Overview of Cranial Nerves 3rd Cranial Nerve Palsies (Oculomotor) Vasculopathic Third Nerve Palsy Snapshot Symptoms Treatment Mrs. Roberts, a 65-year-women with a history of diabetes and hypertension presents in the emergency room with the right eye deviated outward and ptosis. The pupils are normal. She complains of a slight headache Third nerve deficit is outward rotation from medial rectus weakness and ptosis from levator palpebrae weakness. Pupil response and size is normal. Normal pupil size is important in distinguishing from a compressive third nerve palsy. Because it is non-compressive, treated as nonemergent. Compressive Third Nerve Palsy Mrs. Roberts, a 65-year-women with a history of diabetes and hypertension presents in the emergency room with the right eye deviated outward and obvious ptosis. The pupil is dilated and unreactive. She complains of a slight headache. Third nerve deficit is outward rotation from medial rectus weakness and ptosis form levator palpebrae weakness. Pupil is dilated and unreactive because of compression on the dorsal medial portion of the third nerve. Pupil response is important in distinguishing from a vasculopathic third nerve palsy. Because it is compressive, treat as emergent. 4th Cranial Nerve Palsy Superior Oblique Palsy Mr. Jones, was brought to the ER after being struck by a car. His right eye is deviated outward and upward. Caused from CN IV damage and is usually caused from trauma. 5th Cranial Nerve Palsy V1 loss of sensation in the face, scalp and cornea loss of blink reflex V2 loss of sensation in the maxillary region of the face (maxillary skin, teeth, nasal cavity, etc) V3 loss of sensation in the mandibular region of the face (mandibular skin, teeth, anterior 2/3rds of the tongue) weakness with chewing; jaw deviation towards weaker side Trigeminal neuralgia recurrent shock-like pain that is short-lasting affecting one or more divisions of the trigeminal nerve most commonly V2 and V3 6th Cranial Nerve (Abducens) Palsy Lateral Rectus Palsy A 5-year-old child with a posterior fossa tumor complains of diplopia. On exam the child is noted to have stabismus. Commonly associated with brain tumors in the pediatric population. Presents with diplopia (double vision) because they supress the nerve of the affected eye. It is a sign of increased intracranial pressure. Eye exam reveals strabismus from abducens involvement.