PEER-REVIEW REPORTS

Selective Propofol Injection into the M1 Segment of the Middle Cerebral Artery (MCA
Wada Test) Reduces Adverse Effects and Enhances the Reliability of the Wada Test
for Determining Speech Dominance
Masazumi Fujii, Shigeru Miyachi, Noriaki Matsubara, Takeshi Kinkori, Shigenori Takebayashi, Takashi Izumi,
Tomotaka Ohshima, Arihito Tsurumi, Osamu Hososhima, Toshihiko Wakabayashi, Jun Yoshida

Key words
䡲 Internal carotid artery䡲 MCA Wada test䡲 Middle cerebral artery䡲 Propofol䡲 Speech dominance䡲 Wada test
Abbreviations and Acronyms
ACA: Anterior cerebral artery
fMRI: Functional magnetic resonance imaging
ICA: Internal carotid artery
MCA: Middle cerebral artery
MEG: Magnetoencephalography
MRI: Magnetic resonance imaging
PCA: Posterior cerebral artery
PcomA: Posterior communicating artery
From the Department of Neurosurgery, Nagoya
University Graduate School of Medicine,
Nagoya, Japan
To whom correspondence should be addressed:
Shigeru Miyachi, M.D. [E-mail: smiyachi@med.nagoya-u.ac.jp]
Citation: World Neurosurg. (2011) 75, 3/4:503-508.
DOI: 10.1016/j.wneu.2010.10.048
Journal homepage: www.WORLDNEUROSURGERY.org
Available online: www.sciencedirect.com
1878-8750/$ - see front matter Published by Elsevier Inc.

䡲 OBJECT: The Wada test is had been the most reliable for determining speech
dominance. Drugs injected into the internal carotid artery, however, may beheterogeneously distributed as the result of asymmetry of the anterior cerebral
arteries and the presence of a fetal-type posterior cerebral artery. Variations in
drug distribution could occasionally alter consciousness and complicate theevaluation of the test results. We examined selective propofol injection into theM1 segment of the middle cerebral artery (MCA Wada test).
䡲 METHODS: For the MCA Wada test (17 patients), 7 or 8 mg of propofol was
injected via a microcatheter navigated into the M1 segment, and language
function was evaluated by patient performing several tasks. The conventional
Wada test (internal carotid artery [ICA] Wada test) was performed in four patients(both the ICA and MCA Wada tests were performed in one patient). The efficacy
and adverse effects of both procedures were evaluated; all tests were performed
by well-trained interventional neuroradiologists.
䡲 RESULTS: Immediately after propofol injection during the MCA Wada test, patientsdeveloped transient contralateral hemiplegia and transient aphasia (in the case of
injection on the dominant side). Confusion and other severe adverse effects did notoccur during the MCA Wada test, but two of four patients who underwent the ICA
Wada test showed altered consciousness that affected the performance of the test.
䡲 CONCLUSIONS: The MCA Wada test is a feasible and reliable preoperativeevaluation, if performed by a trained team of interventional neuroradiologists.

INTRODUCTION
Although several noninvasive modalities areavailable for the evaluation of speech function,suchasfunctionalmagneticresonanceimaging(fMRI), magnetoencephalography, and nearinfrared spectroscopic topography, the Wada
test is used for determining speech dominancebefore surgery for brain tumors because it is themost reliable method (1, 3, 8, 10). Before thesurgicalresectionoftumorsorotherlesionsthat
are located near the speech center, it is crucial toidentify the dominant hemisphere deﬁnitely
and choose an appropriate surgical strategy,
such as awake craniotomy or usual craniotomy
under general anesthesia. Information of language examinations when a certain area of thecortex is suppressed is more reliable than thosewhenactivated.Oftheaforementionedpreoperative examinations, only the Wada test involves
temporary suppression of brain function andtheinjectionofanestheticsintothecarotidarteryfor the evaluation of speech dominance (1, 3).
Propofol is frequently used to perform the
Wada test because, nowadays, amobarbital is
not available in many countries (5, 7). However, the injection of propofol into the internal
carotid artery (ICA) has been reported to induce disturbance of consciousness, which
obscures the results of the Wada test. Takayama et al. (7) and Mikuni et al. (5) reported
that adverse effects occurred during the performance of the Wada test in approximately
one-third of patients. Drug distribution after
injection into the ICA probably varies frompatient to patient, depending on the topography of the cerebral arteries, which in turnmainly depends on the structure of the circleof Willis. The drug may be delivered to thebrainstem via the branches of a fetal-type pos-WORLD NEUROSURGERY 75 [3/4]: 503-508, MARCH/APRIL 2011terior cerebral artery (PCA) or to both medial
frontal lobes via the anterior communicatingartery. To minimize such variations in drug
distributions, reduce the frequency and severity of adverse effects, and improve the reliability of the test, we propose that super-selective
injection of propofol into the M1 portion of
middle cerebral artery (MCA) be used to determine speech dominance in patients withbrain tumors.

METHODS
Subjects
During the course of 3 years (from March
2006), 20 brain tumor patients underwent
Wada tests for the preoperative evaluation of
language dominance. All the patients had intrinsic tumors within or around one of the

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Patient
NumberLeft Side

Type of
Wada
Test

Injection
Amount of
Propofol

Left insularcortex andbasal ganglea

ICA

4

Mild

Eye diversion toright, left-sided
hemianopsia,
spatial agnosia

Fetal type
PCA

Uni. ACA

5

Anaplastic
oligoastrocytoma

Left temporal
lobe

ICA

10

None

None

Fetal type
PCA

N/A

R

Cavernous
hemangioma

Left frontal
lobe

ICA

10

Coma for 5 min

None

No PcomA

R

Anaplastic
oligodendroglioma

Left temporal
lobe

ICA

10

Coma

N/A

MCA

8

None

Age,
Years

Handedness

Pathological
Diagnosis

1

62

R

Astrocytoma

2

31

R

3

26

4

57

Tumor
Location

Disturbance ofConsciousness

Other
AdverseEffectTopography:
PCA and
PcomA

Injection
Amount of
Propofol

Other
AdverseEffectTopography:
PCA and
PcomA

Topography:
ACA

Mild

Involuntary
movement ofright upper
limb and left
face

No PcomA

Uni. ACA

L

10

None

Continuationof oralcounting

N/A

N/A

R

Uni. ACA

10

Coma for 5 min

None

No PcomA

Bil. ACA,
transientL

Fetal type
PCA

Uni. ACA

N/A

N/A

N/A

Fetal type
PCA

Uni. ACA

L

Involuntary
movement ofleft hand,continuation oforal counting

No PcomA

Bil. ACA,
transient

5

None

None

Transientvisualization

Bil. ACA,
transient

L

Topography:
ACA

Disturbance ofConsciousness

Dominant
HemisphereR

Anaplastic
oligoastrocytoma

Left frontal
lobe

MCA

8

ApathyNone

No PcomA

Uni. ACA

8

None

None

No PcomA

Uni. ACA

R

6

73

R

Astrocytoma(gemistcytic)

Left frontal
lobe

MCA

7

None

None

No PcomA

Bil. ACA,
dominant

7

None

Involuntary
movement ofright upper
limb (flexion)

No PcomA

Absent ACA

L

7

40

R

Oligodendroglioma

Left frontal
lobe

MCA

7

None

None

No PcomA

Bil. ACA,
transient

7

None

None

No PcomA

Uni. ACA

L

8

40

R

Astrocytoma

Left frontal
lobe

MCA

7

None

None

Fetal type
PCA

Uni. ACA

7

None

Involuntary
No PcomA
movement ofleft hand(perseveration)

Bil. ACA,
transient

L

9

56

R

Anaplastic
oligodendroglioma

Left frontal
lobe

MCA

8

None

None

Fetal type
PCA

Uni. ACA

8

None

None

Transientvisualization

Bil. ACA,
transient

L

10

36

R

Glioblastoma

Left frontal
lobe

MCA

8

Mild

Involuntary
movement ofleft upper limb

Fetal type
PCA

Bil. ACA,
transient

8None

Involuntary
movement ofright upper
limb (flexion)

Transientvisualization

Bil. ACA,
transient

L

11

50

L

Oligodendroglioma

Right temporal
lobe

MCA

10

None

None

Transientvisualization

Bil. ACA,
transient

8

None

None

Transientvisualization

Bil. ACA,
transient

R

12

35

R

Anaplastic
astrocytoma

Left frontal
lobe

MCA

8

None

None

Fetal type
PCA

Uni. ACA

8

None

None

Fetal type
PCA

Bil. ACA,
transient

L

13

75

R

Glioblastoma

Left frontal
lobe

MCA

7

None

None

Fetal type
PCA

Absent ACA

7

None

None

Fetal type
PCA

Bil. ACA,
dominant

L

14

37

R

Glioblastoma

Left temporal
lobe

MCA

9

Mild

Involuntary
movement ofleft hand,continuation oforal counting

Transientvisualization

Bil. ACA,
transient

7

None

Involuntary
movement ofleft lower
limb (flexion)

Fetal type
PCA

Bil. ACA,
transient

L

Continues

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MASAZUMI FUJII ET AL.

504

Table 1. Clinical Characteristics of 20 Patients Who Underwent ICA and MCA Wada Tests and Adverse Effects During the Procedure

PEER-REVIEW REPORTS

L
Bil. ACA,
dominant

WORLD NEUROSURGERY 75 [3/4]: 503-508, MARCH/APRIL 2011

In patient 4, the ICA Wada test was performed on the right hemisphere and the MCA Wada test on both hemispheres.

PCA, posterior cerebral artery; ACA, anterior cerebral artery; R, right; ICA, internal carotid artery; N/A, not available; L, left; unil., unilateral; bil., bilateral; MCA, middle cerebral artery; PcomA, posterior communicating artery.

Transientvisualization
None
8
36
20

R

Anaplastic
astrocytoma

Left frontal
lobe

MCA

None

Involuntary
movement ofleft hand,flexion of arm

Transientvisualization

Uni. ACA

8

None

R
Bil. ACA,
transientTransientvisualization
Mild
8
56
19

L

Anaplastic
oligodendroglioma

Left frontal
lobe

MCA

Mild

Involuntary
movement ofleft arm (flexion)

No PcomA

Bil. ACA,
transient

8

None

L
Bil. ACA,
transientTransientvisualization
None
7
MCA
45
18

L

Low-grade glioma

Right frontal
lobe

None

None

No PcomA

Bil. ACA,
transient

7

None

L
Uni. ACA
No PcomA
None
61
17

R

Glioblastoma

8
MCA
Left temporal
lobe

Mild

Continuation oforal counting

No PcomA

Bil. ACA,
transient

7

Involuntary
movement ofleft lower
limb (flexion)

L
Uni. ACA
Transientvisualization
Mild
55
16

L

Anaplastic
oligodendroglioma

8
MCA
Right temporal
lobe andinsular cortex

None

None

Fetal type
PCA

Bil. ACA,
transient

8

None

L
Bil. ACA,
transient
No PcomA
None
None
7
Bil. ACA,
transient
Fetal type
PCA
None
7
MCA
42
15

R

Astrocytoma
Grade2

Left frontal
lobe

None

Other
AdverseEffectOther
AdverseEffectInjection
Amount of
Propofol
Tumor
Location
Pathological
Diagnosis
Handedness
Age,
Years
Patient
NumberTable 1. Continued

MCA WADA TEST FOR SPEECH DOMINANCE TESTING

Type of
Wada
Test

Disturbance ofConsciousness

Right Side

Topography:
PCA and
PcomA

Topography:
ACA

Injection
Amount of
PropofolDisturbance ofConsciousness

Left Side

Topography:
PCA and
PcomA

Topography:
ACA

Dominant
Hemisphere

MASAZUMI FUJII ET AL.

speech centers on anatomical images and still
maintained good speech function. Informed
consent was obtained before the test from all
patients according to the clinical research
protocol approved by the institutional review
board of Nagoya University Hospital. The
Wada test with propofol injection into the ICA(ICA Wada test) was performed in four patients (seven procedures), and the Wada testwith super-selective injection of propofol into
the MCA (MCA Wada test) was performed in
17 patients (34 procedures). The effectivenessof the test (determination of speech dominancy), adverse effects during the procedure,
and complications after the procedure were
evaluated. One patient underwent both ICA
and MCA Wada tests because the injection of
propofol into the right ICA induced disturbance of consciousness and no languagetasks could be performed.

Angiographic Findings of the Circle ofWillisCerebral angiography was performed in all
patients at the same time, and 6 mL of contrast medium (Iopamiron 300; Bayer Schering Pharma, Osaka, Japan) was injected into
the ICA at the rate of 4 mL/s. The posterior
communicating artery (PcomA) and PCA
were visualized and grouped on the cerebral
angiogram as follows: both PcomA and PCA
not visualized, group P1; PcomA and PCA
transiently visualized, group P2; and fetaltype PCA, group P3. Findings of anterior
cerebral artery (ACA) were also grouped
as follows: ACA not visualized, group A1,
ACA visualized unilaterally: group A2, both
ACAs visualized transiently: group A3, andboth ACAs clearly visualized; group A4.

ICA Wada Test Procedure
The Wada test was performed on both hemispheres for each patient, ﬁrst on the suspected nondominant side and then on thesuspected dominant side. The ICA Wada test
was performed as described by Takayama etal. (7). In brief, a 4-Fr. catheter (Selecon PA;
Cinical Supply Co. Ltd., Gifu, Japan) was inserted into the ICA via the transfemoral route.
To test for retrograde amnesia, patients were
instructed to memorize a word and a card.
They started counting aloud from the number
one while opening and closing the hand on
the side contralateral to the injected artery.
When they had counted to seven, 10 mg of

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propofol in 10 mL of saline solution was manually injected at the rate of 1 mL/s. If 10 mg of
propofol did not produce paresis of the contralateral extremities, up to 3 mg of propofol
was administered as a bolus. The patients performed language tasks, including picturenaming, reading, repetition, comprehensionof spoken commands, calculation, and orientation. Language function was evaluated at 3
minutes after the initiation of propofol injection. Memory–retention tests were initiatedafter language function returned to normal,
usually 5–10 min after the injection of propofol. After the completion of all tasks, anotherangiogram was obtained to assess catheter
position and adverse vascular events such as
occlusion and spasm of the cerebral arteries.
MCA Wada Test Procedure
In the MCA Wada test, a 4- or 5-Fr. guiding
catheter was introduced into the ICA via thefemoral approach, and then a 0.021-inch internal diameter microcatheter (eg, Rapid
Transit; Cordis Neurovascular Inc., Miami
Lakes, FL) was navigated into the M1 segmentof the MCA with a microwire guiding. Afterthe injection of the contrast medium throughthe microcatheter, both the frontal andtemporal branches of the MCA were clearlyvisualized on the angiogram with minimal inﬂuence of laminar blood ﬂow. The microcatheter was carefully placed so that it was notwedged into a perforator. These microcatheterization was performed by well-trained interventional neuroradiologists. Women wereadministered 7 mg of propofol and men 8 mgof propofol. Additional propofol (up to 3 mg)
was administered when contralateral hemiplegia was not observed at these doses. The
rest of the procedure of the MCA Wada test
was identical to that of the ICA Wada test.
Assessment of catheter position and adverse
vascular events were also performed before
the withdrawal of the microcatheter.

RESULTS
Table 1 displayed the summary of clinicalcharacteristics of 20 patients who underwent
ICA and MCA Wada tests and adverse effects
during the procedure. Both ICA and MCA
Wada tests were performed in one patient.
ICA Wada Test
All four patients demonstrated contralateral
hemiplegia after the injection of up to 10 mg

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MCA WADA TEST FOR SPEECH DOMINANCE TESTING

of propofol (total dose). Three patients
showed moderately or severely altered consciousness; those symptoms were all transient and there was no remaining adverse effect. The right hemisphere could not be
evaluated at all in one patient (who is presented in the section “Illustrative Case”). Another patient fell into a coma, and several minutes elapsed between the injection of propofol
and the initiation of the tasks, shortening thetime window for the tasks and complicating
the interpretation of the results obtained. One
patient demonstrated mild tendency to sleep,
as well as head and eye version, which occurred together. This patient had to be kept
awake by some stimulation during the task;
nevertheless, the test results were sufﬁciently
clear to identify the dominant hemisphere.

MCA Wada Test
All 17 patients developed contralateral hemiplegia immediately after the injection of
propofol into the M1 segment. Additional
propofol was administered during 2 of the
34 procedures (2 mg of propofol in each) to
produce complete hemiplegia. All patients
also showed aphasia or dysphasia affecting at least one side. Apathy or mild alteration of consciousness was observed in six
patients (seven procedures). These symptoms, however, were very mild and did nothinder the determination of speech dominance. No patients experienced severe adverse effects such as increased muscle tone
with twitching and rhythmic movements or
tonic posture. Mild and transient involuntary movements of the contralateral extremities, however, were frequently observed.
Further, seven patients (nine procedures)showed ﬂexion of the contralateral extremities, preservation of the opening and closing movements of the hands, etc., for a few
minutes after injection of propofol. Hemiparesis fully recovered within 4 minutes andspeech function within 10 minutes. No permanent complications were observed after
the Wada test in this series.

11 (27.5%), and fetal-type PCA (group P3) in
14 (35%). Both ACAs were transiently visualized (group A3) and continuously visualized(group A4) in 21 (52.5%) and 3 (7.5%) hemispheres, respectively.

ILLUSTRATIVE CASE
A 57-year-old right-handed man presented
with generalized convulsive seizures. An MRI
study revealed a left temporal tumor extending into the left parietal lobe with intratumoral hemorrhage (Figure 1A, 1B). Clinicalsigns and symptoms and an fMRI study indicated that the dominant hemisphere for language function was the left hemisphere. To
conﬁrm this, the Wada test was performed
preoperatively. First, the ICA Wada test was
performed on the right hemisphere as described previously. Immediately after injection of 10 mg of propofol, the patient became
unconscious and did not respond to any verbal questions and orders, and therefore, noneof the tasks could be undertaken. Cerebral angiography revealed that both PCAs were of the
fetal type: group P3 (Figure 1C). Both ACAs
were independent: group A2 (Figure 1D).
Therefore, super-selective injection of propofol into the right MCA was performed to avoid
distribution of the anesthetic to the ACAs andthe right PCA, which usually supplies thebrainstem. Injection of anesthetic into thesearteries may be partially responsible for thesubsequent alteration of consciousness. The
injection of 8 mg of propofol into the M1 segment of the right MCA did not induce disturbance of consciousness. The patient was able
to correctly reply to questions and obey verbal
commands. The same dose of propofol was
injected into the M1 segment of the left MCA,
and clear symptoms of aphasia without alteration of consciousness were observed. Theseﬁndings strongly suggested the left hemisphere was the dominant hemisphere for language function.

DISCUSSION
Angiographical Findings of the Circle ofWillis
The summary of angiographic ﬁndings ofthe circle of Willis with injection of the contrast medium into the ICA also is displayedin Table 1. Of 40 hemispheres, transient visualization of the PCA (group P2) was noted in

The accuracy and quality of the surgicalresection of brain tumors, especially gliomas, has remarkably improved since the introduction of image-guided surgery andawake craniotomy. With the use of sophisticated image-guided surgery, total resection or near total resection of gliomas is
being increasingly reported along with im-WORLD NEUROSURGERY, DOI:10.1016/j.wneu.2010.10.048

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Figure 1. MRI and angiogram of the illustrative case (patient 4 in Table 1). A and B,
Enhanced T1-weighted image (axial and sagittal views) showing an irregularly
enhancing tumor (arrows) in the left superior temporal gyrus, where the sensory
language area is supposedly located. C and D, Angiogram of the right ICA(anteroposterior and lateral view) showing a well-developed posterior
communicating artery and posterior cerebral artery (fetal-type PCA). E, Selective
angiogram of the right middle cerebral artery with contrast medium injected into
the M1 segment. Note that two M2 branches are visualized well.

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MCA WADA TEST FOR SPEECH DOMINANCE TESTING

provement in patient survival (2). However,
the more extensive the resection, the greater isthe risk of postoperative neurological deﬁcit,
especially in the case of tumors located neareloquent areas such as the speech centers.
Awake craniotomy is one of the acceptedstrategies for resecting tumors located near
the speech centers while avoiding postoperative aphasia (6). During awake craniotomy, language mapping is performed by
the use of direct electrical stimulation of thecortex to localize important speech areas.
The success of awake craniotomy depends on
the preoperative determination of speech
dominance and the acquisition of information about language function when the area inand around the lesion is suppressed. The resection of an activated cortical area identiﬁed
on fMRI and magnetoencephalography withlanguage tasks does not necessarily translate
into postoperative neurological deﬁcit. Conversely, the resection of inactive cortical areas
does not guarantee freedom from neurological complications. The Wada test evaluates
language function when the cortex is suppressed, and therefore, this test is still themost reliable and important examination forthe preoperative evaluation of speech dominance in patients with lesions that are locatedaround the speech centers (1, 3).
Because amobarbital is not available inmany countries, propofol frequently is usedduring the Wada test. However, the Wada
test with propofol injection is associatedwith relatively frequent adverse effects, including altered consciousness (5, 7). These
adverse effects have an apparently negative
inﬂuence on the reliability of the Wada test.
In our small series of patients who underwent ICA Wada tests, disturbance of consciousness was observed in three of four
patients, and the disturbance was severe in
two patients. Mikuni et al. (5) reported theadverse effects of propofol injection into
the ICA during the Wada test. They foundmoderate and severe side effects in 13 of 58(25%) patients (5). The side effects included altered consciousness or confusion(six patients) and increased muscle tone
with twitching and rhythmic movements or
tonic posture (seven patients). The frequency and severity of intraprocedural disturbance of consciousness were apparently
lower during the MCA Wada tests than during the ICA Wada tests in our study and in
the Wada tests in the abovementioned
study. In our study, no severe adverse effects

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occurred during the 34 procedures, including 17 MCA Wada tests. In six (37%) patients, apathy or mild disturbance of consciousness occurred. These side effects
corresponded to the grade 1 symptoms reported by Mikuni et al. (5) and were notsevere enough to hinder the performance ofthe tasks. The MCA Wada test was not associated symptoms caused by peripheral vessel anastomosis, such as lacrimation, eyepain, and face contortion.
Drug distribution after injection into the
ICA varies from patient to patient, depending on the topography of the cerebral arteries, which mainly depends on the structureof the circle of Willis. The drug may be delivered to the brainstem via the branches ofa fetal-type PCA or to the medial frontal
lobes via the ACA. In our study, transientvisualization of the PCA or fetal-type PCA
was noted in 25 hemispheres (group P2 andP3: 62.5%). In theses patients with visualization of PCAs, it is possible that anesthetics injected into the ICA will be delivered tothe brainstem. Bilateral visualization of the
ACA was noted in 24 hemispheres (group
A3 and A4: 60%) and may inﬂuence consciousness and mood. Distribution of theanesthetics into the contralateral frontal
lobe must be avoided while determining thedominant language hemisphere. The MCA
Wada test is highly advantageous because
it minimizes the variations in drug distributions, is associated with few intraprocedural adverse effects, and is accurate for determining speech dominance. Hajek et al.
(4) performed selective amobarbital tests
for the determination of language function
in ﬁve epileptic patients. They found that
selective injection of the anesthetic into the
cerebral arteries was efﬁcacious for determining language function of the corresponding brain area. Urbach et al. (9) also
reported the role of the MCA Wada test withamobarbital injection for the preoperativeevaluation of epilepsy patients. They concluded that the MCA Wada test can be used
to preoperatively assess the risk of motor
deﬁcit after functional hemispherectomy.
However, they also reported that the spatial
resolution of the MCA Wada test was inadequate even when the microcatheter was inserted into the peripheral branches of the
MCA. Therefore, they recommended that
subdural grid electrodes be used to evaluate
the distribution of the cortical language
area.

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MCA WADA TEST FOR SPEECH DOMINANCE TESTING

Regarding the technical aspects of superselective MCA injection, maneuvering of
the microcatheter is mandatory. The catheter tip must be located in the proximal M1
segment, and all M2 branches should be
visualized on the angiogram. We used 7 mgof propofol in female patients and 8 mg inmale patients. Additional injection of anesthetics for the complete paralysis of thecontralateral extremities was required in 2
of 34 procedures (additional dose, 2 mg
each; one male and one female patient). The
MCA Wada test requires lower doses of
propofol than the ICA Wada test, in which
10 –15 mg is used for brain tumor patients.
Thus, the effect of the drug on whole brain
is lower in the former test than in the latter.
All patients demonstrated aphasia on injection of the anesthetic into at least one MCA.
Paralysis of the extremities and aphasia
were both transient, and the patients usually recovered within 4 and 10 minutes, respectively. Some patients started recoveringfrom aphasia at 5 minutes. Therefore, we
recommend that patients should be given
language tasks within 5 minutes after the
injection of the anesthetic.
The advantages of the MCA Wada test are as
follows: decreased severity of side effects thatinﬂuence the test results, more consistent determination of speech dominance, and requirement of low doses of anesthetics. Its disadvantage is that medial temporal lobe structures
cannot be evaluated. Thus, this test cannot be
used to evaluate memory dominance since thememorycentersareusuallyintheterritoryofthe
PcomAand/orthePCA.Acertainamountofskill
is required to perform the MCA Wada test because it involves microcatheterization, and if the
microcatheter manipulation is performed bysurgeons who are not familiar with it, catheterization-related complications may occur. In ourstudy, all procedures were performed by a teamtrained in intravascular treatment, and we havenever encountered such complications. With
dramatic technical and instrumental improvements, interventional neuroradiology has become the main therapy for many cerebral diseases. The MCA Wada test is a feasible andreliable preoperative evaluation, if performed bya trained team of interventional neuroradiologists.

of “The Neuroendovascular Team” of Nagoya
University Graduate School of Medicine, fortheir generous assistance in this study.

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Conflict of interest statement: The authors declare that thearticle content was composed in the absence of any
commercial or financial relationships that could beconstrued as a potential conflict of interest.
received 22 February 2010; accepted 21 October 2010
Citation: World Neurosurg. (2011) 75, 3/4:503-508.
DOI: 10.1016/j.wneu.2010.10.048

ACKNOWLEDGMENTS

Journal homepage: www.WORLDNEUROSURGERY.org

The authors thank Takehiro Naito, Kenichi
Haraguchi, and Tsuyoshi Ichikawa, members

Available online: www.sciencedirect.com
1878-8750/$ - see front matter Published by Elsevier Inc.

WORLD NEUROSURGERY, DOI:10.1016/j.wneu.2010.10.048