Artery of Percheron Stroke: A Case Report With a Diagnostic Challenge

Abstract

Artery of Percheron (AOP) is a unique anatomical variant of blood supply to the paramedian thalamus and also to the rostral part of the midbrain. It arises from the P1 part of the posterior cerebral artery. Obstruction of this artery accounts for the infarction of the bilateral thalamus with or without the involvement of the midbrain. Symptoms of artery of Percheron infarction may differ with respect to the portion of the brain it supplies and its different anatomical variations. The various symptoms include memory loss, altered consciousness, vertical gaze palsy, and others. Diagnosis is difficult due to a variety of clinical presentations and differential diagnoses like viral infections or tumors. Artery of Percheron infarction rarely occurs, and early diagnosis is a challenge as it is often missed on a conventional CT scan and even on an MRI scan of the brain. Delay in diagnosis and initiation of treatment must be avoided in such cases. We report a case of this 57-year-old male who had vertical gaze palsy and irrelevant talks, which was evaluated further and found to be the artery of Percheron infarct on MRI brain and treated with antiplatelets after which the symptoms of the patient ameliorated, and he was discharged after five days of admission.

Keywords: artery; brain; midbrain; thalamus; tumour.

Figure 1. DWI axial section of the brain at the level of thalamus showing restricted diffusion in bilateral paramedian thalami consistent with the infarct of artery of Percheron (a variant of P1 segment of the posterior cerebral artery)

DWI - diffusion-weighted imaging

Figure 2. DWI axial section of the brain at the level of thalamus showing restricted diffusion in the right paramedian thalamus and left cerebellum (A), with corresponding dark signals on ADC (B)

DWI - diffusion-weighted imaging; ADC - apparent diffusion coefficient

Figure 3. Type I variant of perforator supply of thalamus and the rostral midbrain

Figure 4. Type IIa variant of perforator supply of thalamus and the rostral midbrain

Figure 5. Type IIb variant of perforator supply of thalamus and the rostral midbrain

Figure 6. Type III variant of perforator supply of thalamus and the rostral midbrain