ABSTRACT
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.
ABSTRACT
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
ABSTRACT
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. 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. 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]. 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
ABSTRACT
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
ABSTRACT
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. 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 [1000/2000Hz] 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. With high frequency stimuli, mean amplitude in early onset blind subjects obtained 14.13 +/- 5.53 micro v and was 17.59 +/- 8.17 micro v with low frequency. With high and low frequency, mean latency of P300 obtained 295.60 +/- 31.33 ms and 317.38 +/- 21.71 ms 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. 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
Subject(s)
Humans , Male , Female , Adult , Evoked Potentials, Auditory , Event-Related Potentials, P300 , Blindness , Neuronal PlasticityABSTRACT
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]. 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. 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<0.01]. Increasing of the glutamate level resulted from the adenosine receptor blocking brings about changes in conduction in the central auditory pathway
Subject(s)
Humans , Male , Caffeine , Students , GlutamatesABSTRACT
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
Subject(s)
Humans , Rehabilitation , Evaluation Studies as Topic , Cross-Sectional Studies , Surveys and QuestionnairesABSTRACT
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. 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. 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. It seems digital hearing aids may be more beneficial to reduce disability caused by hearing loss than analog and programmable hearing aids are