ASSR and Auditory neuropathy
Posted on 07/17/07 22:50:57
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PostPosted: Tue May 04, 2004 4:56 am Post subject: ASSR and Auditory neuropathy
Greetings from Manipal , INDIA ! I introduce myself as Amit Gupta( Lecturer in Audiology , Dept. of Speech and Hearing, College of Allied Health Sciences, Kasturba Medical College, a constituent college of the Manipal Academy of Higher Education, Manipal, India)
Recently i came across a client with auditory neuropthy with following audiological findings: ABR absent OAE present and ASSR present with severe hearing loss at low frequencies to moderately severe hearung loss at high frequencies bilaterally As per my knowledge one possible explanation could be that ABr requires more synchrony of nerve fibres than ASSr , (Correct me if i am wrong). Is there any other physiological reason.
Posted on 07/17/07 22:56:27
Number of posts: 1
PostPosted: Sun Oct 23, 2005 10:11 pm Post subject:
A recent study (Abstract shown below) from Acta otorrinolaringologica espanola
Volume 56, Issue 6, June 2005, Pages 240-245 it discusses MSSRs and ABRs giving similar recorded thresholds but different behavoural thresholds in two patients with AN/AD.
Stable auditory evoked potentials in the study of two patients with auditory neuropathy
Tapia Toca, M.C., Savio LÃ³pez, G
INTRODUCTION: We described the results of the auditory multiple steady state response (MSSR) technique in the assessment of two patients with auditory neuropathy (AN). The aim of this study was to corroborate the correspondence between the MSSR generators elicited by amplitude modulated tones ranging between 80-100 Hz, with the generators of auditory brain stem response (ABR). Moreover, we would also try to demonstrate the validity of the MSSR in the diagnosis of AN in children. MATERIAL AND METHODS: Two children diagnosed of hyperbilirrubinemia, aged, 18 months and 10 years have been studied with MSSR (500, 1000, 2000 and 4000Hz); ABR with clicks; OAE; behavioural audiometry; MRI and acoustic reflexes. RESULTS: A difference between electrophysiological and behavioural audiogram in both cases diagnosed with auditory neuropathy have been found. The auditory thresholds were similar using the two types of evoked potentials (MSSR and ABR). Both techniques showed an increment of auditory threshold congruous with a severe auditory impairment, while behavioural audiometry showed only a mild elevation of auditory threshold. We can also see how the threshold differed between frequencies using behavioral audiometry and MSSR. CONCLUSION: It is concluded that our findings are in agreement with previous studies and they sustain the theory about the coincidence of MSSR at fast rate (80-110 Hz) and ABR generators. Also, we demonstrate the usefulness of the MSSR as an objetive electroaudiometric tool in patients with auditory neuropathy as ABR. This technique is thus a recommendable test to complete the audiological study in infants with AN, to establish a more precise treatment.
subject: response from sasha8
Posted on 07/17/07 22:58:53
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PostPosted: Wed Dec 21, 2005 12:33 amï¿½ï¿½ï¿½ Post subject: response ï¿½ï¿½ï¿½ ï¿½
WOW, I@N, you are the first user to respond to another user outside of the picton group! Thank you...let's hope this board becomes more interactive.