Permanent Sensorineural Hearing Research Articles

Language Processing in Toddlers with Permanent Congenital Sensorineural Hearing Impairment: A Preliminary Functional Magnetic Resonance Imaging (fMRI) Study

Language Processing in Toddlers with Permanent Congenital Sensorineural Hearing Impairment: A Preliminary Functional Magnetic Resonance Imaging (fMRI) Study

Comparison of characteristics of acoustic analysis and non-verbal intelligence in preschool children with normal hearing and with hearing loss

An important role in development of speech and language belongs to the threshold characteristics of auditory sensitivity as well as to the degree of maturation of central mechanisms of auditory processing. The ability of differentiation of sounds, analysis of temporal characteristics and the level of intelligence affect the development of speech skills. A comprehensive assessment of auditory perception and cognitive development was conducted in two groups of preschool children aged 4.5 to 6 years. The main group consisted of 10 children with permanent bilateral sensorineural hearing loss, all of them were experienced users of hearing aids; 10 children with normal hearing were included in the control group. All children underwent psychophysical testing (whisper test, repetition of “quasi-words”, identification of speech signals with similar acoustic characteristics, pairs of consonants “z-s”, “p-t”, “g-k”); acoustical analysis of speech samples with the reproduction of speech from hearing; assessment of non-verbal intelligence (by means of the Raven’s Colored Progressive Matrices). The obtained results indicate significant differences in the characteristics of the acoustic analysis of speech signals of children with normal hearing and hearing impairments, no significant differences have been observed in non-verbal intelligence characteristics of children in these groups. Besides, the children with hearing loss have high fatigability. These data may indicate the symptoms of central auditory processing disorders in hearing impaired children. To identify these problems it is necessary to use psychophysical tests and specialized questionnaires.

Outcome of Preterm Infants With Postnatal Cytomegalovirus Infection via Breast Milk: A Two-Year Prospective Follow-Up Study.

Approximately 15% of preterm infants may develop postnatal cytomegalovirus (CMV) infection from seropositive mothers via breast milk and are at risk for neurological sequelae in childhood. The aims of this study were to assess the effects and outcomes on growth, neurodevelopmental status, and hearing in very low birth weight (VLBW) premature infants with postnatal CMV infection via breast milk at the corrected age of 12 and 24 months.The prospective follow-up study population comprised all living preterm children (n = 55) with a birth weight ≤1500 g and gestational age of ≤35 weeks, who had been participated in our “postnatal CMV infection via breast milk” studies in 2000 and 2009, respectively. The cohort of children was assessed at 12 and 24 months. Clinical outcomes were documented during hospitalization and after discharge. Long-term outcomes included anthropometry, audiologic tests, gross motor quotient, Infant International Battery, and neurodevelopmental outcomes; all were assessed at postcorrected age in 12 and 24 months during follow-up visits.Of the 55 infants enrolled in the study (4 noninfected infants were excluded because their parents did not join this follow-up program later), 14 infants postnatally acquired CMV infection through breast-feeding (infected group) and were compared with 41 infants without CMV infection (control group). No significant differences were observed between the groups with regard to baseline characteristics, clinical outcomes, anthropometry, or psychomotor and mental development on the Bayley scale of infant development. None of the infants had CMV-related death or permanent sensorineural hearing loss.Transmission of CMV from seropositive mother via breast milk to preterm infants does not appear at this time to have major adverse effects on clinical outcomes, growth, neurodevelopmental status, and hearing function at 12 and 24 months corrected age.

Therapeutic effect of edaravone on inner ear barotrauma in the guinea pig

Inner ear barotrauma (IEB) that is caused by acute pressure changes can often lead to permanent severe sensorineural hearing loss (SNHL). However, the mechanism that causes IEB is still unknown. In the current study, we assessed the involvement of reactive oxygen species (ROS) in IEB and the therapeutic effect of 3-methyl 1-phenyl-2-pyrazolin-5-one (edaravone), which is a free radical scavenger. To create the IEB model, guinea pigs were subjected to quick pressure changes that resulted in acute SNHL. The animals were then divided into two groups, an edaravone-treated IEB group and a non-treated IEB group that only received normal saline. Immunohistochemical analyses for 8-hydroxy-2-deoxyguanosine (8-OHdG) and 4-hydroxy-2-nonenal (4-HNE) were performed to examine the amount of oxidative DNA damage and lipid peroxidation that occurred in guinea pig cochlea. To assess the curative efficacy of edaravone, auditory brainstem response (ABR) testing was performed to evaluate auditory function. Strong immunoreactivities against 8-OHdG and 4-HNE were observed in the inner ear tissues of the non-treated IEB group. Lesser amounts of immunoreactivity were observed in the same region of the edaravone-treated IEB group as compared to the non-treated IEB group. Furthermore, ABR measurement revealed that there was a faster improvement in the threshold shift for the edaravone-treated IEB group as compared to that of the non-treated IEB group. At the final 7-week time point, the threshold shift for the edaravone-treated IEB group was significantly smaller as compared to the non-treated IEB group. These results strongly suggest that ROS is produced in the cochlea in response to acute pressure changes and that ROS plays an important role in the pathophysiology of IEB. Furthermore, edaravone treatment had a therapeutic effect on IEB-induced acute SNHL and thus, edaravone might possibly be able to be used as a therapeutic treatment for IEB.