39 / 412
presented to an outside otolaryngologist and were later
referred. The median time of presentation to an outside oto-
laryngologist was 2.1 months, while the median time of pre-
sentation to a WUSM otolaryngologist was 9.5 months (
P
\
.001). Given the very low rate of patients previously treated,
we conclude that this 7.4-month difference in median is the
period during which patients were observed by the outside
otolaryngologist for possible recovery prior to referral to
WUSM. The etiology with the largest delay between symp-
tom onset and treatment was trauma at 563 months, while
several etiologies had delays of only 0.5 months. Etiologies
with the greatest percentage of patients presenting to an out-
side otolaryngologist before a WUSM otolaryngologist
included carotid surgery (18.2%), laryngeal surgery (25.0%),
parathyroid surgery (16.7%), thyroid surgery (12.1%), laryn-
geal cancer (20.0%), thyroid cancer (28.6%), idiopathic
causes (16.9%), CVA (22.2%), and neck radiation (25.0%).
Figure 2
displays histograms of time of presentation to
any otolaryngologist and to a WUSM otolaryngologist
within 3 years of symptom onset, as well as cumulative per-
centages of patients who presented within this time window.
It can be seen that 81% of patients present within 6 months,
89% within 1 year, and 93% within 2 years. In
Figure 3
,
the same data focus on the first 4 months after onset, during
which 44% present within the first month (many during the
same hospital stay during which the paralysis began), 63%
within 2 months, 71% within 3 months, and 75% within 4
months. These are the patients for whom an early interven-
tion strategy might be an option. The cumulative plots for
all patients and for WUSM-only have similar contours
because the WUSM referral group comprises 90.2% of the
patients.
Table 4
shows the first 4-month presentation data by
etiology, excluding those groups with less than 10 patients.
Etiologies with the greatest percentage of patients present-
ing to the WUSM within a 4-month period included esopha-
geal cancer (90.9% present within 4 months), skull base
surgery (88.9%), esophageal surgery (86.5%), intubation
(86.2%), lung surgery (84.9%), and lung cancer (82.2%).
Etiologies with the lowest percentage of patients presenting
to the WUSM within a 4-month period included idiopathic
causes (54.8%), CVA (55.6%), thyroid cancer (57.1%), and
carotid surgery (59.1%). In patients who had UVFP caused
by thyroid surgery, 66.4% presented to the WUSM within 4
months, and in patients with parathyroid surgery, 72.2%
presented to the WUSM within 4 months.
Discussion
Etiology of UVFP
In this large retrospective study of UVFP, most of the etio-
logic findings were similar to 2 other large series, by
Rosenthal et al
15
and Takano et al,
16
as shown in
Table 5
.
Surgical/iatrogenic causes of UVFP are more common than
nonsurgical causes, and thyroid/parathyroid surgeries are
implicated more often than other types of surgery but do
not comprise most surgical etiologies overall. Intubation
injuries and idiopathic UVFP frequencies are similar in all
3 series, and the condition occurs on the left side in nearly
two-thirds of cases. Among nonsurgical cases, malignancy
was the most common category, most often lung cancer.
Malignancy of the lung was the most common cause in 3
previous studies.
1-3
The risk of iatrogenic injury to the recurrent laryngeal
nerve in different surgical procedures has been widely
Table 1.
Etiology of Unilateral Vocal Fold Paralysis.
Etiology
No. (% of Total)
Surgery
Cardiac surgery
58 (6.2)
Carotid surgery
22 (2.3)
Cervical spine surgery
48 (5.1)
Tracheostomy
2 (0.2)
Esophageal surgery
37 (3.9)
Lung surgery
73 (7.8)
Mediastinal surgery
17 (1.8)
Laryngeal surgery
4 (0.4)
Lateral neck surgery
61 (6.5)
Parathyroid surgery
18 (1.9)
Thyroid surgery
140 (14.9)
Skull base surgery
18 (1.9)
Intracranial surgery
24 (2.6)
Total
522 (55.6)
Malignancy
Laryngeal cancer
20 (2.1)
Esophageal cancer
11 (1.2)
Lung cancer
73 (7.8)
Skull base tumor
18 (1.9)
Lymphoma
1 (0.1)
Mediastinal mass
5 (0.5)
Metastatic cancer
24 (2.6)
Parotid cancer
1 (0.1)
Thyroid cancer—direct invasion
14 (1.5)
Total
167 (17.8)
Idiopathic
124 (13.2)
Intubation
58 (6.2)
Trauma
30 (3.2)
CVA
18 (1.9)
Transesophageal echocardiogram
1 (0.1)
IJ catheter placement
1 (0.1)
Infected vagal nerve stimulator
1 (0.1)
Neck infection
1 (0.1)
Right skull base osteomyelitis
1 (0.1)
Neck radiation
8 (0.9)
Lung radiation
2 (0.2)
Thoracic deformity
1 (0.1)
Ankylosing spondylitis
1 (0.1)
Sarcoidosis
2 (0.2)
Total
938 (100.0)
Abbreviations: CVA, cerebral vascular accident; IJ, internal jugular.
Otolaryngology–Head and Neck Surgery 151(2)
19