Electrocochleographic Signal Analysis: Condensation and Rarefaction Click Stimulation Contributes to Diagnosis in Meniere's Disorder

Clinical Significance of the Summating Potential—Action Potential Ratio and the Action Potential Latency Difference for Condensation and Rarefaction Clicks in Meniere's Disease

“…11,12,14,15 The objective of this study was to improve our understanding of the diagnostic significance of the SP/ AP ratio and the AP con-rar difference in Meniere's disease, which was addressed by investigating 1) how the SP/AP ratio and the AP con-rar difference are related to the hearing levels, 2) the correlation between the SP/AP ratio and the AP con-rar difference, and 3) the occurrence rates of an enhanced SP/ AP ratio and an increased AP con-rar difference in different stages of Meniere's disease in 67 patients with definite Meniere's disease.…”

Da eletrococleografia transtimpânica em pacientes com e sem hydrops endolinfático e limiares auditivos iguais ou maiores que 50 decibéis

“…A questão do diagnóstico eletrococleográfico nos pacientes com limiares auditivos maiores ou iguais a 50 dB não foi resolvida pela associação de parâmetros proposta neste estudo (SP/AP, I/BSL e II/ BSL), mas a solução pode estar no uso de técnicas diferentes, com estí-mulos que permitam maior seletividade de freqüên-cia 18,27,28 ou até mesmo na mudança da maneira de avaliação dos parâmetros obtidos no exame. 22 Sass ressaltou a eficiência diagnóstica da eletrococleografia com tone burst de 1 KHz.…”

Electrocochleography Potentials Evoked by Condensation and Rarefaction Clicks Independently Derived by a New Numerical Filtering Approach

“…In particular, in Levine et al [1992] and Johansson et al [1997] systematic differences between the N 1 latencies in the rarefaction and condensation click cases were pointed out, ranging from 0.1 ms in the normal up to 0.70 ms in the pathologic subjects. The diversity of cochlear potentials evoked by clicks of opposite polarity may constitute a valuable indicator in the differential diagnosis of cochlear pathologies Orchik et al, 1998;Sass et al, 1998]. Unfortunately, such an indicator cannot be supplied by the CM cancellation method conventionally used in the literature.…”

“…Unfortunately, such an indicator cannot be supplied by the CM cancellation method conventionally used in the literature. Indeed, Sass et al [1998] have recently stated that 'the use of condensation and rarefaction stimuli merits increased attention as they represent true electrophysiologic responses compared to alternating stimulus responses, which are derived from two electrophysiologic responses, and in which the main parameters have been influenced by averaging and storing techniques'.…”

“…More importantly, physiologic theory, mathematical modeling and clinical evidence [Biondi and Grandori, 1976;Levine et al, 1992;Margolis et al, 1992;Hall, 1992], conclude that CAP and CM in response to condensation and rarefaction clicks may be significantly different, especially in the presence of cochlear pathologies (see Johansson et al [1997] for an attempt to quantify the differences between the N 1 latencies obtained under the two stimulation modalities). Indeed, recent contributions suggested that assessing the influence of stimulus polarity on ECochG potentials may be of help in the understanding of abnormal cochlear responses and in the differential diagnosis of hearing disorders [Sass et al, 1998;Orchik et al, 1998]. In the following, we will denote the cochlear potentials evoked in the condensation and rarefaction click stimulation case, respectively by CAP+ and CM+ and CAP-and CM-.…”