A 78-year-old man comes to the office due to a 6-month history of progressive bilateral buttock pain that radiates to his thighs and calves. The pain is worse with ambulation but improves with leaning on a cane or sitting; the patient has had to limit his activity as he is unable to walk more than 2-3 blocks. He has no pain at night and no problems with bowel or bladder function. Over-the-counter ibuprofen has provided moderate relief. The patient has a history of coronary artery bypass grafting 6 years earlier for 3-vessel coronary artery disease. His other medical conditions include type 2 diabetes mellitus, hypertension, and hypercholesterolemia. Physical examination shows normal strength, reflexes, and sensation in his legs. A straight leg raise test does not reproduce the pain. Ankle-brachial index is 1.1 on the right and 1.2 on the left (normal 0.9-1.3). Hemoglobin A1c is 8%. Which of the following is most likely responsible for this patient's current condition?

Question

A 78-year-old man comes to the office due to a 6-month history of progressive bilateral buttock pain that radiates to his thighs and calves.  The pain is worse with ambulation but improves with leaning on a cane or sitting; the patient has had to limit his activity as he is unable to walk more than 2-3 blocks.  He has no pain at night and no problems with bowel or bladder function.  Over-the-counter ibuprofen has provided moderate relief.  The patient has a history of coronary artery bypass grafting 6 years earlier for 3-vessel coronary artery disease.  His other medical conditions include type 2 diabetes mellitus, hypertension, and hypercholesterolemia.  Physical examination shows normal strength, reflexes, and sensation in his legs.  A straight leg raise test does not reproduce the pain.  Ankle-brachial index is 1.1 on the right and 1.2 on the left (normal 0.9-1.3).  Hemoglobin A1c is 8%.  Which of the following is most likely responsible for this patient's current condition?

Quizplus · Accepted Answer

11ec25c8_d529_6737_bc81_5145c4765125_MD0003_00 This patient with lower extremity pain relieved with spinal flexion has typical features of lumbar spinal stenosis. Spinal stenosis is due to narrowing of the spinal canal with resulting compression of lumbar nerve roots. Common contributing factors include degenerative arthritis of the spine (spondylosis/spinal osteoarthritis), including degenerative disk disease, and thickening of the ligamentum flavum, leading to mechanical narrowing and compression. narrowing of the spinal canal The pain of spinal stenosis is often associated with activity, as lumbar extension during walking worsens the narrowing of the canal. This is termed neurogenic claudication and can resemble the lower extremity vascular claudication seen in obstructive atherosclerotic arterial disease. Although this patient's pain likely reflects spinal stenosis/neurogenic claudication, both spinal stenosis/neurogenic claudication and vascular claudication can be seen in older patients with multiple atherosclerotic risk factors. In contrast to the pain of vascular claudication, that of neurogenic claudication is postural rather than exertional. It can persist at rest if the spine remains extended but is lessened by spine flexion (eg, walking uphill, leaning on an assistive device), often referred to as the "shopping cart sign." In this patient, the pattern of the pain (eg, improves when leaning on cane) and the normal ankle-brachial index are more consistent with neurologic than vascular claudication (Choice A). shopping cart sign (Choice B) Diabetic peripheral neuropathy causes burning or tingling pain that begins in the feet and progresses proximally in a "stocking-glove" distribution. Postural back pain is not characteristic. (Choice C) Spinal cord compression (eg, due to malignancy) presents acutely or subacutely with back pain, paralysis, hyperreflexia, fecal incontinence, or urinary incontinence/retention. Given this patient's 6-month history of positional back pain and his normal physical examination, his symptoms are likely due to nerve root compression rather than spinal cord compression. (Choice E) The spondyloarthropathies (eg, ankylosing spondylitis) are more common in younger patients. They are characterized by back pain and stiffness that worsen with rest and improve with activity. (Choice F) Vertebral compression fractures typically present with acute back pain following a minor injury (eg, ground-level fall). The pain usually diminishes with time. (Choice G) Vertebral metastasis is characterized by constant, dull pain that is worse at night. Patients often have a history of malignancy or systemic symptoms (eg, weight loss). Educational objective: Lumbar spinal stenosis is most commonly caused by degenerative changes in the spine and presents with low back and leg pain. The leg pain of neurogenic claudication is position-dependent (exacerbated by lumbar extension) and persists even while standing still. Vascular claudication is exertion-dependent and resolves with standing still. References: The reliability of differentiating neurogenic claudication from vascular claudication based on symptomatic presentation. (http://www.ncbi.nlm.nih.gov/pubmed/24284143)

A 78-Year-Old Man Comes to the Office Due to a 6-Month