PubMed · 3751542
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
M Russolo, P Poli. [Biphasic stapedial reflex].. https://pubmed.ncbi.nlm.nih.gov/3751542/
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
In non-randomized clinical studies, the regression phenomenon can confound interpretation of the effectiveness of an intervention. The regression effect arises due to daily variation and/or misclassification of the biologic marker used in selection as well as in the assessment of the intervention effect. We consider a scenario in which the selection criterion for a subject's participation in the study is such that he/she must have a positive diagnostic test at screening. The disease status is then reassessed at the end of intervention. Thus, two repeated measurements of a binary disease outcome are available, with only selected subjects having a second measurement upon follow-up. We propose methods for estimating the change in event probability resulting from implementing the intervention while adjusting for the misclassification that produces the regression effect. We extend this approach to estimation of both the placebo and intervention effects in placebo-controlled studies designed with a misclassified binary outcome. Analyses of two biomedical studies are used for illustration.
OBJECTIVE: Tinnitus is one of the most common and distressing otological symptoms. Although numerous therapeutic modalities have been tried, there is no consensus regarding effective therapeutic agents up to now. The effects of lidocaine on tinnitus have been reported in literature using either subjective or audiologic tests. Nevertheless, the otoacoustic emissions (OAEs) have not been utilized to demonstrate lidocaine's effect on the cochlea in the English literature. The aim of this study was to evaluate the effect of lidocaine on tinnitus by considering the alterations with tinnitus, it induces on OAEs and subjective symptoms. METHODS: This study was performed in 30 patients with tinnitus. Twenty-eight of the patients had normal hearing and two of them evidenced mild sensorineural hearing loss. To determine the severity of tinnitus, the patients were required to fill out a tinnitus scoring scale before lidocaine infusion on the same day. Then, lidocaine was administered intravenously to each patient at a dose of 1.5 mg/kg body weight over a period of 30 min. Spontaneous otoacoustic emissions (SOAEs) and distortion product otoacoustic emissions (DPOAEs) were measured three times; namely before lidocaine injection, at 25 min after injection and on the next day. The severity of tinnitus was scored again 1 d, 1 wk and 1 mo after lidocaine administration. RESULTS: Immediately after infusion, four patients (13.3%) declared total suppression of tinnitus, whereas three patients (10%) reported only partial relief in tinnitus subjectively. The patients, who had a subjective improved response (group 1) were compared with the patients, who had no response (group 2). Statistically significant changes (p<0.05) in DPOAE response/growth or input/output (I/O) functions were observed at 1, 2, 3, 4 and 6 kHz frequencies in lidocaine responders and at 1, 2, 3, 4 and 5 kHz frequencies in no responders at different primary stimulus levels. Statistically significant changes (p<0.05) were seen at 2 kHz for 53 dB and at 3 kHz for 62 dB SPL primaries in both groups. When the significant results of these two groups were compared with each other, differences were found insignificant. CONCLUSION: Systematic OAE measurements revealed that no changes occurred in SOAE and DPOAE levels in that alterations disappeared the next day. Subjective relief from tinnitus was stated in some of the patients and lasted for 4 wk at longest.
Tympanometry provides useful quantitative information about the presence of fluid in the middle ear, mobility of the middle ear system, and ear canal volume. Its use has been recommended in conjunction with more qualitative information (e.g., history, appearance, and mobility of the tympanic membrane) in the evaluation of otitis media with effusion and to a lesser extent in acute otitis media. It also can provide useful information about the patency of tympanostomy tubes. Tympanometry is not reliable in infants younger than seven months because of the highly compliant ear canals of infants. Tympanogram tracings are classified as type A (normal), type B (flat, clearly abnormal), and type C (indicating a significantly negative pressure in the middle ear, possibly indicative of pathology). According to the Agency for Healthcare Research and Quality guidelines on otitis media with effusion, the positive predictive value of an abnormal (flat, type B) tympanogram is between 49 and 99 percent. A type C curve may be useful when correlated with other findings, but by itself it is an imprecise estimate of middle ear pressure and does not have high sensitivity or specificity for middle ear disorders.