[Comparison of masking level difference in patients with multiple sclerosis and healthy control group Ghassem Mohamadkhani]

Multiple sclerosis [MS] is a neurological disorder that involves central nervous system. Studies have showed that multiple sclerosis affects behavioral central auditory tests, such as masking release or masking level difference [MLD]. The purpose of this study is to compare the masking level difference between multiple sclerosis patients and normal subjects. This cross sectional and non-interventional study was conducted on 32 multiple sclerosis patients aged between 20-50 years and 32 controls matched for age and gender in Faculty of Rehabilitation, Tehran University of Medical Sciences. masking level difference test was performed on each subject. The mean masking level difference in the two groups was significantly different [p<0.01] however, gender did not prove to play a role in this difference. As part of the multiple sclerosis diagnosis panel, masking level difference test is an efficient modality for evaluation of hearing impairment and monitoring of rehabilitation progress

Amplitude changes of the electrically evoked compound action potential in children with cochlear implants: preliminary results

Use of electrical instead of acoustical stimulation has made much objective electrophysiological evaluation possible. This is useful for management process of young children before and after the cochlear implant. These evaluations have been used for assessment of neuronal survival before cochlear implant and for monitoring of prosthesis function during and after the surgery. Electrically evoked compound action potential is one of these tests which makes a valid and reliable objective evaluation possible. The aim of this study was to evaluate the potential's amplitude changes three months after receiving the device in pediatric cochlear implant recipients. In this longitudinal study, changes of the potential's amplitude in four given electrodes in four sessions after receiving the device are evaluated by approximately one month intervals in children implanted in Amir Alam and Hazrat-e-Rasoul hospitals, Tehran in July to December 2007. The mean amplitude of the electrodes did not significantly change in different sessions, while there was significant difference between the first and the other electrodes' responses in every session [P<0.05]. Due to high reliability of the responses, the clinician can fit the speech processor for a long time. Better responses in apical electrodes may lead to develop an effective coding strategy

[Vestibular evoked myogenic potential in congenitally blind patients versus normal subjects]

Conventional balance test such as electronystagmography and videonystagmography, which are vision-dependant, are not practical in blind patients. Instead, vestibular evoked myogenic potential, not needing any vision, seems to be a more appropriate test for evaluating the vestibular system, in these patients. This study aimed to assess the prevalence and the latencies of p13 and n23 waves among congenitally blind and sighted participants evaluated by vestibular evoked myogenic potential. In a cross-sectional study, vestibular evoked myogenic potential was recorded for 20 slighted and 20 congenitally blind subjects, aged 18 to 30 years old, using 500 Hz-tone bursts [95 dBnHL]. Vestibular evoked myogenic potentials responses were present in all [100%] of the participants. Considering the results of the both ears, there was no significant difference between mean p13 and n23 latencies of the two groups [p>0.05]. Formation of vestibular evoked myogenic potentials reflex arc and neural pathway in congenitally blind patients is similar to slighted individuals; hence, the development of this pathway is independent of the visual system. Vestibular evoked myogenic potentials test is a useful test to assess vestibular function of the blinds

Comparison of short tone burst-evoked and click-evoked vestibular myogenic potentials in healthy adults

Vestibular evoked myogenic potential [VEMPs] is one of the clinical tools to evaluate vestibular function. The VEMPs can be recorded from sternocleidomastoid muscle by auditory stimulation with various sound stimuli and are thought to have saccular origin. The aim of this study was to compare the VEMP responses evoked by short [500 Hz] tone burst [STB] with those evoked by click stimuli in healthy young individuals. Thirty healthy volunteers [15 males, 15 females] with ages of 18 to 30 years were enrolled in this study. Subjects were instructed to sit on a chair and rotate their head to the opposite side of the recording muscle. The VEMPs was recorded using 500 Hz STB and then click sound stimuli to each ear. The p13 and n23 latencies, p13-n23 peak-to-peak amplitude and VEMPs thresholds were obtained for further analysis. The VEMP responses were present in all subjects for STB and ware not recorded in one subject for click. The latencies of p13 and n23 of STB-VEMP were significantly longer, and the p13-n23 amplitudes were significantly greater for STB-VEMP [p < 0.05], and thresholds were higher for clicks [p < 0.05]. No significant difference was obtained between both ears and genders. [p > 0.05]. The VEMP responses were significantly different between the stimuli of STB and click, and the norms of different stimuli should be established for clinical interpretations. According to these data, we recommend STB stimuli in comparison with clicks for clinical diagnosis

Auditory brainstem responses in autisnc children in comparison with normal children

One of the most important problems of children who suffer from autism is abnormality in receiving and integrating sensory inputs, especially hearing input. It has been shown that brainstem has a key role in receiving, encoding and integrating hearing input. Auditory brainstem response [ABR] is a tool by which we can evaluate this function. The purpose of this study was to assess and to compare autistic and normal children brainstem hearing function. This case-control study was conducted on thirty [58 ears] autistic and thirty [57 ears] normal 6-12 years old children. The children with autism were divided into slight and severe subgroups according to Autism Diagnostic Interview-Revised questionnaire. Clickevoked ABR was recorded and compared between groups. There was significant difference between two groups V and III wave latencies and I-III and I-V interpeak latencies [p < 0.05]. In fact, comparison of the results of autism subgroups with normal children indicated that the latencies of the severe subgroup significantly prolonged. Increasing latencies of ABR waves in severe subgroup maybe due to abnormality in low level of brainstem. Brainstem abnormality may result in exacerbating the symptom of autism. It is therefore suggested that ABR is included in diagnostic test batteries for these patients

[Internal evaluation of audiology department, faculty of rehabilitation, Tehran university of medical sciences, Iran]

Internal Evaluation means assessment of abilities and potentials. To promote the quality of education, research, health and finally rehabilitation is one of the most important roles and responsibilities of the universities. Promotion of quality of the theoretical and practical education for the Audiology students provides this major with its final goal that is to serve society. The purpose of this study was to evaluate the strength, weaknesses, opportunities and threats [SWOTs] of the Audiology department and to identify the ways of diminishing weaknesses and threats. This descriptive cross-sectional study was conducted on undergraduates, postgraduates, graduates, academic staff, and the director of Audiology department in 9 areas, including management flowchart, educational programs, instructional methods and curriculum models, students, educational areas and equipments, graduate, academic staff, research, and treatment. Data were collected by questionnaires. Results were analyzed descriptively and were expressed in raw and percentage. The scores of areas in two measures were as follows: management flowchart 4.36 [87.31%], educational programs 4.17 [83.58%], instructional methods and curriculum models 4.01 [80.26%], students 3.43 [68.60%], educational areas and equipment 3.60 [72.11%], from the view of undergraduates, post graduates, faculties, graduates 3.60 [72.03%], academic staff 4.03 [80.6%], research 3.52 [70.4%], and treatment 4.54 [90.80%]. The highest score was, therefore, of the treatment area and the lowest belonged to the educational area and equipments. The score of the Audiology department, as the main factor was 3.89 out of 5 which was 77.88%. Audiology group total score indicates the desirable status that can be promoted to the most desirable if SWOTs are considered

Comparison of middle latency auditory evoked potentials in learning disability and normal 7-12 year- old children

Learning disability [LD] is one of the most prevalent problems among elementary school children. Approximately 10 percent of all elementary school children suffer from this problem. It has been determined that learning disability is predominantly accompanied with subtle impairment in central auditory nervous system. The main idea of this study was to evaluate middle latency auditory evoked potential [MLAEPs] in learning disabled children. This cross-sectional study investigated middle latency auditory evoked potential in children with learning disability [n = 31] compared to normal children [n = 31]. Latencies and amplitudes of MLAEPs results with different stimulus intensity and binaural stimulation were compared between two groups. Compared to control group, learning disabled children exhibited smaller amplitudes for all the components except the right ear Na and Pa. There is no significant difference between two groups for latencies of the components. It seems that middle latency auditory evoked potential may be useful in diagnosis and evaluation of learning disabled children although more investigation is required

[ effect of music on hearing of string musicians]

Hearing sensitivity is so vital for musicians as loud music can cause hearing loss. The aim of this study was to assess hearing sensitivity of musicians in order to determine the effects of music exposure on hearing organ. This case-control study was conducted on 15 string musicians with musicianship history of more than 10 years and 15 normal hearing subjects. They all were male and 20-30 years old. TEOAE and DPOAE performed and after otoscopy, immittance and pure tone audiometry in octave frequencies between 250 to 16000 Hz. There is not significant difference between pure tone thresholds of two groups for all frequencies. A significant difference of TEOAE is found between two groups for total response and amplitudes of TEOAE .DPOAE amplitudes are not significantly different between two groups. Musicianship may affect TEOAE amplitudes, but cannot affect results of PTA and DPOAE. Therefore this can be useful to detect cochlear lesions secondary to music exposure and also as a tool in hearing protection program