Bilateral thalamic stroke due to occlusion of the artery of Percheron in a patient with patent foramen ovale: a case report

Bilateral thalamic infarcts: Percheron territory

Blood supply to the human thalami is complex and multiple variants exist. The artery of Percheron is one of those variants and is characterized by a solitary arterial trunk that branches from one of the proximal segments of either posterior cerebral artery and sup- plies blood to the paramedian thalami. Its occlusion results in bilateral paramedian thalamic infarction sometimes extending to the midbrain. We report a case of bithalamic infarction secondary to occlusion of the artery of Percheron. We will illustrate the complex clinical symptomatology and underscore the role of imaging, especially MRI, for diagnosis.

Artery of Percheron Infarction: A Case Report of Bilateral Thalamic Stroke Presenting with Acute Encephalopathy

The artery of Percheron (AOP) is a relatively rare anatomic variant in which a solitary arterial trunk branches from the proximal segment of the posterior cerebral artery and provides arterial supply to the paramedian region of the thalami bilaterally and often to the rostral part of the midbrain. Occlusion of the artery of Percheron results in bilateral paramedian thalamic infarcts with and without midbrain involvement. Recognition of this condition as an acute stroke may be challenging due to various nonlocalized clinical presentations, given the wide range of neurological functions subserved by the thalamus. Prompt neuroimaging, preferably with magnetic resonance imaging (MRI), in conjunction with familiarity with this relatively rare vascular variation can facilitate initiation of appropriate time contingent thrombolytic treatment and improved long-term prognosis. We present a case of a 56-year-old African American female with a bilateral thalamic infarct secondary to the artery of Percheron thromboembolism. This patient presented unresponsive without focal neurologic findings but with an initial Glasgow Coma Score (GCS) of 7, and subsequent computed tomographic (CT) head revealed bilateral thalamic hypodensities. Confirmatory MRI exhibited bilateral subacute thalamic infarcts, which were thought to be embolic with the source from the left ventricular thrombus as the patient had at least three distinct clots. Unfortunately, the patient’s mental status did not improve significantly, and she was discharged to a nursing facility for extended care. AOP infarction may be missed on vascular imaging utilizing CT, MRI, and even catheter angiography. Clinical recognition that the AOP is one of the only single artery occlusions that can affect bilateral structures and frequently present solely as altered mental status without focal neurologic deficits is crucial to the diagnosis.

The Clinical and Cognitive Spectrum of Artery of Percheron Infarction: 1-Year Follow-Up

OBJECTIVE

Survivors of patients with artery of Percheron infarction (API) often have a prolonged and disabling form of cognitive impairment that remains insufficiently characterized. We aimed to examine the clinical and cognitive features of API in the short and long term after stroke.

METHODS

We reviewed 6400 patients with a first-ever stroke included in the Stroke Registry between 2011 and 2021. The diagnosis of API was based on clinical diagnosis and imaging confirmation. All patients underwent neuropsychological assessment at hospital stay and 1 year after stroke. A z-score of each patients' cognitive test point was calculated, and a z-score inferior to 2 was considered as pathological.

RESULTS

Of the 10 patients enrolled, all had cognitive impairment, consciousness, and behavioral disorders at stroke onset. Six patients had pure bilateral thalamic involvement while four had bilateral thalamic and rostral midbrain involvement. At 12 months, 50% of patients had global mental state scores 2 SD below the population mean (z-score mean ± SD, -2.17 ± 0.4). Most of the prefrontal cortex cognitive processes including executive functions such as planning and cognitive control (z-score mean ± SD, -3.92 ± 0.3), processing speed (-4.42 ± 0.5), working memory (-3.97 ± 0.3) were severely impaired at stroke onset. Especially in patients with thalamic and rostral midbrain involvement, deficiencies in executive function (z-score mean ± SD, -2.60 ± 0.4), processing speed (-2.22 ± 0.5), working (-3.76 ± 0.4), and episodic memory (-2.23 ± 0.3) continued 12 months after stroke.

CONCLUSIONS

The occlusion of the artery of Percheron results in severe behavioral and cognitive disorders in the short and long term after stroke.

Artery of Percheron Stroke as an Unusual Cause of Hypersomnia: A Case Series and a Short Literature Review

The thalamus and the mesencephalon have a complex blood supply. The artery of Percheron (AOP) is a rare anatomical variant. Occlusion of this artery may lead to bithalamic stroke with or without midbrain involvement. Given its broad spectrum of clinical features, AOP stroke is often misdiagnosed. Usually, it manifests with the triad of vertical gaze palsy, memory impairment, and coma. In this article, we report three cases of bilateral thalamic strokes whose clinical presentations were dominated by a sudden onset of hypersomnia. We also reviewed last 5 years’ publications related to the AOP strokes in males presenting sleepiness or equivalent terms as a delayed complication. The AOP stroke may present a diagnostic challenge for clinicians which should be considered in the differential diagnosis of hypersomnia.

Artery of Percheron Infarction: A Characteristic Pattern of Ischemia and Variable Clinical Presentation: A Literature Review

The Artery of Percheron (AOP) is an uncommon anatomic variant that provides arterial supply to the paramedian region of the thalami and bilaterally to the rostral part of the midbrain; it is a solitary arterial trunk that branches from a proximal segment of the posterior cerebral artery (PCA). Although AOP infarction results in a characteristic pattern of ischemia-namely bilateral paramedian thalamic infarct with or without midbrain involvement-it may cause diagnostic difficulties due to the variety of its clinical presentations and wide differentials, as well as its small diameter and the difficulty of obtaining visualization through diagnostic imaging. Early neuroimaging of AOP infarction and correct diagnosis are mandatory for early initiation of the appropriate treatment and better patient outcomes. In this study, we discuss imaging the patterns of AOP infarction and its differentials and clinical presentation.

Stroke masquerading as cardiac arrest: the artery of Percheron

The artery of Percheron (AOP) is a rare arterial variant of the thalamic blood supply. Due to the densely packed collection of nuclei it supplies, an infarction of the AOP can be devastating. Here we highlight a patient who had an AOP stroke in the community, which was initially managed as cardiac arrest. AOP strokes most often present with vague symptoms such as reduced conscious level, cognitive changes and confusion without obvious focal neurology, and therefore are often missed at the initial clinical assessment. This case highlights the importance of recognising an AOP stroke as a cause of otherwise unexplained altered consciousness level and the use of MRI early in the diagnostic work-up.

Artery of Percheron infarction a rare anatomical variant and a diagnostic challenge: Case report

The Artery of Percheron (AOP) is an uncommon anatomic variant that provides arterial supply to the paramedian region of the thalami and bilaterally to the rostral part of the midbrain; it is a solitary arterial trunk that branches from a proximal segment of the posterior cerebral artery (PCA). Although AOP infarction results in a characteristic pattern of ischemia, namely bilateral paramedian thalamic infarct with or without midbrain involvement, it may cause diagnostic difficulties due to the variety of its clinical presentations and wide differentials, as well as its small diameter and the difficulty of obtaining visualization through diagnostic imaging. Early neuroimaging of AOP infarction and correct diagnosis are mandatory for early initiation of the appropriate treatment and better patient outcomes. This study discusses the imaging patterns and imaging differentials of AOP infarction and its clinical presentation. A 55-year-old man presented to the emergency department unconscious with Glasgow Coma Scale score of 4. Pupillary light reflex on both eyes was poorly reactive with dilatated right pupil. The patient flexed his arm and extended his leg on painful stimulus. Laboratory tests and electrocardiogram were unremarkable. Emergency cerebral CT scan and transcranial Doppler ultrasound were normal. He gradually regained consciousness with residual somnolence, ptosis, and vertical gaze palsy. Second CT scan showed bilateral paramedian thalamic areas of hypodensity, CT angiography (CTA) was unremarkable. MRI showed bilateral high-signal intensity on paramedian thalami fast spin echo T2, FLAIR, and diffusion-weighted sequences, low signal on apparent diffusion coefficient sequence. MR angiography (MRA) revealed an abnormal tiny vessel arising from the P1 segment of the left posterior cerebral artery. Imaging findings were consistent with AOP infarction. Aspirin was started, 4 hours after admission the patient regained consciousness, and gradually improved on the following days till he was discharged on the 15th day, with mild neurologic deficit. AOP must be considered whenever paramedian thalamic infarction is noted in neuroimaging. The difficulty in visualizing the AOP using diagnostic imaging is due to its small diameter, leading to the limited abilities of MRA and CTA to diagnose AOP infarction. An absence of evidence of AOP infarction in MRA or even CTA does not exclude its diagnosis. Good knowledge of the imaging characteristics of AOP infarction will help in early diagnosis and the achievement of good patient outcomes.

ARTERY OF PERCHERON BRAIN INFARCTION: REVIEW OF LITERATURE AND CLINICAL CASE

Artery of Percheron is an anatomical version of the cerebral vessels, in which one artery, departing from the proximal part of one of the posterior cerebral arteries, supplies the paramedial thalamus and the rostral part of the midbrain. The Artery of Percheron brain infarction is often manifested by impaired consciousness, oculomotor disorders and neuropsychological symptoms. The diagnosis of the Artery of Percheron brain infarction is carried out using computed and/or magnetic resonance imaging (MRI). Intravenous thrombolysis and endovascular treatment methods are used in therapeutic window. Further secondary prevention is recommended. The prognosis is favorable with the timely treatment. A clinical case of a 43-year-old woman with acute oculomotor disorders is presented. A neurological examination revealed paresis of the vertical gaze, diplopia. MRI showed a bilateral acute infarction of both paramedial thalamuses. An angiographic study revealed saccular aneurysm of the A1 segment of the right anterior cerebral artery. After treatment, the patient was discharged with minimal neurological deficit.

Artery of Percheron Infarction: A Short Review

One uncommon type of ischemic stroke is occlusion of the artery of Percheron (AOP) leading to infarction of the paramedian thalami and mesencephalon. There are several variants of thalamic blood supply, and identifying the potential presence and infarction of an AOP is important in diagnosis and treatment of ischemic strokes affecting the thalami and mesencephalon, especially because of the unusual and variable presentation of these forms of ischemic strokes. This short review includes and discusses the case of a 58-year-old woman with an AOP infarct and indicates the importance of recognizing an AOP infarct early despite its clinical variations in order to treat the stroke in a timely fashion. This short review also includes a discussion of imaging modalities in such cases and clinical differential diagnoses to consider with management strategies.

EEG-correlated fMRI of human alpha (de-)synchronization

OBJECTIVES

We investigated blood oxygenation level-dependent (BOLD) brain activity changes in wakefulness and light sleep and in relation to those associated with the posterior alpha rhythm, the most prominent feature of the clinical EEG. Studies have reported different sets of brain regions changing their oxygen consumption with waxing and waning alpha oscillations. Here, we hypothesize that these dissimilar activity patterns reflect different wakefulness-dependent brain states.

METHODS

We recorded BOLD signal changes and electroencephalography (EEG) simultaneously in 149 subjects at rest. Based on American Academy of Sleep Medicine criteria, we selected subjects exhibiting wakefulness or light sleep (N1). We identified brain regions in which BOLD signal changes correlated with (i) clinical sleep stages, (ii) alpha band power and (iii) a multispectral EEG index, respectively.

RESULTS

During light sleep, we found increased BOLD activity in parieto-occipital regions. In wakefulness compared to light sleep, we revealed BOLD signal increases in the thalamus. The multispectral EEG-index revealed hippocampal activity changes in light sleep not reported before.

CONCLUSION

Changes in alpha oscillations reflect different brain states associated with different levels of wakefulness and thalamic activity. We can link the previously described parieto-occipital pattern to drowsiness. Additionally, in that stage, we identify hippocampal activity fluctuations.

SIGNIFICANCE

Thalamic activity varies with early changes of wakefulness, which is important to consider in resting state experiments. The EEG-indexed activation of the hippocampus during light sleep suggests that memory encoding might already take place during this early stage of sleep.

Bithalamic Infarction (Artery of Percheron Occlusion) after Anterior Cervical Discectomy and Fusion

Bithalamic infarction resulting from occlusion of the artery of Percheron after cervical spine surgery is a rare pathological entity. Diagnosis and early detection are challenging. Prompt management may help to improve the outcome. We present a case of a 39-year-old male patient, smoker, diagnosed with multiple cervical disc herniations, who underwent Anterior Cervical Discectomy and Fusion (ACDF) for C3-C4, C4-C5, and C5-C6. During the 2-hour and 50-minute surgery, the patient was lying supine with his neck hyperextended. The intraoperative procedure was uneventful. During surgery, blood pressure ranged around 110 mmHg∖50 mmHg. At the end of surgery, the patient's recovery from general anesthesia was normal with no delaying or complication; on next the day, patient developed a sudden loss of consciousness. Urgent brain computed tomography (CT) was normal; two days later, follow-up CT and CT Angiography (CTA) revealed bilateral thalamic infarction with right vertebral artery occlusion from its origin. Intraoperative surgical manipulation, hypotensive anesthesia, and prolonged neck hyperextension might have contributed to stroke in this patient. ACDF carries a potential risk for posterior circulation stroke. Artery of Percheron infarction should be considered in the differential diagnosis of patients developing a sudden loss of consciousness after ACDF. Vertebral artery thrombosis should be taken into account as an important possible cause of embolism.

[Revisiting eponyms of arteries of the brain]

This article describes the eponymous terms in anatomical nomenclature of the cerebral arteries. There are historical references revealing the etymology of described eponyms, including information about the professional and personal life of doctors and scientists who had first discovered or described particular structure of the cerebral arterial network. Chronology of the discovery of the cerebral arterial circle is described in details. It is shown that some eponymous terms contain the names of several doctors who studied a particular medical issue simultaneously, which is a reflection of the stages of the medical science development and the evidence of the continuity of scientific knowledge.

Degeneration of paramedian nuclei in the thalamus induces Holmes tremor in a case of artery of Percheron infarction

RATIONALE

Holmes' tremor is an uncommon neurologic disorder following brain insults, and its pathogenesis is undefined. The interruption of the dento-rubro-thalamic tract and secondary deterioration of the nigrostriatal pathway are both required to initiate Holmes' tremor. We used nuclear medicine imaging tools to analyze a patient with concurrent infarction in different zones of each side of the thalamus. Finding whether the paramedian nuclear groups of the thalamus were injured was a decisive element for developing Holmes' tremor.

PATIENT CONCERNS

A 36-year-old woman was admitted to our department due to a bilateral paramedian thalamic infarction. Seven months after the stroke, a unilaterally involuntary trembling with irregularly wavering motions occurring in both her left hand and forearm.

DIAGNOSIS

Based on the distinct features of the unilateral coarse tremor and the locations of the lesions on the magnetic resonance imaging (MRI), the patient was diagnosed with bilateral paramedian thalamic infarction complicated with a unilateral Holmes' tremor.

INTERVENTIONS

The patient refused our recommendation of pharmacological treatment with levodopa and other dopamine agonists based on personal reasons and was only willing to accept physical and occupational training programs at our outpatient clinic.

OUTCOMES

We utilized serial anatomic and functional neuroimaging of the brain to survey the neurologic deficit. A brain magnetic resonance imaging showed unequal recovery on each side of the thalamus. The residual lesion appeared larger in the right-side thalamus and had gathered in the paramedian area. A brain perfusion single-photon emission computed tomography (SPECT) revealed that the post-stroke hypometabolic changes were not only in the right-side thalamus but also in the right basal ganglion, which was anatomically intact. Furthermore, the brain Technetium-99m-labeled tropanes as a dopamine transporter imaging agents scan ( Tc-TRODAT-1) displayed a secondary reduction of dopamine transporters in the right nigrostriatal pathway which had resulted from the damage on the paramedian nuclear groups of the right-side thalamus.

LESSONS

Based on the functional images, we illustrated that a retrograde degeneration originating from the thalamic paramedian nuclear groups, and extending forward along the direct innervating fibers of the mesothalamic pathway, played an essential role towards initiating Holmes' tremor.

Bilateral internuclear and internal ophthalmoplegia due to artery of Percheron infarction

The artery of Percheron (AOP) infarction always manifests as paramedian bilateral thalamic infarcts and might present as paramedian midbrain infarcts. Despite the limited MRA evaluation, due to small size of the artery, careful evaluation of the patient's history, the clinical presentation with imaging findings can facilitate the proper diagnosis.

Midbrain and bilateral paramedian thalamic stroke due to artery of Percheron occlusion

INTRODUCTION

Bilateral thalamic strokes are rare manifestations of posterior circulation infarcts. Usually the etiology is cardioembolic or small vessel disease combined with individual anatomical predisposition. The symptoms include a variety of neurological deficits depending on thalamic structure involvement, such as paresthesias or numbness, hemiparesis with increased reflexes and Babinski sign, third cranial nerve palsy, speech and cognition disturbance, memory impairment and stupor. Neuroimaging usually reveals ischemic loci in adequate thalamic nuclei.

CASE PRESENTATION

We report a case of 61-year-old man, active smoker (25/per day, 50 pack-years) with untreated hypertension who presented at admission consciousness impairment (Glasgow Coma Scale score 9 points), left pupil dilatation without reaction to light, left eye deviation downwards and outwards, vertical gaze paralysis and left-sided hemiplegia. Initial brain computed tomography (CT) was normal. Brain magnetic resonance with diffusion weighted imaging and fluid attenuation inversion recovery sequences (MR DWI/FLAIR) performed on admission showed ischemic changes in bilateral thalami, which were confirmed in routine MRI. Thrombosis of basilar artery and cerebral venous was excluded in CT angiography. Further diagnostic assessment revealed hyperlipidemia, paroxysmal atrial fibrillation and renal cancer with hepatic metastases.

CONCLUSION

Bilateral thalamic stroke due to artery of Percheron occlusion is a rare presentation of stroke, which can be overlooked in routine CT scan. If diagnosed, it requires further evaluation for stroke risk factors, especially cardiovascular disorders associated with increased embolic risk.

Bilateral thalamic stroke due to occlusion of the artery of Percheron in a patient with a patent foramen ovale

The artery of Percheron (AOP) is a rare vascular variant in which a single dominant thalamoperforating artery arises from the P1 segment and bifurcates to supply both paramedian thalami. Occlusion of this uncommon vessel results in a characteristic pattern of bilateral paramedian thalamic infarcts with or without mesencephalic infarctions. We report a case of a 37-year-old man with acute bilateral thalamic infarcts. The scans revealed symmetric bilateral hyperintense paramedian thalamic lesions consistent with an acute ischemic event. The posterior circulation was patent including the tip of the basilar artery and both posterior cerebral arteries, making the case compatible with occlusion of the AOP. This type of infarct is associated with embolic phenomena, and further evaluation revealed a patent foramen ovale as the source of emboli in the cerebrovascular circulation. The occlusion of the AOP is a rare cause of coma in young patients, and early recognition of this rare disease entity may lead to more favorable outcomes.

Acute Occlusion of the Percheron Artery during Pregnancy: A Case Report and a Review of the Literature

OBJECTIVES

The Percheron artery (PA) is a rare variant vessel. Its acute occlusion can cause a bilateral symmetrical thalamic stroke, clinically manifested as a sudden alteration of consciousness that could vary from sleepiness to coma. In this paper, we illustrate a case of acute PA occlusion in a young, pregnant woman and present a review of the literature, focusing on the possible causes of the acute occlusion.

METHODS

A 35-year-old woman, at the fourth week of pregnancy, came to the emergency department of our hospital because of a sudden onset and persistent loss of consciousness. Brain magnetic resonance imaging (MRI) showed a symmetrical and bilateral thalamic infarction without evidence of other ischemic lesions, compatible with an acute PA occlusion.

RESULTS

The patient, who showed full clinical recovery within a few hours of symptom onset, received a short-term anticoagulant treatment followed by aspirin for long-term prevention.

CONCLUSIONS

We reviewed the literature about the possible causes of acute PA occlusion. This ischemic condition is usually associated with cardioembolic or small-vessel disease. However, in our patient, we did not find any element supportive for coagulative alteration or embolyzing conditions.

PRACTICE

The presence of this type of thalamic stroke should be considered in the management of persistent loss of consciousness. PA occlusion is rare, but it needs a brain MRI examination for a correct diagnosis, a narrow evaluation of all the possible causes, and a long-term anticoagulant therapy. Pregnancy itself should constitute a rare but possible cause of a PA occlusion.

A Case of Midbrain and Thalamic Infarction Involving Artery of Percheron

Blood supply to the thalamus and brainstem have frequent anatomic variations. One of these is where all the perforators to the above areas arise from a single branch of the posterior cerebral artery commonly known as the artery of Percheron. Infarction involving this artery leading to bilateral thalamic and midbrain lesions is not uncommon, but can cause diagnostic difficulties due to the varying clinical presentations possible and the wide differentials. Early brain imaging and diagnosis is important for initiating appropriate treatment. In this case report, we discuss a patient who presented with an artery of Percheron related stroke affecting the mid brain and paramedian thalamic areas. We also discuss the differentials of presentations with similar symptoms.

Contemporary therapeutic strategies for occlusion of the artery of Percheron: a review of the literature

The artery of Percheron (AOP) is a rare anatomic variant of the paramedian thalamic-mesencephalic arterial supply, arising as a solitary arterial trunk from the P1 segment of the posterior cerebral artery. Its occlusion, commonly caused by cardioembolism, leads to distal bilateral paramedian thalamic ischemia, oftentimes affecting the midbrain and/or the anterior thalamus. AOP occlusion presents with a clinical triad of altered mental status, vertical gaze palsy, and memory impairment, along with other associated symptoms. Digital subtraction angiography is effective for detecting AOP, while diffusion weighted MRI is best for diagnosis of its occlusion. Our extensive literature search sought to determine the best forms of treatment for uncomplicated AOP occlusion, with the inclusion criterion of implementation of medical treatment or other forms of therapy in patient recovery from this condition. We conclude that intravenous heparin and thrombolysis with tissue plasminogen activator are effective firstline treatment options for emergent AOP occlusion followed by a prescription of long term anticoagulants, while non-emergent cases without midbrain involvement could be treated through rehabilitation and continual monitoring by medical staff. Clinical trials of higher power are needed for a more comprehensive analysis of the treatment options for AOP occlusion.

Decreased consciousness: bilateral thalamic infarction and its relation to the artery of Percheron

This case series highlights two patients seen in the same stroke centre presenting with unusual symptoms. They were later diagnosed with bilateral thalamic infarcts, probably related to an unusual anatomical variant. The difficulties in establishing the diagnoses due to their relative rarity and complexity could have impacted on patient outcomes.

Bilateral thalamic infarcts due to occlusion of the Artery of Percheron and discussion of the differential diagnosis of bilateral thalamic lesions

The Artery of Percheron is a rare vascular variant in which a single dominant thalamoperforating artery arises from one P1 segment and bifurcates to supply both paramedian thalami. Occlusion of this uncommon vessel results in a characteristic pattern of bilateral paramedian thalamic infarcts with or without mesencephalic infarctions. We report a case of a 31-year-old man with acute bilateral thalamic infarcts and a truncated Artery of Percheron demonstrated on magnetic resonance angiography (MRA). Occlusion of the vessel was presumably due to embolism from a patent foramen ovale that was subsequently closed. The case presentation is followed by a discussion of bilateral paramedian thalamic infarcts including the causes and clinical presentation. The differential diagnosis of vascular and nonvascular etiologies of bilateral thalamic lesions is also discussed.

Embolic infarct presented with bilateral thalamic lesions possibly initiated by an emboli to the artery of Percheron

Bilateral thalamic infarcts are rare and present with varying symptoms. Cardioembolism and small artery disease are the most common etiologic factors. The occlusion of a rare arterial variant called the artery of Percheron results in bilateral thalamic infarcts. Herein, we present the imaging findings of an embolic infarct starting from bilateral thalami, probably due to an emboli to the artery of Percheron first.

Midbrain hematoma presenting with isolated bilateral palsy of the third cranial nerve in a Moroccan man: a case report

Introduction

Bilateral third nerve palsy secondary to a hemorrhagic stroke is exceptional. To the best of our knowledge, no similar case has been reported in the literature.

Case presentation

We describe the case of a 69-year-old Moroccan man who presented with isolated sudden bilateral third nerve palsy. Computed tomography (CT) of the brain revealed a midbrain hematoma. The oculomotor function gradually and completely improved over eight months of follow-up.

Conclusion

Stroke should be included in the differential diagnosis of sudden isolated oculomotor paralysis even when it is bilateral because of the severity of the underlying disease and the importance of its therapeutic implications.