Pathophysiology Practice Questions

Correct Answer: C

Rationale: The correct answer is dementia with Lewy bodies (DLB). Hallucinations, parkinsonian symptoms (like bradykinesia and limb rigidity), and fluctuating cognition are characteristic of DLB. Alzheimer's disease (Choice A) typically presents with memory loss as a prominent feature. Vascular dementia (Choice B) is associated with a history of strokes and step-wise cognitive decline. Frontotemporal dementia (Choice D) often presents with changes in behavior and personality rather than the parkinsonian symptoms seen in this case.

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.

Correct Answer: C

Rationale: The clinical findings of thin hair, exophthalmos, hyperreflexia, and pretibial edema are classic features of Graves disease, an autoimmune disorder that results in hyperthyroidism. Exophthalmos (bulging eyes) and pretibial edema (swelling in the lower legs) are particularly associated with Graves disease due to the autoimmune stimulation of the thyroid gland, leading to increased thyroid hormone production. Subacute thyroiditis (Choice A) typically presents with neck pain and tenderness, while autoimmune thyroiditis (Choice B) is commonly known as Hashimoto's thyroiditis, which presents with hypothyroidism symptoms. Hashimoto's disease (Choice D) is characterized by goiter and hypothyroidism, which contrasts with the hyperthyroidism seen in this patient.

Correct Answer: C

Rationale: The correct answer is C: 'It is usually triggered when the patient bends forward.' Benign positional vertigo is often triggered by changes in head position, such as bending forward. Choices A, B, and D are incorrect. A is incorrect because benign positional vertigo is not typically associated with headaches. B is incorrect because pupillary changes are not a common feature of benign positional vertigo. D is incorrect because nystagmus in benign positional vertigo usually stops when the eyes fixate on an object.

Correct Answer: B

Rationale: Bullous impetigo is the correct answer because it is caused by a Staphylococcus aureus toxin that leads to exfoliation and the formation of large blisters. Herpes simplex I virus (Choice A) causes cold sores and is not associated with exfoliation and blister formation. Necrotizing fasciitis (Choice C) is a severe skin infection involving the deeper layers of skin and subcutaneous tissues, typically caused by bacteria such as Streptococcus or Clostridium species, not Staphylococcus aureus. Cellulitis (Choice D) is a common bacterial skin infection, but it does not involve exfoliation and blister formation as seen in bullous impetigo.