539

SHORT REPORT

Sudden bilateral simultaneous deafness with vertigo as a
sole manifestation of vertebrobasilar insufficiency
H Lee, H A Yi, R W Baloh
.............................................................................................................................

J Neurol Neurosurg Psychiatry 2003;74:539–541

A 68 year old woman presented with bilateral sudden
simultaneous hearing loss and transient spontaneous
vertigo as a sole manifestation of vertebrobasilar
insufficiency. Extensive investigation to exclude other
causes was unremarkable. Magnetic resonance imaging
of the brain, including diffusion images, showed no abnormalities. A magnetic resonance angiogram showed severe
stenosis of the middle third of the basilar artery. A pure
tone audiogram showed moderate sensorineural-type
hearing loss bilaterally. The localisation and mechanism of
an isolated cochleovestibular dysfunction are discussed.

V

ertebrobasilar insufficiency (VBI) can cause sudden
bilateral deafness because the vertebrobasilar system
supplies most of the auditory system including the inner
ears.1–7 Characteristically, sudden bilateral deafness due to VBI
is associated with multiple brain stem or cerebellar signs.1–6 To
our knowledge, sudden bilateral simultaneous deafness with
vertigo has not been reported as a sole manifestation of VBI.
We report on a patient who presented purely with sudden
bilateral deafness and vertigo. This unusual presentation was
due to a selective involvement of the inner ears supplied by the
internal auditory arteries, ordinarily branches of the anterior
inferior cerebellar artery (AICA).

CASE REPORT
A 68 year old woman with long standing non-insulin dependent diabetes mellitus and hypertension suddenly developed
vertigo, vomiting, and bilateral tinnitus. Five minutes later,
she noticed bilateral hearing loss. She had difficulty hearing
her husband speak. She did not have dysarthria, numbness,
weakness, visual distortion, or incoordination. The hearing
loss persisted, but vertigo resolved over a few hours. Two days
previously, she had had two episodes of transient vertigo and
hearing loss involving the left ear that lasted no more than a
few minutes without any accompanying neurological symptoms. The patient had no previous history of hearing difficulty.
There was no prior history of temporal bone fracture, meningitis, autoimmune disease, or exposure to ototoxic drugs.
On admission, she had persistent bilateral hearing loss and
non-specific dizziness with lightheadedness. The results of her
general and neurological examinations were normal except for
the bilateral hearing loss. Extensive blood tests including liver
function tests, complete blood count, urea nitrogen, creatinine,
erythrocyte sedimentation rate, circulating immune complex,
and serum electrolytes were all normal. Antinuclear antibody,
rheumatoid factor, C reactive protein, HIV serology, and
.............................................................
Abbreviations: AICA, anterior inferior cerebellar artery; VBI,
vertebrobasilar insufficiency

Figure 1 Pure-tone air conduction audiograms obtained on two different dates, 15 days apart (+15). The patient’s hearing levels are plotted
against stimulus frequency on a logarithmic scale. The decibels were measured according to the American National Standards Institute, 1989.

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540

Lee, Yi, Baloh

Figure 2 Frontal (A) and lateral (B) views of cerebral magnetic resonance angiogram show a severe stenosis at the junction of the left
vertebral artery (long arrow) and the basilar artery (short arrow). The right distal vertebral artery is also occluded (arrowhead).

treponemal serology (Venereal Disease Research Laboratory test)
were unremarkable. Audiometric testing, performed on admission, showed moderate sensorineural hearing loss of 55 dB with
90% speech discrimination on the left side and 45 dB with 95%
speech discrimination on the right (fig 1). Stapedial reflex
thresholds at multiple frequencies were normal on both sides.
Normal waveform responses were evoked bilaterally on brain
stem auditory evoked potentials. Electronystagmography showed
hypoexcitability (more than 22% asymmetry in our laboratory) to
caloric stimulation on the left side. There were no abnormalities
in saccades, pursuit, or optokinetic nystagmus. Magnetic
resonance imaging of the brain, including diffusion images, was
normal. Magnetic resonance angiography showed severe stenosis of the middle third of the basilar artery and blockage of the
right distal vertebral artery (fig 2). A transthoracic echocardiogram and an electrocardiogram showed no abnormalities. The
patient was treated acutely with a platelet aggregation inhibitor.
Fifteen days later, a follow up pure tone audiogram documented
notable improvement on both sides to 35 dB pure tone average
(fig 1). At last follow up, the patient had no specific complains
and has had no further neurological attacks.

DISCUSSION
The differential diagnosis of bilateral sudden sensorineural
hearing loss includes trauma, autoimmune inner ear disease,
meningitis, syphilis, HIV, and ototoxic drugs.8 Sudden bilateral
deafness is also associated with VBI.1–7 Our patient developed
sudden onset of symptoms and had definite vascular risk factors with longstanding hypertension and diabetes mellitus.
Furthermore, the magnetic resonance angiogram showed
severe stenosis of the middle third of the basilar artery close to
the origin of the AICA. She also had two episodes of transient
cochleovestibular symptoms typical of transient ischaemic
attack before the major bilateral sudden deafness. Extensive
blood tests with erythrocyte sedimentation rate, antinuclear
antibody, Venereal Disease Research Laboratory test, HIV, and
C reactive protein were normal.
Sudden bilateral deafness and VBI
There have been several reports of bilateral deafness due to
VBI.1–7 However, most previous reports1–6 of bilateral deafness
due to VBI have also described associated neurological

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symptoms such as mental change, motor weakness, sensory
loss, or cranial nerve palsy. Brain magnetic resonance images
characteristically showed hyperintensities involving the brain
stem, cerebellum, or both. In 1981, Stephan et al1 described a
patient with sudden bilateral deafness caused by basilar artery
occlusion who later developed bilateral weakness and died 10
hours after the onset. In 1993, Huang et al2 described seven
patients with sudden bilateral deafness caused by VBI, all of
whom had brain stem signs including facial palsy, diplopia,
swallowing difficulty, and bilateral weakness. Brain computed
tomography in six patients showed multiple hypodense
lesions in brain stem and cerebellum. The report did not mention audiometric data, limiting localisation. In 1995, Buttner et
al7 reported on a patient who had a bilateral vestibulocochlear
loss due to VBI without any other neurological symptoms or
sign, as in our case. In comparison with our patient, however,
the patient described by Buttner et al had continuous
prolonged vertigo and bilateral canal paresis on caloric stimulation. They did not conduct specialised auditory testing to
localise the site of hearing loss. In 1998, Deplanque et al3
reported on a patient with unilateral lateral inferior pontine
infarction who presented with bilateral deafness, facial palsy,
Horner syndrome, and ataxia. In 2000, Sunose et al4 described
a patient with bilateral cerebellar infarction who had acute
onset of hearing impairment bilaterally, dizziness, oculomotor
abnormalities, and numbness in the right extremity. In 2001,
Lee et al5 described a patient who had a bilateral sudden deafness as a prodrome of pontocerebellar infarction in the territory of the AICA. In 2002, Toyoda et al6 reported on two
patients with basilar artery occlusion who had bilateral deafness as a warning sign of impending stroke. Both patients died
of extensive infarction in the brain stem and cerebellum. All of
these patients except one7 had multiple neurological signs in
addition to bilateral hearing loss.
Localisation of sudden bilateral deafness
Without pathological confirmation, it is impossible to determine precisely the locus of injury responsible for hearing loss
in our patient. However, in our patient, speech discrimination
and stapedial reflex testing were normal, as were brain stem
auditory evoked potentials, indicating a cochlear site of lesion.9

Sudden bilateral deafness and vertebrobasilar occlusive disease

Predominantly low frequency hearing loss on the pure tone
audiogram suggests that the vascular insufficiency involved
small arterioles within the apex of the cochlea, which is
considered to be a particularly vulnerable site to ischaemia.10
Mechanism of sudden bilateral deafness
Strokes in the territory of the AICA are usually associated with
basilar occlusive disease.11 Because the brain magnetic
resonance angiogram in our patient documented a severe stenosis of the basilar artery close to the origin the AICA, it is
possible that an atheromatous plaque within the basilar artery
extended into the AICA ostia. By this mechanism, decreased
blood flow in both AICA may selectively damage the inner ear
because of its high energy requirements and the lack of
collaterals.5 12 It is also possible that the hearing loss resulted
from emboli originating in the basilar or vertebral arteries, but
the bilateral simultaneous onset would be atypical. Previous
reports10 13 of experimental transient occlusion of the internal
auditory artery have shown that the cochlea is more sensitive
to ischaemia than the vestibular labyrinth. We speculate that
the prominence of hearing symptoms and the absence of the
other neurological symptoms or signs are best explained by
the selective vulnerability of the cochlea to ischaemia.
Clinical relevance
We have previously reported hearing loss as a prodrome of
AICA infarction. Together, these reports highlight the importance of hearing loss as either a sole manifestation or a
warning5 of impending brain stem infarction. Clinicians
should be aware of the possibility of VBI in patients with
bilateral sudden deafness, even when brain stem or cerebellar
signs are absent.
.....................

Authors’ affiliations
*H Lee, H A Yi, Department of Neurology, Keimyung University School
of Medicine, Daegu, South Korea
R W Baloh, Department of Neurology, Division of Surgery (Head and
Neck), UCLA School of Medicine, Los Angeles, California, USA

541
*Also the Brain Research Institute, Keimyung University School of
Medicine, Daegu, South Korea
Correspondence to: Dr H Lee, Department of Neurology, School of
Medicine, Keimyung University, 194 Dongsan dong, Daegu, 700–712
South Korea; hlee@dsmc.or.kr
Received 5 August 2002
In revised form 25 October 2002
Accepted 25 October 2002

REFERENCES
1 Stephan H, Wappenschmidt J, Kiefer H. Occlusion of the basilar artery.
Neurosurg Rev 1981;4:41–52.
2 Huang MH, Huang CC, Ryu SJ, et al. Sudden bilateral hearing
impairment in vertebrobasilar occlusive disease. Stroke 1993;24:132–7.
3 Deplanque D, Godefroy D, Guerouaou D, et al. Sudden bilateral
deafness: lateral inferior pontine infarction. J Neurol Neurosurg
Psychiatry 1998;64:817–8.
4 Sunose H, Toshima M, Mitani S, et al. Sudden bilateral hearing loss and
dizziness occurred with cerebellar infarction. Otolaryngol Head Neck
Surg 2000;122:146–7.
5 Lee H, Whitman GT, Lim JG, et al. Bilateral sudden deafness as a
prodrome of anterior inferior cerebellar artery infarction. Arch Neurol
2001;58:1287–9.
6 Toyoda K, Hirano T, Kumai Y, et al. Bilateral deafness as a prodromal
symptom of basilar artery occlusion. J Neurol Sci 2002;193:147–50.
7 Buttner U, Ott M, Helmchen CH, et al. Bilateral loss of eighth nerve
function as the only clinical sign of vertebrobasilar dolichoectasia. J
Vestib Res 1995;5:47–51.
8 Fetterman BL, Luxford WM, Saunders JE. Sudden bilateral sensorineural
hearing loss. Laryngoscope 1996;106:1347–50.
9 Baloh RW. Dizziness, hearing loss, and tinnitus. New York: Oxford,
1988:89–105.
10 Perman HB, Kimura RS, Fernandez C. Experiments on temporal
obstruction of the internal auditory artery. Laryngoscope
1959;69:591–613.
11 Amarenco P, Rosengart A, DeWitt LD, et al. Anterior inferior cerebellar
artery infarcts. Mechanisms and clinical features. Arch Neurol
1993;50:154–61.
12 Grad A, Baloh RW. Vertigo of vascular origin: clinical and
electronystagmographic features in 84 cases. Arch Neurol
1989;46:281–4.
13 Levine RA, Bu-Saba N, Brown MC. Laser-Doppler measurements and
electrocochleography during ischaemia of the guinea pig cochlea:
implication for hearing preservation acoustic neuroma surgery. Ann Otol
Rhinol Laryngol 1993;102:127–36.

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