A Man with Headache and Double Vision.

A 78 year old man presented with a nine day history of moderately severe left retro-orbital headache. On the day of presentation he developed sudden onset complete drooping of his left eyelid and double vision. His medical history included a right sided nephrectomy for renal cell carcinoma, hypertension, diverticular disease, and polymyalgia rheumatica. His regular drugs were amlodipine 10 mg once daily, lisinopril 5 mg once daily, omeprazole 20 mg once daily, and prednisolone 5 mg once daily. Clinical examination showed complete drooping of his left eyelid with the eyeball displaced outwards and downwards. His left pupil was fixed and dilated (fig 1⇓). The rest of his neurological examination was normal and he had no temporal artery tenderness or jaw claudication. ### 1. What clinical findings are apparent in fig 1? #### Short answer Complete left oculomotor nerve palsy with pupillary involvement. #### Discussion In fig 1, the patient’s left eye is being held open and he has been asked to look straight ahead. It can be seen that the left eyeball is displaced both outwards and downwards. The lateral rectus muscle (sixth nerve) is unopposed by the medial rectus muscle (third nerve), resulting in abduction of the eye. The superior oblique muscle (fourth nerve) is unopposed by the paralysed superior rectus, inferior rectus, and inferior oblique muscles (third nerve), causing downward displacement. He also has a complete ptosis and a fixed dilated pupil. These findings are consistent with complete left oculomotor nerve palsy. The oculomotor nerve has two separate components, each with its own function. The somatic motor component arises from the somatic motor nucleus in the midbrain, which supplies four extraocular muscles and …