Of the three patients with AIE who presented with extreme leukocytosis (≥20), one was a patient with anti‐GAD AIE admitted with severe DKA, another, who was later diagnosed with ADEM, was admitted following a motorcycle accident, and the third, diagnosed with possible seronegative AIE, was admitted following a course of IVMP in another medical facility. This evidence concerns the gene GAD1 and Increased total leukocyte count.