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Radiol Case Rep
Radiol Case Rep
Radiology Case Reports
1930-0433
Elsevier

S1930-0433(24)00858-6
10.1016/j.radcr.2024.08.075
Case Report
Isolated choroid plexus infarction caused by multiple occlusive cerebrovascular lesions
Kajita Michihide MD ab
Yanaka Kiyoyuki MD, PhD a
Takeda Hayato MD ab
Saura Minami MD a
Takahashi Toshihide MD, PhD a
Aiyama Hitoshi MD, PhD a
Saiki Shinji MD, PhD b
Ishikawa Eiichi MD, PhD e-ishikawa@md.tsukuba.ac.jp
c⁎
a Department of Neurosurgery, Tsukuba Memorial Hospital, 1187-299 Kaname, Tsukuba, Ibaraki 300-2622, Japan
b Department of Neurology, Institute of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
c Department of Neurosurgery, Institute of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
⁎ Corresponding author. e-ishikawa@md.tsukuba.ac.jp
07 9 2024
12 2024
07 9 2024
19 12 56335638
13 7 2024
13 8 2024
14 8 2024
© 2024 The Authors. Published by Elsevier Inc. on behalf of University of Washington.
2024

https://creativecommons.org/licenses/by-nc-nd/4.0/ This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
The choroid plexus is the secretory tissue responsible for cerebrospinal fluid production in the brain. Ischemia of the choroid plexus is rare because of its abundant blood supply from multiple arterial systems, including the anterior and posterior choroidal arterial anastomoses. It is not clear under what circumstances isolated choroid plexus infarction occurs. A 56-year-old woman presented to our hospital after experiencing several episodes of paroxysmal dizziness and weakness in her right upper extremity that lasted several hours. She had a 10-year history of hypertension, diabetes mellitus, and hyperlipidemia, which were very poorly controlled. Magnetic resonance imaging confirmed isolated right choroid plexus infarction. Magnetic resonance angiography showed severe stenosis of the cavernous portion of the right internal carotid artery, occlusion of the distal portion of the right posterior cerebral artery, and occlusion of the contralateral left internal carotid artery. Thus, we hypothesized that isolated choroid plexus infarction was caused by ischemia due to both atherosclerotic changes in large vessels spanning multiple vasculatures and microangiopathy around the choroid plexus due to diabetes, hypertension, and hyperlipidemia. In choroid plexus infarction, both occlusive changes in multiple large vessels and microangiopathy may be involved, and the underlying cause of these changes should be thoroughly investigated. Although choroid plexus infarction may not be significant neurologically, it may shed light on further pathogenesis in this complex structure.

Keywords

Atherosclerosis
Choroid plexus
Diabetes mellitus
Infarction
Microangiopathy
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pmcIntroduction

The choroid plexus is a secretory tissue in the brain responsible for producing cerebrospinal fluid [1]. It receives blood from the anterior choroidal artery, a branch of the internal carotid artery, as well as from the lateral and medial posterior choroidal arteries, which are branches of the posterior cerebral artery [2]. Therefore, isolated choroid plexus infarction is extremely rare due to the abundant collateral circulation, including the aforementioned anastomoses. It is generally believed that isolated infarction of the choroid plexus does not manifest with focal cerebral symptoms [2].

Isolated symptomatic choroid plexus infarction is rarely discovered; it is typically found incidentally in association with posterior cerebral artery infarctions, where clinical symptoms are related to parenchymal ischemic lesions of the thalamus, occipital lobe, or cerebellum [[3], [4], [5]].

However, the choroid plexus plays an important role in producing a significant portion of the cerebrospinal fluid (CSF), which contains various hormones and cytokines. These substances act on the thalamus, hypothalamus, pineal gland, and suprachiasmatic nucleus, all located around the third ventricle, and help maintain functions of the autonomic nervous system, such as stress response and circadian rhythm [4,5]. Furthermore, the choroid plexus releases amyloid-beta metabolic enzyme proteins, absorbs amyloid-beta, and excretes it into the blood [6]. These facts suggest that patients with choroid plexus infarction may experience disruptions in circadian rhythm and impaired clearance of waste products from the brain.

We report a case of isolated choroid plexus infarction in a middle-aged woman. This article aims to review the relevant literature and identify the clinical significance and characteristics of this lesion.

Case description

A 56-year-old woman presented to our hospital after experiencing several episodes of paroxysmal dizziness and weakness in her right upper extremity, lasting several hours. She had a 10-year history of hypertension, diabetes, hyperlipidemia, and no history of trauma or exposure to toxic substances. There was no Moyamoya disease or other significant family history, but she had a history of mental illness. Her primary care physician prescribed oral medications; however, her diabetes, in particular, was poorly controlled. Her hemoglobin A1c had deteriorated to about 9% 8 years ago, so insulin therapy was initiated. Sometimes, she voluntarily discontinued therapy, and her medication adherence was low. As a result, her diabetes, hypertension, and hyperlipidemia were very poorly controlled.

On admission, neurological examination revealed right hemiparesis with upper limb predominance and mild dysarthria. On physical examination, her body temperature was 36.8°C, respiratory rate was 16 breaths/min, peripheral oxygen saturation was 98%, and blood pressure was 164/81 mmHg. General laboratory tests showed poor glycemic (blood sugar: 155mg/dL, hemoglobin A1c: 15.5%) and cholesterol control (low-density lipoprotein cholesterol: 206 mg/dL). No inflammatory findings or coagulation abnormalities were observed (prothrombin time: 10.6 seconds, activated partial thromboplastin time: 25.1 seconds, D-dimer: 1.1 µg/dL). Head computed tomography (CT) was normal. However, diffusion-weighted magnetic resonance (MR) imaging revealed very strong signal intensity in the choroid plexus of the right lateral ventricle. This region demonstrated low signal intensity on the apparent diffusion coefficient (ADC) mapping image. It showed signal intensity equal to that of the CSF on T1- and T2-weighted images and slightly higher signal intensity on the fluid-attenuated inversion recovery (FLAIR) sequence. No similar signal changes were observed in other areas, leading to a diagnosis of isolated choroid plexus infarction (Fig. 1).Fig. 1 Magnetic resonance imaging on admission, the right choroid plexus shows signal intensity equal to that of the cerebrospinal fluid on T1- (A) and T2- (B) weighted images and slightly higher signal intensity on the fluid-attenuated inversion recovery sequence image (C). The area shows high signal intensity on the diffusion-weighted image (D) and low signal intensity on the apparent diffusion coefficient map (E).

Fig 1

MR angiography revealed severe stenosis in the cavernous portion of the right internal carotid artery. The distal portion of the right posterior cerebral artery was poorly visualized. In addition, the contralateral left internal carotid artery was occluded, and the major intracranial arteries showed significantly irregular diameters, indicating atherosclerotic changes (Fig. 2). The patient's chief complaint was transient right hemiparesis, suggesting abnormal left-side cerebral blood circulation. In other words, left internal carotid artery occlusion was thought to have occurred relatively recently, causing right hemiparesis. Many atherosclerotic vascular lesions and coexisting microangiopathy due to diabetes, hypertension, and hyperlipidemia were considered to have caused the choroid plexus infarction, which was neurologically asymptomatic. An echocardiogram and 24-hour Holter ECG monitoring were performed to investigate the cardioembolic source of the stroke, but no structural or functional cardiac abnormalities were found.Fig. 2 Magnetic resonance angiography on admission shows stenosis in the cavernous portion of the right internal carotid artery (arrow) and occlusion of the left internal carotid artery (A). The right posterior cerebral artery is occluded distally (arrow) (B).

Fig 2

Ozagrel sodium and cilostazol were administered to treat and prevent cerebral infarction, and atorvastatin was given to control hyperlipidemia. To treat her diabetes, we consulted a diabetologist and resumed insulin therapy. To avoid self-interruption of these therapies, we provided education about the diseases and their treatment. We planned to follow up the patient with MR imaging and single photon emission computed tomography, but she did not consent to these studies. After about 2 weeks, the patient was discharged from the hospital without any symptoms. Her primary care physician continued follow-up treatment.

Discussion

The choroid plexus is located within several ventricles in the brain and receives blood from various arteries. In the lateral ventricles, its vascular supply is primarily derived from the anterior choroidal artery within the anterior circulation, as well as from the medial and lateral posterior choroidal arteries originating from the posterior circulation [2]. Anastomoses between these arteries are often observed, particularly between the anterior and posterior choroidal arteries. The medial posterior choroidal artery also anastomoses with the contralateral medial posterior choroidal artery at the roof of the third ventricle [7]. The abundant blood flow provided by these arterial anastomoses may help protect the tissue from focal ischemia. Although only 6 documented cases of choroid plexus infarction, including the present case (Table 1), [3,4,8,9] the profuse blood flow and the prevalence of vascular anastomoses may account for the rarity of this occurrence. In our case, the cause of isolated choroid plexus infarction likely stemmed from a stenotic lesion due to atherosclerosis affecting multiple vessels. The right posterior communicating artery was well developed, and the posterior circulation was also probably susceptible to the blood flow from the right internal carotid artery.Table 1 Summary of choroid plexus infarction cases.

Table 1Case No.	Author/Year	Age/Sex	Background	Symptoms	Laterality of choroid plexus infarction	Concurrent cerebral infarction	
1	Liebeskind DS et al., 2004	54/M	HT, HPT	Right hemisensory loss Right hemiparesis	Left	Left thalamus
Callosal splenium	
2	Koral K et al., 2007	10/F		Aphasia
Right facial weakness
Right hemiparesis	Left	Left thalamus
Callosal splenium
Left medial occipital lobe	
3	Nabavizadeh SA et al., 2015	50/F	N/A	Left facial & arm weakness
Left homonymous hemianopia	Right	Right occipital lobe
Right thalamus
Bilateral cerebellum
Pons	
4	66/F	HT, DM	Left hemiparesis
Dizziness	Right	Left pons
Bilateral occipital lobe
Right thalamus
Bilateral superior cerebellum	
5	Lee JS et al., 2019	90/F	HT, HL	Psychomotor slowing	Right	None	
6	Present case, 2023	56/F	DM, HT, HL	Dizziness
Dysarthria
Right arm weakness	Right	None	
DM, Diabetes mellitus; F, Female; HL, Hyperlipidemia; HPT, Hyperparathyroidism; HT, Hypertension; M, Male; N/A, not applicable.

Initial stenosis of the cavernous portion of the right internal carotid artery resulted in decreased blood flow to the right cerebral hemisphere and choroid plexus. Subsequent occlusion of the contralateral internal carotid artery possibly compounded the compensatory reduction in blood flow to the right cerebral hemisphere and choroid plexus, leading to ischemia (Fig. 3). Furthermore, most previously reported cases were associated with systemic diseases such as hypertension or diabetes mellitus, recognized as closely related to the onset of cerebral infarction. Diabetes mellitus not only precipitates atherosclerosis affecting large blood vessels but also includes microangiopathy. In our case, in addition to the atherosclerosis-induced lesions in the major arteries, microangiopathy proximal to the choroid plexus, caused by diabetes, hypertension, and hyperlipidemia, had a significant impact. We speculate that the isolated choroid plexus infarction occurred because the effects of atherosclerosis extended to multiple blood vessels, and adequate blood flow from the contralateral side or multiple arteries could not be maintained.Fig. 3 The microangiopathy (dotted lines) with the following 3 pathologies caused the choroid plexus infarction in this case: (A) decreased right (Rt.) cerebral blood flow due to Rt. ICA stenosis, (B) increased dependence of bilateral anterior circulation blood flow on the posterior circulation due to left (Lt.) ICA occlusion, (C) relative blood flow reduction in the choroid plexus of the Rt. lateral ventricle due to distal Rt. PCA occlusion. Abbreviations: ACA, Anterior cerebral artery; Acom, Anterior communicating artery; BA, Basilar artery; ICA, Internal carotid artery; PCA, Posterior cerebral artery, Pcom, Posterior communicating artery.

Fig 3

Moyamoya disease is one of the conditions when stenosis of multiple major cerebral arteries occurs, but there have been no reports of related choroid plexus infarction. In Moyamoya disease, the development of collateral blood circulation is prominent, and in particular, the development of anastomoses between the anterior and posterior choroidal arteries is often observed [10]. Therefore, sole stenosis of multiple major cerebral arteries appears improbable in causing choroid plexus infarction, necessitating the involvement of microangiopathy.

The choroid plexus not only plays an essential role in CSF production but also in maintaining circadian rhythm and clearing waste products from the brain [6,9,11]. Localized damage to the choroid plexus is unlikely to impair these functions, so a local choroid plexus infarction, such as in our case, typically does not cause symptoms. This characteristic often leads to the oversight of choroid plexus infarction, given its asymptomatic nature [2]. In previous reports, choroid plexus infarction occurred simultaneously with ischemic damage to the thalamus, occipital lobe, brainstem, cerebellum, and other brain parenchyma, and neurological symptoms were associated with brain parenchyma ischemia rather than the isolated choroid plexus infarction [[3], [4], [5],8]. Lee et al. reported a case of isolated choroid plexus infarction with frontal lobe symptoms in a 90-year-old woman, speculating that the infarction could decrease cerebrospinal fluid production, resulting in intracranial hypotension [8]. However, their report showed no imaging evidence of intracranial hypotension. Since cerebral fluid balance can be rapidly restored by other areas of the choroid plexus [12], it seems unlikely that an isolated infarction of this structure could cause intracranial hypotension. In our case, the main complaint was right hemiparesis, which appeared to be related to transient ischemia on the contralateral left side relative to the site of choroid plexus infarction. It is plausible that there were no symptoms directly attributable to the choroid plexus infarction itself.

Being asymptomatic, the incidental identification of an isolated choroid plexus infarction through neuroimaging, revealing high signal intensity on diffusion-weighted images, is plausible. Differential diagnoses include cyst and xanthogranuloma of the choroid plexus, intraventricular hemorrhage, pyogenic ventriculitis, and highly cellular primary or metastatic tumors [3]. Although choroid plexus infarction may not manifest neurologically, its recognition is essential to exclude treatable differential disease and to diagnose and treat systemic diseases. Therefore, appropriate laboratory tests and imaging studies should be performed to evaluate background etiologies and differential diagnoses.

Conclusion

When cerebral infarction occurs in a hemodynamically stable region such as the choroid plexus, the underlying diseases causing cerebral ischemia should be closely investigated. This unusual stroke syndrome may shed further light on pathogenesis in this complex structure.

Patient consent

Written informed consent was obtained from the patient for publication of this case report. We applied CARE guidelines for reporting the findings of this case report.

Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Acknowledgments: The authors would like to thank Dr. Alexander Zaboronok of the University of Tsukuba Faculty of Medicine Department of Neurosurgery for professional and language revision.
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