Left Retro-Orbital Pain, Double Vision and Rash on the Forehead

A 62-year-old man reported acute left retro-orbital pain of one week’s duration. Physical examination revealed no abnormalities. Three days later, double vision developed, and the next day a rash appeared on the forehead.

Left Retro-Orbital Pain, Double Vision and Rash on the Forehead

What could be the Diagnosis ?