Low-frequency Conductive Hearing Loss Research Articles

Posterior Semicircular Canal Dehiscence with Vestibulo-Ocular Reflex Reduction for the Affected Canal at the Video-Head Impulse Test: Considerations to Pathomechanisms.

Posterior semicircular canal dehiscence (PSCD) has been demonstrated to result in a third mobile window mechanism (TMWM) in the inner ear similar to superior semicircular canal dehiscence (SSCD). Typical clinical and instrumental features of TMWM, including low-frequency conductive hearing loss (CHL), autophony, pulsatile tinnitus, sound/pressure-induced vertigo and enhanced vestibular-evoked myogenic potentials, have been widely described in cases with PSCD. Nevertheless, video-head impulse test (vHIT) results have been poorly investigated. Here, we present six patients with PSCD presenting with a clinical scenario consistent with a TMWM and an impaired vestibulo-ocular reflex (VOR) for the affected canal on vHIT. In two cases, an additional dehiscence between the facial nerve and the horizontal semicircular canal (HSC) was detected, leading to a concurrent VOR impairment for the HSC. While in SSCD, a VOR gain reduction could be ascribed to a spontaneous "auto-plugging" process due to a dural prolapse into the canal, the same pathomechanism is difficult to conceive in PSCD due to a different anatomical position, making a dural herniation less likely. Alternative putative pathomechanisms are discussed, including an endolymphatic flow dissipation during head impulses as already hypothesized in SSCD. The association of symptoms/signs consistent with TMWM and a reduced VOR gain for the posterior canal might address the diagnosis toward PSCD.

A Cohort Study Comparing Importance of Clinical Factors in Determining Diagnosis and Treatment for Superior Semicircular Canal Dehiscence Syndrome.

To determine which clinical factors have the strongest impact on determining diagnosis and decision for surgical repair for superior semicircular canal dehiscence syndrome (SCDS). A total of 81 patients presented with a suspicion for SCDS between October 2017 and October 2018. 38 patients ultimately were diagnosed with SCDS, and 28 chose surgical repair. Clinical factors of subjective patient symptoms (autophony, sensitivity to loud sounds, vertigo induced by loud sounds, dizziness, hearing their own heartbeats or other visceral organs) and audiogram findings (low frequency conductive hearing loss [CHL], bone-conduction hyperacusis, low cVEMP threshold [<80 db nHL], increased oVEMP [>17 μV] amplitudes) were analyzed with logistic regression to identify factors that predicted those who would ultimately be diagnosed with SCDS and those who would have surgical repair. Preoperative high-resolution CT imaging was performed on all patients. Significant predictors of presence of SCDS from logistic regression included low frequency CHL and increased oVEMP amplitude (p = 0.002 [OR 40, 95%CI 3.8-413], p = 0.001 [OR 93, 95%CI 6.8-1267], respectively). These were also significant predictors of individuals who chose to have surgical repair (p = 0.004 [OR 47, 95%CI 3.5-620], p = 0.001 [OR 126, 95%CI 8.2-1941], respectively). Area under the receiver operating characteristic curve (ROC curve) for these two variables are 93% for diagnosing SCDS and 94% for predicting choice for surgical repair. Low frequency CHL and increased oVEMP amplitude are the strongest predictive factors for making a diagnosis of SCDS and for choosing surgical repair.

Radiologically-proven New Development of Superior Semicircular Canal Dehiscence Associated With Development of Superior Semicircular Canal Dehiscence Syndrome

This report describes a case of development of radiologic superior semicircular canal dehiscence and reviews the literature for pertinent clinical and radiologic findings in patients with superior semicircular canal dehiscence syndrome (SCDS). A 28-year-old man presented with auditory and vestibular symptoms of SCDS and underwent a high-resolution temporal bone computed tomography scan that showed frank dehiscence of the right superior semicircular canal. Diagnosis of SCDS was further verified with audiometric and cervical vestibular-evoked myogenic potential (cVEMP) thresholds. The patient had previously undergone a computed tomography scan 12 years prior for work-up of sudden sensorineural hearing loss that showed no evidence of superior semicircular canal dehiscence bilaterally. A combination of diagnostic and therapeutic interventions was conducted consisting of preoperative audiometric and cVEMP thresholds, followed by middle fossa craniotomy for surgical repair of the dehiscence. Postoperative audiometric and cVEMP thresholds and symptomatic improvement of SCDS after surgical repair of the dehiscence. The patient reported resolution of his clinical symptoms after surgical repair of the dehiscence. Postoperative cVEMP thresholds improved to the normal range and the mild low-frequency conductive hearing loss resolved. To our knowledge, this case report is the first description of radiologically proven new development of superior canal dehiscence. Further prospective studies that include serial imaging examinations may help with visualizing and understanding the temporal evolution of superior canal dehiscence, and better elucidate the relationship between development/ progression of superior canal dehiscence and onset of clinical symptoms.

Dosimetric parameters associated with conductive or sensorineural hearing loss 5 years after intensity-modulated radiation therapy in nasopharyngeal carcinoma

Background: Most previous studies are separate dosimetric analyses of conductive or sensorineural hearing loss, and they are not conducive to a comprehensive assessment of auditory radiation damage.Aims/objectives: Our study aimed to evaluate the long-term incidence of sensorineural hearing loss (SNHL) or conductive hearing loss (CHL) in patients with nasopharyngeal carcinoma (NPC) after intensity-modulated radiation therapy (IMRT), and to investigate the relationship between SNHL or CHL and patient factors, treatment-related factors, and radiation dose parameters.Material and methods: Seventy patients (117 ears) with NPC, who were also treated with IMRT in our hospital from 2006 to 2014, were retrospectively analyzed. Radiation doses to the Eustachian tube (ET), middle ear (ME), cochlear (Co), and internal auditory canal (IAC) were assessed. Pure tone audiometry and impedance audiometry were performed before and during the follow-up period. The relationships between low-frequencies (0.5–2 kHz) or high-frequency (4 kHz) SNHL/CHL and radiotherapy dose parameters were analyzed.Results: Of the 117 ears studied, 7.69% had low-frequency SNHL, 35.9% had high-frequency SNHL, 23.93% had low-frequency CHL, and 18.80% had high-frequency CHL. The incidence of high-frequency CHL was higher in the T4 group than in the T (1–3) group (p < .05). When IAC Dmax > 42.13 Gy or IAC Dmean > 32.71 Gy, the risk of high-frequency SNHL increased in NPC patients. When ME Dmax > 44.27 Gy, ME Dmean > 29.28 Gy, or ET Dmax > 57.23 Gy, the risk of high-frequency CHL in NPC patients increased.Conclusions and significance: SNHL and CHL remain common ear complications after IMRT for NPC. IAC Dmax, IAC Dmean, ME Dmax, ME Dmean, and ET Dmax all need to be carefully considered during the IMRT treatment protocol.

Audiometric findings with voluntary tensor tympani contraction

BackgroundTensor tympani contraction may have a "signature" audiogram. This study demonstrates audiometric findings during voluntary tensor tympani contraction.MethodsFive volunteers possessing the ability to voluntarily contract their tensor tympani muscles were identified and enrolled. Tensor tympani contraction was confirmed with characteristic tympanometry findings. Study subjects underwent conventional audiometry. Air conduction and bone conduction threshold testing was performed with and without voluntary tensor tympani contraction.Main outcome measureChanges in air conduction and bone conduction thresholds during voluntary tensor tympani contraction.ResultsAudiometric results demonstrate a low frequency mixed hearing loss resulting from tensor tympani contraction. Specifically, at 250 Hz, air conduction thresholds increased by 22 dB and bone conduction thresholds increased by 10 dB.ConclusionsPrevious research has demonstrated a low frequency conductive hearing loss in the setting of tensor tympanic contraction. This is the first study to demonstrate a low frequency mixed hearing loss associated with tensor tympani contraction. This finding may aid in the diagnosis of disorders resulting from abnormal tensor tympani function. Tensor tympani contraction should be included on the differential for low frequency mixed hearing loss.

40-Hz Sinusoidal Auditory Steady-State Response and Tone Burst Auditory Brainstem Response Using a Kalman Filter to Determine Thresholds Pre- and Post-Myringotomy With Grommet Tube in Children With Mild, Low-Frequency Conductive Hearing Loss.

Accurate estimation of mild, low-frequency hearing loss is difficult in young children. This study aimed to determine the accuracy of 40-Hz sinusoidal auditory steady-state response (sASSR) compared with tone burst auditory brainstem response (TB-ABR) to detect mild, low-frequency hearing loss in children with otitis media with effusion and to measure postoperative thresholds. Thresholds at 500 and 4000 Hz were measured behaviorally and electrophysiologically using TB-ABR and 40-Hz sASSR with a Kalman filter in 26 children with otitis media with effusion. Recording was conducted preoperatively and postoperatively while children were actively awake. Repeated measures mixed analyses of variance were conducted to determine effects among measures and the two test frequencies. Both 40-Hz sASSR and TB-ABR accurately detected preoperative and postoperative thresholds and were within 5-10 dB of the behavioral thresholds at 4000 Hz. At 500 Hz, the mean 40-Hz sASSR threshold was only 5 dB above the behavioral thresholds and 18 dB better than the 500-Hz ABR threshold. Positive correlations were found but not between 40-sASSR and TB-ABR at 500 Hz. Also, the interrater judgment of the response was better for sASSR (89%) than TB-ABR (83%). The 40-Hz sASSR is more accurate than TB-ABR in determining a mild, low-frequency threshold.

Quantification of hearing loss in patients with posterior semicircular canal dehiscence

Conclusion: Patients with posterior semicircular canal dehiscence (PSCD) have low frequency conductive hearing loss similar to patients with superior semicircular canal dehiscence (SSCD) secondary to a pathologic third window. Objectives: PSCD can result in conductive hearing loss, but the magnitude of this hearing loss remains to be quantified. Patients with SSCD have been shown to have low frequency conductive hearing loss. The underlying pathophysiology of hearing loss from PSCD and SSCD is similar and related to a pathologic third window. Method: A PubMed search was completed for a meta-analysis of patients with PSCD. Articles with quality audiograms were obtained. Air conduction thresholds for ears with posterior semicircular canal dehiscence were compared to the opposite ear as well as normal control data. Results: Eight articles with 21 patients with PSCD and quality audiograms were included. Two patients had bilateral PSCD and one of those was excluded because hearing thresholds were at the limit of the audiometer. Patients with posterior semicircular canal dehiscence have statistically significant lower air conduction thresholds in frequencies at and below 2000 Hz.

Persistent conductive or mixed hearing loss after the placement of tympanostomy tubes

ObjectiveDescribed is a case series of clinical findings in children with persistent conductive or mixed hearing loss following tympanostomy tube placement for serous otitis media. Study designRetrospective chart review. SettingTertiary pediatric hospital. Subjects/methodsMedical records of thirty-nine children who were referred for either conductive or mixed hearing loss post-tympanostomy tube placement were reviewed for clinical histories, physical examinations, audiological evaluations, diagnostic studies, consultations, and surgical findings. Approval was obtained from the Boston Children's Hospital Institutional Review Board. ResultsCauses of hearing loss included ossicular abnormalities, cochlear abnormalities, ‘third window’ effects, cholesteatomas, genetic syndromes, and unknown causes. In four patients with isolated mild low-frequency conductive hearing loss, the cause was the presence of functional tubes. All patients diagnosed with a genetic syndrome had bilateral hearing loss. Patients with mixed hearing loss were diagnosed with cochlear abnormalities, ‘third window’ effects, or genetic syndromes. Computed tomography led to diagnosis in sixteen of twenty-five patients. Vestibular-evoked myogenic potential testing suggested a diagnosis in three of four patients. ConclusionIn children with persistent hearing loss following tympanostomy tube placement, identifying the laterality and type of hearing loss appears to be of importance in diagnosis. Patients with bilateral hearing loss should be considered for genetic testing, given the possibility of a syndrome. Patients identified with a mixed hearing loss should be evaluated for inner ear anomalies. Patients with mild, low-frequency hearing losses should be monitored audiologically and investigated further only if the hearing loss progresses and/or there is no resolution following tube extrusion.

Otologic and audiologic manifestations of hutchinson‐gilford progeria syndrome

To define the audiologic and otologic phenotype of Hutchinson-Gilford progeria syndrome (HGPS). Prospective case series. Fifteen patients with HGPS were enrolled in a prospective natural history study; 14 were evaluated in the neurotology clinic, and 11 received audiologic evaluations. The physical exam and audiologic findings of these patients were reviewed to define an otologic and audiologic phenotype for HGPS in the largest series of subjects in the literature. All patients were noted to have stiff auricular cartilages, small or absent lobules, and hypoplasia of the lateral soft-tissue portion of the external ear canal leading to a shortened canal. Ten of 14 patients (71%) had dry cerumen impaction, and four of 14 patients (29%) reported a history of recurrent otitis media. Nineteen of 22 ears (86.4%) demonstrated low-frequency conductive hearing loss in the 250 to 500 Hz range. Sixteen of 22 ears (73%) had type A tympanograms; three of 22 ears (14%) displayed bimodal or "W" peaked tympanograms; two of 22 ears (9%) had type B tympanograms; one of 22 ears (4%) had a type C tympanogram. Nine of 10 patients had distortion product otoacoustic emissions consistent with normal peripheral hearing sensitivity. HGPS is caused by a mutation in the LMNA gene resulting in the production of an abnormal nuclear protein; this in turn affects nuclear structure and function. Patients with HGPS have characteristic otologic features due to cartilaginous and subcutaneous tissue abnormalities and typically demonstrate low-frequency conductive hearing loss despite largely normal tympanometry. It is important to be aware of these conditions in managing these patients.

Development of canal cholesteatoma in a patient with prenatal isotretinoin exposure

Purpose To describe the clinical and radiologic findings in a case of isotretinoin embryopathy-like syndrome and discuss management of hearing loss, congenital external auditory canal (EAC) stenosis, and EAC cholesteatoma. Methods Review of medical, audiological, and radiological records. Results An 8 year old female presented with bilateral moderate conductive hearing loss, bilateral microtia, left EAC stenosis, and right EAC atresia, secondary to prenatal isotretinoin exposure. Comorbidities included developmental delay, ventricular septal defect, hypotonia, and retinal maldevelopment. The left EAC was sharply upsloping with a 2 mm-diameter meatus. Computed tomography (CT) scan of the temporal bone demonstrated normal middle and inner ears bilaterally; serial CT scans over 6 years demonstrated progressive development of left canal cholesteatoma. Implantation of a right BAHA system was performed, followed by left canalplasty and excision of cholesteatoma with facial nerve monitoring. An endaural incision was utilized to avoid compromising future microtia repair. Postoperative left-sided hearing improved to mild low-frequency conductive hearing loss rising to normal at 2000 Hz and above. Conclusions Despite extensive precautions for its use, isotretinoin remains a cause of major birth defects, including sensorineural, conductive or mixed hearing loss. Congenital EAC stenosis is much less common than congenital atresia or acquired stenosis; optimal surgical approaches vary depending on hearing status and facial nerve anatomy. Close monitoring for development of canal cholesteatoma is necessary.

Phenotype and course of Hutchinson-Gilford progeria syndrome.

Hutchinson-Gilford progeria syndrome is a rare, sporadic, autosomal dominant syndrome that involves premature aging, generally leading to death at approximately 13 years of age due to myocardial infarction or stroke. The genetic basis of most cases of this syndrome is a change from glycine GGC to glycine GGT in codon 608 of the lamin A (LMNA) gene, which activates a cryptic splice donor site to produce abnormal lamin A; this disrupts the nuclear membrane and alters transcription. We enrolled 15 children between 1 and 17 years of age, representing nearly half of the world's known patients with Hutchinson-Gilford progeria syndrome, in a comprehensive clinical protocol between February 2005 and May 2006. Clinical investigations confirmed sclerotic skin, joint contractures, bone abnormalities, alopecia, and growth impairment in all 15 patients; cardiovascular and central nervous system sequelae were also documented. Previously unrecognized findings included prolonged prothrombin times, elevated platelet counts and serum phosphorus levels, measured reductions in joint range of motion, low-frequency conductive hearing loss, and functional oral deficits. Growth impairment was not related to inadequate nutrition, insulin unresponsiveness, or growth hormone deficiency. Growth hormone treatment in a few patients increased height growth by 10% and weight growth by 50%. Cardiovascular studies revealed diminishing vascular function with age, including elevated blood pressure, reduced vascular compliance, decreased ankle-brachial indexes, and adventitial thickening. Establishing the detailed phenotype of Hutchinson-Gilford progeria syndrome is important because advances in understanding this syndrome may offer insight into normal aging. Abnormal lamin A (progerin) appears to accumulate with aging in normal cells. (ClinicalTrials.gov number, NCT00094393.)

The effect of superior canal dehiscence on cochlear potential in response to air-conducted stimuli in chinchilla

A superior semicircular canal dehiscence (SCD) is a break or hole in the bony wall of the superior semicircular canal. Patients with SCD syndrome present with a variety of symptoms: some with vestibular symptoms, others with auditory symptoms (including low-frequency conductive hearing loss) and yet others with both. We are interested in whether or not mechanically altering the superior canal by introducing a dehiscence is sufficient to cause the low-frequency conductive hearing loss associated with SCD syndrome. We evaluated the effect of a surgically introduced dehiscence on auditory responses to air-conducted (AC) stimuli in 11 chinchilla ears. Cochlear potential (CP) was recorded at the round-window before and after a dehiscence was introduced. In each ear, a decrease in CP in response to low frequency (<2 kHz) sound stimuli was observed after the introduction of the dehiscence. The dehiscence was then patched with cyanoacrylate glue leading to a reversal of the dehiscence-induced changes in CP. The reversible decrease in auditory sensitivity observed in chinchilla is consistent with the elevated AC thresholds observed in patients with SCD. According to the ‘third-window’ hypothesis the SCD shunts sound-induced stapes velocity away from the cochlea, resulting in decreased auditory sensitivity to AC sounds. The data collected in this study are consistent with predictions of this hypothesis.

Otolaryngological manifestations of cleidocranial dysplasia, concentrating on audiological findings.

Cleidocranial dysplasia is an autosomal dominant skeletal syndrome characterized by open skull sutures and clavicular hypoplasia or aplasia. It results from mutations in the transcription factor CBFA1 required for osteoblast differentiation and normal bone formation. Therefore, mutations in CBFA1 would be expected to cause conductive or sensorineural hearing loss, or both. The objective of the study was to evaluate the auditory function and head and neck manifestations of patients with cleidocranial dysplasia. Case series. Patients with cleidocranial dysplasia who were identified from the case records of the Craniofacial Anomalies Center at the University of California San Francisco (San Francisco, CA) gave medical and developmental history, underwent a general physical examination and a thorough head and neck examination, and completed a comprehensive audiological evaluation. Four families with eight affected individuals in all and one sporadic case were studied. The nine patients showed highly variable expression of abnormalities. Head and neck examination demonstrated abnormal cranial sutures, broad nasal root, clavicular hypoplasia or aplasia, and abnormally high arched palate. Although seven of nine patients showed eustachian tube dysfunction, recurrent otitis media in childhood requiring surgical intervention was not common. Hearing loss was present in three of nine patients (33%). One patient had a 40-dB mixed hearing loss, the second had a 25-dB low-frequency conductive hearing loss, and the third had a 45-dB high-frequency sensorineural hearing loss. In patients with cleidocranial dysplasia, eustachian tube dysfunction, conductive hearing loss, and sensorineural hearing loss are common because of structural and functional changes of the temporal bone and palate. Therefore, patients with cleidocranial dysplasia should be evaluated routinely by an otolaryngologist and undergo complete audiological testing.

Hearing results in retrolabyrinthine vestibular neurectomy

Patients having retrolabyrinthine vestibular neurectomy (RLVN) may have complications that compromise hearing. While most reviews have emphasized sensorineural loss, less attention has been given to conductive hearing loss, which may complicate RLVN. Hearing results of 25 consecutive cases of RLVN performed for Meniere's disease with incapacitating vertigo were tabulated according to 1985 American Academy of Otolaryngology (AAO) guidelines. Nine patients (36%) had improved hearing postoperatively, 5 (20%) had no change in hearing, and 11 (44%) had worse hearing postoperatively. The most commonly observed audiometric change was low-frequency conductive hearing loss, presumably secondary to partial ossicular fixation by bone dust or fat fibrosis in the attic and antrum. Five patients (20%) had low-frequency conductive hearing losses that increased by 10 dB or greater over preoperative levels. An additional 7 patients had lesser losses at low frequencies. One patient had a flat conductive hearing loss. Six (24%) of the patients had a decrease in bone levels of greater than 10 dB. Overall hearing results in this study are comparable to those of other series in the literature. Causes and prevention of conductive hearing loss in RLVN are discussed, and a format for presentation of hearing data that will highlight conductive hearing loss after surgery for Meniere's disease is presented.

Temporal bone histopathology of paget's disease with sensorineural hearing loss and narrowing of the internal auditory canal

A temporal bone report is presented of a patient with progressive sensorineural hearing loss and advanced Paget's disease involving the skull. The histopathology reveals Pagetic bone invading the internal auditory canal and compressing the cochlear division of the VIIIth cranial nerve resulting in severe neural degeneration. There are no other histopathologic abnormalities present in the cochlea to explain the hearing loss. A low-frequency conductive hearing loss was also present, but no histopathologic correlate could be identified.

Tomography of the temporal bone in Paget's disee.

TOMOGRAPHY OF THE TEMPORAL BONE IN PAGET'S DISEASEJERRY P. PETASNICK, M.D.Audio Available | Share