Effects of cervical epidural block and stellate ganglion block on auditory brainstem responses
Ohta, S.; Terada, Y.; Matsumoto, S.; Suzuki, M.
Masui. Japanese Journal of Anesthesiology 37(10): 1206-1211
1988
ISSN/ISBN: 0021-4892 PMID: 3199504 Document Number: 321427
We investigated the effects of cervical epidural block (EPI) and stellate ganglion block (SGB) on the auditory brainstem response (ABR) in thirteen patients. EPI and SGB were performed with the injection of 10ml of 1% lidocaine into the epidural space (C7 .apprx. Th1) and 7 .apprx. 8 ml of 1% mepivacaine, respectively. The sections of the ABR examined were the waves I, III and V, of which peak and interpeak latencies (IPLs) were measured before and at 15, 30, 45 and 60 min after each nerve block. In EPI group (n = 6), I latency remained unchanged, but III and V latencies significantly increased at 15, 30, 45 and 60 (the wave III only) min after EPI. I-III and I-V IPLs significantly increased in accordance with the changes of latencies of III and V, and III-V IPL increased significantly at 15 min after EPI. In SGB group (n = 7), SGB produced no significant changes in the ABR. These results suggest that EPI causes alteration in the ABR by the effect of local anesthetic which probably permeates brainstem and the subarachnoid portion of acoustic nerve via cerebrospinal fluid through dura mater, and the blockade of cervical sympathetic activity has no effect on the ABR.