We describe a patient with a Raeder's paratrigeminal neuralgia consisting of left-sided frontal and orbital pain, Homer syndrome (including anhydrosis of the forehead), and sensory loss in the territory of the first division of the trigeminal nerve. The involvement of the ophthalmic nerve is not consistent with the usual localization of this syndrome to the pericarotid sympathetic plexus. Oculosympathetic and sympathetic fibers supplying the sweat glands of the forehead join the ophthalmic nerve in the cavernous plexus localized in the cavernous sinus. Therefore, this seems to be the most likely site of the lesion when the ophthalmic nerve is involved.
