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-Noncontrast CT scan image showing bilateral paramedian thalamic areas of hypodensity measuring about 15 × 11 mm (white arrows).
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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 pat...
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Context 1
... that time, he was noted to have ptosis and ocular movement examination revealed vertical gaze palsy. Another CT scan was performed on the second day and showed bilateral paramedian thalamic areas of hypodensity measuring approximately 15 × 11 mm ( Fig. 6 ), but CT angiography (CTA) was unremarkable. MRI was done, fast spin echo T2 and FLAIR sequences showed bilateral high-signal intensity on the paramedian thalami and rostral midbrain ( Fig. 7 ). ...
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Citations
... The thalamus serves as a hub for transmitting signals related to both sensory and motor functions and also plays an important role in regulating sleep, alertness, and consciousness. The perforating branches of the P1 and P2 segments of the posterior cerebral artery (PCA) and the posterior communicating artery (PComA) provide a rich blood supply to the thalamus and midbrain [1]. The thalamic vascular supply is traditionally divided into four territories: anterior, paramedian, inferolateral, and posterior, but there may be some variation and overlap. ...
The posterior communicating artery (PcomA), P1 and P2 segments of the posterior cerebral arteries (PCAs) give rise to numerous small branches that chiefly supply the thalamus and midbrain. Thalamic vascular supply is classically categorized into four regions: anterior, paramedian, infero-lateral and posterior. Despite significant variations and overlap in the blood supply, this traditional classification helps in understanding the vascular anatomy of the thalamus. Gerard Percheron extensively studied thalamic blood supply and described its anatomical variants depending on its origin. The artery of Percheron (AOP) is a rare anatomical variation of paramedian-mesencephalic arterial supply in which a solitary arterial trunk arises from the PCA and distributes bilaterally to both paramedian thalami and often to the rostral part of the midbrain. During routine dissection of the brain of a 46-year-old female in the department of anatomy, it was seen that thalamo-perforating artery (AOP) took origin as a single trunk from the P1 segment of the left PCA. The specimen was dissected and photographed for documentation and to see more details. The exact prevalence of AOP remains unknown, but various studies show that it can be present in 7% to 11.7% of subjects. Detailed knowledge of AOP anatomical variation is crucial for interpreting neuroimaging results or performing different neuro-endovascular techniques at the basilar bifurcation, particularly in patients with bilateral thalamic and midbrain infarctions.
... Percheron, 26 where one single branch supplies the described region bilaterally, is prone to this pattern of ischemia. [27][28][29] Therefore, lesions in LiPS patients can stretch from the pons rostral, involving the mesencephalon and reaching as far as into the thalamus when the rostral part of the basilar artery and the bifurcation is occluded. ...
The locked-in syndrome (LiS) is defined as the loss of most voluntary muscle movements with preserved cognitive abilities due to a ventral pontine lesion. However, some patients may also have severe impairment of consciousness [locked-in plus syndrome (LiPS)]. Here we aimed to explore structural differences between LiS and LiPS patients of vascular aetiology, focusing on lesion patterns and locations to better delineate the clinical spectrum of LiS and LiPS. In this retrospective case series study, we report nine patients (two women), ages 29–74 years (median 50) with LiS and LiPS who were diagnosed between 2007 and 2021. Clinical parameters, MRI findings including the lesioned structures, and a shape feature calculation are presented for every patient. The lesioned structures were determined by a senior neuroradiologist. Two of nine patients had fully retained consciousness (LiS) and seven showed various degrees of impaired consciousness (LiPS). Lesions of LiS patients are round and confined to the pons, whereas lesions of LiPS patients are more elongated and reach neighbouring areas such as the mesencephalon, thalamus or ascending reticular activating system. Lesions involving the mesencephalon and the thalamus are strong indicators of LiPS, whereas for lesions restricted to the pons, the dorsal extension and the associated damage to the ascending reticular activating system are crucial to differentiate LiS from LiPS. Recognizing LiPS using clinical and radiological findings is important as these patients may need different therapies and care and, most importantly, should not be mistaken as unresponsive wakefulness syndrome.
... In variant IIb, the perforating arteries arise from the artery of Percheron (AOP) which supplies the paramedian thalamus and rostral midbrain. 3 In these variants, the AOP comes from a part of the posterior cerebral artery, namely, the P1 segment. Variant III is the arcade variant which gives off small perforating branches from one arterial arc which bridges the P1 segments and the PCAs together. ...
The thalamus is a walnut-sized structure that is located in the brain which receives rich blood supply from posterior cerebral artery and its communicating branches. One of the unusual presentations is the infarction of artery of percheron. Hereby reporting a case of 68-year-old female with no known co-morbidities who presented to the emergency department with complaints of sudden onset loss of consciousness in the morning. On further investigation, was found to have infarction of one of the variants of thalamic perforating arteries.
... However, the size of the AOP is extremely small and difficult to identify using conventional angiography (4). Over the past 20 years, only a few reports have been published on the confirmation of the AOP with digital subtraction angiography (4)(5)(6)(7)(8)(9)(10)(11), and cases of AOP detection by computed tomography angiography (CTA) (12,13) or magnetic resonance angiography (MRA) (8,14,15) are even rarer (Table S1). ...
... Thalami are symmetric, paired, midline structures of the diencephalon regulating consciousness, sleep, and alertness (5). The thalamus and the midbrain have a complex arterial supply mainly originating from the posterior cerebral artery (PCA) (6). The artery of Percheron is one of four variants of this complex blood supply system and only counts 0.7% of all (5,7). ...
... Currently, MRI is the gold standard to demonstrate AOP infarction (9), Axial magnetic resonance imaging (MRI) presenting bilateral high-signal intensity on the paramedian thalamus in (A) T2-weighted sequence, and (B) FLAIR sequence. and routine initial CT scan is often normal (6,9,16). Lazzaro et al. first identified four patterns of AOP infarction, including bilateral paramedian thalamic with midbrain (43%), bilateral paramedian thalamic without midbrain (38%), bilateral paramedian thalamic with anterior thalamus and midbrain (14%), and bilateral paramedian thalamic with anterior thalamus without midbrain (5%) (18). ...
... Deep venous thrombosis may result in bilateral symmetric involvement of the thalami. While abnormally hyperdense veins could be seen on CT scans, corresponding T1 hyperintensity from a clot in the sinuses may be seen on MR images (6,20,21). Other differential diagnoses could include primary neoplasm, metabolic and toxic disorders, and infections (20). ...
The incidence of stroke or transient ischemic attacks (TIA) in atrial fibrillation (AF) catheter ablation procedures is around 1% and may be unnoted under anesthesia. The artery of Percheron (AOP) infarction is a rare kind of stroke with heterogeneity in manifestation, which further makes the perioperative early detection and diagnosis a challenge. Herein, we present one patient who underwent AF ablation and presented mental status alteration after withdrawing anesthetics. An emergency head CT was obtained, which revealed no apparent pathological changes. A late MRI test confirmed the diagnosis of AOP infarction. With oral anticoagulants and rehabilitation therapies, the patient’s awareness improved and fully recovered on the sixth-month follow-up. Variability in manifestation, no positive radiological finding on initial CT, and a low incidence has made few clinicians to gain much experience with this type of infarct, which delays the diagnosis and initiation of appropriate treatment.
... El tálamo es un centro de relevo entre los mecanismos motores y sensitivos, también regula la conciencia, vigilia y el sueño. Tras su afectación, la representación de sus signos y síntomas suelen variar, por lo que se considera una patología con importancia diagnóstica 8,9 . ...
Introducción: La vascularización del tálamo fue descrita por Percheron en el siglo XX. La irrigación del tálamo proviene principalmente de las conexiones que establecen la arteria carótida interna y la arteria basilar, es decir, circulación vascular cerebral anterior y posterior. La arteria de Percheron, ante situaciones de isquemia, ocasiona lesión en el tálamo con injuria bilateral. Objetivo: Analizar caso clínico propuesto, literatura médica y evidencia científica actual relacionada. Metodología: Reporte descriptivo de un paciente de 45 años, ingresado en el Hospital General Guasmo Sur, Ecuador. Cuadro clínico de 20 horas de evolución previa al ingreso, caracterizado por deterioro del sensorio, se realizan neuroimágenes, compatibles con isquemia bitalámica, y revisión bibliográfica en la literatura mundial. Resultados: En TAC de cerebro inicial se visualiza imagen hipodensa bilateral en región talámica. En RMN evidencia lesiones en área de tálamo, hiperintensidad en Flair (Fluid Attenuated Inversion Recovery), T2 y DW (diffusion), hipointensidad en T1 y ADC (Apparent Diffusion Coefficient). Paciente cursa GOS (Glasgow Outcome Scale) 3 PTS. Discusión: Las lesiones bitalámicas son infrecuentes, la prevalencia oscila del 0,1 % al 0,6 %. Cabe destacar la relevancia diagnóstica, la mayor parte de ellas corresponde a un origen embólico. Conclusión: Cuadro clínico compatible con la tríada clásica de Percheron, que consiste en: parálisis vertical de la mirada, alteración cognitiva, coma. Los estudios de neuroimagen permiten dilucidar el infarto talámico paramediano, síndrome de Percheron.
... The diameter of AOP is so small that magnetic resonance angiography (MRA) cannot show it, and even digital subtraction angiography (DSA) cannot show its existence, stenosis or occlusion in most cases. Only a few authors found AOP obstruction through DSA [9,10]. MRI, especially diffusion weighted imaging (DWI), plays an important role in the diagnosis of acute AOP infarction. ...
... Acute AOP ischemia has great variability with respect to symmetry, size, and territory, which is mainly due to the thalamic arteries vary between individuals. These differences are related to the parent vessel from which each branch arises, the number and position of the arteries and their tributaries [9,12,18]. Paramedian bithalami of the 23 patients showed high signal intensity on FLAIR with restricted diffusion and hypointense in the ADC map (positive in 100%). Valentina Francioni et al. [19] presented mismatch between DWI and FLAIR mismatch of hyperacute paramedian bithalami ischemia, which points out the DWI and ADC map is very important for the differentiation and therapy in acute AOP infarction. ...
... Similar to previous studies [23,24], we also analysis the relationship between AOP infarction region and clinical presentation. Based on previous report, 6,9 No case involving bilateral paramedian and anterior thalamic infarction with midbrain involvement was found. The thalami contain reticular and intralaminar nuclei, associative nuclei, effector nuclei, sensory nuclei and limbic nuclei. ...
Background
So far, the diagnosis of acute artery of percheron (AOP) infarction is uncommon. In this study, patients with acute AOP infarction were studied to explore the relationship of imaging findings, clinical manifestations and prognosis of acute AOP infarction.
Materials
A total of 23 patients with acute AOP infarction in our institution from 2014 to 2019 were reviewed retrospectively. All cases were evaluated by computed tomography (CT) and magnetic resonance imaging (MRI). The modified Rankin scale (MRS), blood examination, electrocardiogram and transthoracic echocardiography were used for detailed clinical and prognostic evaluation. All standard risk factors for these patients were recorded. The MRS scores were performed 90 days after discharge.
Results
Four different types of acute AOP infarction were identified: (a) bilateral paramedian thalamic infarction (BPTI, 52%); (b) bilateral paramedian thalamic with rostral midbrain infarction (BPTRMI, 30%), (c) bilateral paramedian and anterior thalamic infarction (BPATI, 13%), and (d) bilateral paramedian thalamic with red nuclei infarction (BPTRNI, 4%). These patients had consciousness disorder, memory dysfunctions, vertical gaze paresis and mesencephalothalamic syndrome. The 65% of patients with BPTI and BPATI experienced relatively good functional recovery and could carry out daily life activities (MRS score ≤ 2). However, patients with BPTRMI may have an unfavorable outcome.
Conclusions
Although the clinical features are variable, DWI or ADC map can improve the diagnosis of acute AOP infarction patterns. Acute AOP occlusion requires immediate diagnosis and treatment to obtain more favorable outcome and avoid additional unnecessary procedures.
... ere have been reported cases of bilateral thalamic strokes, who presented mainly with sudden onset of hypersomnia and fluctuating arousal as the thalamus plays an important role in sleep regulation and in maintaining arousal. Hypersomnolence can be due to the interruption of noradrenergic and dopaminergic pathways from the ascending reticular activating system to the thalamus [14][15][16]. One case report stated that there was significant improvement in the state of alertness after administering modafinil 100 mg twice a day [8]. ...
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.
... Artery of Percheron infarction poses a potential diagnostic challenge due to its elusive clinical presentation and the typical lack of CT imaging anomalies. The small size of the AOP may render the visualization of the vessel and possible occlusions difficult, in conventional imaging modalities such as CT and MRI, [ Figs. 2,3 ] further contributing to delays in the diagnosis of AOP infarction [15] . Delays in performing an MRI result in a late diagnosis, significantly impacting the management and prognosis of these patients, as was the case of our patient. ...
The artery of Percheron (AOP) represents a rare anatomic variant of the posterior circulation. It is a solitary trunk that provides bilateral arterial supply to the rostral midbrain and paramedian thalamus. AOP infarction presentation varies, most often presents with altered mental status, memory impairment, and supranuclear vertical gaze palsy. Diagnosis of the AOP infarct is most often missed in the initial CT scan. A majority of these diagnoses are made outside the window of thrombolytic treatment for ischemic stroke.
We report a case of a 67-year old male with a history of well-managed diabetes mellitus type 2 and hypertension, presented in the ER sudden onset severe drowsiness. On a physical exam, we found left pupil dilation and left eye deviation. Initial CT scan showed no pathological changes. The diagnosis was made on the third day of hospitalization via an MRI. Our case highlights the unusual presentation and that an absence of evidence of AOP infarction in CT scan does not exclude its diagnosis. The artery of the Percheron infarct requires a comprehensive clinical and radiological examination.
A male patient in his early 40s presented to the emergency department with an acute onset of respiratory distress and facial oedema, indicative of anaphylaxis. These symptoms emerged 2 hours subsequent to a wasp sting on the left side of his face. Despite initial stabilisation, the patient’s state deteriorated into somnolence and disorientation. Notably, he denied any history of seizures, sensory or motor deficits, or bowel/bladder complications. Physical examination unveiled no focal neurological deficits. Routine laboratory tests and drug screening yielded no significant findings. Subsequent brain MRI with angiography exposed bilateral thalami diffusion restriction, strongly implying an acute infarction within the artery of Percheron territory, an atypical vascular variant. The sequence of events, alongside the absence of other conclusive aetiologies, indicated a wasp sting-induced thalamic infarction driven by vasogenic and thrombogenic effects of inflammatory substances.
