HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Correspondence: Submit a response Alert me when this article is cited Alert me when Correspondence are posted Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by James, M. L. Articles by Husain, A. M. Search for Related Content PubMed PubMed Citation Articles by James, M. L. Articles by Husain, A. M. Related Collections Related Articles

Brainstem auditory evoked potential monitoring

When is change in wave V significant?

From the Department of Medicine (Neurology) (Drs. James and Husain), Duke University Medical Center, and Neurodiagnostic Center (Dr. Husain), Veterans Affairs Medical Center, Durham, NC.

Address correspondence and reprint requests to Dr Husain, Duke University Medical Center, 202 Bell Bldg., Box 3678, Durham, NC 27710; e-mail: aatif.husain{at}duke.edu

Background: The probability of hearing loss during cerebellopontine angle (CPA) surgery can be reduced by using brainstem auditory evoked potential (BAEP) intraoperative monitoring (IOM). A wave V latency prolongation of 1.0 milliseconds or amplitude decrement of greater than 50% is arbitrarily considered the point when damage to hearing occurs.

Objective: To determine the accuracy of wave V changes in predicting hearing impairment.

Methods: Patients undergoing BAEP IOM for surgery in the CPA region were evaluated. The greatest wave V latency and amplitude change was determined. Patients were divided into four groups depending on degree of change of wave V: Group 1 consisted of minimal change, whereas Group 4 was permanent loss of wave V. The frequency of hearing loss in each group was compared.

Results: Data from 156 patients were reviewed. When all patients were analyzed, the frequency of hearing loss was not significantly different between the groups. When patients with CPA tumor were excluded, a significantly higher number of patients in Group 4 had hearing loss. Analysis of the patients with CPA tumor showed no difference in the frequency of hearing loss in any of the groups; even a large number (50%) of Group 1 patients had hearing impairment.

Conclusions: During brainstem auditory evoked potential intraoperative monitoring, the type of surgery is important when interpreting significance of changes of wave V. For non–cerebellopontine angle tumor surgery, hearing loss occurs usually only with permanent loss of wave V; much smaller changes may be important in cerebellopontine angle tumor surgery.

See also page 1522

Disclosure: The authors report no conflicts of interest.

Received March 28, 2005. Accepted in final form July 22, 1005.

Related Articles

November 22 Highlights
Neurology 2005 65: 1518-1519. [Full Text] [PDF]

This article has been cited by other articles:

				D. L. Loiselle and M. R. Nuwer When should we warn the surgeon?: Diagnosis-based warning criteria for BAEP monitoring Neurology, November 22, 2005; 65(10): 1522 - 1523. [Full Text] [PDF]