J Neurosurg 119:1125–1128, 2013
©AANS, 2013

Partly reversible central auditory dysfunction induced by
cerebral vasospasm after subarachnoid hemorrhage
Case report
Ester Ponzetto, M.D.,1 Marco Vinetti, M.D.,1 Cécile Grandin, M.D., Ph.D., 2
Thierry Duprez, M.D., 2 Vincent van Pesch, M.D., Ph.D., 3 Naїma Deggouj, M.D., 4
Renaud Lhommel, M.D., 5 and Philippe Hantson, M.D., Ph.D.1
Departments of 1Intensive Care, 2Medical Imaging and Radiology, 3Neurology, 4Otorhinolaryngology, and
5
Nuclear Medicine, Université catholique de Louvain, Cliniques Saint-Luc, Brussels, Belgium
The authors describe a rare case of central auditory dysfunction induced by cerebral vasospasm after aneurysmal subarachnoid hemorrhage (SAH). A 55-year-old woman who was admitted after aneurysmal SAH developed
cerebral vasospasm on Day 3 affecting mainly the right middle cerebral artery (MCA) and partly the left MCA.
The vasospasm became refractory to conventional therapy and was ultimately improved by intraarterial infusion of
nimodipine in the right MCA and angioplasty. Severe auditory dysfunction was apparent from Day 10 as the patient
was not reactive to speech or environmental sounds. Brain MRI on Day 17 demonstrated infarcted areas mainly
in the right hippocampus, medial occipital lobe, and thalamus. The patient underwent further examination using
audiometry, speech testing, auditory evoked potentials, functional MRI, and cerebral PET. The initial diagnosis was
extended nonverbal agnosia and total pure word deafness. The central auditory dysfunction improved over 6 months,
with persisting hyperacusis, tinnitus, and amusia. Central auditory dysfunction is a rare complication after SAH.
While cortical deafness may be associated with bilateral lesions of the temporal cortex, partly reversible central
auditory dysfunction was observed in this patient after prominently unilateral right temporal lesions. The role of the
interthalamic connections can be discussed, as well as the possibility that a less severe vasospasm on the left MCA
could have transiently impaired the left thalamocortical auditory pathways.
(http://thejns.org/doi/abs/10.3171/2013.7.JNS13674)

Key Words
•
subarachnoid hemorrhage
•
vasospasm
•
central deafness
event-related potentials
•
functional magnetic resonance imaging
•
cerebral FDG positron emission tomography
•
functional neurosurgery
•
vascular disorders

C

ortical deafness is a rare auditory condition as-

sociated in all cases with bilateral lesions of the
primary auditory cortex located in the temporal
lobes.4 We report a case of central auditory dysfunction
due to severe vasospasm after aneurysmal subarachnoid
hemorrhage (SAH). This patient was examined using several techniques (tonal and speech audiometry, brainstem
and long-latency auditory evoked potentials, event-related potentials to elicit P300, blood oxygenation level–dependent [BOLD] functional MRI [fMRI], and FDG PET)
over several months to characterize the central origin of
auditory dysfunction and to determine the uni- or bilateral
feature of the brain injury.
Abbreviations used in this paper: BOLD = blood oxygenation
level–dependent; fMRI = functional MRI; GCS = Glasgow Coma
Scale; HTA = hearing threshold average; MCA = middle cerebral
artery; SAH = subarachnoid hemorrhage; SPL = sound pressure
level.

J Neurosurg / Volume 119 / November 2013

•

Case Report
Clinical Presentation. A 55-year-old right-handed
woman was admitted to the ICU for an SAH caused by
the rupture of a right posterior communicating artery aneurysm. The patient had no previous medical history, and
her hearing was normal before this episode. On admission,
her Glasgow Coma Scale (GCS) score was 10/15, corresponding to Grade IV according to the World Federation
of Neurological Societies grading scale. Oral nimodipine
was administered to prevent cerebral vasospasm. The right
posterior communicating artery saccular aneurysm was
successfully treated by endovascular coil embolization.
Postprocedural brain CT revealed diffuse SAH, prominently within the right sylvian fissure, together with hemorrhagic contamination of the third and fourth ventricles,
thus far classified as Fisher Grade 4. At this time, the patient had a GCS score of 11/15 (E4, V1, M6). On Day 3,
the patient’s neurological status worsened, and her GCS
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E. Ponzetto et al.
score was 8/15. Transcranial Doppler examination demonstrated increased velocities in both middle cerebral arteries
(MCAs), prominently on the right side, suggesting bilateral
and asymmetrical vasospasm. This was further confirmed
by conventional catheter digital subtraction angiography.
As vasospasm became refractory to intravenous nimodipine infusion, the drug was administered intraarterially
directly within the right MCA. This resulted in transient
angiographic improvement. The procedure was repeated
with milrinone on Day 10 and was followed by angioplasty
of the terminal segment of the right internal carotid artery
and of the M1 segment of the right MCA. The patient’s neurological status gradually improved from Day 10; however,
high velocities were still recorded on transcranial Doppler examination within both MCAs (still prominently on
the right). Complete subsidence of vasospasm was finally
noted on Day 21. The patient was discharged from the ICU
on Day 22, with left hemiparesis and pyramidal syndrome,
hemisensory neglect, slight left upper limb tactile hypesthesia, static and kinetic ataxia, and limitation of left eye
abduction. The patient left the hospital on Day 43. Neuropsychological and speech rehabilitation was continued in
an outpatient setting.

History of Auditory Dysfunction. Auditory dysfunction was evident from Day 10 since the patient reacted
to some noise stimulation, such as the weak noises of the
bedside alarms, but she did not exhibit spontaneous behavioral reaction to broad categories of sounds such as
speech, music, or most environmental sounds. Identification of environmental noises was limited to 33%. The
patient’s elocution was fluent and grammatically correct,
but she surprisingly whispered until Day 29, at which
point she began to speak too loudly. No detection or recognition of oral words was observed. However, lip-reading speech comprehension was preserved. She was able to
read and write correctly, and her ability to execute written
tasks was preserved. When her attention was oriented to
speech, she described spoken conversation as sounding
like a noise, and sometimes buzzing, and she complained
of tinnitus. A clear lip-reading benefit was observed in
speech perception.
The training of the audiovisual speech discrimination during 10 minutes was associated with the correct
discrimination of auditory-attended words presented only
orally and in closed set condition. The discrimination in
open set appeared with delay, first only in the auditoryattended condition and later in the unattended one.

Investigations

Audiometry. The external auditory meatus and tym-

panic membrane were normal. On Day 25, tonal audiometry showed a hearing threshold average (HTA) for the
frequencies 250–4000 Hz at an 80-dB hearing level in the
right ear and no perception in the left. After a few minutes
of hearing training, the HTA reached 30 dB in the right ear
only in the auditory-attending condition. Correct repetition
of 5 words concerning body parts or animals was observed
at the 75-dB sound pressure level (SPL) in the free field. On
Day 71, the HTA was 20 dB for the right ear and 30 dB for
the left ear. A maximum of 90% correct repetition of bisyllabic French words was recorded at 45 dB SPL in the free
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field and only 50% at 40 and 50 dB SPL. All audiometry
tests were possible only when the patient was selectively
paying attention to the auditory modality.
At the 6-month follow-up, the patient’s auditory dysfunction greatly improved; speech audiometry showed
100% correct intelligibility at 40 dB in the right ear and
maximum 80% at 55 dB in the left. The patient presented
with hyperacusis and persisting tinnitus, as well as amusia (that is, an inability to recognize and reproduce musical tones), which is currently improving after training.
Speech Testing. The patient was tested 6 times during the course of her hospital stay. The audiovisual material provided 4 experimental conditions: audiovisual
congruent condition (1), auditory condition (2), visual
condition (3), and audiovisual incongruent condition (4).
Accordingly, the patient was asked to identify the word
illustrated by the figure (1), to repeat the word (2), to repeat the world only with the lip reading (3), and to repeat
what she understood (4). The patient had few responses
in the audiovisual congruent test and simple visual test,
but no responses in simple auditory test and audiovisual
incongruent test, meaning that the patient needed a visual
support to understand a word. Nine examinations were
obtained over a 4-month follow-up period. The 4 experimental conditions improved, especially the conditions
“simple auditory test” (2) and “audiovisual incongruent
test” (4), meaning the patient reached the ability to understand sounds even without visual and/or lip-reading
support.
Auditory Evoked Potentials. Brainstem auditory
evoked potentials by clicks showed normal morphology
and latencies. Waves Jewett V thresholds were 30 dB bilaterally. The late latency auditory evoked potentials were
initially absent, but on Days 30 and 37, exogenous auditory responses reappeared, albeit only when the patient was
attentive to the stimuli. Using a classic oddball paradigm,
no event-related potential, such as a P300 wave, could be
elicited in either passive or active discrimination tasks.
Brain MRI. A brain MRI study obtained on Day 17
showed recently infarcted areas in the right hippocampus,
medial occipital lobe, and thalamus together with smaller
ischemic lesions within the cerebellum, posterior areas
of the pons (both sides), and periaqueductal vicinity. On
Day 46, the lesions were stable, and BOLD fMRI was
performed using 3 language tasks. A reading task clearly
demonstrated monolateralization of the language to the
left hemisphere with unequivocal activation of the Broca
and Wernicke areas. An auditory task alternating short
word definitions and reverse sentences gave widespread
activations solely located within the left hemisphere but
with no clear focus in the putative language areas. An auditory task alternating short word definitions and silence
gave only one focus of activation in the left primary auditory cortex.
A BOLD fMRI examination was repeated 4.5 months
later. The patient demonstrated major improvement with
the second task, and enlargement of the activated temporal primary area, appearance of a mirror activation of
the primary area of the right temporal lobe, and bilateral
activation of the auditory associative areas were noted.
Cerebral PET. Cerebral FDG PET imaging performed
J Neurosurg / Volume 119 / November 2013

Central auditory dysfunction after SAH-related vasospasm
on Day 22 showed significant reduction in metabolism in
the right thalamus, temporal, occipital lobes, and parietal
cortex (Fig. 1). Left hemispheric metabolism had normal
level and distribution.

Discussion

Cortical deafness is a rare auditory disorder that is always associated with bilateral lesions of the temporal cortex.4 It can be defined as a condition in which there is no
central auditory processing, whereas peripheral auditory
pathways have preserved functioning.1 The syndrome was
first reported and termed “cortical deafness” by Wernicke
and Friedlander in 1883, but the term is not fully appropriate, as this condition can also be observed in cases of
auditory perception impairment or attention disorder.4,10
Indeed, the condition has been shown in patients suffering from extensive bilateral destruction of the auditory
cortices that a mechanism of selective “top-down” attention associated with the prefrontal cortex could exert a
crucial modulatory effect on auditory perception within
the remaining auditory system.1
The condition is often associated with 2 other disorders of auditory processing, namely auditory nonverbal agnosia and pure word deafness. Auditory agnosia is
defined as a selective dysfunction of recognizing meaningful nonverbal sounds and is due to lesions in the associative auditory areas of the nondominant cerebral
hemisphere.10 The term “pure word deafness,” which
was first used by Kussmaul in 1877, refers to an inability to understand spoken words, despite intact hearing,
speech production, and an ability for reading. In contrast
to sensory aphasia, reading and writing are preserved in
word deafness because they are not fed by auditory input.
Bitemporal vascular lesions are usually the cause of the
disorder.10 It has been argued that, because cortical deafness frequently resolves into nonverbal auditory agnosia
or pure word deafness, these syndromes may represent
a pathophysiological continuum. 4 Clinical study has suggested the involvement of neural radiations to the auditory
cortex rather than lesions of the cortex itself.12 The term
“central deafness” could therefore be more appropriate.
A number of cases of cortical deafness in children and

adults have been reported in the literature, with the most
frequent causes being congenital and cerebral infarction
or hemorrhage.2,3,6,13 To date, cortical deafness has been
reported in only 2 cases of SAH. In one case, an old infarction was found in the left temporal lobe prior to the
occurrence of SAH. Cortical deafness was caused by vasospasm contralateral to a preexisting temporal lobe infarction. Evaluation of cerebral blood flow was not performed
in that case.8 In the second case, transient cortical auditory dysfunction was caused by SAH-related vasospasm of
which subsequent parenchymal ischemic damage was depicted in both temporal lobes on diffusion-weighted MRI.11
The authors hypothesized that transient ischemia involving
bilateral auditory cortices and radiations was the cause of
reversible cortical auditory dysfunction.
Our case illustrates the continuum that exists for
“central deafness.” At the early stage, the patient presented with extended nonverbal agnosia and total pure
word deafness, and later on, limited nonverbal agnosia
and extended word deafness, and finally, progressive and
delayed recovery from word deafness with progressive
improvement of word discrimination.
Pure tone audiometry is an essential part of the assessment of patients with suspected central auditory pathology.4 In individuals with hearing disorders, the presence of
normal pure tone audiometry makes the diagnosis of a central auditory disorder more likely. However, abnormal audiometry is not an exclusion criterion for central auditory
pathology; tonal audiometry may be negatively impacted
by auditory agnosia.
Blood oxygenation level–dependent fMRI is a powerful tool for recording neuronal activation in the healthy
and diseased human brain. This modality detects local
increases in relative blood oxygenation (concentration
of oxyhemoglobin vs that of deoxyhemoglobin) that are
direct consequences of neurotransmitter action and thus
reflect local neuronal signaling.5 In our patient, auditory
BOLD fMRI performed at the time of vasospasm revealed
the absence of activation of language areas and unilateral
activation of the left primary auditory area. The lack of
activation of the right auditory cortex was probably due
to the diffuse vasospasm-related parenchymal ischemic

Fig. 1. Dedicated brain FDG PET acquisition (C), after coregistration and fusion (B) with FLAIR FS-4 mm MRI sequence (A),
illustrating the consequences of SAH-related vasospasm on the metabolism of the right hemisphere structures, particularly the
thalamus, the occipital and temporal (mesial and lateral) lobes and orbitofrontal cortex (arrows). The metabolic activity of the left
hemisphere was preserved.

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damage, prominently in the right hemisphere as shown
on conventional MRI. In turn, a delayed fMRI control
examination revealed dramatic improvement in the extent of left-sided areas of activation and the appearance
of mirror contralateral ones. FDG PET imaging has been
widely used to study brain metabolism in a wide range of
CNS disorders.7 In concordance with the results of fMRI,
a significant reduction of right thalamic temporal, occipital, and parietal cortex metabolism was noted at the acute
phase of the disease process.
The auditory system has a unique neuroanatomy not
present in other sensory modalities, such as vision. Similar
to the eyes, each ear projects information to the 2 cerebral
hemispheres. However, unlike the visual system, which has
a direct mapping from one-half of the visual field to the
contralateral visual cortex, the auditory system transmits
information about sound in all parts of space to both hemispheres.9 The occurrence of cortical deafness in this case
seemed paradoxical, as temporal damage was not demonstrated bilaterally. This could occur because of the disappearance of right-left thalamic connections inducing a
functional deafferentation of the intact left thalamocortical
tract. Another hypothesis could be that diffuse vasospasm
caused bilateral hypoperfusion of the temporal cortex at a
sufficient degree to produce neuronal dysfunction but insufficient to produce MR signs of cytotoxic edema, which
is a well-known phenomenon. Upon subsidence of diffuse
vasospasm, right ischemic lesions were responsible for the
residual clinical feature of amusia, which is known to occur after damage to the associative auditory areas of the
nondominant hemisphere.10 Hyperacusis is known to occur
after damage to the auditory circuit, resulting in a disinhibition of the remaining functional pathways.
Finally, bilateral pontine lesions as seen on MR images could result in functional impairment of auditory
input pathways to both temporal cortices. These lesions
could have been partially reversible, as the patient showed
clinical improvement and as neurophysiological recordings demonstrated reappearance of late latency auditory
evoked potentials. It is noteworthy that no P300 component was ever recorded in this patient during follow-up,
suggesting permanent damage to the associative areas
generating this event-related potential component. The
patient had a favorable outcome as she improved to having partial auditory agnosia due to the right hemispheric
lesions, which was a feature consistent both with PET and
fMRI findings.

Conclusions

This case illustrates the highly complex functional
neuroanatomy of the auditory pathways. To our knowledge, this is the first case of central auditory dysfunction
documented by such a comprehensive workup including
morphological, functional, and metabolic techniques.
The patient improved from having apparently pure cortical deafness to partial auditory agnosia due to unilateral
ischemic lesions in the setting of post-SAH vasospasm.
Functional improvement seen on BOLD fMRI correlated
with clinical improvement.
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Disclosure
The authors report no conflict of interest concerning the materials or methods used in this study or the findings specified in this
paper.
Author contributions to the study and manuscript preparation
include the following. Conception and design: Ponzetto. Acquisition
of data: Grandin, Duprez, van Pesch, Deggouj, Lhommel. Analysis
and interpretation of data: Hantson, Ponzetto. Drafting the article:
Hantson, Ponzetto, Vinetti. Critically revising the article: Hantson,
Vinetti, Grandin, Duprez, van Pesch, Deggouj. Approved the final
version of the manuscript on behalf of all authors: Hantson. Study
supervision: Hantson.

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Manuscript submitted April 4, 2013.
Accepted July 29, 2013.
Please include this information when citing this paper: published online August 23, 2013; DOI: 10.3171/2013.7.JNS13674.
Address correspondence to: Philippe Hantson, M.D., Ph.D.,
De­part­ment of Intensive Care, Cliniques St-Luc, Avenue Hippocrate,
10, 1200 Brussels, Belgium. email: philippe.hantson@uclouvain.be.

J Neurosurg / Volume 119 / November 2013