Faculty Bibliography

The surgical management of labyrinthine fistulas caused by cholesteatoma remains controversial. Forty cases (41 ears) of labyrinthine fistulas were reviewed. This represented 10% of our total series of cholesteatomas in adults and children (426 ears). Clinical presentation, extent of disease, results of fistula testing and audiometric studies, and radiographic findings were analyzed. A canal wall-down procedure was performed in all but one patient. Generally an attempt was made to completely remove the cholesteatoma, to graft the fistulous area, and to reconstruct the middle ear mechanism in one stage. The matrix was preserved in patients with large fistulas where the involved ear was the only hearing one, when the matrix was adherent to the underlying optic duct, and in selected elderly persons. Long-term followup did not reveal a significant difference in hearing, degree of vertigo, or incidence of recidivism when those patients in whom the matrix was removed were compared with those in whom the matrix was preserved. The importance of recognizing the presence of a labyrinthine fistula preoperatively is stressed, along with the need to be prepared for an unexpected fistula. Operative management is described

The utility of digital filtering for the purpose of improving waveform morphology and improving peak detection was investigated. Unfiltered (i.e., only standard analog filtering) and digitally filtered (i.e., analog plus post hoc digital filtering) ABRs from both young and elderly subjects were independently scored by eight experienced clinicians. Measures of intrascorer and interscorer variability were obtained for the absolute latencies of waves I, III, and V. Results suggest that digital filtering tends to increase the reliability of latency measurements when ABRs are characterized by poor morphology.

Throughout the industrial world, technology and techniques are now available so that any child, no matter how young or how impaired, can have an accurate and precise assessment of middle ear function, auditory reactivity, and physiological processing of auditory stimuli. Yet, a major problem exists in the lack of timely identification of many children with hearing impairments. Presently, identification systems are primarily proactive and are based on technology. These consist of testing of infants with biological risk factors and the use of hearing screening programs at various times during the first decade of life. The reactive sources of referral appear to be inadequate, an impression that is supported by the data on the delay of diagnosis. These inadequacies appear to be due to a lack of awareness on the part of health providers as to the potential hearing losses; ignorance concerning the ability to diagnose them; and a lack of awareness of the potential of effective intervention. Two additional approaches are suggested which would be added to those already existing for improving the number of children who will have their diagnoses made in a timely fashion. The first of these is educational: health providers should have required and continuing education concerning the effects of hearing loss, the ability to diagnose, and to intervene effectively. A parallel educational program should be provided for the public. The second is the periodic assessment of speech and language from early infancy through the first few years of life for all children. This would enable children with suspected impairments to be referred for definitive testing.(ABSTRACT TRUNCATED AT 250 WORDS)

EO-199, a demethylated analog of the novel class I antiarrhythmic drug EO-122 was found to antagonize the antiarrhythmic activity of EO-122 and that of procainamide (Class IA). EO-199 did not block significantly the activity of a class IB antiarrhythmic agent, lidocaine. EO-199 also displaced the specific binding of [3H]EO-122 to rat heart membranes similarly to procainamide whereas lidocaine did not. The correlation between binding experiments and pharmacological effects points to a possible subclassification of these drugs; the two chemical analogs EO-199 and EO-122, as well as procainamide (IA) but not lidocaine (IB), compete at the same site or the same state of the sodium channel. The availability of a specific antagonist might be useful for studying the mechanism of action of antiarrhythmic drugs as well as an antidote in cases of antiarrhythmics overdose intoxication.