Journal of Clinical and Diagnostic Research. 2019 Dec, Vol-13(12): MC01-MC05 1 1 DOI: 10.7860/JCDR/2019/42222.13326 Original Article Ear, Nose and Throat Section Auditory and Preverbal Skill Improvements between Early and Late Cochlear Implantees: Evidence from LittlEARS Questionnaire INTRODUCTION The term critical period (Biological Maturation) is used to depict neurosensory development that takes place in children, plasticity of neurosensory period is maximum at earlier ages when compared to late ages. There are number of developmental process that takes place during critical period which include myelination, dendritic pruning and axonal growth [1]. Gable S et al., in 2000 stated that at birth, the human brain is still not developed completely. In initial three years of life, the brain organises and reinforces the connections with neighbouring neurons. These connections happen when stimulus is transmitted to and forth between the neurons. Axons sends messages and dendrites receive them and hence these connections form synapses. These synapses become more complex as the child grows. Though the amount of neurons remains constant, the amount of synapses increases day by day with new experiences in the initial three years of life. After three years of age, spreading of synapses slows down until about ten years of age. During the critical period, the brain multiplies the synapses that it needs and this period takes place in the initial three years of life. Few synapses will stay permanently in brain and few will be eliminated. This is where experience plays an important role in wiring a young child’s brain [2]. Literature reported by Kappel V et al., states that there is a possible anatomical or functional change at the level of auditory system with respect to the new arrival of information and their view strongly supports the auditory plasticity mechanism [3]. So it is important to know the mechanism behind how an individual with hearing impaired react to the auditory events. Hearing loss has an effect on decreasing the calibre to perceive and detect sounds, which also affects the individual’s limitation in other domains such as social, and emotional development. Musiek FE et al., reported that, the auditory system’s plasticity increases with the influence from the environment [4]. They also reported that plasticity in the sensory system can be seen in both peripheral pathways and central pathways. Transmitting acoustic information can make changes in physiological, biochemical or anatomical properties of the central neurons (it is also a biodynamic phenomenon). The auditory system is capable of recognising itself even though changes occur (plasticity), since stimulus input changes (i.e., decreased input for cochlear injury or increased input for postnatal development and when assistive devices are placed). Individuals with congenital severe to profound hearing loss require management options. These management options include hearing aids, Cochlear implants (CI) [5] and Auditory Brainstem Implants (ABI) [6]. The outcomes of treatment depends on the age at Implantation and Duration of Deafness. Various studies support the fact that early Implantation results in better prognosis. Sharma A et al., conducted a study in 2002 by comparing P1 responses in early and late implantees, they had found out that early implanted children had better wave morphology and earlier P1 latency response [7]. Zhang F et al., studied the effect of mismatch negativity in late implanted children, where they had found out that moderate to poor performers had small or absent Mismatch Match Negativity (MMN) thus concluding that late implantation not only has an effect on the auditory cortical level but also affects the cognitive level [8]. There are several studies that have documented the effect of early and late implantation using objective test measures, but there are several limitation in relying only on objective test procedures as it is time consuming, restricted to laboratory and difficult to measure patient perspective outcomes. On the other hand subjective tests are easy to administer, less time saving, cost effective and gives us patient perspective and realistic outcomes. Subjective tests can be directly administered to the patients or given in the form of a questionnaire to parents. KR RAHUL 1 , DEEPIKA JAYACHANDRAN 2 , RANJITH RAJESWARAN 3 , ABISHEK UMASHANKAR 4 Keywords: Auditory verbal therapy, Critical period, Development, Early preverbal skills, Objective measures, Subjective measures ABSTRACT Introduction: Children with hearing loss are either fitted with hearing aid or implanted with Cochlear implants and Brainstem Implants. It is essential for these children to undergo intervention during the critical period, a lot of objective evidences such as Brainstem Evoked Response Audiometry, Late Latency Response and Mismatch Negativity have shown the benefit of early implantation, there is also a need to document subjective evidences to show the outcomes of early implantation. Aim: To compare the auditory performance in early and late Implantees using LittlEARS Auditory Questionnaire. Materials and Methods: A cross-sectional descriptive study was designed. Children with bilateral profound hearing loss, unilateral cochlear implant users and implant ages between six months to 24 months were considered for the study. A hundred random samples of parents of Congenital Hearing Impaired children participated. A Tamil translated version of LittlEARS Auditory Questionnaire was administered to the parents of cochlear implantees, the samples were grouped as early implantees and late implantees. Mean scores were analysed and compared between the groups using descriptive and inferential statistics. Results: Results reveal early Implantees had a better mean (28.52) score of auditory development than late implantees (27.69) and statistical significance (<0.005) was not obtained between the groups. This shows that the performance did not significantly differ between the groups, in terms of auditory behaviour and early preverbal skills. Conclusion: LittlEARS Auditory Questionnare is a better and promising tool to measure outcomes in cochlear implant and also provides us the evidence, the need for early implantation.