Artery of Percheron Infarct: An Acute Diagnostic Challenge with a Spectrum of Clinical Presentations

Abstract

The artery of Percheron (AOP) is a variant of the paramedian thalamic vasculature that supplies blood to the medial aspect of the thalamus and the rostral midbrain. The presentation of an infarct in this territory varies widely and is often characterized by nonspecific neurological deficits, with altered mental status, decreased level of consciousness, and memory impairment being among the most common. AOP infarcts are often missed on initial computed tomography (CT) scan, and additional imaging is usually not done due to low suspicion for stroke in most cases. There have been an increasing number of reports of AOP infarction, illustrating the diversity of clinical presentations and the challenge this presents to clinicians in the acute setting. Lacking the classic signs of stroke, many of these patients experience a delay in recognition and treatment, with the majority of diagnoses occurring outside the tissue plasminogen activator (tPA) window. This case highlights the unusual presentation and diagnostic difficulty of a patient with an AOP infarct, and serves as a reminder to include thalamic pathology in patients presenting with vague neurological symptoms and no obvious signs of stroke.

Artery of Percheron infarction with persistent amnesia: a case report of bilateral paramedian thalamic syndrome

“…Next, ischemia of this region can present in a variety of ways and is not limited to the classically described paramedian thalamic syndrome [3]. Finally, MRI is the gold standard for diagnosis of AOP infarction, while CT is routinely used as first-line imaging for standard stroke diagnosis [7]. In our case, MRI was performed more than 24 h after the patient's initial symptom onset that identified restricted diffusion within the thalami and midbrain bilaterally.…”

“…Rarer clinical presentations have been described, including patients presenting with severe bradycardia, parkinsonism and convulsive seizures [ 4 – 6 ]. Infarction within the vascular territory of the AOP is an important differential diagnosis to consider in an individual presenting to the Emergency Department (ED) with fluctuating level of consciousness (LOC), especially when considering that initial head computed tomography (CT) is typically normal [ 7 ]. Magnetic resonance imaging (MRI) is currently the gold standard for diagnosis of bilateral paramedian thalamic infarction.…”

Artery of percheron and endoscopic endonasal surgery: Case report and review of the literature

“…Clinical presentation of AOP occlusion[ 7 8 9 10 11 12 13 14 15 16 17 18 19 ] is variable due to interindividual differences in thalamus anatomy and function, as well as to the variability in its vascularization. However, the presentation mainly includes vertical oculomotor palsy, memory involvement, and alterations in the level of consciousness.…”

Acute Onset of Hypersomnolence and Aphasia Secondary to an Artery of Percheron Infarct and a Proposed Emergency Room Evaluation

“…Vascular supply to the thalamus is described as anterior territory supplied by tuberothalamic (polar) artery, the paramedian territory supplied by the thalamosubthalamic (paramedian) artery, inferolateral territory supplied by thalamogeniculate (inferolateral) artery, and the posterior territory supplied by the posterior choroidal artery [8]. The exact supply to each territory can vary due to anatomical differences and the size of the adjacent vascular territories [9]. AOP is a rare anatomical variant, which supplies bilateral paramedian thalami and the rostral mesencephalon via a single dominant thalamic perforating artery arising from the P1 segment of a PCA.…”

“…If the MRI brain is positive, implying acute ischemia and the patient remains within the therapeutic window for thrombolysis, IV tPA should be administered. Maintaining a high suspicion for thalamic infarct, with AOP occlusion as one etiology, and a low threshold for MRI in patients presenting acutely with otherwise unexplainable neurological symptoms may facilitate diagnosis and decrease morbidity [9].…”