Given that our patients are from diverse backgrounds and regions, delivery of timely, equitable, and appropriate treatment takes leadership on the part of the physician. —Matthew L. Bush, MD, PhD
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June 2019
Case 4: Child with Recently Diagnosed Unilateral SNHL
The next case involves a 5-year-old with recently diagnosed mild-moderate unilateral SNHL who is supposedly doing well socially and cognitively. Should this child have a hearing aid?
Judith E. C. Lieu, MD, MSPH, a professor in the department of otolaryngology-head and neck surgery at Washington University in St. Louis, said, “This is one of the most difficult situations because, although speech and language delays are common in children with profound hearing loss, this is not the case with mild-moderate unilateral hearing loss. Because this child has not yet had academic or behavioral problems, the parents are probably not prepared for a hearing aid. There is no solid evidence for a hearing aid, so it comes down to parent preference and whether they are concerned about the child falling behind.”
She added, “I just want to highlight this fundamental point: Even though we think the ears are the center of hearing, it is actually the brain—and that is where the issues arise later on.”
CMV is the most common non-genetic cause of hearing loss in children, with roughly 10% to 15% of patients eventually developing hearing deficits.
Case 5: Child with Single-Sided Deafness
The next case involves a 6-year-old with SSD.
While delays in speech-language development are common, they are not universal, said Dr. Lieu, adding that the child’s quality of life may be negatively affected by severe-to-profound UHL. Cognitive development may be negatively affected and is mediated by phonological processing, and there is a cortical network development that may be maladaptive. However, she added, “There is no solid evidence for or against amplification, so we are all working on our best judgment.”
“One study showed that 24% of these children experience academic weakness or executive function (per teachers),” she said (Laryngoscope. 2012;122:2088–2095). “And there is data indicating high rates of special education among children with unilateral hearing loss [Otol Neurotol. 2016;37:1577–1582]. The risk for educational issues doesn’t mean that all kids have delays, however. For example, there are otolaryngologists and medical students with single-sided deafness who do very well.”
With regard to hearing rehabilitation, frequency modulated (FM)
systems can benefit speech recognition in noise, while conventional hearing aids show trends toward improvement in speech perception, said Dr. Lieu. CROS [contralateral routing of signal] aids have shown mixed outcomes with regard to auditory perception (Otolaryngol Head Neck Surg. 2017;157:565–571). Other work has shown that bone conduction aids provide consistent gains in speech reception thresholds (SRT) and speech discrimination and improvement in hearing in noise, but provide inconsistent results with sound localization (Int J Pediatr Otorhinolaryngol. 2017;94:45–51).”
“There is a lot of hope that CI is the answer for single-sided deafness but, at this point, it is just hit or miss,” said Dr. Lieu. “There are no high-quality studies proving that it really works in this group of kids.”
There are studies showing that UHL does impact brain development, she added. Rachakonda’s work from 2014 using diffusion tensor imaging of white matter tracts showed several white matter tracts with decreased integrity in children with UHL (Front Syst Neurosci. 2014;8:87). Jung’s 2017 research using resting state functional connectivity on MRI with blood oxygen level dependent signals that vary temporally in sync showed that children with UHL displayed adaptive and maladaptive connections, impaired auditory and executive functions, weakened executive function networks, and a lack of suppression of the default mode networks (Laryngoscope. 2017;127:2636–2645).
“There are changes in the brain when there is hearing deprivation, both in the white matter and gray matter,” she said. “UHL results in whole brain adaptations; these are long haul situations, and often a hearing aid will not provide immediate improvement. This requires that someone work with the child for weeks, months, or even years before they see a difference.”