Genetic biomarkers of neuroplasticity in the treatment of children with prelingual deafness with cochlear implantation

Abstract

In congenital deafness, the absence of sensory stimulation results in the auditory system’s deprivation, so a child cannot develop verbal communication. Delivery of acoustic stimulation to the sensory cortex via cochlear implant starts the cascade of molecular processes in neurons and promotes cortical synapses’ formation. Neural tissue of a juvenile brain possesses a vast capacity to change neuronal connections’ strength in response to environmental stimuli. Although, on average, the functional results of cochlear implantation in small children are good, there is still a large variability of the outcomes. Identification of genetic biomarkers of neuroplasticity after cochlear implantation might facilitate clinical management of implanted children, giving them better chances of developing proficient spoken language. This chapter discusses the findings of the research grant funded by the National Science Centre (SONATA UMO 2013/14/D/NZ5/03337) carried on a group of 70 children. The study verified the hypothesis that a specific set of matrix metalloproteinase-9 (MMP-9) and brain-derived neurotrophic factor (BDNF) gene variants predisposes children diagnosed with prelingual congenital deafness implanted before 2 years of age to better respond to cochlear implantation. The other hypothesis tested in that study was the relationship between plasma levels of MMP-9 and BDNF before cochlear implantation and hearing and speech rehabilitation results.