Annals of Otology, Rhinology & Laryngology 116(6):407-410.
© 2007 Annals Publishing Company. All rights reserved.

Bilateral Sudden Profound Hearing Loss and Vertigo as a Unique
Manifestation of Bilateral Symmetric Inferior Pontine Infarctions
Roberto Bovo, MD; Rocco Ortore, MD; Andrea Ciorba, MD;
Anna Berto, MD; Alessandro Martini, MD
Objectives: We present a case of sudden bilateral profound deafness and vertigo, without any accompanying neurologic
signs, secondary to bilateral infarctions of the cochlear and vestibular nuclei.
Methods: Vertigo, vomiting, tinnitus, and bilateral profound deafness suddenly developed in a 65-year-old woman without any accompanying neurologic signs. In particular, she did not present dysarthria, numbness, cranial nerve palsies, or
visual or cerebellar signs.
Results: Magnetic resonance imaging of the brain revealed 2 fresh infarctions of 8 to 10 mm symmetrically localized in
the posterolateral bulbopontine junction. Angiography revealed a complete occlusion of the basilar artery, with a wellrepresented backward flow of its distal portion from the carotid artery via posterior communicating arteries. Excluding
a transient ischemic attack that occurred 16 days after the acute episode, the patient had had no other neurologic events
at 8 months of follow-up.
Conclusions: Acute vertigo and sudden deafness in a patient with known cerebrovascular occlusive disease may represent the warning signs of an impending brain stem or cerebellar infarction, even when other neurologic signs are absent.
These events are fortunately very rare, but should be considered by clinicians who see patients with vertigo.
Key Words: bilateral sudden hearing loss, cochlear nucleus infarction, pontine infarction, sudden hearing loss, vertigo,
vestibular nucleus infarction.

developed vertigo with nausea, vomiting, and bilateral tinnitus. A few hours later she noticed sudden
hearing loss in her left ear, and after 12 more hours,
the deafness became bilateral, making her unable to
hear at all. Her clinical history revealed long-standing hypertension and a cerebrovascular accident in
her childhood that caused a left pyramidal hemisyndrome whose actual sequelae were a slight motor
deficit in the left arm and leg. A fourth ventricular
enlargement, documented on a previous computed
tomographic scan, had been stable for many years.
For the other aspects there was a negative history,
in particular with regard to head trauma, meningitis, autoimmune diseases, ototoxic drugs, and other
neurologic events. Objective examinations revealed
a horizontal right-beating nystagmus of 2° without
any accompanying neurologic signs (excluding the
sequelae of the old left hemiparesis). In particular,
she did not have dysarthria, numbness, cranial nerve
palsies, or visual or cerebellar signs. Pure tone audiometry revealed a bilateral sensorineural deafness
that was profound in the right ear (95 dB) and total
in the left. This was in contrast with her normal audiogram that was found in our outpatient files for
2003. Otoacoustic emissions were absent, and auditory brain stem responses to clicks at maximum in-

INTRODUCTION

Sudden deafness and vertigo in an older patient
with known cerebrovascular occlusive disease suggests the likelihood of vertebrobasilar ischemia, because the vertebrobasilar system supplies most of
the auditory pathways and the inner ear. Among
overall cases of vertebrobasilar ischemia, bilateral
and simultaneous deafness are extremely rare, accounting for 0.44% to 3.4% of total cases, and literature reports are few.1-11 These bilateral forms are
generally due to occlusion of the basilar or the vertebral arteries and have a severe prognosis. In fact,
although hearing and vestibular symptoms sometimes represent the opening clinical feature, the patients soon manifest multiple brain stem or cerebellar signs such as crossed sensory loss, lateral gaze
palsy, facial palsy, Horner syndrome, or cerebellar
dysmetria.
We report a patient who had vertigo and sudden
bilateral profound deafness as the sole manifestation
of bilateral symmetric infarctions at the posterolateral bulbopontine junction.
CASE REPORT

In January 2006, a 65-year-old woman suddenly

From the Department of Audiology, Ferrara University, Ferrara, Italy.
Correspondence: Roberto Bovo, MD, Dept of Audiology, Arcispedale S Anna, Corso Giovecca 203, IT-44100 Ferrara, Italy.

407

Downloaded from aor.sagepub.com at UNIV OF MICHIGAN on April 19, 2015

408

408

Bovo et al, Bilateral Sudden Hearing Loss

Fig 1. Contrast-enhanced magnetic resonance image of
brain shows 2 fresh infarctions symmetrically localized
in posterolateral bulbopontine junction.

tensity (125 dB sound pressure level) were absent.
An electrocochleogram demonstrated bilateral normal cochlear potentials, and the compound action
potential of the nerve was absent.
Contrast-enhanced magnetic resonance imaging
of the brain revealed 2 fresh infarctions symmetrically localized in the posterolateral bulbopontine junction (Fig 1). The lesions measured about 10 mm and
involved bilaterally the cochlear and inferior vestibular nuclei. Magnetic resonance angiography documented the total absence of blood flow signal in the
basilar artery. Brain angiography (Fig 2) confirmed
the occlusion of the basilar artery, with a well-represented backward flow of its distal portion and of the
superior cerebellar arteries from the carotid artery
via posterior communicating arteries. Either these
last arteries, or the posteroinferior cerebellar arteries
(which originated from the vertebral arteries), had
a larger-than-normal diameter. Echo color Doppler
scans of the carotid and vertebral arteries, an electrocardiogram, and a transesophageal echocardiogram
appeared normal, thus excluding a cardiac source of
embolism. Vascular risk factors were an increased
plasma level of homocysteine (55.9 mmol/L) and
hypercholesterolemia (280 mg/dL); the results of
the remaining blood examinations were within normal limits. After a few days, the vertigo and the nystagmus resolved completely, but the patient continued to complain of nonspecific dizziness and bilateral tinnitus. During the entire admission her general condition was stable, and she was treated with
antihypertensive and antithrombotic drugs, hypolipemics, and B complex vitamins. Twelve days later, the patient was discharged without any improvement of the auditory threshold or the tinnitus. Vestibular symptoms were absent, excluding a slightly
ataxic gait. Unfortunately, the vestibular function

could not be evaluated, because the patient refused a
caloric test. We recommended a vibrating cutaneous
device for the detection of alarm sounds and training in lipreading given by a speech pathologist. Four
days after discharge, the patient had a transient is­
chemic attack with dysarthria, numbness, and paresis of the upper right arm. She underwent an urgent
nonenhanced cerebral computed tomographic scan,
which demonstrated no change with respect to the
previous one, and she was kept under observation
for 24 hours. Aside from this episode, there were
no neurologic events after 10 months of follow-up.
The most recent audiogram revealed no changes in
the auditory thresholds, and no other rehabilitative
treatment was deemed useful.
DISCUSSION

Occlusion of the basilar artery is a rare event with
a high mortality rate and a poor functional outcome
in survivors. The initial symptoms can develop as a
disturbance of hearing and/or vestibular functioning,
although neurologic signs of brain stem and cerebellar ischemia follow within 24 to 48 hours in most
cases. A quick diagnosis and initiation of adequate
therapy are thus decisive.
Our case is peculiar because of 1) a bilateral and
profound sudden deafness due to a bilateral and
symmetric infarction at the posterolateral bulbopontine junction; 2) the absence of neurologic signs
other than vertigo (and the stable sequelae of a cerebrovascular accident during childhood), despite the
complete occlusion of the basilar artery; 3) the presence of a significant backward flow from the carotid arteries via posterior communicating arteries that
probably, over the years, permitted minimal but just
sufficient blood flow in the posterior regions; and
4) no other remarkable ischemic attacks during 10
months of follow-up, excluding a transient ischemic
attack that occurred 16 days after the first episode.
As far as we know, this is the first case of bilateral
sudden deafness with such characteristics. In fact,
among the patients described in the literature who
survived ischemic attacks, not one had bilateral profound deafness due to a well-documented bilateral infarction of the cochlear and vestibular nuclei.
In our case, the occlusion of the basilar artery was
probably progressive and permitted the development
of good collateralization. Welsh et al12 documented
a significant difference in the potential for intracerebral collateralization and regional perfusion due to
developmental or structural variability in the posterior communicating arteries, or more generally
in the circle of Willis. Most probably, our patient
has a favorable configuration of the circle of Willis.

Downloaded from aor.sagepub.com at UNIV OF MICHIGAN on April 19, 2015

409

Bovo et al, Bilateral Sudden Hearing Loss

409

Fig 2. Brain angiograms with contrast perfusion show occlusion
of basilar artery. A) Right and B) left vertebral arteries demonstrate occlusion at origin of basilar artery (arrows). C) Right
common carotid artery demonstrates well-represented backward flow of distal portion of basilar artery (arrow) and of superior cerebellar arteries via posterior communicating arteries
(arrowhead).

A

B

C

Huang et al2 observed 7 patients who had sudden bilateral hearing impairment among 503 patients with
vertebrobasilar occlusive disease. The main initial
neurologic symptoms were sudden bilateral hearing impairment, tinnitus, and vertigo. Acute labyrinthitis or Meniere’s disease was the initial diagnosis,
but subsequently all of the patients developed brain
stem or cerebellar signs, including facial and/or other cranial nerve palsy, diplopia, and bilateral weakness. Ichikawa et al3 reported a similar case with
an abrupt onset of bilateral hearing loss but without vertigo. The patient was hospitalized and treated
for “idiopathic deafness.” Two days later he manifested brain stem and cerebellar symptoms. In these
extremely rare cases, bilateral sudden hearing loss
may mimic a functional disturbance, that is to say, a

fictitious or a conversion deafness.1 The hypothesis
of a functional deafness was also initially considered in our patient, but an urgent cerebral magnetic resonance imaging scan was requested soon after
her admission.
The differential diagnosis of bilateral deafness
also includes head trauma, autoimmune inner ear
diseases, disseminated encephalitis, human immunodeficiency virus infection, syphilis, drug ototoxicity,1 and acute drug addiction, whereas in the case
of hearing loss due to bacterial meningitis, the clinical history permits an easy diagnosis. Huang and
Young10 encountered a patient with basilar artery
occlusion manifesting as vertigo, subsequently followed by bilateral sudden deafness and dysarthria

Downloaded from aor.sagepub.com at UNIV OF MICHIGAN on April 19, 2015

410

Bovo et al, Bilateral Sudden Hearing Loss

and terminating in a coma state within 6 hours. A review of the patient’s history showed that he had had
2 episodes of transient vertigo 2 weeks before a major stroke. Restated, patients with basilar artery occlusion often have transient vertiginous attacks before a fatal stroke. Embolism of the vertebrobasilar
system is probably more common than is generally
considered; a potential cardiac source of embolism
has been reported in 22% to 70% of patients with
infarcts in the vertebrobasilar region.13 With our patient, a cardiologic and vascular evaluation seemed
to exclude a possible source of embolism, either artery-to-artery or cardiogenic. Moreover, a bilateral
and symmetric distribution of embolism, as in this
case, would be very atypical.

410

After 8 months, the deafness of our patient did not
ameliorate. This outcome concurs with the observations of Lee and Baloh.11 In their series of vascular
sudden deafness, the improvement rate in patients
with profound hearing loss was significantly lower
than that in patients with less-than-profound hearing
loss (40% versus 89%; p < .01).
In conclusion, acute vertigo and sudden deafness in a patient with known cerebrovascular occlusive disease may represent the warning signs of
an impending brain stem or cerebellar infarction,
even when other neurologic signs are absent. These
events are fortunately very rare, but should be considered by clinicians who see patients with vertigo.

REFERENCES

1. Lehnhardt E. Acute inner ear deafness [in German]. HNO
1991;39:378-85.
2. Huang MH, Huang CC, Ryu SJ, Chu NS. Sudden bilateral hearing impairment in vertebrobasilar occlusive disease.
Stroke 1993;24:132-7.
3. Ichikawa H, Fukui T, Negishi A, Sugita K, Kanda M.
A case of bilateral cerebellar peduncle infarction with bilateral hearing impairment of a sudden onset [in Japanese]. Rinsho
Shinkeigaku 1994;34:569-76.
4. Fetterman BL, Luxford WM, Saunders JE. Sudden bilateral sensorineural hearing loss. Laryngoscope 1996;106:134750.
5. Deplanque D, Godefroy D, Guerouaou D, Laureau E, De­
saulty A. Sudden bilateral deafness: lateral inferior pontine infarction. J Neurol Neurosurg Psychiatry 1998;64:817-8.
6. Sunose H, Toshima M, Mitani S, Suzuki M, Yoshida F,
Takasaka T. Sudden bilateral hearing loss and dizziness occurred with cerebellar infarction. Otolaryngol Head Neck Surg
2000;122:146-7.
7. Schmiz A, Haibt-Luttke G, Albrecht G, Hagen R, Gustorf-Aeckerle R. Thrombosis of the basilar artery — a rare differential sudden deafness diagnosis and vestibular failure [in

German]. Laryngorhinootologie 2000;79:253-9.

8. Toyoda K, Hirano T, Kumai Y, Fujii K, Kiritoshi S, Iba­
yashi S. Bilateral deafness as a prodromal syndrome of basilar
artery occlusion. J Neurol Sci 2002;193:147-50.

9. Lee H, Yi HA, Baloh RW. Sudden bilateral simultaneous
deafness with vertigo as a sole manifestation of vertebrobasilar
insufficiency. J Neurol Neurosurg Psychiatry 2003;74:539-41.
10. Huang CC, Young YH. Vertigo with rebound nystagmus
as an initial manifestation in a patient with basilar artery occlusion. Eur Arch Otorhinolaryngol 2005;262:576-9.

11. Lee H, Baloh RW. Sudden deafness in vertebrobasilar
ischemia: clinical features, vascular topographical patterns and
long-term outcome. J Neurol Sci 2005;228:99-104.
12. Welsh LW, Welsh JJ, Lewin B, Dragonette JE. Incompetent circle of Willis and vertebrobasilar insufficiency. Ann Otol
Rhinol Laryngol 2003;112:657-64.

13. Bogousslavsky J, Cachin C, Regli F, Despland PA, Van
Melle G, Kappenberger L. Cardiac sources of embolism and cerebral infarction — clinical consequences and vascular concomitants: the Lausanne Stroke Registry. Neurology 1991;41:8559.

Downloaded from aor.sagepub.com at UNIV OF MICHIGAN on April 19, 2015