Effect of tympanostomy tubes on transient-evoked otoacoustic emissions

It is well documented that Otitis media with effusion [OME] is a very common childhood disease which precludes otoacoustic emissions [OAEs] recording. Trials of medical treatment may fail to resolve effusion and tympanostomy tubes may be recommended. The aim of the present study was to determine the prevalence of transient-evoked otoacoustic emissions [TEOAEs] in ears with patent tympanostomy tubes from children with normal hearing sensitivity. TEOAEs were measured in 64 children [128 ears] with normal hearing and patent tympanostomy tubes 4-8 weeks after surgery. Shepard grommet-type tube was inserted in 104 ears and T-type tube was inserted in 24 ears. Results indicate that passing TEOAEs was present in 123 ears [96%]. Of the 5 ears [4%] in which TEOAEs failed to be recorded, 1 ear has a Shepard grommet-type tube and the remaining 4 ears have T-type tubes. Analysis of TEOAEs by frequency bands demonstrated that in ears with grommet-type tubes and passed emissions [103 ears], TEOAEs was absent at 5 KHz band only in 24 ears [23%] and absent at 4 and 5 KHz bands only in 30 ears[29%]. While in ears with T-type tubes and passed emissions[20 ears], TEOAEs was absent at 5 KHz band only in 11 ears [55%] and absent at 4 and 5 KHz bands only in 16 ears[80%]. The use of T-type tube appeared to decrease the probability of obtaining normal TEOAEs in ears with normal peripheral hearing. However, the use of grommet-type tube had a negligible effect on recording TEOAEs, In conclusion, TEOAEs can be reliably used to test the function in the presence of tympanostomy tubes at least in frequency bands 1,2 and 3 KHZ and it is not necessary to wait until of the tubes

Mismatch negativity in auditory neuropathy patients

Mismatch negativity [MMN] is a negative component in the auditory event-related potential. There has been increased interest in using the MMN as a clinical diagnostic tool because it might provide an objective neural measure of auditory discriminability. Auditory neuropathy [AN] is characterized by a paradoxical absence of auditory brainstem evoked potentials with presence of otoacoustic emissions, in patients whose pure-tone thresholds were slightly elevated. The present study was designed to investigate the detectability of MMN in cochlear hearing loss and AN patients and to test the effectiveness of MMN as an indicator of auditory discrimination at cortical level, particularly in patients with AN, if any. This study consisted of sixty subjects divided into three groups: [Group 1] 20 AN patients, [group 2] 20 patients with bilateral moderate SNHL of cochlear origin and [group 3] 20 normal peripheral hearing subjects. All participants were submitted to: full medical history, otoscopy, basic audiological evaluation. TEOAEs, ABR for neuro otologic diagnosis and MMN testing. The results of the present study demonstrated that SNHL had a significant impact on the timing of the brain processes involved in the detection and discrimination of stimuli. Moreover, no significant differences were found between AN patients and patients with cochlear hearing loss as far as MMN latencies

Pulsatile tinnitus: Audiologic and MR imaging diagnostic lssues

Pulsatile tinnitus often presents a diagnostic and management dilemma to the neurologist. Correct diagnosis is imperative because in the majority of cases, there is a treatable underlying etiology. In addition, failure to make proper diagnosis may be disastrous because in some patients, a life-threatening intracranial disease may be present. This study was carried out aiming to investigating the feasibility of differentiating the possible causes of pulsatile tinnitus, particularly in patients with normal otoscopy, using clinical, audiological and radiological, tools. 29 patients complaining of pulsatile tinnitus were evaluated by history taking, clinical examination, laboratory investigations, otoscopy, basic audiological evaluation, MRI for petrous bone and brain and MRA. Glomus jugulare tumor was diagnosed in 3 patients. Benign intracranial hypertension [BIH] was diagnosed in 4 patients. Intraventricular neoplasm in 2 patients. Internal carotid artery stenosis in one patient. Post-traumatic pseudoaneurysm in one patient. Scalp AVM in one patient. Temporal bone metastasis in one patient. Severe anemia in one patient and no identifiable cause [idiopathic] in 15 patients. A unilateral mild low frequency pseudosensorineural hearing loss was identified in 10 patients with normal otoscopy. Hearing loss was normalized after elimination of tinnitus by applying a light digital pressure over the ipsilateral internal jugular vein

Intratympanic dexamethasone in diabetic and hypertensive patients with sudden sensorineural hearing loss

Systemic steroid therapy has been considered a mainstay for treatment of idiopathic sudden sensorineural hearing loss [ISSNHL], specially among those who suspect a viral etiology. Unfortunately, some patients are poor candidates for systemic steroids. The aim of the present study is to evaluate the efficacy of intratympanic dexamethasone injection for diabetic and hypertensive patients with SSNHL in whom systemic steroid therapy is hazardous. This study was undertaken prospectively on 26 diabetic and hypertensive patients with unilateral moderately severe and severe SSNHL in whom there was a history of a recent upper respiratory tract infection. The patients were 14 men [53.8%] and 12 women I with an age range 43-68 years. Under local anaesthesia. 0.5 ml of dexamethasone [24 mg/mi] was injected in the tympanic cavity. injection was performed on three separate occasions over 10 days. Hearing was assessed by pure-tone and speech audiometry immediately before, twice weekly during therapy and within 3 weeks after therapy was discontinued. Pure-tone average [500, 1000 and 2000Hz] improved in 15 patients [57, 7%]. 7 patients [27%] recovered to normal hearing threshold levels 5 patients [19.2%] improved to a degree of mild hearing loss and :3 patients [11.5%] improved to a degree of moderate hearing loss. A hearing recovery rate of 57.7% in ISSNHL could be considered a good and encouraging response rate in a group of patients who an not tolerate systemic steroid therapy and may be considered beyond therapeutic reach

Stapes surgery: preinsertion technique

Two hundred ears with otosclerosis have been operated upon using stapedotomy technique with insertion of the prosthesis before removal of the superstructure [preinsertion technique] in 100 ears and the usual stapedotomy technique as described by Schuknecht in 100 ears. The postoperative air-bone gap, calculated as the difference between the postoperative air and bone conduction levels, was smaller in the stapedotomy technique for all frequencies except at 2000 Hz, the differences were statically insignificant except at 4000 Hz, the mean postoperative air-bne gap was 8.7 dB and 7.5 dB for the 1st and 2nd group, respectively, which is statistically insignificant. We found no postoperative loss of bone conduction exceeding 15 dB in this series of patients. There was a deterioration of more than 10 dB in four ems, one in the first group and three in the second group. According to ow results we conclude that the small fenestra technique provides good results with minimal complications in treatment of otosclerosis. The preinsertion technique provides more advantages, being easier and minimize trauma to the inner ear

Stapes surgery: comparison between different prostheses

Four hundred and fifty ears with otosclerosis have been operated upon using 3 different types of prostheses [Teflon piston in 217 ears, Teflon platinum in 133 ears and House prostheses in 100 ears]. Greater hearing gains were obtained with the use of Teflon piston and Teflon platinum than House prostheses with statistically significant advantage at 2000-4000 Hz. The mean postoperative air-bone gap was not statistically significant with the use of the 3 prostheses but at 2000 and 4000 Hz the ABG was significantly larger with the use of House prostheses. According to our results, we conclude that Teflon piston and Teflon platinum provide better results than house prostheses and are considered the prostheses of choice for otosclerosis surgery

Electrooculographic analysis in myasthenia gravis

Myasthenia gravis is an autoimmune disease affecting the neuro-muscular junction of skeletal muscles that is characterized by fatigable muscle weakness. It commonly affects the extraocular muscles. The aim of the present study was to use a non-invasive and a quantitative tool [electronystagmography] to evaluate the different eye movement abnormalities in myasthenia gravis and the efficacy of treatment in such patients. This study was conducted on 15 patients of both genders. Oculography tests were performed to all patients deprived from medication for 12 hours, and after medical treatment by 2-3 hours. Statistical analysis was done using Excel version release 2000. None of the patients showed spontaneous nystagmus whether in eyes open or closed situations. Two of the patients showed eccentric gaze nystagmus that was direction fixed. Although the mean values of saccadic acceleration, latency and peak velocity were close to the normative values, they showed statistically significant improvement after medical treatment. The smooth pursuit and accordingly the optokinetic tests showed gain abnormalities that statistically significantly improved after therapy. This study suggests that quantitative recording of eye movements have as good or better discriminative ability and could make a significant contribution to diagnosis and efficacy of drug therapy in myasthenia gravis