Artery of Percheron Infarction: Clinical Presentation and Outcomes

Abstract

Background and objectives: Occlusion of the artery of Percheron (AOP) produces bilateral thalamic infarction classically leading to deficits of arousal. This nonspecific presentation complicates the diagnosis of acute ischemic stroke. We sought to describe the spectrum of clinical presentation, diagnostic neuroimaging findings, and outcomes in AOP infarction (AOPi).

Methods: We conducted a keyword search of our health system's neuroimaging database from 2014 to 2022 to identify patients with AOPi. We abstracted patient demographics, clinical presentation, neuroimaging findings, acute treatment, and modified Rankin Scale (mRS) scores (at baseline, 3 months, and 12 months). We used descriptive statistics to report our findings.

Results: Our initial keyword search identified 192 potential AOPi cases. Fifteen cases of AOPi were confirmed and included in our study (8 female [53%], median age 65 years [interquartile range (IQR): 59.5-79.5], median presenting NIHSS 6 [IQR: 2-22]). Common clinical findings on presentation were systolic blood pressure (SBP) > 140: 12 patients (80%); decreased level of consciousness (LOC): 11 patients (73%); diplopia: 8 patients (57%); disorientation: 6 patients (42%); dysarthria: 4 patients (28%); and acute memory/cognitive disturbance: 3 patients (21%). Twelve cases (80%) presented to the emergency department (ED). Median time from symptom onset to ED arrival was 774.5 minutes (IQR: 202.25-3789.0), 4 cases (27%) arrived within 4.5 hours, and one patient (7%) received intravenous thrombolysis. The median time from ED arrival to stroke diagnosis was 519.0 minutes (IQR: 227.5-1307). Head CT was only diagnostic when obtained >570 minutes from time last known well; MRI was diagnostic at all time points. Rates of functional independence (mRS ≤2) at baseline, 3 months, and 12 months were 64%, 21%, and 18%, respectively.

Discussion: The diagnosis of stroke was considerably delayed in patients with AOPi, and only one patient received IV thrombolysis. SBP >140, impaired consciousness, and diplopia were the most common findings at presentation. CT was often nondiagnostic, but MRI demonstrated bilateral thalamic infarct in all cases. AOPi caused considerable long-term morbidity. Clinicians should maintain a high degree of suspicion for AOP stroke and consider thrombolysis in appropriately selected patients.

Figure 1. Features of Acute Clinical Presentation

(A) Radar plot depicting the share of presenting symptoms among patients with an artery of Percheron occlusion. SBP >140: 12 patients (80%); decreased LOC: 11 patients (73%); diplopia: 8 patients (57%); disorientation: 6 patients (42%); dysarthria: 4 patients (28%); and acute memory/cognitive disturbance: 3 patients (21%). SBP, LOC, and pupils were assessed in all 15 patients; the remainder was reported in 14 patients because they could not be assessed in a single patient because of intubation. (B) Bar plot depicting the frequency of presentations stratified by NIHSS range. LOC = level of consciousness; SBP = systolic blood pressure.

Figure 2. Acute Neuroimaging Findings

(A–C) A depiction of an artery of Percheron infarct of the bilateral thalamic and left midbrain on axial and coronal views of a noncontrast head CT in 3 different patients from our cohort. (D–E) Diffusion-weighted imaging (1.5 T) MRI of the typical appearance of the artery of Percheron territory occlusion in a single patient. (F) MRI demonstrating “V-sign” or diffusion restriction of the pial surface of the midbrain. (G–I) CT perfusion (CTP) study from a study participant with cerebral blood flow (CBF), cerebral blood volume (CBV), and Tmax images depicting a perfusion defect consistent with acute ischemia in the territory of the artery of Percheron—a concomitant perfusion deficit in the left medial temporal lobe was related to intracranial atherosclerosis and did not produce associated symptoms or result in infarction. All pathologies are marked by a red arrow.

Figure 3. Ordinal Plot Demonstrating the Change in mRS Between the Premorbid State, 3-Month Follow-Up, and 12-Month Follow-Up

Independent functional status is demarcated by the thin line drawn between the mRS scores from different time points. mRS = modified Rankin Scale.