ARTICLE IN PRESS

Case Report

Anterior Choroidal Artery Infarction Evaluated with
I-Imp Single-Photon Emission Computed Tomography and
7 Tesla Magnetic Resonance Imaging

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Te-Hsiung Wang, MD,* Naoto Jingami, MD,* Tomohisa Okada, MD,†
Tomoyuki Yunoki, MD,* Shigeru Ohtsuru, MD,* and Kaoru Koike, MD*
Anterior choroidal artery (AchA) infarction remains a challenging diagnosis
although it was first described almost 100 years prior. N-isopropyl-p-[123I]iodoamphetamine single-photon emission computed tomography (123I-IMP SPECT)
and 7 Tesla magnetic resonance angiography (7T-MRA) are not routinely performed in cases of AchA infarction. Therefore, the application of 123I-IMP SPECT
and 7T-MRA for AchA infarction has not been reported previously. A 67-year-old
man presented with disturbed consciousness, gaze preference to the left, aphasia,
right homonymous hemianopia, and right hemiparesis. Brain magnetic resonance
imaging revealed infarction of the left posterior limb of the internal capsule. Left
middle cerebral artery was clearly seen on MRA. However, 123I-IMP SPECT on day
13 showed cortical hypoperfusion which indicated thalamus involvement with neural deactivation. Additionally, 7T-MRA on day 15 revealed an intact left AchA suggesting reperfusion. The neurological deficits improved gradually after treatment
and rehabilitation. This case demonstrates AchA infarction with cortical hypoperfusion associated with thalamus involvement, which was clarified by performing
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I-IMP SPECT and 7T-MRA. Perfusion analysis and evaluation of detailed vascular anatomy in stroke can be expected to elucidate pathological conditions.
Key Words: Anterior choroidal artery infarction—Monakow's syndrome—
thalamus—SPECT—7T-MRA
© 2019 Elsevier Inc. All rights reserved.

Introduction
Anterior choroidal artery (AchA) infarction, known as
Monakow's syndrome, presents with a classical triad—
hemiplegia, hemianesthesia, and homonymous hemianopsia.1 Differentiation from lacunar infarction of the
From the *Department of Primary Care and Emergency Medicine,
Kyoto University Graduate School of Medicine, Kyoto, Japan; and
†Human Brain Research Center, Kyoto University Graduate School
of Medicine, Kyoto, Japan.
Received December 13, 2018; revision received February 5, 2019;
accepted February 11, 2019.
Address correspondence to Naoto Jingami, MD, Department of Primary Care and Emergency Medicine, Kyoto University Graduate
School of Medicine, 54 Shogoin-Kawaharacho, Sakyoku, Kyoto 6068507, Japan. E-mail: njingami@kuhp.kyoto-u.ac.jp.
1052-3057/$ - see front matter
© 2019 Elsevier Inc. All rights reserved.
https://doi.org/10.1016/j.jstrokecerebrovasdis.2019.02.007

lenticulostriate arteries is difficult in small lesions. We
describe a case of left AchA infarction evaluated with
N-isopropyl-p-[123I]-iodoamphetamine single-photon emission computed tomography (123I-IMP SPECT) and
7 Tesla magnetic resonance angiography (7T-MRA).

Case Report
A 67-year-old man with a history of hypertension and
lacuna infarctions presented to the emergency department
with lethargy, disturbed consciousness, and right hemiparesis. High blood pressure (222/139 mmHg) with normal sinus
rhythm was noticed. Right homonymous hemianopia was
confirmed by visual threat assessment. Nonfluent aphasia
and gaze preference toward the left side were noted. Diffusion-weighted magnetic resonance imaging (MRI) revealed
high signal intensity limited to the left posterior limb of internal capsule suggesting acute infarction (Fig 1A). AchA

Journal of Stroke and Cerebrovascular Diseases, Vol. &&, No. && (&&), 2019: && &&

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T.-H. WANG ET AL.

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infarction was suspected due to the clinical symptoms and
posterior limb of internal capsule lesion. Aspirin, clopidogrel,
argatroban, and edaravone were administered. 123I-IMP
SPECT revealed hypoperfusion in the left frontal and parietal
lobes (Fig 1D). 7T-MRA showed an intact left AchA (Fig 1F).

Discussion
The neurological manifestations, including right hemiparesis and right homonymous hemianopia, indicated left
AchA infarction involving the pyramidal tract and lateral
geniculate body. The lesion responsible for other symptoms such as disturbed consciousness, aphasia, and gaze
preference was in the thalamus, according to the blood
supply distribution and its corresponding functions.2
The frontal and parietal hypoperfusion in 123I-IMP
SPECT3 indicated thalamus involvement with neural
deactivation4 of known connections between the frontal
and parietal lobes and the thalamus.5 Such cortical hypoperfusion revealed via 123I-IMP SPECT in AchA infarction
can be a specific finding for AchA infarction.
7T-MRA has higher resolution which helps visualize the
arterial inflow signal, and is therefore expected to be useful
in the field of stroke.6,7 The mechanism of AchA infarction is
known to be associated with small vessel disease or embolism,8 and visualization of small vessels is important.9 The
enhanced left AchA on 7T-MRA indicated possible reperfusion. Therefore, we presumed that the embolized AchA was
recanalized. This case demonstrated an unexpected pathological condition resulting from focal ischemia, which was
revealed by 123I-IMP SPECT perfusion and 7T-MRA, thus
indicating the usefulness of these methods for visualizing
thinner vessels and identifying the mechanism of stroke.

References

Figure 1. Brain magnetic resonance imaging (MRI) showing left acute anterior choroidal artery (AchA) infarction and N-isopropyl-p-[123I]-iodoamphetamine single-photon emission computed tomography (123I-IMP SPECT)
analyzed with three-dimensional stereotactic surface projection (3D-SSP)
showing hypoperfusion in the left frontal and parietal lobes. Diffusionweighted image on the day of admission revealed high intensity in the left posterior limb of the internal capsule (arrow) (A). 3 Tesla MRA on the day of
admission showed intact large arteries, but it was difficult to evaluate the
AchA (B). Flair attenuated inversion recovery image on the day of admission
indicated old multiple microinfarcts (C). There was no apparent hypoperfusion
in the thalamus. However, the hypoperfusion of the left frontal and parietal
lobes on 123I-IMP SPECT on the 13th day after admission indicated left thalamus involvement due to left acute AchA infarction (arrowheads) (D). Hypoperfusion in the left frontal and parietal lobes was revealed in 3D-SSP as well
(arrowheads). Hypoperfusion in the contralateral cerebellum (asterisked arrowheads) can be explained through crossed cerebellar diaschisis, also known as
Monakow's effect (E). High resolution 7 Tesla MRA with isotropic 0.25 mm
resolution on the 15th day after admission demonstrated enhanced left AchA
(arrowheads) (F).(Color version of figure is available online.)

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