A 68-year-old man is evaluated for visual loss in the left eye that resolved spontaneously within several hours. The patient has a history of hypertension, type 2 diabetes mellitus, coronary artery disease, and ischemic cardiomyopathy. He has smoked a pack of cigarettes daily for the past 40 years. Physical examination reveals a left carotid bruit but no neurologic deficits. A carotid duplex ultrasound shows 85% stenosis of the left internal carotid artery, and carotid angiography with stenting is performed. During the procedure, atherosclerotic debris embolize to the artery shown (red arrow) on the cerebral magnetic resonance angiograph below. Which of the following actions is most likely to be impaired in this patient?

Question

A 68-year-old man is evaluated for visual loss in the left eye that resolved spontaneously within several hours.  The patient has a history of hypertension, type 2 diabetes mellitus, coronary artery disease, and ischemic cardiomyopathy.  He has smoked a pack of cigarettes daily for the past 40 years.  Physical examination reveals a left carotid bruit but no neurologic deficits.  A carotid duplex ultrasound shows 85% stenosis of the left internal carotid artery, and carotid angiography with stenting is performed.  During the procedure, atherosclerotic debris embolize to the artery shown (red arrow) on the cerebral magnetic resonance angiograph below.  Which of the following actions is most likely to be impaired in this patient?

Quizplus · Accepted Answer

11ec160b_35b5_a251_9249_9b0293418903_MD0001_00 This cerebral magnetic resonance angiogram shows a 3D reconstruction of the circle of Willis, with the top representing superior regions and the bottom representing inferior regions. The internal carotid arteries are the large vessels seen bilaterally near the center of the image (blue arrow). Each gives off a middle cerebral artery (green arrow) to supply lateral brain regions and an anterior cerebral artery (red arrow), which extends medially and then superiorly. Each anterior cerebral artery supplies the medial region of the ipsilateral hemisphere, from the frontal pole to the parietooccipital sulcus. Occlusion of the anterior cerebral artery would affect sensory and motor function of the contralateral leg and foot while predominantly sparing the contralateral arm/face (cortical homunculus). Patients with bilateral anterior cerebral artery occlusion can also develop significant behavioral symptoms (eg, abulia) and urinary incontinence if the frontal micturition center (eg, medial frontal lobe/cingulate gyrus) is affected. (Choices B, C, D, and E) Occlusion of the middle cerebral artery would affect motor control of the hand (eg, gripping), face/mouth (eg, whistling), and throat (eg, swallowing) out of proportion to the leg. It can also result in Broca aphasia (due to damage of the dominant frontal lobe), anosognosia and spatial neglect of the contralateral side (due to damage of the nondominant parietal lobe), conjugate gaze deviation toward the side of the stroke, and contralateral homonymous hemianopsia (due to damage of the optic radiations in the subcortical temporoparietal lobe). Educational objective: The anterior cerebral arteries supply the medial portions of the 2 hemispheres (frontal and parietal lobes). Occlusion can cause contralateral motor and sensory deficits of the lower extremities, behavioral changes, and urinary incontinence. __________ References: Anterior cerebral artery and Heubner's artery territory infarction. (http://www.ncbi.nlm.nih.gov/pubmed/22377877)

A 68-Year-Old Man Is Evaluated for Visual Loss in the Left