A 64-year-old man has had difficulty walking for 6 months, experiencing muscle cramps in his right thigh after walking a block on level ground. The cramps subside quickly with rest. He has also had decreased sexual performance. Medical history is significant for hypercholesterolemia and myocardial infarction. The patient smokes a pack of cigarettes daily but does not use alcohol or illicit drugs. He is afebrile. Blood pressure is 128/78 mm Hg, pulse is 76/min, and respirations are 16/min. Cardiac auscultation reveals normal S1 and S2, and equal vesicular breath sounds are heard over the bilateral lungs. The abdomen is soft and without masses. There is no peripheral edema, muscle tenderness, or muscle weakness. Which of the following is the most likely cause of this patient's symptoms?

Question

A 64-year-old man has had difficulty walking for 6 months, experiencing muscle cramps in his right thigh after walking a block on level ground.  The cramps subside quickly with rest.  He has also had decreased sexual performance.  Medical history is significant for hypercholesterolemia and myocardial infarction.  The patient smokes a pack of cigarettes daily but does not use alcohol or illicit drugs.  He is afebrile.  Blood pressure is 128/78 mm Hg, pulse is 76/min, and respirations are 16/min.  Cardiac auscultation reveals normal S1 and S2, and equal vesicular breath sounds are heard over the bilateral lungs.  The abdomen is soft and without masses.  There is no peripheral edema, muscle tenderness, or muscle weakness.  Which of the following is the most likely cause of this patient's symptoms?

Quizplus · Accepted Answer

This patient's muscle pain, which occurs with exercise and remits with rest, is consistent with intermittent claudication; smoking is an important risk factor. Claudication is usually due to atherosclerosis of the large arteries, specifically resulting from fixed stenoses caused by lipid-filled intimal plaques that bulge into the arterial lumen (atheromas). These stenoses prevent a sufficient increase in blood flow to muscles during exercise, leading to ischemic muscle pain. The pain is rapidly relieved by rest, as residual blood flow is adequate to meet the metabolic demands of resting, but not exercising, muscle. Thigh claudication is suggestive of occlusive disease of the ipsilateral external iliac artery or its more distal branches (ie, common femoral, superficial femoral, profunda femoris arteries). Accompanying impotence and/or gluteal claudication suggests more proximal aortoiliac occlusion (so-called Leriche syndrome), which, in addition to affecting the external iliac artery, also diminishes blood flow to the internal pudendal and gluteal branches of the internal iliac artery. (Choice A) Granulomatous inflammation of the arterial media occurs in temporal (giant cell) arteritis, the most common form of systemic vasculitis in adults. This condition typically affects patients age >50 and causes headache, facial pain, jaw claudication, and visual loss. (Choice B) Hyaline arteriolosclerosis involves homogeneous deposition of hyaline material in the intima and media of small arteries and arterioles, typically in patients with hypertension or diabetes mellitus (both absent in this patient). The underlying structure of the vessel wall is maintained, but the intima is thickened and the arterial lumen narrowed. (Choice D) Medial band-like calcifications occur in medial calcific sclerosis (Mönckeberg arteriosclerosis). The condition is characterized by calcified deposits in muscular arteries and typically affects individuals age >50. Although visible radiologically and often palpable on physical examination, these calcifications are clinically asymptomatic because they do not narrow the vessel lumen. (Choice E) Onion-like concentric thickening of arteriolar walls due to layers of smooth muscle cells and reduplicated basement membrane is seen in hyperplastic arteriolosclerosis, which can occur in severe chronic hypertension (eg, blood pressure >180/120 mm Hg). Although arterioles in all tissues may be affected, those in the kidneys, retinas, and intestines are most common; skeletal muscle is less likely to be symptomatically involved. Educational objective: Intermittent claudication describes muscle pain that is reproducibly caused by exercise and relieved by rest; it occurs due to atherosclerotic stenoses (lipid-filled intimal plaques) in the large arteries that prevent sufficient blood flow to exercising muscle. The lower extremities are most commonly affected; however, proximal lesions (ie, aortoiliac occlusion) can cause gluteal claudication and/or impotence.

A 64-Year-Old Man Has Had Difficulty Walking for 6 Months