TY - JOUR
T1 - Positive auditory cortical responses in patients with absent brainstem response
AU - Kawase, Tetsuaki
AU - Kanno, Akitake
AU - Takata, Yusuke
AU - Nakasato, Nobukazu
AU - Kawashima, Ryuta
AU - Kobayashi, Toshimitsu
N1 - Funding Information:
We wish to thank the staff of Kohnan Hospital Ryogo Center for their continuous support of this work. This study was supported by a grant from the Ministry of Education, Culture, Sports, Science and Technology-Japan (Grant-in-Aid for Exploratory Research 15659401 ). The authors declare no conflicts of interest.
PY - 2014/1
Y1 - 2014/1
N2 - Objective: To compare the detectability of the different auditory evoked responses in patients with retrocochlear lesion. Methods: The 40-Hz auditory steady state response (ASSR) and the N1m auditory cortical response were examined by magnetoencephalography in 4 patients with vestibular schwannoma, in whom the auditory brainstem response (ABR) was absent. Results: Apparent N1m responses were observed despite total absence of the ABR or absence except for small wave I in all patients, although the latency of N1m was delayed in most patients. On the other hand, clear ASSFs could be observed only in one patient. Very small 40-Hz ASSFs could be detected in 2 patients (amplitude less than 1. fT), but no apparent ASSFs were observed in one patient, in whom maximum speech intelligibility was extremely low and the latency of N1m was most prolonged. Conclusion: The N1m response and 40-Hz ASSR could be detected in patients with absent ABR, but the N1m response appeared to be more detectable than the 40-Hz ASSR. Significance: Combined assessment with several different evoked responses may be useful to evaluate the disease conditions of patients with retrocochlear lesions.
AB - Objective: To compare the detectability of the different auditory evoked responses in patients with retrocochlear lesion. Methods: The 40-Hz auditory steady state response (ASSR) and the N1m auditory cortical response were examined by magnetoencephalography in 4 patients with vestibular schwannoma, in whom the auditory brainstem response (ABR) was absent. Results: Apparent N1m responses were observed despite total absence of the ABR or absence except for small wave I in all patients, although the latency of N1m was delayed in most patients. On the other hand, clear ASSFs could be observed only in one patient. Very small 40-Hz ASSFs could be detected in 2 patients (amplitude less than 1. fT), but no apparent ASSFs were observed in one patient, in whom maximum speech intelligibility was extremely low and the latency of N1m was most prolonged. Conclusion: The N1m response and 40-Hz ASSR could be detected in patients with absent ABR, but the N1m response appeared to be more detectable than the 40-Hz ASSR. Significance: Combined assessment with several different evoked responses may be useful to evaluate the disease conditions of patients with retrocochlear lesions.
KW - Auditory evoked field
KW - Auditory steady state response
KW - Magnetoencephalography
KW - N1m
KW - Vestibular schwannoma
UR - http://www.scopus.com/inward/record.url?scp=84890191866&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84890191866&partnerID=8YFLogxK
U2 - 10.1016/j.clinph.2013.06.184
DO - 10.1016/j.clinph.2013.06.184
M3 - Article
C2 - 23895952
AN - SCOPUS:84890191866
VL - 125
SP - 148
EP - 153
JO - Electroencephalography and Clinical Neurophysiology - Electromyography and Motor Control
JF - Electroencephalography and Clinical Neurophysiology - Electromyography and Motor Control
SN - 1388-2457
IS - 1
ER -