Background <p>The paramedian thalamic artery has four types of anatomical variants, among which type IIb is commonly referred to as the artery of Percheron (AOP). Occlusion of this artery typically results in bilateral paramedian thalamic infarction, with variable involvement of the rostral midbrain. We report a case of acute ischemic stroke caused by AOP occlusion, which is a rare complication of a neurointerventional procedure.</p> Case presentation <p>A 51-year-old male underwent stent placement due to severe stenosis with dissection of the V4 segment of the left vertebral artery. After the procedure, he presented with classic symptoms of AOP infarction, including acute altered consciousness and memory impairment. Magnetic resonance imaging (MRI) revealed bilateral paramedian thalamic and rostral midbrain infarction. He was diagnosed with an acute ischemic stroke caused by AOP occlusion and achieved a favorable outcome with symptomatic therapy, supportive care, and rehabilitation.</p> Conclusions <p>This case underscores that in patients who have stenosis with dissection undergoing neurointerventional procedures, heightened vigilance is required for the complication of distal embolization, and distal blood flow should be repeatedly assessed. When neurological deficits, such as altered consciousness, arise after the procedure, the possibility of AOP infarction should be considered, especially in patients with an anatomical variant of this artery. Timely MRI and treatments such as intravenous thrombolysis and endovascular therapy should be performed.</p>