The Hearing of Erastus "Deaf" Smith, Hero of the Texas Revolution.

OBJECTIVES: To describe the speech and hearing abilities of Erastus "Deaf" Smith, the first Texas Ranger, and speculate on the etiology of his hearing loss. METHODS: Review of credible historical data of what Erastus could and could not hear, descriptions of his voice, and loudness tolerance. Modern analysis of acoustical physics data generated by 0.69-inch diameter non-spinning musket balls. RESULTS: The onset of Erastus' bilateral hearing loss was early childhood. He could hear some. He was intolerant of very loud sounds. His speech was "weak", "squeaky" and high-pitched. He did not use manual communication. He could not hear musket balls passing near his head. The frequency of sound generated by flying 0.69-inch diameter musket balls has been determined as predominantly in the range of 2000-2500 Hz. In contrast to most bilateral childhood sensorineural hearing losses that are worse in high and mid frequencies, Erastus' hearing loss was worse in the low and mid frequencies - preserving at least some high-frequency hearing. CONCLUSION: Erastus' reverse-slope hearing problem may well have been attributable to incomplete partition type III. If you can't hear it, you can't speak it. LEVEL OF EVIDENCE: NA Laryngoscope, 2024.

Comprehensive genetic testing of Chinese SNHL patients and variants interpretation using ACMG guidelines and ethnically matched normal controls.

Hereditary hearing loss is a monogenic disease with high genetic heterogeneity. Variants in more than 100 deafness genes underlie the basis of its pathogenesis. The aim of this study was to assess the ratio of SNVs in known deafness genes contributing to the etiology of both sporadic and familial sensorineural hearing loss patients from China. DNA samples from 1127 individuals, including normal hearing controls (n = 616), sporadic SNHL patients (n = 433), and deaf individuals (n = 78) from 30 hearing loss pedigrees were collected. The NGS tests included analysis of sequence alterations in 129 genes. The variants were interpreted according to the ACMG/AMP guidelines for genetic hearing loss combined with NGS data from 616 ethnically matched normal hearing adult controls. We identified a positive molecular diagnosis in 226 patients with sporadic SNHL (52.19%) and in patients from 17 deafness pedigrees (56.67%). Ethnically matched MAF filtering reduced the variants of unknown significance by 8.7%, from 6216 to 5675. Some complexities that may restrict causative variant identification are discussed. This report highlight the clinical utility of NGS panels identifying disease-causing variants for the diagnosis of hearing loss and underlines the importance of a broad data of control and ACMG/AMP standards for accurate clinical delineation of VUS variants.

Relation of public health staffing to follow-up after newborn hearing screening in three health districts in Georgia, 2009-2015.

OBJECTIVE: To describe the association, or non-association, of public health district staffing (specifically, Early Hearing Detection and Intervention [EHDI] coordinator/navigator) and loss to follow-up in newborns who did not pass hearing screening in selected public health districts in Georgia, USA. METHODS: By Freedom of Information request, data regarding newborn hearing screening and loss to follow-up for diagnostic testing and staffing were acquired for three districts in Georgia for six years. The districts were chosen because their coordinator/navigator positions were unfilled at times. RESULTS: Lapses in staffing of the district EHDI coordinator/navigator position aligned temporally with decreased follow-up. Aggregate three district data showed that follow-up rates in quarter-years with a fulltime navigator were higher than quarter-years without a full-time navigator (p < .001). CONCLUSION: Lapses in staffing dedicated to EHDI navigation-coordination correlated with poorer follow-up after not passing newborn hearing screening.

Jugular dominance is unrelated to isolated unilateral congenital aural atresia in children.

OBJECTIVES: The right jugular foramen is usually larger than the left in Homo sapiens, but it is unknown if right-sided jugular dominance is also more common amongst those with unilateral congenital aural atresia. We hypothesized that the dominant (i.e. larger) jugular foramen in children with isolated, non-syndromic, unilateral congenital aural atresia would be contralateral to the atretic ear. METHODS: We reviewed high-resolution computed tomography scans of the temporal bones of 70 children with isolated, non-syndromic, unilateral congenital aural atresia. Images were viewed in the transverse (axial) plane by a board-certified neuroradiologist and a board-certified otolaryngologist. Consensus opinion was recorded. Multiple logistic regression was used to assess the impact of age, sex, and side of aural atresia on jugular dominance. RESULTS: Jugular foramen dominance was not associated with the side of aural atresia (P = 0.20), age (P = 0.50) or sex (P = 0.76). Right-sided jugular dominance (46/70, 65.7%) was more common in both left- and right-sided unilateral aural atresia (P = 0.004). CONCLUSIONS: The side of jugular foramen dominance is not associated with the side of aural atresia in children with isolated, non-syndromic, unilateral congenital aural atresia. Right-sided jugular dominance is more common irrespective of unilateral aural atresia.

Mandibular condylar hypoplasia in children with isolated unilateral congenital aural atresia.

OBJECTIVES/HYPOTHESIS: We hypothesized that children with isolated nonsyndromic unilateral congenital aural atresia have subclinical mandibular condylar hypoplasia ipsilateral to the atretic ear, and that the Jahrsdoerfer score is associated with the degree of condylar hypoplasia. STUDY DESIGN: Retrospective self-controlled case series. METHODS: We reviewed high-resolution computed tomography scans of the temporal bones of 68 children with isolated nonsyndromic unilateral congenital aural atresia. Images were viewed in the transverse (axial) plane perpendicular to the axis of the mandibular ramus and scanned from the mandibular notch to the condylar top. The slice where the condyle had the largest cross-sectional area was measured and checked for correlation with atresia status, age, and sex. The Jahrsdoerfer score of the atretic ear was calculated and correlated with condyle cross-sectional area, age, and sex. RESULTS: Cross-sectional area of the condyle ipsilateral to the atretic ear was, on average, 8.41 mm2 smaller than the contralateral condyle (P < .0001). The Jahrsdoerfer score was not associated with the condylar cross-sectional area, age, or sex. CONCLUSION: Isolated nonsyndromic unilateral congenital aural atresia is associated with mild hypoplasia of the mandibular condyle ipsilateral to the atretic ear. This is consistent with the hypothesis that congenital aural atresia is a variant of craniofacial (hemifacial) microsomia. LEVEL OF EVIDENCE: 4. Laryngoscope, 128:1191-1195, 2018.

Inner ear anomalies in children with isolated unilateral congenital aural atresia.

OBJECTIVES/HYPOTHESIS: We aim to define the frequencies of anomalies of the inner ear, oval window, and round window ipsilateral to isolated non-syndromic unilateral aural atresia. METHODS AND MATERIALS: Retrospective case series. We reviewed high resolution computed tomography scans of the temporal bones of 70 children with isolated non-syndromic unilateral congenital aural atresia. Scans were reviewed according to the Jahrsdoerfer criteria and further evaluated for anomalies of the vestibule, semi-circular canals, cochlea, internal auditory canal and vestibulocochlear nerve. RESULTS: Inner ear dysplasia was seen in two of 70 atretic ears: one with a dysmorphic lateral semicircular canal and another with a large vestibule assimilating the lateral semicircular canal. Abnormalities of the oval window and round window ipsilateral to the atresia were identified in 21% (15) and 7% (5), respectively, of the atretic ears. Oval window and round window abnormalities were associated with disproportionately lower Jahrsdoerfer scores compared to aural atresia patients without these abnormalities (P < 0.001 and P = 0.04, respectively). CONCLUSION: Compared to studies that included syndromic or bilateral atresia cases, we found inner ear and oval window abnormalities less common in children with isolated non-syndromic unilateral aural atresia. However, round window anomalies seem to occur at about the same frequency.

Cilia distribution and polarity in the epithelial lining of the mouse middle ear cavity.

The middle ear conducts sound to the cochlea for hearing. Otitis media (OM) is the most common illness in childhood. Moreover, chronic OM with effusion (COME) is the leading cause of conductive hearing loss. Clinically, COME is highly associated with Primary Ciliary Dyskinesia, implicating significant contributions of cilia dysfunction to COME. The understanding of middle ear cilia properties that are critical to OM susceptibility, however, is limited. Here, we confirmed the presence of a ciliated region near the Eustachian tube orifice at the ventral region of the middle ear cavity, consisting mostly of a lumen layer of multi-ciliated and a layer of Keratin-5-positive basal cells. We also found that the motile cilia are polarized coordinately and display a planar cell polarity. Surprisingly, we also found a region of multi-ciliated cells that line the posterior dorsal pole of the middle ear cavity which was previously thought to contain only non-ciliated cells. Our study provided a more complete understanding of cilia distribution and revealed for the first time coordinated polarity of cilia in the epithelium of the mammalian middle ear, thus illustrating novel structural features that are likely critical for middle ear functions and related to OM susceptibility.

Malleus and incus: correlates of size.

OBJECTIVES: Wide ranges of dimensions of the malleus and incus have been reported for various human populations. Unaddressed are concordance of malleus and incus sizes, bilateral symmetry, whether ossicle size correlates with otitis media, and whether second-branchial arch derivatives have more variability than first-arch derivatives. We sought to quantitatively describe the malleus and incus in a population not heretofore reported, with the following hypotheses in mind: 1) an ear's malleus and incus sizes are concordant; 2) a cranium's malleus and incus sizes have bilateral symmetry; 3) the sizes of the malleus and incus are unrelated to the mastoid-size indicator of childhood otitis media; and 4) second-branchial arch derivatives have more variability than do first-arch derivatives. METHODS: We performed a postmortem material analysis of 41 adult crania without clinical otitis. RESULTS: The sizes of clinically normal mallei (eg, 21.2 to 30.7 mg) and incudes (eg, 24.4 to 37.4 mg) were varied. Concordance of malleus mass and incus mass was found. However, no relation of malleus and incus sizes with mastoid size was found. The variability of first-arch derivatives was similar to that of second-arch derivatives. CONCLUSIONS: Clinically normal mallei and incudes had masses and dimensions that varied even more than previously reported. Nevertheless, bilateral symmetry was exhibited, as was concordance of masses.

A low-cost exon capture method suitable for large-scale screening of genetic deafness by the massively-parallel sequencing approach.

Current major barriers for using next-generation sequencing (NGS) technologies in genetic mutation screening on an epidemiological scale appear to be the high accuracy demanded by clinical applications and high per-sample cost. How to achieve high efficiency in enriching targeted disease genes while keeping a low cost/sample is a key technical hurdle to overcome. We validated a cDNA-probe-based approach for capturing exons of a group of genes known to cause deafness. Polymerase chain reaction amplicons were made from cDNA clones of the targeted genes and used as bait probes in hybridization for capturing human genomic DNA (gDNA) fragments. The cDNA library containing the clones of targeted genes provided a readily available, low-cost, and regenerable source for producing capture probes with standard molecular biology equipment. Captured gDNA fragments by our method were sequenced by the Illumina NGS platform. Results demonstrated that targeted exons captured by our approach achieved specificity, multiplexicity, uniformity, and depth of coverage suitable for accurate sequencing applications by the NGS systems. Reliable genotype calls for various homozygous and heterozygous mutations were achieved. The results were confirmed independently by conventional Sanger sequencing. The method validated here could be readily expanded to include all-known deafness genes for applications such as genetic hearing screening in newborns. The high coverage depth and cost benefits of the cDNA-probe-based exon capture approach may also facilitate widespread applications in clinical practices beyond screening mutations in deafness genes.

Severe diarrhea-dehydration in infancy permanently alters auditory function.

Of the myriad etiologies of sensorineural hearing impairment, metabolic stress is rarely considered. I posit that severe dehydration in conjunction with hypoxia, at least during infancy, prompts permanent changes in the cochlea. In a population-based prospective study of otitis media, children without otitis were found to have at age 4-8 years, worse auditory thresholds if as an infant had been hospitalized for diarrhea-dehydration. What is more, stapedius reflex thresholds tended to be lower in children who had been hospitalized for diarrhea-dehydration: that is, less acoustic energy for arousal or to be frightening. The hypothesis that the transient metabolic stress of dehydration with hypoxia prompts permanent sensorineural hearing impairment with reduced uncomfortable loudness thresholds, is both (1) consistent in an evolutionary sense with a subsequent survival advantage, and (2) subject to verification both by descriptive studies of children undergoing ECMO (ExtraCorporeal Membrane Oxygenation) or care for congenital diaphragmatic hernia, and by animal studies.

Tympanum-canal angles anteriorly, anteroinferiorly, and inferiorly: a postmortem study of 41 adult crania.

The angles formed by the tympanic membrane and the external ear canal anteriorly, anteroinferiorly, and inferiorly can pose surgical challenges, and the spaces they form can harbor iatrogenic cholesteatoma. The range of values previously reported for these angles--27 degrees to 60 degrees--seems not to have been determined in a clinically applicable manner. To clinically describe the tympanum-canal angles, assess bilateral symmetry, assess the angles relative to mastoid pneumatization, and assess the relationship of the angles to manubrium orientation in the skull, the author conducted a postmortem anatomic study of 41 bequeathed adult crania without clinical otitis media. As viewed through the external ear canal, the tympanum-canal angles were measured in 10 degrees increments anteriorly, anteroinferiorly, and inferiorly relative to the line of the manubrium. Mastoid sizes were determined radiographically. In the right ear, the tympanum-canal angles ranged from 40 degrees to 60 degrees anteriorly (median: 55 degrees), from 50 degrees to 70 degrees anteroinferiorly (median: 60 degrees), and from 70 degrees to 80 degrees inferiorly (median: 75 degrees). Bilateral symmetry was found (each rs > or = 0.69, p < 0.001). Although the angles did not correlate with either mastoid pneumatization or manubrium orientation relative to the Frankfort plane, nonvisualization of the annulus anteriorly was significantly more common in specimens with well-pneumatized mastoids (p < 0.05). The author concludes that the tympanum-canal angles anteriorly, anteroinferiorly, and inferiorly have comparatively narrow ranges, exhibit bilateral symmetry, and are unrelated to both mastoid size and manubrium orientation in the skull.

Jacobson's nerve clues to the round window niche.

The round window niche is used as a primary guide to cochleostomy for cochlear implantation, but sometimes the niche is not visible through the dissected facial recess. In such cases, Jacobson's nerve may be a guide to the niche. The objectives of this study were to depict the distance from Jacobson's nerve to the lip of the round window niche, and how this distance may relate to orientation of the manubrium as viewed through the external ear canal. Also, are these distances related to mastoid pneumatisation size? The study involved post-mortem anatomic dissection of 41 bequeathed adult crania (82 temporal bones). Viewing with an operative microscope, distances were measured with a fenestrometer-type instrument. Mastoid sizes were determined radiographically. Jacobson's nerve was identifiable in 81 of 82 temporal bones. Distances from Jacobson's nerve to the lip of round window niche averaged 2.1 mm, range zero to 3.2 mm. Distances from Jacobson's nerve to the round window niche were not obviously associated with either mastoid size or orientation of the manubrium in the head. If the main trunk of Jacobson's nerve is visible on the promontory (as it is in > or =95% of cases), with 95 per cent certainty it is within 3.3 mm of the lip of the round window niche. Distances from Jacobson's nerve to the lip of the round window niche do not correlate with either manubrium orientation as viewed through the external ear canal, or the extent of mastoid pneumatisation.

The malleus-stapes offset.

BACKGROUND: The malleus-stapes offset create challenges during ossiculoplasty, specifically the positioning of an interposed incus or replacement prosthesis relative to the manubrium. OBJECTIVES: To depict the malleus-stapes offset, its relationship to the orientation of the manubrium as viewed through the external ear canal relative to a horizontal plane, and mastoid pneumatization size. STUDY DESIGN: Postmortem anatomic dissection of 41 bequeathed adult crania (82 temporal bones) without clinical otitis. METHODS: The malleus-stapes offset was analyzed both as a surgeon does intraoperatively and from above through the tegmen tympani. Mastoid sizes were determined radiographically. RESULTS: : From the surgeon's perspective, for the right ear, the "height" (manubrium to caput stapedis) ranged from 0 to 1.5 (mean, 0.5) mm; the "horizontal" offset ranged from 1.0 to 4.0 (mean, 2.2) mm. Differences in angular offset, as viewed transcanally versus trans-tegmenally, averaged 8.5 degrees (range to 53 degrees). Both height and horizontal offset exhibited wide intersubject variability, quite weak bilateral symmetry, and no relationship with either manubrium orientation or mastoid size. CONCLUSION: Reliable determination of the malleus-stapes offset is difficult. Because the error of visual offset assessment exceeds the generally accepted 45 degrees alignment allowance for an ossicular prosthesis, visualized ossiculoplasty alignment should be perfect. The ranges of manubrium-stapes offset do not correlate with either manubrium orientation or the extent of mastoid pneumatization.

Cochlear implantation via the middle fossa: surgical and electrode array considerations.

Cochlear implantation via the middle cranial fossa may access the entire length of the cochlea without opening the middle ear. Concerns include safety and electrode array design. The objectives of this study were to determine the depth to the superior portion of the basal turn (SPBT) and distances from the facial and greater petrosal nerves, and to describe some ideas about electrode arrays. The study involved operative dissection of 41 bequeathed otitis-free adult crania (82 temporal bones). Mastoid size was assessed by x-ray. Commercially available MED-EL split arrays were inserted. The depth from the floor of the middle cranial fossa to SPBT of the cochlea ranged from 0.5 mm to 4.2 mm. Small mastoid size correlated with shallow depth. Distances from the centre of the SPBT to the labyrinthine portion of the facial nerve, to the geniculate ganglion, and to the greater petrosal nerve ranged from 1.0 mm to 3.0 mm, 2.0 mm to 3.2 mm, and 1.8 mm to 2.8 mm, respectively. More than 75% of electrodes inserted toward the round window extended into the vestibule. Insertions toward the cochlear apex had a median insertion depth of 12 mm (range 6 mm to 18 mm). The middle cranial fossa approach appears safe and allows electrode access to nearly the full length of the cochlea. Electrode arrays specific for this route of implantation are needed, together with a rigorous study comparing outcomes of this route of implantation with traditional implantation through the facial recess.

Rhabdomyomatous hamartomata of the pharyngeal region with bilateral microtia and aural atresia: a new association?

BACKGROUND: Bilateral microtia with aural atresia is rare. Rhabdomyomatous hamartomata containing salivary tissue, situated bilaterally and symmetrically simulating the palatine (faucial) tonsils, has apparently not been reported. We present the combination of these findings in two unrelated patients. CASES: In the first case, the patient was exposed prenatally to 13-cis-retinoic acid (isotretinoin) and has typical features of this exposure, including bilateral microtia with aural atresia and bilateral 7th nerve palsies. Due to symptoms of obstructive sleep apnea, patient 1 had a "tonsillectomy" and adenoidectomy. Histopathologic studies demonstrated rhabdomyomatous hamartomata containing salivary and striated muscle tissue in place of the palatine tonsils. In the second case, the patient had been prenatally exposed to alcohol, cocaine, and marijuana. He has been noted to have developmental delay and behavioral issues in addition to bilateral microtia with aural atresia. "Tonsillectomy" and adenoidectomy were performed to alleviate chronic upper respiratory infections and snoring. Again, histopathologic studies of the tissue submitted as "tonsil" demonstrated rhabdomyomatous hamartomata containing salivary and muscle tissue. Although an extended banded karyotype and subtelomere panel were normal, a genetic etiology for the second patient's features cannot be excluded. CONCLUSIONS: We hypothesize that the findings of bilateral microtia with aural atresia and rhabdomyomatous hamartomata containing salivary and muscle tissue in the area of the palatine tonsils may represent a newly recognized association, which may have a teratogenic and/or genetic etiology.