Yun-Hoon Choung

Intratympanic Dexamethasone Injection for Refractory Sudden Sensorineural Hearing Loss

Objective: This case‐control study aimed to analyze the effect of intratympanic dexamethasone injection (ITDI) as a treatment option for patients with sudden sensorineural hearing loss (SSNHL) who were refractory to classic oral steroid treatment.

'Bow and lean test' to determine the affected ear of horizontal canal benign paroxysmal positional vertigo.

Objective: One of the problems in the management of horizontal semicircular canal benign paroxysmal positional vertigo (HSC‐BPPV) is the difficulty in determining the affected ear using Ewalds second law. The purpose of this study is to develop the new “bow and lean test (BLT)” to easily determine the affected ear of HSC‐BPPV and evaluate its efficiency.

Graphene-incorporated chitosan substrata for adhesion and differentiation of human mesenchymal stem cells†

A simple method that uses graphene to fabricate nanotopographic substrata was reported for stem cell engineering. Graphene-incorporated chitosan substrata promoted adhesion and differentiation of human mesenchymal stem cells (hMSCs). In addition, we proposed that nanotopographic cues of the substrata could enhance cell-cell and cell-material interactions for promoting functions of hMSCs.

Various causes and clinical characteristics in vertigo in children with normal eardrums

OBJECTIVE The differential diagnosis of vertigo in children is extensive. Otitis media and middle ear effusion could be the most common causes of vertigo in children, but there are some problems in detecting the other causes for vertigo because they are one of most frequent diseases of childhood. The purpose of this study is to review the clinical characteristics and both the audiological and vestibular findings of vertigo in children with normal eardrums, who do not show otitis media or middle ear effusion, and to assist in making a differential diagnosis of vertigo. METHODS The fifty five children (< 16 years old) with vertigo, who visited the Department of Otolaryngology, Ajou University Hospital, Suwon, South Korea between January 1995 and December 2001 were selected for this study. These excluded the patients with abnormal eardrums/tympanograms or those that did not perform questionnaires, audiological, or vestibular evaluations. They were retrospectively analyzed for clinical symptoms, vestibular functions, and differential diagnosis. RESULTS The most common causes for vertigo in children were migraine in 17 (30.9%) and benign paroxysmal vertigo of childhood (BPVC) in 14 (25.5%). Other less frequent causes included four cases of trauma, two cases each of Menieres disease, delayed endolymphatic hydrops, benign positional vertigo, and one case only for cerebellopontine angle tumor, seizure, acute vestibular neuritis, juvenile rheumatoid arthritis, leaving ten cases (18.2%) as unclassified. Abnormal findings were noted in 13 (23.6%) in pure tone audiogram, 3 (5.5%) in positioning test, 6 (10.9%) in bithermal caloric test, and 36 (65.5%) in rotation chair test. CONCLUSIONS The vertigo in children with normal eardrums, who did not show otitis media or middle ear effusion, was most commonly caused by migraine and BPVC. These findings have shown to be very different from those with adult vertigo. The evaluation of vertigo in children requires a questionnaire for extensive and complete history taking, audiograms and vestibular function tests. And in selected cases, electroencephalography, hematological evaluation, imaging of the brain or temporal bone should be performed.

Synergistic effects of nanotopography and co-culture with endothelial cells on osteogenesis of mesenchymal stem cells.

Inspired by the aligned nanostructures and co-existence of vascular cells and stem cells in human cancellous bone, we quantitatively investigated the relative contributions of nanotopography and co-culture with human umbilical endothelial cells (HUVECs) to the osteogenesis of human mesenchymal stem cells (hMSCs). Although both nanotopography and co-culture independently enhanced the osteogenesis of hMSCs, osteogenesis was further enhanced by the two factors in combination, indicating the importance of synergistic cues in stem cell engineering. Interestingly, nanotopography provided a larger relative contribution to the osteogenesis of hMSCs than did co-culture with HUVECs. Furthermore, the osteogenesis of hMSCs was also affected by the density of parallel nanogrooves, exhibiting a maximum at a 1:3 spacing ratio, as defined as the ratio of ridge width to groove width. Analysis of (i) biochemical soluble factors, (ii) hMSC-substrate interaction and (iii) hMSC-HUVEC interaction suggests that (ii) and (iii) play a crucial role in mediating osteogenic phenotypes.

Bilateral versus unilateral sudden sensorineural hearing loss

OBJECTIVES: To analyze the clinical characteristics and treatment results between bilateral (bi-) and unilateral (uni-) sudden sensorineural hearing loss (SSNHL). STUDY DESIGN AND SETTING: A retrospective study. METHODS: Three hundred twenty-four patients with SSNHL were classified into two groups; simultaneous bi-SSNHL (n = 16) and uni-SSNHL (n = 308). We compared clinical characteristics, medical history, hearing level, and treatment results between the 2 groups. RESULTS: The incidence of bi-SSNHL was 4.9 percent of overall patients with SSNHL. Bi-SSNHL occurs more commonly in patients of older age, with preexisting diabetes mellitus, and lipid panel abnormalities compared with uni-SSNHL. Ten patients (62.5%) in the bi-SSNHL group showed hearing recovery in 1 or both ears compared with 56.5 percent of patients with uni-SSNHL. Only 12 (37.5%) of all 32 ears recovered in bi-SSNHL, which was significantly lower than in uni-SSNHL. CONCLUSION: Bi-SSNHL has a very low incidence and lower recovery rate than uni-SSNHL. Recognition of similarities and differences between bilateral and unilateral SSNHL can help in counseling and managing the patients.

Efficacy of 3 Different Steroid Treatments for Sudden Sensorineural Hearing Loss: A Prospective, Randomized Trial

Objectives We treated patients with idiopathic sudden sensorineural hearing loss (ISSNHL) with several protocols on an outpatient department (OPD) basis. The study compared the efficacy of 3 different steroid treatments for ISSNHL. Study Design A prospective randomized controlled study. Setting Tertiary referral center. Methods A total of 60 patients diagnosed with ISSNHL were treated through OPD. They were randomly and equally divided into 3 groups based on therapy: oral steroid for 10 days (group I), intratympanic dexamethasone injection (ITDI) 4 times (group II), and both (group III). Pure-tone average (PTA) was measured by taking 4 frequencies (0.5, 1, 2, and 3 kHz). Hearing change was evaluated by comparing pre- and posttreatment PTAs. Recovery rate was assessed by American Academy of Otolaryngology—Head and Neck Surgery (AAO-HNS) Clinical Practice Guidelines. Results The hearing gain was 12.8 ± 15.4 decibels (dB) in group I, 12.1 ± 14.6 dB in group II, and 21.9 ± 26.2 dB in group III. The recovery rate was 60% in groups I and III and 55% in group II. The overall recovery rate was 58.3% (35 of 60 patients). There was no significant difference in hearing gain and recovery rates for the 3 groups. Frequency-specific hearing gain also did not differ significantly among groups. Conclusion Three different treatment protocols (oral steroid, ITDI, or the combination) resulted in similar hearing recovery rates. Therefore, OPD-based systemic and/or local steroid therapy can be recommended as an initial treatment in ISSNHL.

Isolated congenital ossicular anomalies

Conclusions: Isolated congenital ossicular anomalies are diverse. Our proposed modified Teunissen and Cremers classification will be helpful for the evaluation of congenital ossicular anomalies as well as the prediction of surgical outcome. Objectives: The aim of this study was to describe isolated congenital ossicular anomalies encountered in patients who have normal eardrums and to evaluate their surgical outcome based on their classification. Patients and methods: A total of 78 patients (94 ears) with congenital ossicular anomalies were reviewed. The preoperative and postoperative audiological findings, surgical findings, and temporal bone CT results were analyzed. Results: Twenty-one types of ossicular anomalies were identified in this study. A stapes footplate fixation was the most common anomaly and this was usually bilateral. However, the anomalies that were associated with the incus and malleus were usually unilateral. The congenital ossicular anomalies were classified into five types according to the status of the stapes footplate. Using this modification of a prior classification system, the more severe anomalies of the stapes footplate could be identified, and the worst postoperative hearing result could be predicted.

Rare cases of Ménière's disease in children

Classical Ménières disease is rarely found in children and literature regarding it is scarce. In general, the frequency of Ménières disease in children is only 0.4-7.0 per cent of that in adults. The progression pattern of Ménières disease in children is not known well. Here, we report three cases of Ménières disease in children less than 15 years old, treated over nine years. The three cases comprise 14- and 13-year-old boys and a nine-year-old girl. Two of the three patients initially complained only of recurrent bouts of vertigo, without any tinnitus, ear fullness or hearing impairment. In all three cases, the early pure tone audiograms showed only high tone frequency loss, regardless of subjective hearing loss, and the decrease in the hearing threshold was observed one to eight years after the dizziness attacks began. The hearing threshold was usually decreased to a level of mild or moderate hearing impairment. After diuretic treatment, vertigo was generally well controlled, and some cases showed improvement in hearing. Of the total number of patients with Ménières disease who visited our department over nine years, 2.6 per cent (3/114) were children, and the overall incidence of Ménières disease in children with vertigo was 2.0 per cent (3/147). In conclusion, Ménières disease in children rarely develops and may have characteristics of high tone loss in initial audiograms.

Development of water‐insoluble chitosan patch scaffold to repair traumatic tympanic membrane perforations

Perforated tympanic membranes (TM) and otitis media can be managed with a paper patch or tympanoplasty. However, a paper patch is not biocompatible and tympanoplasty requires complex aseptic surgical procedures. A novel biocompatible patch with a water-insoluble chitosan as the main component was prepared. Optimal mechanical characteristics of a water-insoluble chitosan patch scaffold (CPS) was approximately 40 microm in thickness, 7 MPa in tensile strength, and 107% in percent elongation, even though the characteristics varied significantly depending on the concentrations of chitosan and glycerol. SEM of the CPSs showed a very smooth surface as compared with that of the paper patches. These CPSs showed no cytotoxicity and had a stimulating effect on the proliferation of TM cells in in vitro study. In in vivo study, 4 (21.1%) and 17 (89.5%) TMs out of 19 adult rats with CPSs showed no perforations at 1 and 2 weeks, respectively. However, left control TMs showed healing of 0 (0%) at 1 week and 18 (94.7%) at 2 weeks. TEM findings of regenerated eardrums using CPSs showed thinner, smoother, and more compact tissues than spontaneously healed eardrums. A CPS was more effective than spontaneous healing to repair traumatic TM perforations.