HSC Section 6 Nov2016 Green Book

Spataro et al

and so on, with a maximum/minimum value of 6 0.5. This value was determined and plotted for each etiology. Statistical significance was determined based on a null hypothesis that the frequency on each side was the same, using a x 2 test. Median presentation time to an outside otolaryngologist was compared with median referral presentation time to a WUSM otolaryngologist. For this analysis, patients who ini- tially presented to the WUSM were excluded. Due to wide variance in presentation times and nonnormally distributed data, the mean presentation times were not presented. To com- pare median presentation times between the 2 groups, a paired Wilcoxon rank sum test was used. Histograms were also gen- erated incorporating all data, displaying number of patients and cumulative percentage of patients by time of presentation. Percentages of patients per etiology who presented at 2, 3, and 4 months after symptom onset were also calculated. Results Of the charts reviewed, 938 patients met inclusion criteria for this study; 497 (53%) were women and 441 (47%) were men. The average age of patients was 56.9 years (range, 18- 93 years). Overall, 621 (66.2%) patients had left-sided UVFP, while 317 (33.8%) patients had right-sided UVFP. Table 1 displays the etiologies of unilateral vocal fold paralysis. In total, 522 (55.6%) patients had UVFP due to iatrogenic effects related to surgery. The most frequently observed surgery related to UVFP was thyroid/parathyroid surgery, noted in 158 (16.8%) patients. Lung surgery (n = 73 [7.8%]), cardiac surgery (n = 58 [6.2%]), and cervical spine surgery (n = 48 [5.1%]) were the next most common surgical causes of UVFP. In total, 358 patients (38.2%) had UVFP due to causes not directly related to surgical intervention. Malignancy was the cause of UVFP in 167 (17.8%) of patients. Lung malig- nancy (n = 73 [7.8%]), metastatic malignancy (n = 24 [2.6%]), skull base malignancy (n = 18 [1.9%]), and direct invasion by thyroid malignancy (n = 14 [1.5%]) were most common. Idiopathic UVFP was noted in 124 patients (13.2%). Other less common causes of UVFP included intu- bation (n = 58 [6.2%]), trauma (n = 30 [3.2%]), cerebral vascular accident (CVA; n = 18 [1.9%]), and neck radiation (n = 8 [0.9%]). Table 2 shows the laterality of UVFP based on etiology. In total, 622 (66.2%) patients had left-sided UVFP. This table shows the difference between right- and left-sided UVFP. Left-skewed etiologies of UVFP, represented by negative values, and right-skewed etiologies of UVFP, rep- resented by positive values, are plotted in Figure 1 . In addition to the expected left-sided predominance of intrathoracic etiologies (lung surgery, cardiac surgery, eso- phageal surgery, and lung malignancy), other significantly left-sided causes included idiopathic, intubation, carotid sur- gery, and skull base malignancy. There were no etiologies that were significantly skewed to the right. Table 3 shows the median time of presentation for the 92 patients (9.8% of study population) who initially

reinnervation of opposing muscle groups by the same nerve, leading the muscles to contract simultaneously. In canine models, reinnervating axons begin reaching the vocal fold muscles within 3 months of injury. Therefore, treatments to prevent unfavorable synkinesis would need to be adminis- tered within this time frame. 22,23 The objective of this study was to determine how often patients with UVFP present to the Washington University School of Medicine (WUSM) within 3 to 4 months of symptom onset. These patients might be eligible for a clinical trial of early intervention for the prevention of synkinesis. A review of literature revealed no previous studies focusing on time of presentation of patients with UVFP. Etiology and laterality data were also collected and reported. Methods Approval for the study was obtained from the WUSM Institutional Review Board. Adult patients ( . 18 years of age) seen between January 1, 2002, and January 1, 2012, with a diagnosis of unilateral vocal fold paresis or paralysis (based on International Classification of Diseases, Ninth Revision and Current Procedural Terminology codes) were identified via a query of electronic medical records. In most cases, the diagnosis of UVFP was made by the attending physician based only on examination of the larynx; electro- myography or cricoarytenoid joint palpation was performed in only a small percentage of patients. In all cases, the diag- nosis was confirmed by flexible fiberoptic examination or videostroboscopy. Each patient’s chart was reviewed and data were col- lected and stored in an electronic database. Data included age at initial visit, sex, date of visit to a WUSM otolaryn- gologist, date of presentation to a non-WUSM otolaryngolo- gist (in any), primary symptom, date of symptom onset, side of paralysis, etiology of paralysis, initial and subsequent treatment received, date of initial treatment, voice improve- ment, and fiberoptic examination vocal fold movement out- comes. From this information, the time intervals from symptom onset to initial presentation to an otolaryngologist and the time interval from initial presentation to referral to WUSM (if made), were calculated. The specific reason for referral to the university was not usually recorded in the chart, but very few had been previously treated. Diagnosis of idiopathic UVFP was confirmed by negative imaging along the course of the vagus and recurrent laryngeal nerves. Patients with incomplete records were excluded. Data were analyzed by first determining percentages of men and women in the study population, laterality of UVFP, and etiology. To evaluate laterality, a calculation for left-right skew was devised as follows: Skew 5 # cases on right = total # cases ð Þ 0 : 5 : With this formula, it can be seen that if there is a perfect 50-50 split, the skew is zero; as the proportion of left-sided cases increases, the value becomes more negative (moves to the left),

18