Nebil Göksu

Anatomy of the Guinea Pig Temporal Bone

The middle ear of guinea pigs has long been used for experimental studies, but no detailed information about its temporal bone anatomy is available. In 18 adult guinea pigs, the temporal bone, eustachian tube, and inner ear anatomy, in addition to the anatomy of the middle ear, were investigated under the dissection microscope. In addition to properties of the eardrum, ossicles, air cell system, and cochlea previously described, the appearance of Huschkes foramen and the crista stapedis in an adult guinea pig ear, the structure of the eustachian tube, the architecture of the internal auditory canal, and the communication of the mastoid cells with the tympanic bulla are described. Differences and similarities among guinea pigs, other experimental animals, and humans are discussed to show the advantages and disadvantages of the guinea pig ear for experimentation.

Radiographic Evaluation of Children with Nasopharyngeal Obstruction Due to the Adenoid

The adenoidal-nasopharyngeal ratio (ANR) was proposed as a convenient and practical method to evaluate adenoidal enlargement. We analyzed cephalometric radiographs of 150 children divided into 6 subgroups according to clinical assessment (possible adenoidectomy candidates [PACs] and controls) and age. Our purpose was to investigate the predictive reliability of different ANRs calculated on the same reference line. Each of the ANRs described in this study presented statistically significant differences between PACs and control groups, and highly significant correlations with clinical symptoms of nasal obstruction. Further, the mean adenoidal depth was significantly larger in PACs than in normals, and it was found that the adenoidal depth in PACs did not show a significant decrement with age, in contrast to normals. On the other hand, although nasopharyngeal depth was not different between PACs and normals, an age-dependent increment was observed in PACs, in contrast to normals. Thus, it could be said that the ANR is a more reliable method for determining whether adenoidal hyperplasia is clinically significant or not, rather than the size of the adenoid or nasopharynx.

Hydatid Cyst of the Pterygopalatine Fossa

Abstract Echinococcus disease (hydatid cyst) is caused by a small tapeworm, Taenia echinococcus or Echinococcus granulosus. The clinical course of this disease depends on the site of involvement and size of the cyst. The majority of hydatid cysts appear in the liver (65%), lungs (25%), and, less frequently, in the spleen, kidneys, heart, bone, and central nervous system (CNS). The diagnosis is made most commonly by radiographs; computed tomography (CT) scanning; serologic tests, including indirect hemagglutination, latex agglutination, and immunoelectrophoresis; and skin tests. Surgery is the only treatment for hydatid cysts. Treatment with mebendazole or albendazole may be tried, if surgery is not possible because of general condition of the patient; however, the results are unpredictable.1

Facial reanimation with end-to-end hypoglossofacial anastomosis: 20 years' experience.

OBJECTIVE This study aimed to evaluate retrospectively the results of experience with end-to-end anastomosis of cranial nerves VII and XII, performed due to transection of the facial nerve during acoustic neuroma removal. METHODS We assessed the facial reanimation results of 33 patients whose facial nerves had been transected during acoustic neuroma excision via a retrosigmoid approach, between 1985 and 2006, and who underwent end-to-end hypoglossofacial anastomosis. We compared the facial nerve functions of patients receiving short term (two to three years) and long term (more than three years) follow up, and we assessed any complications of the anastomosis. RESULTS A House-Brackmann grade III facial function was achieved in 46.2 and 86.4 per cent of the patients in the short and long term, respectively. House-Brackmann grade IV facial function was achieved in 53.8 and 13.6 per cent of the patients in the short and long term, respectively. There was a statistically significant difference between the facial recovery results, comparing the short and long term follow-up periods (p = 0.03). Disarticulation was the most common complication, seen in 19 (57.6 per cent) patients; numbness of the tongue was the next commonest (10 (30.3 per cent) patients). None of the patients developed dysphagia. CONCLUSION Despite such morbidities as disarticulation and tongue numbness, end-to-end hypoglossofacial anastomosis is still an effective procedure for the surgical rehabilitation of static and dynamic facial nerve functions. Significant improvement in facial nerve function can occur more than three years post-operatively.

Predictive value of acoustic reflectometry (angle and reflectivity) and tympanometry.

OBJECTIVE Tympanometry and acoustic reflectometry are suggested tools for confirmation of otoscopic diagnosis of secretory otitis media. The issues on sensitivity and specificity of both devices are contradictory. In this study, our purpose was to compare sensitivity and specificity of both devices and to look for whether it is possible to reach higher values by combining them. METHODS This study included 150 normal ears and 150 ears with chronic effusion. In tympanometry, only B tracings were accepted as predictor of effusion. In acoustic reflectometry, reflectivity (cut point: 5) and curve angle with two cut-points (75 degrees and 90 degrees) were used. RESULTS Acoustic reflectometry presented higher specificity by both reflectivity (cut point: 5) and by curve angle (cut point: 75 degrees) (99.33% by both) than tympanometry (92%) (chi2 analysis, P < 0.001). But, their sensitivities (65.33 and 78%) were lower than tympanometry (96%) (chi2 analysis, P < 0.001). With curve angle of 90 degrees, specificity of acoustic reflectometry decreased to 85.33%, sensitivity increasing to 97.33%, which was not different from tympanometry (chi2 analysis, P > 0.1). When data of curve angle and tympanometry were combined, specificity and sensitivity of the combined test were found to be 91.33 and 100%, respectively. CONCLUSIONS (i) Acoustic reflectometry should not be proposed as a better device than tympanometry, because its test efficiency was not higher than tympanometry. (ii) The only advantage of AR (reflectivity > or = 5 and curve angle < or = 75 degrees) was its high specificity to effusion. In addition, higher curve angles than 90 degrees were found to be highly predictive for normal ears as much as tympanometry. But, predictivity of curve angle between 76 degrees and 90 degrees was low. (iii) When tympanograms and curve angle were combined, it was found that prediction of this combination for curve angles between 76 degrees and 90 degrees was perfect. (iv) We consider that both test devices provide complementary data to each other, which would be particularly important for screening studies and that they are good tools for confirmation of clinical impression, particularly for less experienced clinicians.

Functional outcomes of Vibrant Soundbridge applied on the middle ear windows in comparison with conventional hearing aids

Abstract Conclusion: Vibrant Soundbridge (VSB) application to the middle ear windows yields better functional outcomes than conventional hearing aids. However, speech discrimination scores obtained with VSB and conventional hearing aids are similar. Objective: To assess audiological outcomes of round and oval window applications of VSB in comparison with conventional hearing aids. Methods: Nineteen adult patients were included in the study. The patients had mild to moderate, moderate or moderate to profound conductive or mixed hearing loss. During surgery the floating mass transducer (FMT) was placed on the round (n = 14) or oval (n = 5) window. After the surgery, audiometric evaluation and free field audiometric evaluation of both ears was carried out. Results: The hearing thresholds in the low frequencies were not significantly different between the conventional hearing aids and VSB. The functional gains obtained with oval and round window approaches were similar except for 500 Hz. The hearing thresholds in the mid and high frequencies were significantly better with VSB than the conventional hearing aids. The functional gain in the low frequencies was not significantly different between VSB and conventional hearing aids. The functional gain in the other frequencies was significantly better with VSB than conventional hearing aids.

Otoacoustic emissions and effects of contralateral white noise stimulation on transient evoked otoacoustic emissions in diabetic children

OBJECTIVE In this study, our aim was to determine presence of dysfunction in the efferent auditory system of children with type-I diabetes mellitus (DM) presenting no evidence of symptomatic neuropathy. METHODS Thirty children with type-I DM (DM group) and 31 age matched healthy children (control group) with normal hearing and middle ear function were entered to the study. Distortion product otoacoustic emissions (DPOAE), transiently evoked otoacoustic emissions (TEOAE), and spontaneous otoacoustic emissions (SOAE) measurements were performed. Then, the TEOAE recording was repeated while a continuous broadband white noise (bandwidth: 50-8000 Hz) presented at 40 dB SL was delivered to the contralateral ear for efferent auditory system suppression. RESULTS We found that contralateral stimulation (CS) with white noise resulted in significantly more pronounced suppression of the TEOAE response amplitude in healthy controls compared to DM group at 2000 and 4000 Hz frequencies. Further, a relatively higher percentage of the controls had suppression in at least three frequencies compared to DM group. SOAE prevalence was found to be higher in the DM group. CONCLUSIONS Our findings suggest presence of a dysfunction in medial olivocochlear efferent system in diabetic children. This may be regarded as an early central manifestation of diabetic neuropathy.

GJB2 and mitochondrial A1555G gene mutations in nonsyndromic profound hearing loss and carrier frequencies in healthy individuals

This study aimed to assess mutations in GJB2 gene (connexin 26), as well as A1555G mitochondrial mutation in both the patients with profound genetic nonsyndromic hearing loss and healthy controls. Ninety-five patients with profound hearing loss (>90 dB) and 67 healthy controls were included. All patients had genetic nonsyndromic hearing loss. Molecular analyses were performed for connexin 26 (35delG, M34T, L90P, R184P, delE120, 167delT, 235delC and IVS1+1 A → G) mutations, and for mitochondrial A1555G mutation. Twenty-two connexin 26 mutations were found in 14.7% of the patients, which were 35delG, R184P, del120E and IVS1+1 A → G. Mitochondrial A1555G mutation was not encountered. The most common GJB2 gene mutation was 35delG, which was followed by del120E, IVS1+1 A → G and R184P, and 14.3% of the patients segregated with DFNB1. In consanguineous marriages, the most common mutation was 35delG. The carrier frequency for 35delG mutation was 1.4% in the controls. 35delG and del120E populations, seems the most common connexin 26 mutations that cause genetic nonsyndromic hearing loss in this country. Nonsyndromic hearing loss mostly shows DFNB1 form of segregation.

Practical Use of MESNA in Atelectatic Ears and Adhesive Otitis Media

Objective: MESNA is a synthetic sulfur compound that produces mucolysis by disrupting disulfide bonds. This study aimed to address indications and technique of MESNA application in otologic surgery, especially in retraction pockets and adhesive otitis media. Methods: MESNA application was performed in 42 ears of 39 patients. The diagnoses were retraction pockets fixed to incudostapedial joint, stapes or promontorium, and adhesive otitis media in 24 and 17 ears, respectively. Calculations were performed according to 24 ears of 23 patients with follow-up data. Results: One or more of the following surgical interventions were performed: MESNA application alone and ventilation tube insertion, reinforcement or mastoidectomy in addition to MESNA application. Sensorineural hearing loss was not encountered after MESNA application. The operation was successful in 79.2%. Overall revision surgery was needed in 20.8% of the ears. In 71.4% of the ears treated with MESNA alone, revision surgery was needed. Conclusion: In the light of our experience, we advocate the use of MESNA in atelectatic ears, because it makes the operation easy and safe by allowing elevation of the tympanic membrane by its mechanical and chemical actions.

Evaluation of the Results of Endoscope-Assisted Acoustic Neuroma Surgery through Posterior Fossa Approach

The objective of this study was to evaluate the results of endoscope-assisted acoustic neuroma surgery in posterior fossa approach. Between 1996 and 2002, 60 consecutive patients with acoustic neuroma were operated via the retrosigmoid suboccipital approach. Standard 4-mm sinus endoscopes at different angles were used during the surgeries either for inspection or tumor endoscopic dissection. Clinical parameters and treatment outcome were evaluated retrospectively. Tumor sizes were small, medium and large in 46.6, 45 and 8.3% of the patients, respectively. The hearing preservation rate, which did not correlate with tumor size (p > 0.05), was 24.4%. The need for facial reanimation surgery, which was needed in 5% of patients, was significantly higher in the large tumors than in the small and medium tumors (p < 0.001). Cerebrospinal fluid fistula rate, which was not related to tumor size (p > 0.05), was 13.3%. Tumor recurrence or residual tumor was not encountered at all. In conclusion, endoscopes give accurate information about the relationship between the tumor and the adjacent structures and help control the fundus of the internal auditory canal to ensure complete tumor removal. It is also helpful in visually verifying the continuity of the facial and cochlear nerves. The use of endoscopes does not appear to increase the hearing preservation rate, but is very helpful in complete tumor removal in the posterior fossa approach.