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Coffee, of which caffeine is a critical component, is probably the most frequently used psychoactive stimulant in the world. The effects of caffeine on the auditory and vestibular system have been investigated under normal and pathological conditions, such as acoustic trauma, ototoxicity, auditory neuropathy, and vestibular disorders, using various tests. Lower incidences of hearing loss and tinnitus have been reported in coffee consumers. The stimulatory effect of caffeine is represented by either a shorter latency or enhanced amplitude in electrophysiological tests of the auditory system. Furthermore, in the vestibular system, oculomotor testing revealed significant effects of caffeine, while other tests did not reveal any significant caffeine effects. It could be that caffeine improves transmission in the auditory and vestibular systems' central pathways. Importantly, the effects of caffeine seem to be dose-dependent. Also, inconsistent findings have been observed regarding caffeine's effects on the auditory and vestibular systems and related disorders. Overall, these findings suggest that caffeine does not strongly influence the peripheral auditory and vestibular systems. Instead, caffeine's effects seem to occur almost solely at the level of the central nervous system.

Background and Objectives The blockage of adenosine receptors by caffeine changes the levels of neurotransmitters. These receptors are present in all parts of the body, including the auditory and vestibular systems. This study aimed to evaluate the effect of caffeine on evoked potentials using auditory brainstem responses (ABRs) and cervical vestibular-evoked myogenic potentials (cVEMPs) in a double-blind placebo-controlled study. Subjects and Methods Forty individuals (20 females and 20 males; aged 18-25 years) were randomly assigned to two groups: the test group (consuming 3 mg/kg pure caffeine powder with little sugar and dry milk in 100 mL of water), and the placebo group (consuming only sugar and dry milk in 100 mL water as placebo). The cVEMPs and ABRs were recorded before and after caffeine or placebo intake. Results A significant difference was observed in the absolute latencies of I and III (p0.050). Conclusions It seems that the extent of caffeine’s effects varies for differently evoked potentials. Latency reduction in ABRs indicates that caffeine improves transmission in the central brain auditory pathways. However, different effects of caffeine on auditory- and vestibular-evoked potentials could be attributed to the differences in sensitivities of the ABR and cVEMP tests.

Aging has several effects on auditory processing with the most important effect known as speech perception impairment in noise.The aim of the present study was to investigate the effects of aging on spatial hearing using quick speech in noise (QSIN) and binaural masking level difference (BMLD) tests and speech, spatial, and qualities of hearing scale (SSQ) questionnaire.The study was carried out on 34 elderly people, aged 60-75 years, with normal peripheral hearing and 34 young participants, aged 18-25 years. Using SSQ questionnaire and QSIN and BMLD tests, the spatial auditory processing ability was compared between the two groups.Comparison of mean scores using independent t test showed that there was a significant difference in the mean scores of QSIN, BMLD tests and SSQ questionnaire between the two groups (p 0.001). Sex was not found to have any effect on the results (p 0.05).Structural and neurochemical changes that occur in different parts of the central nervous system by aging affect various aspects of spatial auditory processing, such as localization, the precedence effect, and speech perception in noise.Lower scores of older adults with normal hearing in SSQ questionnaire and behavioral tests, compared with younger participants, may be considered as their weak performance in spatial auditory processing. The results of the present study reconfirm the effects of aging on spatial auditory processing, such as localization and speech perception in noise.

Background and Aim: Vestibular system has several anatomical connections with cognitive regions of the brain. Vestibular disorders have negative effects on cognitive performance. Hearing-impaired patients, particularly cochlear implant users, have concomitant vestibular disor­ders. Previous studies have shown that attention assigned to postural control decreases while per­forming a cognitive task (dual task) in hearing-impaired children. Since the vestibular system and postural control performance develop around 15−16 years of age, the aim of this study was to compare postural control performance during dual task in adolescent boys with normal hearing and cochlear implant (CI) users with congenital hearing-impairment. Methods: Postural control was assessed in twenty 16−19 year old cochlear implant boys and 40 normal hearing peers with force plate. The main outcomes were displacement in posterior- anterior and medial-lateral planes, and mean speed with and without cognitive task and under on/off-device conditions. Caloric test was per­formed for CI users in order to examine the peri­pheral vestibular system. Results: Ninety-five percent of CI users showed caloric weakness. There were no significant diff­erences in postural control parameters between groups. All performances deteriorated in the foam pad condition compared to the hard surface in all groups. Total mean velocity significantly increased during dual task in normal hearing group and in CI users with off-device. Conclusion: Although CI users had apparent vestibular disorders, their postural control in both single and dual-task conditions was identical to the normal peers. These effects can be attributed to the vestibular compensation that takes place during growing. Keywords: Balance; postural control; dual task; congenital hearing loss; cochlear implant

Background and Aim: Presbycusis is a prevalent chronic condition in the elderly which may have potential adverse effects on social and emotional aspects of their life. There is no one to one relationship between audiogram and the perceived handicap in elderly. A good way to measure hearing handicap are self-assessment tools. This study was aimed to translate, adapt and establish face validity of Short form of Hearing Handicap Inventory for the Elderly (HHIE-S) and the correlation with pure-tone and speech audiometry results as well as score of the other self-assessmnet tool (Self-Assessment of Communication: SAC) in the Iranian elderly. Methods: HHIE-S was translated into Persian and face validity was established. It was administered in 80 elderly participants. Correlation of their scores with their pure tone averages of 3 and 4 frequencies (PTA0.5-1-2 and PTA0.5-1-2-4), word recognition score (WRS) in quiet, and SAC scores was determined. Results: The experts mean scores to PHHIE-S was 99.63%. There were significant correlations between PHHIE-S with SAC (r = 0.89; p < 0.001), PTA0.5-1-2 (r = 0.4; p < 0.001), PTA0.5-1-2- 4 (r = 0.6; p 0.05). Conclusion: Simply evaluation of the hearing levels is not adequate in elderly. Self-assessment tools can shed light on the specific disability induced by hearing loss. PHHIE-S appears to be an easy and fast tool that may helpful to distinguish patients who might need rehabilitative services. Keywords: Elderly; presbycusis; selfassessment; handicap

Background and Aim: Spatial hearing plays an important role in listening in complex hearing situations, including contributing to localization, lateralization, spatial release from masking, dis­tance estimation from a sound source, and per­ceiving a signal in noise. Questionnaires are use­ful tools for assessing spatial processing disorder in adults. Given the high prevalence of this disorder in children and that the extent of chil­dren’s ability in completing questionnaires is not clear, this study aimed to evaluate the response validity of children to the Persian translation of the child version of the Speech, Spatial and Quality of Hearing Scale (PSSQ-Ch). Methods: The child version of the SSQ was translated into Persian and cross-culturally adap­ted. The final version was administered to 150 children (6 to 12 years of age) with normal hearing. The children’s response validity was evaluated qualitatively and the percentage of valid responses calculated for each of 7 age groups. Results: Across the three sections, the percen­tage of valid responses for children under age 10 was minimum 44.4% and maximum 83.3%, and the mode was around 60%. There was no child in the under-10 age group who answered all ques­tions validly. The response validity of children aged 10 or more was higher with a minimum of 93.3%, a maximum of 100% and mode of 100%. Conclusion: Children ≥ 10 years can reliably respond to the PSSQ-Ch. The response validity of children below 10 years is low; therefore, this questionnaire cannot be used as a self-assessment questionnaire in children below age 10. Keywords: Spatial hearing; binaural hearing; children; validation; self-assessment questionnaire

Purpose Approximately 1.3 billion people worldwide have vision impairment. The aim of the present study was to investigate the influence of Late-Onset blindness on cervical vestibular evoked myogenic potentials (cVEMP) responses. Accordingly, this study was performed to investigate and compare the parameters of the cVEMP test in sighted and late-onset blind individuals. Materials and method In this cross-sectional- comparative study, cVEMP was recorded by presenting a tone burst stimulus of 500 Hz with an intensity of 95 dBnHL in 20 sighted and 20 late-onset blind individuals aged between 18 and 30 years old. Results cVEMP was observed in all the individuals (100%). The average latency of P13 and N23, amplitude, amplitude ratio, and VEMP threshold did not differ significantly between the two groups (p > 0.05). Conclusion The findings of the study revealed that the formation of the neural pathway and reflex arch of cVEMP is similar between late-onset blind and sighted individuals. Thus, cVEMP can be a suitable test for assessing the vestibular function of late-onset blind people.

Background and Aim: In unilateral sudden sensorineural hearing loss (SSNHL), the ves­tibular system may be involved in addition to the auditory system. Several hearing assess­ments have shown that the disease course and the patient's improvement, at least two step of vestibular assessments can help in better control of the patient's balance function. The aim of this study was to evaluate the results of cervical ves­tibular evoked myogenic potentials (cVEMP) and video head impulse test (vHIT) used for assessment of saccule and semicircular canals before and after steroid therapy. Methods: Twenty three patients with SSNHL were evaluated for auditory and vestibular func­tion before and after steroid therapy. The results of cVEMP and vHIT were compared between intact and impaired ears and between pretest/posttest stages before and after treatment. Results: For 26.08% of patients, the cVEMP response was absent in the affected ear, but after treatment it was reported for all patients. There was a significant difference in vestibulo-ocular reflex (VOR) gain for both posterior and ante­rior semicircular canals of affected ear before and after treatment, but it was not significantly different after treatment as VOR gain increased. Conclusion: Dysfunction of nervous and vesti­bular systems in SSNHL is possible. Steroid therapy can improve the vestibular function and hearing of these patients. Therefore, vestibular evaluation can be used to determine the extent of lesions in SSNHL. Keywords: Unilateral sudden sensorineural hearing loss; vestibular evoked myogenic potentials; saccule; semicircular canals; video head impulse test

There are several anatomical connections between vestibular system and brain areas construct spatial memory. Since subliminal noisy galvanic vestibular stimulation (GVS) has been demonstrated to enhance some types of memory, we speculated that application of noisy GVS may improve spatial memory in a rat model of intracerebroventricular streptozotocin (ICV-STZ)-induced cognitive impairment. Moreover, we attempted to determine the effect of repeated exposure to GVS on spatial memory performance. The spatial memory was assessed using Morris water maze test. The groups received 1 (ICV-STZ/GVS-I) or 5 (ICV-STZ/GVS-II) sessions, each lasting 30 min, of low amplitude noisy GVS, or no GVS at all (Control, ICV-saline, ICV-STZ/noGVS). Hippocampal morphological changes investigated with cresyl violet staining and the immediate early gene product c-Fos, as a neuronal activity marker, was measured. Hippocampal c-Fos positive cells increased in both GVS stimulated groups. We observed significantly improved spatial performance only in ICV-STZ/GVS-II group. Histological evaluation showed normal density in ICV-STZ/GVS-II group whereas degeneration observed in ICV-STZ/GVS-I group similar to ICV-STZ/noGVS. The results showed the improvement of memory impairment after repeated exposure to GVS. This effect may be due in part to frequent activation of the vestibular neurons and the hippocampal regions connected to them. Our current study suggests the potential role of GVS as a practical method to combat cognitive decline induced by sporadic Alzheimer disease.

Background and Aim: Several studies have shown the anatomical associations between the vestibular system and cognitive processes, especially spatial memory. One of the first problems that occur in Alzheimer's disease (AD) is spatial memory deficits. The preclinical stage of AD is mild cognitive impairment (MCI). Amnestic type of MCI (aMCI) is more likely to progress to AD. Previous studies have demonstrated high incidence of vestibular disorders in AD patients; however, the balance system of aMCI patients has not been investigated. Therefore, the present study aimed to investigate vestibulo-ocular reflex (VOR) impairments in aMCI patients compared with control group. Methods: In this cross-sectional study VOR gain and catch-up saccades in six semicircular canals were measured in 12 aMCI patients and 12 normal controls using video head impulse test. Results: Vestibulo-ocular reflex gains in direction of all vertical semicircular canals were lower in aMCI- compared with normal-group (right anterior canal 0.74±0.17 vs 0.87±0.12; right posterior canal 0.77±0.10 vs 0.90±0.10; left anterior canal 0.87±0.10 vs 0.97±0.11; left posterior 0.72±0.18 vs 0.87±0.90). Catch-up saccades were found in direction of all canals in aMCI patients while there were no saccades in normal groups. Conclusion: In aMCI patients there was more vestibular dysfunction, which might be associated with cognitive deficits especially spatial type. In brief, vestibular investigation is suggested in aMCI patients.

Background and Aim: Recent studies have reported connections between vestibular function and cognition and also reported more prevalence of vestibular impairment in patients with Alzheimer's disease. Because patients with amnestic mild cognitive impairment (aMCI) are more likely to develop Alzheimer's disease, this study was conducted to evaluate vestibular dysfunction of otolith organs in aMCI patients compared to normal subjects. Methods: In our case-control study, 11 patients (22 ears) with aMCI with mean age of 56.73±8.83 years and 11 normal participants (22 ears) with mean age of 54.30±7.4 years were eva­luated for ocular and cervical vestibular evoked myogenic potentials (o- and cVEMP). Occurrence of VEMP responses, amplitude, latency and threshold of these waves were recorded and compared between the two groups. Results: Ocular VEMP was absent in 63.6% of aMCI patients and in 18.2% of the normal group. The difference was significant (p=0.002), while occurrence rate, amplitude, latencies and threshold of cVEMP were not significantly different between the two groups (p>0.05). McNemar's test showed that there was no significant relationship between occurrences of two potentials in aMCI group. Conclusion: These findings show the presence of vestibular dysfunction, especially in the pathways of ocular vestibular evoked potential, in patients with amnestic mild cognitive impairment. Given that previous studies have shown that cVEMP was absent in Alzheimer's disease, absence of oVEMP can be used as an indicator for predicting future impairment in individuals with amnestic MCI.

Background and Aim: Creatine plays an important role in the regulation of cellular energy in high energy demand organs such as the inner ear. It is also believed to play a protective role. This article reviewed the mechanisms and effects of creatine on the auditory and vestibular systems. Recent Findings: Creatine transporters and creatine kinase enzymes are involved in converting creatine to creatine phosphate. Phosphate is a fuel cell available in the cochlear and vestibular hair cells and the protective cells, striavascularis, peripheral and central neural pathways to the auditory cortex. It provides essential ATP for auditory and vestibular system performance. Creatine kinase prevents cochlear damage by regulating the metabolism of energy in marginal layers of the striavascularis and preventing free radical production in stressful situations. It also plays an important role in vestibular compensation. Creatine kinase dysfunction leads to an increase in the threshold of auditory brainstem potentials and a reduction in vestibular performance. The use of creatine improves vestibular evoked myogenic potentials and neurologic symptoms. Conclusion: Creatine and creatine kinase protein is essential for normal hearing and balance function and sensitivity. Creatine kinase deficiency impairs the functioning of these two systems; however, creatine consumption may boost the sensitivity of the vestibular system and neurological performance. Effects of the creatine consumption on the auditory system have not yet been examined.

Background and Aim: Navigation information is processed and stored in different brain areas such as hippocampus. Since multiple pathways has been reported between vestibular nuclei and hippocampus and also cognitive dysfunction specifically in spatial memory is induced by vestibular deficits, it can be assumed that vestibular system stimulation ameliorates spatial memory. The aim of study was to evaluate the effect of galvanic vestibular stimulation on normal individual’s spatial memory. Methods: In this experimental-interventional study, sixty 18-30-years-old women were randomly allocated in intervention and control groups. Intervention group undergone subthreshold bilateral bipolar galvanic vestibular stimulation and control group received sham stimulation. Stimulation was presented for 15 minutes. Corsi Block Tapping (CBT) test scores were compared before and after subthreshold bipolar galvanic vestibular stimulation exposure or no stimulation in each group and between groups. Results: All test parameters were the same in both groups before stimulation (p

Background and Aim: Auditory temporal processing reveals an important aspect of auditory performance, in which a deficit can prevent the child from speaking, language learning and reading. Temporal resolution, which is a subgroup of temporal processing, can be evaluated by gap-in-noise detection test. Regarding the relation of auditory temporal processing deficits and phonologic disorder of children with dyslexia-dysgraphia, the aim of this study was to evaluate these children with the gapin-noise (GIN) test. Methods: The gap-in-noise test was performed on 28 normal and 24 dyslexic-dysgraphic children, at the age of 11-12 years old. Mean approximate threshold and percent of corrected answers were compared between the groups. Results: The mean approximate threshold and percent of corrected answers of the right and left ear had no significant difference between the groups (p>0.05). The mean approximate threshold of children with dyslexia-dysgraphia (6.97 ms, SD=1.09) was significantly (p

Background and Aim: Since utricle is the main damaged organ in benign paroxysmal positional vertigo (BPPV), ocular vestibular evoked myogenic potential (oVEMP) may be an appropriate method to evaluate the utricule dysfunction and the effect of disease recurrence rate on it. This study aimed to record myogenic potential in patients with benign paroxysmal positional vertigo. Methods: In a cross-sectional study, ocular myogenic potential was recorded in 25 healthy subjects and 20 patients with benign paroxysmal positional vertigo using 500 Hz-tone bursts (95 dB nHL). Results: In the affected ear, mean amplitude was lower and mean threshold was higher than those in the unaffected ear and in the normal group (p0.05). Frequencies of abnormal responses in the affected ears were higher than in unaffected ears and in the normal group (p

Background and Aim: Some risk factors for obstructive sleep apnea (OSA) such as upper respiratory airways abnormalities and obesity overlap with the risk factors for Eustachian tube dysfunction (ETD). In this study, we investigated the prevalence of ETD in a population of patients with OSA. Methods: Tubal dysfunction was determined by tympanometry and inflation-deflation test in 36 patients diagnosed with severe OSA and 20 normal participants. Results: More than 80% of patients with OSA had concomitant ETD at least in one ear. Obese participants had a smaller tympanometric peak pressure (TPP) shift after inflation-deflation test than non-obese subjects. There was no signifycant correlation between TPP shift and duration of OSA. Conclusion: High prevalence of concomitant ETD was determined in patients with severe OSA and obese individuals. Tubal function testis suggested in patients referred for OSA evaluation.

Objective: In neural response telemetry, intracochlear electrodes stimulate the auditory nerve and record the neural responses. The electrical stimulation is sent to the auditory nerve by an electrode and the resulted response, called electrically evoked compound action potential, is recorded by an adjacent electrode. The most important clinical applications of this test are evaluation and monitoring the intra and postoperative responses of auditory nerve and help to primary setting of speech processor. The aim of this study was evaluating the potential's slope of amplitude growth function changes three monthes after receiving the devise in pediatric cochlear implant recipients. Materials & Methods: This longitudinal study evaluated the potentials' slope of amplitude growth function changes in four given electrodes in four sessions after receiving the devise by approximately one month's intervals in all of the children who implanted in Amir Alam and Hazrat-e-Rasoul hospitals in 2007, July to December. Friedman test was used to analyse the results. Results: Electrically evoked compound action potential's mean slope of each electrode was more in later sessions relative to first session, while there was significant difference between the 1st and the other electrodes’ responses in every session (P

The aim of this study was to study P3 with high and low frequency stimulus in blind subjects to study neuroplasticity. The P3 was recorded in 70 dBnHL. Comparison of results between two groups showed that there were no statistically significant differences between amplitudes and latencies of P3 with high frequency stimuli. However, in low frequency the difference between amplitudes was significant. Neuroplasticity seemed to occur in visual cortex in both groups. The activation patterns of the occipital cortex varied between these two groups and this could be demonstrated with low frequency stimuli better than with high frequency stimuli.

Background and Aim: Although the ability of speech perception has been improved in implanted subjects with recent progress in technology, cochlear implantation alone is not enough and more aural rehabilitation is necessary. The aim of this study was to assess improvement of speech perception in children with cochlear implant.Methods: Fourteen cochlear implanted children with a mean age of 5.5 years participated in this study. Auditory training was performed in 10 to 43 sessions. Speech recognition and perception were evaluated every 3 months. Third evaluation was done only for 4 patients.Results: Mean total score of the first evaluation was 43.21%, of the second was 63.76%, and of the third evaluation was 78%. All children obtained complete score for sound awareness at the first evaluation. In environmental sounds discrimination, 71.3%, 84.36%, and 100% answered completely to the questions of three evaluations respectively. In speech sounds discrimination, 34.7% in the first, 57.04% in the second, and 85% in the third evaluation obtained the complete score, and in auditory memory, complete responses were 21% for the first, 57.12% for the second, and 83% for third evaluation. In story rephrasing and comprehension, no one answered to questions completely. However, 12.83% obtained the complete score in the second and third evaluations. There were statistically significant differences between the first and the second evaluation (p=0.002)Conclusion: Sound awareness ability seems to be achieved rapidly. Development of speech and environmental sound discrimination abilities, particularly speech comprehension which is the most important skill, need more impressive training.

Background and Aim: Previous studies suggest that auditory stimulus frequency in normal subjects contribute to both P300 amplitude and latency measures. As occipital cortex devotes to other modalities including auditory inputs, the purpose of this study was to determine the effects of stimulus frequency in early blind subjects.Methods: fifteen early blind subjects (8 males and 7 females) with mean age of 25.13±4.27 years were tested. Cognitive potential P300 was recorded in response to high (1000/2000 Hz ) and low (250/500 Hz) frequencies auditory stimuli using an oddball task in 70 dB nHL. While participants answered to target stimulus, amplitude and latency of P300 was recorded.Results: With high frequency stimuli, mean amplitude in early onset blind subjects obtained 14.13 ±5.53µv and was 17.59±8.17µv with low frequency. With high and low frequency, mean latency of P300 obtained 295.60±31.33ms and 317.38±21.71ms respectively.Comparison of results between two stimuli showed that there were statistically significant differences between amplitudes (p=0.008) and latencies (p=0.001) of cognitive potential P300.Conclusion: Changing low frequency to high frequency results in decreasing both amplitude and latency. It seems that auditory stimuli frequency affect the P300 parameters in blind subjects.

Background and Aim: Conventional balance tests 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.Methods: In a cross-sectional study, vestibular evoked myogenic potential was recorded for 20 sighted and 20 congenitally blind subjects, aged 18 to 30 years old, using 500 Hz-tone bursts (95 dBnHL).Results: 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).Conclusion: Formation of vestibular evoked myogenic potentials reflex arc and neural pathway in congenitally blind patients is similar to sighted 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.

Background and Aim: Vestibular evoked myogenic potentials (VEMP) originate from the saccule and the inferior vestibular nerve. In this study, the prevalence of VEMP and latency of the p13 and n23 were compared between three groups of individuals, including symptomatic and asymptomatic Meniere's disease cases and normal participants.Methods: This study was conducted on 42 cases with the mean age of 40.48 years; thirty were Meniere's disease patients, of which 19 were symptomatic and 11 were asymptomatic; twelve were normal participants. The VEMP were recorded with 500 Hz tone bursts at 120 dBpeSPL. Then the prevalence and latency of the waves were analyzed and compared in the three above mentioned groups.Results: The prevalence of VEMP in symptomatic Meniere's disease patients (52.6%) was significantly less than asymptomatic individuals (90.9%) and also normal subjects (100%)(p0.05). The latency of p13 for symptomatic, asymptomatic and normal participants was 16.41, 15.20 and 14.14 ms, respectively and the latency of n23 for these groups was 20.25, 18.77 and 18.50 ms, respectively.Conclusion: In Meniere's disease, after medical management, the succule probably regains normal function resulting in re-existence of VEMP. It seems that there is no change in the latency of the waves, most likely due to involvement of the inner ear and intactness of the nerve. VEMP may be a useful test for diagnosis of Meniere's disease and additionally for monitoring the trend of medical management.

Background and Aim: In neural response telemetry (NRT), intracochlear electrodes stimulate the auditory nerve and record the neural responses. The electrical stimulation send to the auditory nerve by an electrode and the resulted response, called electrically evoked compound action potential (ECAP), is recorded by an adjacent electrode. The most important clinical applications of this test are evaluation and monitoring the intra and postoperative responses of auditory nerve and help to primary setting of speech processor. The aim of this study was evaluating of the potential's threshold changes in three monthes after receiving the devise in pediatric cochlear implant recipients.Materials and Methods: This longitudinal study evaluated the potential's threshold in four given electrodes in four sessions after receiving the device by approximately one months intervals in children implanted in Amir Alam and Hazrat-e-Rasoul hospitals in 2007, July to December.Results: ECAP mean threshold level of each electrode did not significantly change in differnent sessions, while there was significant difference between apical and basal electrodes’ responses in every session(p

Background and Aim: Blocking of the adenosine receptor in central nervous system by caffeine can lead to increasing the level of neurotransmitters like glutamate. As the adenosine receptors are present in almost all brain areas like central auditory pathway, it seems caffeine can change conduction in this way. The purpose of this study was to evaluate the effects of caffeine on latency and amplitude of auditory brainstem response(ABR).Materials and Methods: In this clinical trial study 43 normal 18-25 years old male students were participated. The subjects consumed 0, 2 and 3 mg/kg BW caffeine in three different sessions. Auditory brainstem responses were recorded before and 30 minute after caffeine consumption. The results were analyzed by Friedman and Wilcoxone test to assess the effects of caffeine on auditory brainstem response.Results: Compared to control group the latencies of waves III,V and I-V interpeak interval of the cases decreased significantly after 2 and 3mg/kg BW caffeine consumption. Wave I latency significantly decreased after 3mg/kg BW caffeine consumption(p

Background and Aim: 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. Materials and Methods: 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. Results: 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%.Conclusion: Audiology group total score indicates the desirable status that can be promoted to the most desirable if SWOTs are considered.

Background and Aim: Creatine is an energy-supplying protein in neuromuscular system with a protective role in relieving neurological symptoms. Since the enzymes and other mechanism involved in the conversion of creatine in the inner ear and vestibular nuclei are found in abundance, the aim of this study was to measure the effects of creatine on cervical vestibular evoked myogenic potentials (cVEMP) parameters. Methods: In this double-blind study, 35 healthy males aged 20-25 were randomly divided into an interventional (given creatine monohydrate) and a placebo groups (given maltodextrin). Participants received 5 g of dissolved powders in 250 ml water 4 times/days for 5 consecutive days. Cervical myogenic potentials were recorded before and after intervention with 500 Hz tone burst in 95 dBnHL. Results: In intervention group, cVEMP amplitudes increased from 41.86 to 55.71 μV and p13 and n23 latencies decreased from 13.81 and 22.61 to 13.32 and 21.69 ms, respectively. Also thresholds decreased from 85.52 to 81.71dBnHL. All changes were statistically significant (p

Background and Aim: Motion sickness (MS) is usually generated when there is a mismatch between the senses which serve balance. One of these senses is related to vestibular system, so it is highly possible that MS reflects in vestibular test results. But there are some conflicts in correlation between vestibular findings and MS. Thus, the objective of this study was to provide an overview of vestibular tests findings in individuals with MS. Recent Findings: It has been demonstrated that susceptible subjects to different types of MS have more pathologic results in vestibular tests, such as eye movement recordings and vestibular evoked myogenic potentials (VEMPs) results, asymmetry ratios and posturography results in particular. Conclusion: Based on abnormalities in various vestibular tests related to MS, possible contribution of signals from any part of the vestibular organ is likely in sensory conflict and triggering MS. Vestibular test results apparently can separate subjects with different susceptibilities to MS, but it seems difficult to differentiate susceptibilities to various types of MS.

Background and Aim: Caffeine at low doses blocks adenosine receptors. These receptors are present in all parts of the body including auditory and vestibular system. This study aimed to evaluate the effects of caffeine on cervical vestibular evoked myogenic potential (cVEMP). Methods: In this interventional double-blind study, 40 cases (20 females and 20 males) aged 18-25 years were randomly assigned into two groups: the test group, 3 mg/kg caffeine and little sugar and dry milk in 100ml water, and the control group, placebo including sugar and dry milk in 100ml water. Myogenic potential was recorded before and after intervention with 500 Hz tone burst in 95 dBnHL. Results: The statistical analysis revealed that there was no significant difference in p13 and n23 latency and amplitude asymmetry. However, the mean amplitudes of right ear (p=0.04) and two ears (p=0.02) of test group indicated a significant increase after caffeine ingestion. The results showed no significant difference in caffeine group compared to the placebo group in any of parameters and ears (p>0.05). Conclusions: With current study small sample size we found no effect of 3 mg/kg dose of caffeine on cervical vestibular evoked myogenic potential. Although after intervention the significant increase in the amplitude of all samples was notable, no significant difference was found between the two groups. The present study was the first research in this area, however, larger sample size and different doses of caffeine is suggested for future studies.

Background and Aims: As the hearing aid technology progressively promotes toward replacing analog hearing aids with digital and programmable ones, comparison of the patient satisfaction of those kinds of hearing aids by means of a valuable tool seems so necessary. So, the aim of this study was to compare self-reported benefit of analog, digitally controlled programmable and digital hearing aids for reducing disability caused by hearing impairment in mild to severe sensorineural hearing impaired persons. Materials and Methods: This cross-sectional study was performed on 90 persons with mild to severe sensorineural hearing loss dividing into three groups: 43 subjects were fitted with digital, 15 with programmable, 32 with analog hearing aids. After pure tone audiometry, Abbreviated profile of hearing aid benefit (APHAB) was completed before and one month after using hearing aids to determine the benefit of them. Results: Global APHAB mean scores for digital, programmable and analog hearing aids were 49.05, 33.19 and 39.53, respectively. Ease of Communication subscale mean scores were 53.46 for digitals, 37.66 for programmables and 39.09 for analogs. Background noise subscale mean scores for digital programmable and analog hearing aids were 46.36, 25.53 and 35.31, respectively. Global and also both subscale mean scores showed significant difference between digital hearing aids and programmable and analog ones. There was no significant difference between reverberation subscale mean scores of three groups. Conclusion: It seems digital hearing aids may be more beneficial to reduce disability caused by hearing loss than analog and programmable hearing aids are.

Background and Aim: One of the most significant complaints of children with learning disability (LD) is difficulty in understanding speech in the presence of background noise. Different studies have shown that the medial olivocochlear bundle(MOCB) may play a role in hearing in noise. The MOCB function can be evaluated by the contralateral suppression of tone burst evoked otoacoustic emissions (TBEOAEs).The aim of the present study was to evaluate frequency specifications of MOCB by the contralateral suppression of TBEOAEs at 1,2,3 and 4 KHz in response to contralateral white noise in LD students. Materials and Methods: This case-control study was conducted on 34 LD students aged 7-11 years and 31 normal students matched for age.The contralateral suppression of TBEOAEs was evaluated by comparing TBEOAEs amplitudes with and without contralateral white noise. Results: In the absence of noise there was no significant difference between TBEOAEs amplitudes of two groups. In the presence of noise significant decrease was seen in TBEOAEs amplitudes at 1,2,3 and 4 KHz in both groups. In LD students the amount of this decrement at 1,2 and 4 KHz was lower than in the normal students. Conclusion: A significant diminished suppression effect at 1,2 and 4 KHz in LD students indicates that at these frequency regions MOCB function was reduced. Therefore it suggests that the assessment of MOCB by evaluating the suppression effect of TBEOAEs included in the test battery approach used in the diagnostic of LD students.

Background: Facial schwannoma is a rare tumor arising from any part of the nerve. Probable symptoms are partial or facial weakness, hearing loss, visible mass in the ear, otorrhea, loss of taste, rarely pain, and sometimes without any symptoms. Patients should undergo a complete neurotologic history, examination with documentation of facial and auditory function, specially C.T. scan or M.R.I. Surgery is the only treatment option although the decision of when to remove facial schwannoma in the presence of normal facial function is difficult. Case: A 19-year-old girl with all above symptoms in the right side except loss of taste is diagnosed having facial schwannoma with full examination, audiometric, and radiological tests. She underwent surgery. In follow-up facial function were mostly restored. Conclusion: The need for careful assessment of patients with Bell's palsy cannot be overemphasized. In spite of the negative results if still there is any suspicoin, total facial nerve exploration is necessary.

Auditory perceptual and visual-spatial characteristics of subjective tinnitus evoked by eye gaze were studied in two adult human subjects. This uncommon form of tinnitus occurred approximately 4-6 weeks following neurosurgery for gross total excision of space Occupying lesions of the cerebellopontine angle and hearing was lost in the operated ear. In both cases, the gaze evoked tinnitus was characterized as being tonal in nature, with pitch and loudness percepts remaining constant as long as the same horizontal or vertical eye directions were maintained. Tinnitus was absent when the eyes were in a neutral head referenced position with subjects looking straight ahead. The results and implications of ophthalmological, standard and modified visual field assessment, pure tone audio metric assessment, spontaneous otoacoustic emission testing and detailed psychophysical assessment of pitch and loudness are discussed

Previous studies suggest that cochlear implant (CI) alone cannot probably provide all needs of many implanted subjects and more aural rehabilitation is necessary to maximize the benefits of device. Recent studies show that targeted auditory training significantly increases speech perception in CI recipients. The longitudinal studies have demonstrated that the greatest gains in performance occur in the first 3 months of use. The aim of this study was to assess improvement of speech perception in children with cochlear implants.