Faculty Bibliography

Cigarette smoking is a major risk factor for head and neck cancer, and individuals who continue to smoke past diagnosis and treatment are at elevated risk for further disease. In a randomized controlled trial, a state of the art provider-delivered smoking cessation intervention was compared to a usual care advice control condition. The intervention consisted of surgeon- or dentist-delivered advice to stop smoking, a contracted quit date, tailored written materials, and booster advice sessions. Subjects were 186 patients with newly diagnosed first primary squamous cell carcinomas of the upper aerodigestive tract who had smoked cigarettes within the past year. At randomization, 88.2% of subjects were current smokers. At 12-month follow-up, 70.2% of subjects completing the trial (n = 114) were continuous abstainers; among baseline smokers alone the continuous abstinence (CA) rate was 64.6%. The cotinine validation rate at 12 months was 89.6%. Modeling techniques were utilized in order to derive expected CA rates, which included noncompleter subjects (n = 72). The CA rate expected at 1 year for the entire patient population was 64.2%, and for smokers alone the expected CA rate was 59.4%. Logistic regression analysis carried out on baseline smokers identified predictors of 12-month CA status. These included medical treatment, stage of change, age, nicotine dependence, and race. The intervention effect was not significant, although the sign of the effect was positive. Based on these findings, we recommend systematic brief advice to stop smoking for head and neck cancer patients, with a stepped care approach for patients less able to quit.

Merkel cell carcinoma (MCC) of the skin is an uncommon, but highly aggressive neoplasm with a marked propensity for local and distant metastasis. Despite the fact that more than half of the 600 cases of MCC reported in the literature involved primary sites in the head and neck, MCC has rarely been discussed in otolaryngology publications. We present five new cases of MCC of the head and neck and summarize 89 additional cases from the literature in which detailed treatment and survival data were given. Our findings again emphasize the difficulty in making the initial histopathologic diagnosis of MCC and demonstrate the necessity of early diagnosis and multimodality treatment.

Surgery for correction of primary hyperparathyroidism utilizing a standard bilateral neck exploration has a success rate of approximately 90 to 95%. With the inception of pre-operative localization studies that were 90% accurate in localizing the diseased gland, the concept arose that a unilateral exploration could be as successful as a bilateral exploration. Bilateral exploration of the neck for hyperparathyroidism exposes the patient to a greater potential of morbidity for hypoparathyroidism and recurrent laryngeal nerve injury. It is our feeling based on personal experience that unilateral parathyroidectomy in selective cases can be as successful as the bilateral operation and be more cost effective, saving over $1,100 (U.S.) per case.

Auditory brainstem responses (ABRs) were recorded from 20 normal neonates and 10 normal-hearing adults. The spectral compositions of ABRs from both groups were compared. Results indicated that significant amounts of low-frequency information are concentrated below 150 Hz in both the neonate and the adult ABRs although the neonate ABR has a slightly greater percentage of low-frequency information than that of the adults. This has implications for filtering during ABR recording. A low high-pass setting which preserves more of the low-frequency information will allow enhanced detectability of wave V in neonate ABRs recorded at low stimulus intensities. Furthermore, our experience indicates that the use of a 30- to 3,000-Hz bandpass is feasible in the neonatal intensive care unit as well as in the regular newborn nursery. Therefore the use of a 30- to 3,000-Hz bandpass is recommended for neonate ABR recordings.

Laser Scanning Confocal Microscopy (LSCM) and specific labeling techniques were employed to examine the distributing of F-actin and microtubules in the reticular lamina of the guinea pig and monkey organ of Corti. Actin specific label was found in the circumferential belt of adherens junction at the borders between cells in the reticular lamina, and in the cuticular plate of hair cells. The distribution of actin in the adherens junction belt was asymmetric. Actin label was not found in the fonticulus, where the microtubule organizing center resides. Actin free areas were also found between the junctional actin and the cuticular plate. Microtubule specific label was very intense in supporting cells. In normal hair cells, the spatial distribution of tubulin at the reticular lamina is mutually exclusive with that of actin. After noise exposure, a belt of actin was found in the central portion of degenerating outer hair cells, possibly representing a constricted circumferential junction. Expanded supporting cells replaced degenerating hair cells and maintained the confluence of the reticular lamina during the dynamic process of scar formation. A complex network of actin-rich cables appeared at sites of degenerating inner hair cells, suggesting that more than two supporting cells are involved in scar formation for inner hair cells. LSCM proved an attractive method for analysis of the organ of Corti since preparation of the tissue is relatively rapid, preparation artefacts are minimized, different markers in the same specimen may be co-localized and out-of focus fluorescence blurring is eliminated.

The effect of systematic variations in the relative levels (L1, L2) of two primary tones (f1, f2) on the amplitude of the distortion product otoacoustic emission (DPOAE) at 2f1-f2 and f1 < f2 was investigated in 14 ears from 7 normally hearing human subjects. The primary tones (f2:f1 = 1.23) were geometrically centred at the standard clinical frequencies of 0.5, 1, 1.5, 2, 3, 4, 6 and 8 kHz. The quantity L1-L2 was varied systematically from -10 dB through + 10 dB with L2 held constant at 75 dB SPL for negative values, L1 held constant at 75 dB SPL for positive values, and L1 = L2 = 75 dB SPL at 0 dB relative difference. The maximum amplitudes of the distortion products were generated when L1 = L2 at all geometric centre frequencies except 8 kHz. The reduction of the DPOAE with reduction of L1 was linear at a rate that gradually increased as a function of geometric mean frequency. To a lesser extent, the reduction of the DPOAE with reduction of L2 also was linear but at a rate that systematically decreased as a function of geometric mean frequency. The results suggest, that to maximize the level of the distortion product for clinical purposes, the relative levels of the primary tones should be equal to each other, at least when overall stimulus levels are around 75 dB SPL and f2:f1 = 1.23.

Parametric variations in the ratio of primary-tone frequencies were explored to optimize the amplitude of the 2f1-f2 distortion product otoacoustic emission for clinical purposes. Ten ears from 5 normally hearing human subjects were examined with primary tones geometrically centred around the standard audiometric frequencies of 0.5, 1, 1.5, 2, 3, 4, 6 and 8 kHz. The distortion product at the frequency 2f1-f2 (f1 < f2) was measured at six probe tone frequency ratios (f2:f1) varying between 1.15 and 1.40 using equal level primaries of 75 dB SPL. The results showed that a single f2:f1 ratio between 1.20 and 1.25 provides a reasonable value for clinical use in that it optimizes the magnitude of the distortion product at 2f1-f2, provides for sufficient resolution in the test frequency range, and is applicable to the standard clinical test frequencies.

This study addressed the hypotheses that the growth of the level of distortion product otoacoustic emissions (LDP) with primary-tone level reflects the behavior of a third-order nonlinear polynomial system, and that two sources exist for these distortion products. The results indicated that the 2f1-f2 otoacoustic emission in humans can be measured over a much larger stimulus range than reported previously, even for stimuli (L1 = L2) as low as 10 dB SPL (re 20 microPa). The input/output functions are best described as a straight line with a rate of growth of about 1 dB/dB of stimulus level. For stimulus levels at which metabolically active, nonlinear cochlear processes are in operation, the system does not behave as a simple third-order nonlinear polynomial. Small plateaus and sharp discontinuities or 'notches' can occur in the functions at stimulus levels of approximately 55 dB SPL. These characteristics are consistent with the notion of two separate sources of the LDP, one at low stimulus levels, and one at high levels. An alternative explanation is that the measured otoacoustic emission does not represent only the activity at a single location along the basilar membrane but includes the effects of interactions among similar signals arising from multiple locations, or from the original source via multiple paths.