42 / 412
have actually been cricoarytenoid joint ankylosis or
dislocation that was misdiagnosed as UVFP.
Idiopathic
. This is commonly presumed to be a post-
viral neuropathy, but this would not explain a left-
sided preference unless the distal left recurrent
laryngeal nerve (RLN) is somehow more suscepti-
ble to viral attack than the right. Alternately, there
may be some mechanism in which sudden neck
extension or other postural change causes the left
RLN to be stretched around the aorta. There may
also be differences in intrathoracic connective
tissue near the aorta that predispose to this sort of
injury.
Skull base tumor
. This finding may simply be related
to the relatively low number of patients in this
series.
18
We can find no references indicating a
biological explanation for a left-sided predilection
for skull base tumors.
Time to Presentation
To our knowledge, this study is the first large series to
investigate time to presentation of these patients. It was
found that three-fourths of patients with UVFP seen at the
WUSM present within 3 or 4 months of the onset of symp-
toms. While this is encouraging, it also indicates that there
Table 4.
Percentage of Patients Presenting to Washington University School of Medicine within 2, 3, and 4 Months from Symptom Onset.
a
No. (%)
Etiology
n
Within 2 Months
Within 3 Months
Within 4 Months
Intracranial surgery
24
17 (70.8)
17 (70.8)
17 (70.8)
Skull base surgery
18
15 (83.3)
15 (83.3)
16 (88.9)
Carotid surgery
22
10 (45.5)
13 (59.1)
13 (59.1)
Cervical spine surgery
48
23 (47.9)
26 (54.2)
31 (64.6)
Lateral neck surgery
61
33 (54.1)
36 (59.0)
40 (65.6)
Parathyroid surgery
18
13 (72.2)
13 (72.2)
13 (72.2)
Thyroid surgery
140
81 (57.9)
86 (61.4)
93 (66.4)
Lung surgery
73
51 (69.9)
57 (78.1)
62 (84.9)
Mediastinal surgery
17
12 (70.6)
12 (70.6)
13 (76.5)
Cardiac surgery
58
19 (32.8)
41 (70.7)
44 (75.9)
Esophageal surgery
37
29 (78.4)
31 (83.8)
32 (86.5)
Skull base tumor
18
10 (55.6)
10 (55.6)
12 (66.7)
Laryngeal cancer
20
11 (55.0)
13 (65.0)
13 (65.0)
Thyroid cancer—direct invasion
14
6 (42.9)
6 (42.9)
8 (57.1)
Lung cancer
73
46 (63.0)
54 (74.0)
60 (82.2)
Esophageal cancer
11
9 (81.8)
10 (90.9)
10 (90.9)
Metastatic cancer
24
17 (70.8)
19 (79.2)
19 (79.2)
Idiopathic
124
48 (38.7)
64 (51.6)
68 (54.8)
Intubation
58
40 (69.0)
46 (79.3)
50 (86.2)
Trauma
30
14 (46.7)
18 (60.0)
19 (63.3)
CVA
18
7 (38.9)
9 (50.0)
10 (55.6)
Abbreviation: CVA, cerebral vascular accident.
a
Etiologies with less than 10 patients not shown.
Table 5.
Some Comparisons between the 3 Largest Series of Unilateral Vocal Fold Paralysis Etiologies.
a
Etiology
Rosenthal et al
15
(n = 643)
Takano et al
16
(n = 797)
Present Study (n = 938)
Surgery, total
36.5
51.1
55.6
Thyroid/parathyroid
12.4
14.1
16.8
Nonthyroid
24.1
37.1
38.8
Intubation
5.8
7.3
6.2
Malignancy
18.4
9.9
17.8
Idiopathic
18.5
16.8
13.2
Left side
60.9
b
64.0
66.2
a
All values are percentages.
b
Data reported for only 56.4% of patients in study.
Spataro et al
22