Neurologic Exam-Adult | Cranial Nerve Exam | Anatomy | Pearls

Cranial Nerve Exam - Anatomy 16 - Pearls: Rules of Diplopia. Number 1: Diplopia is maximum in the direction of action of the paretic muscle. Number 2: The most peripherally seen image is the false image and comes from the eye with the paretic muscle. Number 3: Diplopia is horizontal if the medial and lateral recti are involved, and vertical if the elevator or depressor muscles are involved. Intranuclear ophthalmoplegia: A lesion of the medial longitudinal fasciculus causes nystagmus of the abducting eye with absent adduction of the other eye. The lesion is on the side of the non-adducting eye, or the eye that does not adduct. There can be bilateral intranuclear ophthalmoplegia, in which case neither eye adducts on range of motion.