Magnetic resonance spectroscopy and auditory brain-stem response audiometry as predictors of bilirubin-induced neurologic dysfunction in full-term jaundiced neonates.

The purpose of this research was to define the functions of MRS and ABR as predictors of bilirubin-induced neurologic dysfunction (BIND) in full-term neonates who required intervention (phototherapy and/or exchange transfusion). This prospective cohort study was done at the NICU of Tanta University Hospitals over a 2-year duration. Fifty-six full-term neonates with pathological unconjugated hyperbilirubinemia were divided according to MRS and ABR findings into 2 groups: group (1) included 26 cases with mild acute bilirubin encephalopathy (BIND-M score 1-4). Group (2) included 30 cases with neonatal hyperbilirubinemia only. In addition, 20 healthy neonates with similar ages were employed as the controls. When compared to group 2 and the control group, group 1's peak-area ratios of NAA/Cr and NAA/Cho were found to be significantly reduced (P < 0.05). As compared to group 2 and the control group, group 1's Lac/Cr ratio was significantly greater (P < 0.05), but the differences were not significant for group 2 when compared to the control group. Waves III and V peak latencies, I-III, and I-V interpeak intervals were significantly prolonged in group 1 in comparison to group 2 and controls (P < 0.05) with no significant difference between group 2 and control group.   Conclusion: When the symptoms of ABE are mild and MRI does not show any evident abnormalities, MRS and ABR are helpful in differentiating individuals with ABE from patients with neonatal hyperbilirubinemia.    Trial registration:  ClinicalTrials.gov , Identifier: NCT06018012. What is Known: • MRS can be used as a diagnostic and prognostic tool for the differential diagnosis of patients with acute bilirubin encephalopathy, from patients with neonatal hyperbilirubinemia What is New: • ABR is a useful diagnostic and prognostic tool in the care and management of neonates with significantly raised bilirubin. It can be used as early predictor of acute bilirubin encephalopathy in the earliest stage of auditory damage caused by bilirubin.

Transplantation of adipose-derived stromal cells protects functional and morphological auditory nerve integrity in a model of cochlear implantation.

Cochlear implants are considered the gold standard therapy for subjects with severe hearing loss and deafness. Cochlear implants bypass the damaged hair cells and directly stimulate spiral ganglion neurons (SGNs) of the auditory nerve. Hence, the presence of functional SGNs is crucial for speech perception in electric hearing with a cochlear implant. In deaf individuals, SGNs progressively degenerate due to the lack of neurotrophic support, normally provided by sensory cells of the inner ear. Adipose-derived stromal cells (ASCs) are known to produce neurotrophic factors. In a guinea pig model of sensory hearing loss and cochlear implantation, ASCs were autologously transplanted into the scala tympani prior to insertion of a cochlear implant on one side. Electrically evoked auditory brain stem responses (eABR) were recorded 8 weeks after cochlear implantation. At conclusion of the experiment, the cochleae were histologically evaluated. Compared to untreated control animals, transplantation of ASCs resulted in an increased number of SGNs and their peripheral neurites. In ASC-transplanted animals, mean eABR thresholds were lower and suprathreshold amplitudes larger, suggesting a larger population of intact auditory nerve fibers. Moreover, when compared to controls, amplitude-level functions of eABRs in ASC transplanted animals demonstrated steeper slopes in response to increasing interphase gaps (IPGs), indicative of better functionality of the auditory nerve. In summary, results suggest that transplantation of autologous ASCs into the deaf inner ear may have protective effects on the survival of SGNs and their peripheral processes and may thus contribute to long-term benefits in speech discrimination performance in cochlear implant subjects.