Faculty Bibliography

For patients with head and neck squamous carcinoma, a clinical response to induction chemotherapy has correlated with a survival advantage. Similarly, patients with diploid tumors have displayed a survival advantage when compared with patients with aneuploid tumors. This study examined DNA content in 33 patients who had undergone induction chemotherapy as part of two clinical protocols to determine if there was a correlation between the patients with diploid tumors and the patients with a clinical response to chemotherapy. Although patients with stage III tumors had a longer disease-free survival than stage IV patients (p less than 0.0002), the addition of DNA content information did not improve the ability to predict response. Specifically, there was no correlation between DNA content and the response to chemotherapy. In addition, for this group of patients, a diploid DNA content was not correlated with a survival advantage. We conclude that DNA content information did not add significantly to the prediction of clinical outcome in these patients who received induction chemotherapy

Fluosol-DA 20%, a synthetic perfluorocarbon emulsion first developed as a blood substitute, is currently being investigated as a radiation sensitizer. Theoretically, an oxygen-carrying perfluorocarbon emulsion combined with oxygen inhalation might be able to increase tumor response by decreasing the relative proportion of hypoxic tumor cells. Twenty-one patients with advanced head and neck malignancies receiving primary radiation therapy were evaluated for treatment-related toxicity. Mucosal reactions and weight loss during treatment in the group of patients who received the perfluorocarbon emulsion and the group who did not were comparable. Late sequelae appeared comparable. No patient in either group who completed radiation therapy required an interruption of the treatment course. We conclude that Fluosol-DA 20% is a tolerated adjunct to primary radiation therapy. Further study is needed to determine whether the agent will improve local/regional tumor control

Members of the New York Head and Neck Society conducted a multi-institutional review correlating preoperative computed tomography (CT) of the neck with postoperative pathology in 59 patients with squamous cell carcinoma of the oral cavity, pharynx, and larynx, without palpable lymphadenopathy. All underwent CT followed by surgery that included partial or complete cervical lymphadenectomy. Sixteen (28%) patients had occult cervical metastases including 6 (17%) of 36 patients with 'early stage' (T1 and T2) primary tumors and 10 (44%) of 23 patients with 'advanced' (T3 or T4) lesions. There was agreement of CT scan findings with presence or absence of metastatic disease in 41 (69%) of 59 studies, with sensitivity 38%, and with specificity 81%. Findings of central lucency and nodal confluence were highly reliable indicators of malignancy, whereas nodal size bore a less direct relationship. Intravenous contrast medium was useful for anatomical delineation, but not for identification of malignancy. Review of films by a single radiologist did not produce greater diagnostic accuracy than the original interpretations. The authors conclude that while it is not possible to identify all instances of cervical node involvement, employment of CT in addition to physical examination and prognostication based on primary tumor stage will facilitate appropriate selection of patients for elective treatment of the neck

Twenty-seven patients with recurrent pleomorphic adenomas of the parotid gland were seen. This study confirms that superficial parotidectomy with identification and dissection of the facial nerve greatly decreases the incidence of recurrent benign pleomorphic adenoma, and, in the small number that recur, are easier to cure. All lumps in the parotid area should be approached in the same manner, with the surgeon prepared to isolate the facial nerve and perform superficial parotidectomy. This technique is successful because it avoids dissection near the tumor capsule, which is the major cause of recurrence. The procedure recommended for treatment of patients to remove the first recurrent tumor is total parotidectomy and excision of the previous scar. This vigorous approach is dictated by the increasing difficulty of removing further recurrent tumors. Only 67% of patients with recurrent tumors ultimately achieve a tumor-free status. Experienced surgeons can preserve the facial nerve even after multiple operations

Complete medical interviews and physical exams were performed on two stimulated patients by a class of medicine interns. These interviews and examinations were videotaped and were then scored using a rating scale developed by the authors. This system of videotaping and rating complete interviews and physical examinations is called the The Northwestern Evaluation & Training System (NETS). Selected findings are presented and discussed. It is shown how the NETS can be used for educational feedback to the individual student and for quality assurance feedback to training programs regarding the effectiveness of their instruction in interview and physical examination skills

One way in which animals localize sounds along the horizon is by detecting the level differences at the 2 ears. Neurons in the lateral superior olive (LSO) encode this cue by integrating the synaptic drive from ipsilateral excitatory and contralateral inhibitory connections. This synaptic integration was analyzed in 400-500-microns brain slices through the gerbil superior olive. Intracellular recordings from LSO neurons were obtained during the application of independent or conjoint electrical stimuli to the excitatory afferent and inhibitory afferent pathways. Stimulation of ascending fibers from the ipsilateral cochlear nucleus reliably evoked EPSPs and action potentials. Stimulation of the medial nucleus of the trapezoid body (MNTB) consistently evoked IPSPs. The evoked postsynaptic potentials differed in that IPSPs were 2 times the duration of EPSPs. An electrophysiological estimate of convergence indicated approximately 10 excitatory and 8 inhibitory afferents per LSO neuron. MNTB stimulation suppressed synaptically evoked action potentials. When stimulus amplitude was increased to the excitatory pathway, it was generally found that a greater MNTB stimulus was necessary to suppress the action potential. A similar commensurate rise in ipsilateral and contralateral acoustic stimulation was also found to be necessary to give the same criterion response. These results confirm that the LSO can integrate evoked action potentials and IPSPs to encode interaural level. Increasing stimulus voltage was found to decrease both action potential and IPSP latency, suggesting that intensity information may be encoded with temporal cues in the nervous system. It was also found that an evoked burst of action potentials could be inhibited in such a way as to yield intermediate discharge rates, dependent on contralateral stimulus level. Taken together, these results suggest that certain properties related to level-difference coding may be available for intracellular analysis using the brain-slice preparation. Several temporal characteristics of the synaptic potentials, including latency and duration, may play a critical role in this simple computation

Nine children received the Nucleus multichannel cochlear prosthesis. The preoperative evaluation consisted of assessments of auditory function, speech recognition, linguistic skills, and speech production. There were no surgical complications, and recovery in all patients was uneventful. The device was programmed 4 to 5 weeks following surgery, and all children were conditioned to the task. Postoperative training began immediately following device stimulation and is ongoing. Auditory skills and speech production scales were devised to monitor each child's progress. All children have shown varying degrees of improvement in auditory skills and speech production using the implant alone

The speech perception abilities of 15 patients were measured preoperatively using hearing aids and postoperatively using the Nucleus 22-channel cochlear implant over a period of 1, 2, or 3 years. Analysis of mean data revealed that, although the greatest amount of improvement in speech perception scores occurred between the preoperative and 3-month poststimulation evaluation, there was also significant improvement in perception of segmental features and open-set speech recognition over the 3-year time period. When individual patient data were examined, however, it was clear that these improvements were due, in large part, to the performance of a subset of patients who had measurable open-set speech recognition abilities at the time of their 3-month, poststimulation evaluation. Subjects who used the processing scheme that included coding of F1 showed significantly more improvement over time than subjects who used the original F0F2 processing scheme exclusively. It was concluded that open-set speech recognition ability at 3 months is an important prognostic indicator of continued improvement in speech perception abilities over time

This article describes the use of principal components analysis to derive a composite score from a battery of 24 audiologic tests. The composite score is being used as the primary outcome variable in a clinical trial comparing the efficacy of three cochlear implant devices for people with bilateral, profound hearing loss. The first principal component from the within-class pooled variance-covariance matrix over four time periods was chosen to establish the coefficients for the composite score. This component accounted for 61% of the total variance of the 24 audiologic tests. The first principal component had its largest coefficients associated with the most difficult audiologic tests. The mean composite score of all patients improved over time; some patients showed dramatic improvement. The changes in the composite score over time were also closely related to subjective impressions of implant performance by the patient, audiologist, and otolaryngologist