158 / 232
months;
P
¼
.02) and a bilateral EVA group (75.0 vs. 48
months; range, 38–102.5 vs. 0–208 months;
P
¼
.008).
Hearing Loss Severity
The median PTAs at the initial and final audiometric
assessments for all ears with hearing loss (n
¼
243) were
50 (range, 10–130) and 57 (range, 7.5–122.5), respectively.
Nine ears had an isolated HFPTA (median HFPTA was
35.8; range, 20–57.5). Patients with hearing loss and uni-
lateral EVA had slightly better hearing than those with
bilateral EVA, although this difference was not statisti-
cally significant (47.5 [range, 10–130] vs. 55.6 [range, 12–
130], respectively;
P
¼
.075). This finding was consistent
when analyzing the better-hearing ear in both groups.
At initial audiometric assessment, there was no
statistical difference between the median PTA of patients
with unilateral hearing loss (n
¼
45) and the better-hear-
ing ear of patients with bilateral loss (n
¼
99; 48.75 vs.
41.25;
P
¼
.4). This finding was consistent when our
cohort was stratified into unilateral and bilateral EVA
groups. Among the 74 patients with unilateral EVA (n
¼
114 ears with hearing loss), there was no significant dif-
ference in the median PTA at the initial audiometric
assessment between ipsilateral ears (n
¼
73) and contra-
lateral ears (n
¼
41; 47.5 [range, 10–130] vs. 41 [range,
14–130], respectively;
P
¼
.9). This finding was consistent
with the final audiometric assessment of ipsilateral and
contralateral PTA values (52.5 [range, 7.5–121.25] vs. 50
[range, 12.5–130], respectively;
P
¼
. 6).
The severity of hearing loss at the initial assessment
was categorized as borderline to mild in 37.4% of ears
with hearing loss, moderate to severe in 45.3% of affected
ears, and profound in the remaining 17.3% of affected
ears. There was no difference in hearing loss severity
between patients with bilateral vs. unilateral EVA (
P
¼
.48; Table I). There was no statistical relationship (
P
¼
.21) between levels of hearing loss severity and whether
the loss was ipsilateral or contralateral to the EVA at ei-
ther the initial or the final audiometric assessment.
Vestibular Aqueduct Measurements
Hearing loss and vestibular aqueduct phenotypes
were compared regarding temporal bone measurements at
the midpoint and the operculum (Table II). No significant
differences were found in the temporal bone measure-
ments between the ears of patients with unilateral EVA
and ipsilateral hearing loss and all ears with EVA and
normal hearing (
P
¼
.4). Operculum measurements were
significantly greater in the ears of patients with bilateral
EVA than in those with unilateral EVA (
P
¼
.025).
TABLE I.
Data Pertaining to Patients With EVA.
Characteristic
Unilateral, n
¼
74
Bilateral, n
¼
70
P
Male
38 (51%)
29 (41%)
.26
Age at identification of hearing loss, mo*
70 (0–324.5) [39.5–106]
54.5 (0–208) [32.5–69.5]
.01
Follow-up time, mo
†
32.8 (0.5–164) [13.5–69.5]
56.3 (0.5–812.5) [33.8–76.8]
.02
3 months of follow-up
55 (74.3%)
61 (87.1)
.05
Unilateral hearing loss at initial assessment
34 (46.0%)
11 (15.7%)
<
.0001
Pure tone average in better-hearing ear, dB
37.9 (10–130) [27.5–65]
50 (6.25–130) [32.5–70]
.19
Hearing loss severity in better-hearing ear
.48
Mild
30 (40.5%)
21 (30.0%)
Moderate
11 (14.9%)
15 (21.4%)
Moderately severe
11 (14.9%)
12 (17.1%)
Severe
3 (4.1%)
7 (10%)
Profound
11 (14.9%)
10 (14.3%)
Normal/borderline
‡
8 (10.8%)
5 (7.1%)
*Range in parentheses and interquartile range (25th and 75th percentile) in brackets.
†
Among 126 patients with follow-up.
‡
High-frequency loss in 6 of 8 patients with unilateral EVA and 1 of 5 with bilateral EVA.
EVA
¼
enlarged vestibular aqueduct.
TABLE II.
Vestibular Measurements of Ears With Hearing Loss.
Bilateral EVA,
129 Ears*
Unilateral EVA and
Ipsilateral Hearing
Loss, 73 Ears
†
Non-EVA Ears and
Contralateral Hearing
Loss, 41 Ears
EVA Ears With Normal
Hearing, 12 Ears
‡
Midpoint, mm (range)
1.7 (0.1–4.1)
1.5 (0.1–3.5)
0.41 (0.1–0.9)
1.25 (0.1–3.8)
Operculum, mm (range)
2.7 (0.68–7.6)
2.3 (0.1–7.5)
1.37 (0.1–1.9)
2.0 (0.8–4.2)
* versus †: midpoint
P
¼
.069, operculum
P
¼
.025
† versus ‡: midpoint
P
¼
.4, operculum
P
¼
.4.
EVA
¼
enlarged vestibular aqueduct.
Laryngoscope 123: June 2013
Greinwald et al.: Unilateral Enlarged Vestibular Aqueduct
136