A 65-year-old woman with a history of diabetes mellitus and hypertension is brought to the emergency department due to double vision and right eye pain. She awoke 2 days ago with right periorbital pain, and several hours later, she noticed double vision that became worse with accommodation. The double vision has been persistent and does not fluctuate throughout the day. The patient has had no headaches, blurry vision, dysarthria, dysphasia, weakness, numbness, or balance problems. Medications include aspirin, lisinopril, and metformin. The patient does not use tobacco, alcohol, or illicit drugs.
Blood pressure is 150/90 mm Hg seated and pulse is 80/min. Neurologic examination shows both horizontal and vertical binocular diplopia with left lateral and upward gazes. There is complete ptosis of the right eyelid, with the eyeball in the down-and-out position. The right pupil is 5 mm, midposition, and nonreactive to light; the left pupil is 3 mm, midposition, and reactive to light. The anisocoria improves with the ambient light off. No eye proptosis, conjunctival injection, periorbital edema, chemosis, or ocular bruit is present. Funduscopic examination reveals no papilledema. The rest of the neurologic examination is normal. Which of the following is the most appropriate next step in management of this patient?

Question

A 65-year-old woman with a history of diabetes mellitus and hypertension is brought to the emergency department due to double vision and right eye pain.  She awoke 2 days ago with right periorbital pain, and several hours later, she noticed double vision that became worse with accommodation.  The double vision has been persistent and does not fluctuate throughout the day.  The patient has had no headaches, blurry vision, dysarthria, dysphasia, weakness, numbness, or balance problems.  Medications include aspirin, lisinopril, and metformin.  The patient does not use tobacco, alcohol, or illicit drugs.
Blood pressure is 150/90 mm Hg seated and pulse is 80/min.  Neurologic examination shows both horizontal and vertical binocular diplopia with left lateral and upward gazes.  There is complete ptosis of the right eyelid, with the eyeball in the down-and-out position.  The right pupil is 5 mm, midposition, and nonreactive to light; the left pupil is 3 mm, midposition, and reactive to light.  The anisocoria improves with the ambient light off.  No eye proptosis, conjunctival injection, periorbital edema, chemosis, or ocular bruit is present.  Funduscopic examination reveals no papilledema.  The rest of the neurologic examination is normal.  Which of the following is the most appropriate next step in management of this patient?

Quizplus · Accepted Answer

11ec193a_9652_f7dc_853d_3fd13011069e_MD0002_00 This patient with diabetes mellitus and hypertension who presents with horizontal and vertical binocular diplopia, ptosis, and a nonreactive pupil has an isolated, acute, non-pupil-sparing third nerve palsy. Injury to the third nerve can occur anywhere along its length, from its origin in the brainstem to the orbit. The parasympathetic fibers responsible for pupil constriction (by controlling the sphincter papillae muscle) run on the outside of the third nerve fascicle and are less susceptible to ischemia but are almost invariably affected by an extrinsic mass. Therefore, third nerve palsies are classically classified as follows: Non-pupil-sparing third nerve palsies are frequently caused by mass effect (eg, intracranial aneurysm, tumor). Aneurysms arise from vessels that have a close anatomic relationship with the third nerve (eg, posterior cerebral artery, superior cerebellar artery, posterior communicating artery). A non-pupil-sparing third nerve palsy (as seen in this patient) should be considered due to an aneurysm until proved otherwise; patients should undergo immediate MR or CT angiography for evaluation.Pupil-sparing third nerve palsies are typically caused by microvascular ischemia; they are associated with diabetes, hypertension, hyperlipidemia, and advanced age. Observation and supportive care may be appropriate in patients with vasculopathic risk factors (eg, diabetes, hypertension), although some physicians advocate for imaging to exclude mass effect with all third nerve palsies (Choice E). Non-pupil-sparing third nerve palsies are frequently caused by mass effect (eg, intracranial aneurysm, tumor). Aneurysms arise from vessels that have a close anatomic relationship with the third nerve (eg, posterior cerebral artery, superior cerebellar artery, posterior communicating artery). A non-pupil-sparing third nerve palsy (as seen in this patient) should be considered due to an aneurysm until proved otherwise; patients should undergo immediate MR or CT angiography for evaluation. Non-pupil-sparing third nerve palsies are frequently caused by mass effect (eg, intracranial aneurysm, tumor). Aneurysms arise from vessels that have a close anatomic relationship with the third nerve (eg, posterior cerebral artery, superior cerebellar artery, posterior communicating artery). A non-pupil-sparing third nerve palsy (as seen in this patient) should be considered due to an aneurysm until proved otherwise; patients should undergo immediate MR or CT angiography for evaluation. Pupil-sparing third nerve palsies are typically caused by microvascular ischemia; they are associated with diabetes, hypertension, hyperlipidemia, and advanced age. Observation and supportive care may be appropriate in patients with vasculopathic risk factors (eg, diabetes, hypertension), although some physicians advocate for imaging to exclude mass effect with all third nerve palsies (Choice E). Pupil-sparing third nerve palsies are typically caused by microvascular ischemia; they are associated with diabetes, hypertension, hyperlipidemia, and advanced age. Observation and supportive care may be appropriate in patients with vasculopathic risk factors (eg, diabetes, hypertension), although some physicians advocate for imaging to exclude mass effect with all third nerve palsies (Choice E). It is important to note that aneurysms may spare the pupil early in the course and that, rarely, patients with microvascular disease may develop complete infarction with pupillary involvement. Therefore, imaging should be considered if the presentation is atypical (eg, if patients develop a pupil-sparing third nerve palsy without having vasculopathic risk factors, if symptoms fail to improve within 6-12 weeks). (Choice B) Non-pupil-sparing third nerve palsy can be caused by an acute brainstem or lacunar stroke; however, patients typically have other deficits. In the case of an isolated non-pupil-sparing third nerve palsy, aneurysmal compression of the third nerve must be ruled out first. If vascular imaging does not reveal an aneurysm, then an MRI of the brain with diffusion protocol can be considered to rule out a small infarct. (Choice C) Myasthenia gravis presents with fluctuating diplopia; the presence of acetylcholine receptor antibodies can confirm the diagnosis. However, the pupillary light reflex is spared, and pain is not a typical feature in myasthenia gravis. (Choice D) Myopathy affecting the extraocular muscles can occur in rare conditions (eg, muscular dystrophy) and causes elevated creatine phosphokinase and aldolase levels. Myopathies typically present with bilateral symptoms affecting skeletal muscles; pupillary light reflex is spared. Educational objective: Non-pupil-sparing third nerve palsies are most concerning for aneurysmal compression; MR or CT angiography should be performed immediately. Pupil-sparing third nerve palsies are most commonly caused by microvascular ischemia associated with diabetes mellitus. __________

A 65-Year-Old Woman with a History of Diabetes Mellitus and Hypertension