WBR0343

Author	[[PageAuthor::Serge Korjian M.D. (Reviewed by Serge Korjian and Yazan Daaboul, M.D.)]]
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 following arrival, the patient loses consciousness, and attempts at arousal are unsuccessful. An emergent brain CT scan is performed and is illustrated below. The physician suspects the patient has a structural abnormality in his brain that might have predisposed to his current symptoms. Which of the following is the most important risk factor associated with this patient's condition? ]]
Answer A	AnswerA::Smoking
Answer A Explanation	[[AnswerAExp::Smoking is not associated with an increased risk of Charcot-Bouchard aneurysms. Smoking is associated with an increased risk of ischemic strokes.]]
Answer B	AnswerB::Hypertension
Answer B Explanation	[[AnswerBExp::Chronic hypertension is the most important risk factor that is associated with Charcot-Bouchard aneurysms and intraparenchymal bleeds. 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. Diabetes mellitus 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. However, Marfan syndrome is not classically associated with an increased risk of Charcot-Bouchard aneurysms.]]
Answer E	AnswerE::Autosomal dominant Polycystic kidney disease
Answer E Explanation	[[AnswerEExp::Autosomal dominant polycystic kidney disease (ADPKD) is classically associated with an increased risk of developing berry aneurysms and subsequent subarachnoid hemorrhages. ADPKD is 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 smaller than 300 μm in diameter. Aneurysms are usually located in the deep brain structures, particularly in the basal ganglia, thalamus, and internal capsule. Charcot-Bouchard aneurysms are associated with chronic uncontrolled hypertension and are a common cause of hemorrhagic strokes, that frequently originates 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 the extent of the hemorrhage, CT scans usually display a localized area of hyperdensity in the brain parenchyma that typically resembles this patient's CT scan image (shown below). Educational Objective: Charcot-Bouchard aneurysms is a major cause of hemorrhagic strokes that is classically 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. First Aid 2014 page 461]]
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, WBRKeyword::Risk factor
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