Faculty Bibliography

Comorbid conditions are medical illnesses that accompany cancer. The impact of these conditions on the outcome of patients with head and neck cancer is well established. However, all of the comorbidity studies in patients with head and neck cancer reported in the literature have been performed using the Kaplan-Feinstein index (KFI), which may be too complicated for routine use. This study was performed to introduce and validate the use of the Charlson comorbidity index (CI) in patients with head and neck cancer and to compare it with the Kaplan-Feinstein comorbidity index for accuracy and ease of use. Study design was a retrospective cohort study. The study population was drawn for three academic tertiary care centers and included 88 patients 45 years of age and under who underwent curative treatment for head and neck cancer. All patients were staged by the KFI and the CI for comorbidity and divided into two groups based on the comorbidity severity staging. Group 1 included patients with advanced comorbidity (stages 2 or 3), and group 2 included those with low-level comorbidity (stages 0 or 1). Outcomes were compared based on these divisions. The KFI was successfully applied to 80% of this study population, and the CI was successfully applied in all cases (P < 0.0001). In addition, the KFI was found to be more difficult to use than the CI (P < 0.0001). However, both indices independently predicted the tumor-specific survival (P = 0.007), even after adjusting for the confounding effects of TNM stage by multivariate analysis. Overall, the CI was found to be a valid prognostic indicator in patients with head and neck cancer. In addition, because comorbidity staging by the CI independently predicted survival, was easier to use, and more readily applied, it may be better suited for use for retrospective comorbidity studies

Spasmodic dysphonia has been successfully treated by thyroarytenoid muscle injections of botulinum toxin (Botox) with dosages ranging from 0.625 to 25 U. In some patients, excessive paralysis with resulting breathiness and aspiration have been noted. In order to maximize the efficiency of Botox injections, the histologic effects of various Botox dosages were examined in the dog. Nine canine thyroarytenoid muscles were injected with 0.5 to 12.5 U of Botox. After 24 hours, the recurrent laryngeal nerve to the injected muscle was electrically stimulated in order to deplete the glycogen within the muscle fibers. Frozen sections of this muscle were then stained for glycogen. Those fibers that retained their glycogen were presumed paralyzed by the Botox injection. The extent of paralysis was found to be dose-related from 1.0 to 7.5 U. At 10 U and above the muscle was completely paralyzed. Spread of the toxin to the lateral cricoarytenoid muscle was seen at doses as low as 1.0 U. Clearly, doses less than 10 U appear sufficient for clinical paralysis.

In 46 patients with renovascular hypertension who underwent renal angioplasty, proteinuria (more than 150 mg/24 hours) was more pronounced than in patients with essential hypertension. The highest levels were seen in patients in whom 1 renal artery was totally occluded. There was no difference between patients with unilateral vs bilateral renal artery stenosis. Proteinuria could not be correlated with serum creatinine level, and in 28% of the patients with renovascular hypertension, proteinuria was present despite a normal creatinine level. Renal angioplasty produced a significant diminution in proteinuria when it resulted in a cure of the hypertension, but no diminution was achieved if blood pressure did not decrease.