Auditory cortical N100 in pre- and post-synaptic auditory neuropathy to frequency or intensity changes of continuous tones.
OBJECTIVE
Auditory cortical N100s were examined in ten auditory neuropathy (AN) subjects as objective measures of impaired hearing.


METHODS
Latencies and amplitudes of N100 in AN to increases of frequency (4-50%) or intensity (4-8 dB) of low (250 Hz) or high (4000 Hz) frequency tones were compared with results from normal-hearing controls. The sites of auditory nerve dysfunction were pre-synaptic (n=3) due to otoferlin mutations causing temperature sensitive deafness, post-synaptic (n=4) affecting other cranial and/or peripheral neuropathies, and undefined (n=3).


RESULTS
AN consistently had N100s only to the largest changes of frequency or intensity whereas controls consistently had N100s to all but the smallest frequency and intensity changes. N100 latency in AN was significantly delayed compared to controls, more so for 250 than for 4000 Hz and more so for changes of intensity compared to frequency. N100 amplitudes to frequency change were significantly reduced in ANs compared to controls, except for pre-synaptic AN in whom amplitudes were greater than controls. N100 latency to frequency change of 250 but not of 4000 Hz was significantly related to speech perception scores.


CONCLUSIONS
As a group, AN subjects' N100 potentials were abnormally delayed and smaller, particularly for low frequency. The extent of these abnormalities differed between pre- and post-synaptic forms of the disorder.


CONCLUSIONS
Abnormalities of auditory cortical N100 in AN reflect disorders of both temporal processing (low frequency) and neural adaptation (high frequency). Auditory N100 latency to the low frequency provides an objective measure of the degree of impaired speech perception in AN.
Dimitrijevic
Andrew
A
Department of Neurology, University of California, Irvine, United States. Electronic address: adimitri@uci.edu.
Starr
Arnold
A
Department of Neurology, University of California, Irvine, United States.
Bhatt
Shrutee
S
Department of Neurology, University of California, Irvine, United States.
Michalewski
Henry J
HJ
Department of Neurology, University of California, Irvine, United States.
Zeng
Fan-Gang
FG
Department of Otolaryngology - Head and Neck Surgery, University of California, Irvine, United States.
Pratt
Hillel
H
Evoked Potentials Laboratory, Technion - Israel Institute of Technology, Haifa, Israel.
D000161:Acoustic Stimulation; D000293:Adolescent; D000328:Adult; D001301:Audiometry, Pure-Tone; D001303:Auditory Cortex / Q000502:physiology* / Q000503:physiopathology; D001309:Auditory Threshold / Q000502:physiology; D003056:Cochlear Nerve; D004569:Electroencephalography; D055724:Electrophysiological Phenomena; D005072:Evoked Potentials, Auditory / Q000502:physiology*; D005260:Female; D006311:Hearing Disorders / Q000503:physiopathology*; D006313:Hearing Loss, Central / Q000503:physiopathology; D006801:Humans; D008297:Male; D008565:Membrane Proteins / Q000235:genetics; D008875:Middle Aged; D009154:Mutation / Q000235:genetics / Q000502:physiology; D010523:Peripheral Nervous System Diseases / Q000235:genetics / Q000503:physiopathology*; D013067:Speech Perception / Q000502:physiology; D013569:Synapses / Q000502:physiology; D013696:Temperature; D055815:Young Adult
D008565:Membrane Proteins; C118457:OTOF protein, human
J Clin Neurophysiol. 2002 Apr;19(2):113-24
11997722
Clin Neurophysiol. 2002 Oct;113(10):1558-65
12350431
Brain. 1974 Mar;97(1):41-8
4434170
Clin Neurophysiol. 2008 Sep;119(9):2111-24
18635394
Clin Neurophysiol. 2009 Feb;120(2):374-83
19112047
J Laryngol Otol. 1980 Aug;94(8):945-64
7430804
J Acoust Soc Am. 1968 Aug;44(2):582-91
5665530
Ann Neurol. 1999 Jul;46(1):36-44
10401778
Clin Neurophysiol. 2009 Jul;120(7):1352-63
19535287
Brain. 2003 Jul;126(Pt 7):1604-19
12805115
Behav Brain Funct. 2008 Mar 31;4:15
18377641
J Neurophysiol. 2005 Jun;93(6):3050-63
15615831
J Acoust Soc Am. 2000 Dec;108(6):3030-5
11144595
J Acoust Soc Am. 2000 Apr;107(4):2155-61
10790041
Science. 1967 Jul 7;157(3784):92-4
6026675
Laryngoscope. 2007 Jul;117(7):1202-8
17471106
J Med Genet. 2006 Jul;43(7):576-81
16371502
Pediatr Clin North Am. 2003 Apr;50(2):331-40, vii-viii
12809326
Clin Neurophysiol. 2005 Mar;116(3):669-80
15721081
J Assoc Res Otolaryngol. 2009 Dec;10(4):545-56
19636622
Clin Neurophysiol. 2009 Feb;120(2):360-73
19070543
J Speech Hear Disord. 1964 Feb;29:14-22
14122664
Brain Res. 2009 Dec 1;1300:97-104
19733158
J Speech Lang Hear Res. 2006 Apr;49(2):367-80
16671850
Trends Amplif. 2005;9(1):1-43
15920648
Int J Audiol. 2007 Jan;46(1):39-46
17365054
Br J Audiol. 1979 Aug;13(3):108-12
486816
Ear Hear. 2000 Dec;21(6):542-53
11132781
J Acoust Soc Am. 1996 Feb;99(2):1040-52
8609287
Am J Hum Genet. 2000 Sep;67(3):591-600
10903124
Ear Hear. 2002 Jun;23(3):239-53
12072616
Brain. 1996 Jun;119 ( Pt 3):741-53
8673487
Biochem Biophys Res Commun. 2010 Apr 9;394(3):737-42
20230791
Prog Retin Eye Res. 2004 Jan;23(1):53-89
14766317
J Neurophysiol. 1967 Jul;30(4):769-93
4962851
Ear Hear. 2008 Jun;29(3):314-25
18344874
Behav Brain Funct. 2005 Dec 01;1:21
16321163
Brain. 2008 Aug;131(Pt 8):2002-12
18515321
J Assoc Res Otolaryngol. 2000 Aug;1(1):33-45
11548236
Hum Mutat. 2008 Jun;29(6):823-31
18381613
Ear Hear. 1998 Jun;19(3):169-79
9657592