A 78-year-old man comes to the office due to a one-month history of progressive dyspnea, generalized weakness, fatigue, and palpitations. He also reports tingling and numbness in both lower limbs. His daughter, who is visiting from another state, adds that since his wife's death a year ago, the patient has not been taking care of himself. Blood pressure is 105/50 mm Hg and pulse is 104/min. Cardiovascular examination shows a displaced apical impulse at the sixth intercostal space, a third heart sound, and high-volume, collapsing carotid pulses. Bilateral basal crackles, 2+ bilateral pedal edema, and mild hepatomegaly are also present. Neurologic examination shows decreased light touch and vibration sense in the feet, with decreased knee and ankle reflexes bilaterally. Laboratory evaluation shows normal blood counts. Deficiency of which of the following nutrients is most likely responsible for this patient's symptoms?

Question

A 78-year-old man comes to the office due to a one-month history of progressive dyspnea, generalized weakness, fatigue, and palpitations.  He also reports tingling and numbness in both lower limbs.  His daughter, who is visiting from another state, adds that since his wife's death a year ago, the patient has not been taking care of himself.  Blood pressure is 105/50 mm Hg and pulse is 104/min.  Cardiovascular examination shows a displaced apical impulse at the sixth intercostal space, a third heart sound, and high-volume, collapsing carotid pulses.  Bilateral basal crackles, 2+ bilateral pedal edema, and mild hepatomegaly are also present.  Neurologic examination shows decreased light touch and vibration sense in the feet, with decreased knee and ankle reflexes bilaterally.  Laboratory evaluation shows normal blood counts.  Deficiency of which of the following nutrients is most likely responsible for this patient's symptoms?

Quizplus · Accepted Answer

11ec160b_36c4_0575_9249_f76265d52388_MD0001_00 Thiamine deficiency causes infantile and adult beriberi as well as Wernicke-Korsakoff syndrome (confusion, ataxia, oculomotor abnormalities, and permanent memory deficits). Manifestations of infantile beriberi appear at age 2-3 months and include a fulminant cardiac syndrome with cardiomegaly, tachycardia, cyanosis, dyspnea, and vomiting. Adult beriberi is categorized as dry or wet depending on cardiac involvement. Dry beriberi is characterized by symmetrical peripheral neuropathy of the distal extremities, with resulting sensory and motor impairments. Wet beriberi includes the addition of cardiac involvement (cardiomyopathy, high-output congestive heart failure, peripheral edema, and tachycardia). Central nervous system involvement (ie, Wernicke-Korsakoff syndrome) occurs primarily with heavy alcohol use. (Choice A) Ascorbic acid (vitamin C) deficiency causes scurvy (petechial hemorrhages, gingival swelling, impaired wound healing, and weakened immune response). (Choice B) Vitamin B₁₂ (cobalamin) deficiency typically presents as macrocytic anemia. Neurologic involvement can cause upper and lower motor neuron dysfunction and sensory peripheral neuropathy. (Choice C) Niacin deficiency causes pellagra (dementia, dermatitis, and diarrhea). (Choice D) Pyridoxine (vitamin B₆) deficiency is characterized by cheilosis, glossitis, dermatitis, and affective symptoms. (Choice E) Vitamin A (retinol) deficiency is characterized by night blindness, xerophthalmia, and vulnerability to infection (especially measles). (Choice F) Common manifestations of vitamin B₂ (riboflavin) deficiency include cheilosis, stomatitis, glossitis, anemia, and seborrheic dermatitis. Educational objective: Thiamine deficiency causes beriberi and Wernicke-Korsakoff syndrome. Dry beriberi is characterized by symmetrical peripheral neuropathy; wet beriberi includes the addition of high-output congestive heart failure.

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