Artery of Percheron Infarct with a Normal Initial MRI: A Case Report

The artery of Percheron is a rare anatomical variant which supplies both the paramedian thalamic and the rostral midbrain. This unique feature is responsible for bilateral thalamic and mesencephalic infarctions if occluded. A single occlusion can lead to a clinical picture of drowsiness and visual disturbances due to the bilateral nature of the structures supplied. We report a case of a patient in altered sensorium with normal early imaging (CT and MRI). Ischemia in the region of the artery of Percheron was revealed three days later with a repeat Magnetic Resonance Imaging. This is one of the few cases reported where early imaging fails to detect an acute stroke in a symptomatic patient.