereby the ability to affect the transmembrane potential of nearby neural elements. Furthermore, upon comparing an array of micro-inductors with a typical multi-site electrode array, magnetically excited arrays retain greater focus in terms of the gradient of induced electric fields. Once combined with further in vivo analysis, this modeling study may enable further exploration of the mechanism of magnetically induced, and focused neural stimulation.