WBR0343

Author	[[PageAuthor::Serge Korjian M.D. (Reviewed by Alison Leibowitz) (Reviewed by Serge Korjian)]]
Exam Type	ExamType::USMLE Step 1
Main Category	MainCategory::Pathophysiology
Sub Category	SubCategory::Neurology
Prompt	[[Prompt::A 64-year-old man presents to the emergency department with acute onset headache, severe nausea, and vomiting. The patient reports that the pain woke him up and he has vomited four times since the episode began. Shortly after arrival, the patient loses consciousness and attempts at arousal are unsuccessful. An emergent brain CT scan is illustrated below. Taking into consideration the presence of a structural abnormality, which of the following is the most important risk factor for this patient's condition? ]]
Answer A	AnswerA::Smoking
Answer A Explanation	[[AnswerAExp::Smoking is not associated with an increased risk of Charcot-Bouchard aneurysms, but may increase the risk of ischemic strokes.]]
Answer B	AnswerB::Hypertension
Answer B Explanation	[[AnswerBExp::Hypertension is the major risk factor for Charcot-Bouchard aneurysms and intraparenchymal bleeds, with 90% of patients presenting with high blood pressure. Hypertension is the single most important risk factor for all types of strokes.]]
Answer C	AnswerC::Diabetes mellitus
Answer C Explanation	[[AnswerCExp::Diabetes mellitus is not associated with an increased risk of Charcot-Bouchard aneurysms, but may increase the risk of ischemic strokes.]]
Answer D	AnswerD::Marfan syndrome
Answer D Explanation	[[AnswerDExp::Marfan syndrome is associated with an increased risk of berry aneurysms and subarachnoid hemorrhage, but not Charcot-Bouchard aneurysms nor intraparenchymal bleeds.]]
Answer E	AnswerE::Polycystic kidney disease
Answer E Explanation	[[AnswerEExp::Polycystic kidney disease is classically associated with an increased risk of developing berry aneurysms and subsequent subarachnoid hemorrhage. The disorder itself not directly associated with an increased risk of Charcot-Bouchard aneurysms.]]
Right Answer	RightAnswer::B
Explanation	[[Explanation::Charcot-Bouchard aneurysms, or microanneurysms, are small dilatations in the brain vasculature that are characteristically located in vessels less than 300 μm in diameter. These aneurysms are usually located in the deep brain structures, particularly the basal ganglia, thalamus, and internal capsule. Charcot-Bouchard aneurysms are linked to chronic uncontrolled hypertension, and are a common cause of hemorrhagic strokes, frequently originating in the basal ganglia, thalamus, pons, or subcortical white matter. Typical manifestations include focal neurological signs, headache, nausea, and altered levels of consciousness. Depending on extent of the hemorrhage, CT scans usually display a localized area of hyperdensity (which appears bright) in the brain parenchyma, typically resembling the image above. Educational Objective: Charcot-Bouchard aneurysms, a major cause of hemorrhagic strokes, are associated with chronic hypertension. References: Image courtesy of Dr Frank Gaillard. Radiopaedia (original file here). Creative Commons BY-SA-NC Strandgaard S, Paulson OB. Cerebrovascular consequences of hypertension. Lancet. 1994;344(8921):519-21.]]
Approved	Approved::Yes
Keyword	WBRKeyword::Charcot-Bouchard aneurysms, WBRKeyword::Hypertension, WBRKeyword::Aneurysm, WBRKeyword::Brain, WBRKeyword::Hemorrhagic stroke, WBRKeyword::Stroke, WBRKeyword::ICH, WBRKeyword::Coma, WBRKeyword::Microaneurysm
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