Multiple sclerosis manifests as asymmetrical and in different parts of the body because:
- A. Autoreactive lymphocytes are causing diffuse patchy damage to the myelin sheath in the central nervous system.
- B. Acetylcholine receptors are destroyed by immunoglobulin G.
- C. Autoreactive T lymphocytes cause progressive loss of neurons in the substantia nigra.
- D. Cortical motor cells degenerate.
Correct Answer: A
Rationale: The correct answer is A. Multiple sclerosis is characterized by the immune system attacking the myelin sheath in the central nervous system. This attack leads to patchy damage on the myelin sheath, resulting in asymmetrical neurological symptoms. Choices B, C, and D are incorrect because they do not accurately describe the pathophysiology of multiple sclerosis. In multiple sclerosis, it is the autoreactive lymphocytes that target and damage the myelin sheath, not acetylcholine receptors, T lymphocytes, or cortical motor cells.
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In which patient would the manifestation of a headache be a sign of a serious underlying disorder?
- A. A 55-year-old man with new onset of headaches that are worse at night and reported mood swings according to his family
- B. A 30-year-old woman with a unilateral throbbing headache with photophobia and nausea
- C. A 60-year-old man with his head feeling full and throbbing and muscle aching around his neck and shoulders
- D. A 40-year-old woman who experiences food cravings, gets irritable, and then develops a pulsatile-like headache on the right side of her head
Correct Answer: A
Rationale: The correct answer is A. New onset headaches in older adults, especially if worse at night, may indicate a serious condition like a brain tumor. Choice B describes symptoms commonly seen in migraines. Choice C describes tension-type headaches. Choice D describes symptoms of a menstrual migraine which is not typically associated with a serious underlying disorder.
In a patient with chronic kidney disease and a hemoglobin level of 9 g/dL, which of the following treatments is most appropriate?
- A. Iron supplementation
- B. Erythropoiesis-stimulating agents
- C. Blood transfusion
- D. Vitamin B12 supplementation
Correct Answer: B
Rationale: In chronic kidney disease, anemia commonly occurs due to decreased erythropoietin production. Erythropoiesis-stimulating agents, such as erythropoietin or darbepoetin, are the mainstay of treatment to stimulate red blood cell production. Iron supplementation is more appropriate for iron-deficiency anemia, not the anemia of chronic kidney disease. Blood transfusion is reserved for severe cases or acute blood loss. Vitamin B12 supplementation is indicated for megaloblastic anemia caused by vitamin B12 deficiency, not specifically in chronic kidney disease-related anemia.
Which of the following conditions is associated with a positive Homan's sign?
- A. Deep vein thrombosis
- B. Peripheral artery disease
- C. Varicose veins
- D. Lymphedema
Correct Answer: A
Rationale: A positive Homan's sign is indicative of deep vein thrombosis. This sign is elicited by dorsiflexing the foot of a patient with the knee slightly flexed, resulting in calf pain. Peripheral artery disease (choice B) is associated with decreased blood flow to the extremities, but it does not produce a positive Homan's sign. Varicose veins (choice C) are enlarged, twisted veins that are typically not related to Homan's sign. Lymphedema (choice D) is swelling caused by a lymphatic system blockage or dysfunction and is not linked to Homan's sign.
Which of the following is a clinical manifestation in a patient with renal impairment associated with polycystic kidney disease?
- A. Suprapubic pain
- B. Periorbital edema
- C. Low serum creatinine level
- D. Palpable kidneys
Correct Answer: D
Rationale: The correct answer is D: Palpable kidneys. Polycystic kidney disease often leads to the development of multiple fluid-filled cysts within the kidneys, causing them to enlarge. Enlarged kidneys can be palpated during a physical examination. Choices A, B, and C are incorrect. Suprapubic pain is not a typical clinical manifestation of polycystic kidney disease. Periorbital edema is more commonly associated with conditions like nephrotic syndrome or heart failure. Low serum creatinine level is not expected in patients with renal impairment due to polycystic kidney disease; instead, elevated serum creatinine levels are more likely.
In which patient is alpha-1 antitrypsin deficiency the likely cause of chronic obstructive pulmonary disease?
- A. A 30-year-old who has smoked for 3 years
- B. A 65-year-old man who worked as a taxi driver most of his life
- C. A 70-year-old woman who smoked for 40 years
- D. A 50-year-old with exposure to secondhand smoke
Correct Answer: A
Rationale: The correct answer is A. Alpha-1 antitrypsin deficiency is a genetic condition that can lead to COPD at a young age, even in light smokers. Choice B is less likely as the patient's occupation does not directly correlate with alpha-1 antitrypsin deficiency. Choice C, a 70-year-old woman with a long smoking history, is more likely to have COPD due to smoking rather than alpha-1 antitrypsin deficiency. Choice D, exposure to secondhand smoke, is not a common cause of alpha-1 antitrypsin deficiency-related COPD.