A 46-year-old woman comes to the office due to worsening lower extremity tingling and numbness. She has also had difficulty walking, especially at night. Review of systems is positive for hair loss. The patient had gastric bypass surgery 5 years ago and has lost 30 kg (66 lb). She was originally prescribed multivitamin and mineral supplements but now takes only zinc. Physical examination shows gait ataxia with loss of vibration and position sensation in the feet. There is mild lower extremity edema and scattered areas of skin depigmentation. Laboratory studies reveal hypochromic microcytic anemia. Deficiency of which of the following is the most likely cause of this patient's current condition?

Question

A 46-year-old woman comes to the office due to worsening lower extremity tingling and numbness.  She has also had difficulty walking, especially at night.  Review of systems is positive for hair loss.  The patient had gastric bypass surgery 5 years ago and has lost 30 kg (66 lb).  She was originally prescribed multivitamin and mineral supplements but now takes only zinc.  Physical examination shows gait ataxia with loss of vibration and position sensation in the feet.  There is mild lower extremity edema and scattered areas of skin depigmentation.  Laboratory studies reveal hypochromic microcytic anemia.  Deficiency of which of the following is the most likely cause of this patient's current condition?

Quizplus · Accepted Answer

11ec25c8_d92f_8627_bc81_e13f78fc2af5_MD0003_00 This woman with distal extremity paresthesia, loss of proprioception and vibration sense, and ataxia has peripheral neuropathy. In association with anemia, skin depigmentation, and edema, this presentation suggests copper deficiency. Acquired copper deficiency is most often due to malabsorption from prior gastric surgery (eg, bariatric surgery). Other risk factors include chronic malabsorptive syndromes (eg, inflammatory bowel disease, celiac disease) and excessive ingestion of zinc, which competes with copper for absorption in the gastrointestinal tract. Copper is a required cofactor in many enzymes, including those involved with protein synthesis, cellular division, iron absorption, and normal central nervous system function. Neurologic manifestations are often the presenting symptoms and begin several years after surgery with a slowly progressive myeloneuropathy similar to subacute combined degeneration from B12 deficiency (eg, paresthesia, numbness, sensory ataxia). Myelopathic symptoms (eg, spasticity, upper motor neuron signs) occur in advanced disease. Hematologic abnormalities are also characteristic. Hypochromic microcytic anemia occurs from copper deficiency-induced impairment of iron absorption, although macrocytic or normocytic anemia is also common. Leukopenia may occur. Other symptoms include hair fragility, skin depigmentation, hepatosplenomegaly, edema, and osteoporosis. The diagnosis is confirmed with low serum copper and ceruloplasmin levels; management includes copper supplementation and discontinuation of zinc. (Choice B) Acute thiamine deficiency can occur after bariatric surgery and results in Wernicke encephalopathy. Although ataxia is common, it typically also causes abrupt onset oculomotor dysfunction and confusion. Korsakoff syndrome is a late manifestation characterized by severe anterograde and retrograde amnesia. Anemia and skin findings are unexpected. (Choice C) Selenium deficiency causes cardiomyopathy and macrocytosis, as well as immune and thyroid dysfunction. It does not typically cause neuropathy or microcytic anemia. (Choice D) Folate deficiency typically causes a megaloblastic, macrocytic anemia (mean corpuscular volume >100 μm³); neurologic dysfunction and skin changes would be unexpected. (Choice E) Vitamin C deficiency classically causes scurvy, which is characterized by petechiae, perifollicular hemorrhage, gingivitis, bruising, and poor wound healing, none of which is seen in this patient. Educational objective: Copper deficiency typically occurs in patients with a history of gastric surgery (eg, bariatric), chronic malabsorption (eg, inflammatory bowel disease), or excessive zinc ingestion. Symptoms include slowly progressive myeloneuropathy similar to that of vitamin B₁₂ deficiency (eg, distal extremity paresthesia, numbness, sensory ataxia), anemia, hair fragility, skin depigmentation, hepatosplenomegaly, edema, and osteoporosis.

A 46-Year-Old Woman Comes to the Office Due to Worsening