WBR0540

Author	[[PageAuthor::Yazan Daaboul, M.D. (Reviewed by Alison Leibowitz) (Reviewed by Serge Korjian)]]
Exam Type	ExamType::USMLE Step 1
Main Category	MainCategory::Pathology
Sub Category	SubCategory::Neurology
Prompt	[[Prompt::A 74-year-old man is brought to the emergency department with a headache, decreased level of consciousness, and an altered mental state. Upon further questioning, the patient reports that he sustained a head trauma 2 weeks prior to presentation. His medical history is significant for coronary artery disease, type 2 diabetes mellitus, hypertension, and hyperlipidemia. A cranial CT scan demonstrates the findings in the image below. Which of the following causes best characterizes the patient's symptoms? ]]
Answer A	AnswerA::Rupture of an arterial branch of the maxillary artery
Answer A Explanation	[[AnswerAExp::Epidural hematoma results from a rupture of the meningeal artery, a branch of the maxillary artery. It is often due to a traumatic injury to the temporal bone. Epidural hematoma is characterized by a "lucid interval", a time delay before clinical symptoms manifest.]]
Answer B	AnswerB::Rupture of a bridging vein
Answer B Explanation	AnswerBExp::Subdural hematoma is characterized by crescent-shaped hemoarrhage upon CT scan.
Answer C	AnswerC::Rutpure of a berry aneurysm
Answer C Explanation	[[AnswerCExp::Subarachnoid hemorrhage often results from a rupture of a berry aneurysm. Berry aneurysms are frequently associated with three pathologies: Marfan syndrome, Ehler-Danlos syndrome, and adult-dominant polycystic kidney disease (ADPKD). Clinically, patients with subarachnoid hemorrhage complain of a severe, sudden-onset headache.]]
Answer D	AnswerD::Reversible ischemia caused by arterial vasoconstriction
Answer D Explanation	[[AnswerDExp::Transient ischemic attack (TIA) is characterized by a reversible vasoconstrictive process, which may manifest as cerebral ischemia and symptoms of stroke that often self-resolve. Although TIA is a reversible condition, it is a serious disease because it often heralds a stroke.]]
Answer E	AnswerE::Decrease in the rate of cerebrospinal fluid (CSF) absorption
Answer E Explanation	AnswerEExp::Communicating hydrocephalus is characterized by a decrease in CSF absorption, causing a build-up of CSF within the ventricles, leading to an increased intracranial pressure (ICP) and papilledema.
Right Answer	RightAnswer::B
Explanation	[[Explanation::A subdural hematoma is characterized by the rupture of a bridging vein. Because the venous pressure system is a low-presure system as compared to the arterial system, the build-up of blood following subdural hematoma is slow and gradual increase in hematoma size develops over a prolonged period of time. On CT scan, subdural hematoma appears as a crescent-shaped hemorrhage that does not cross the falx cerebra but may cross the suture lines. Educational Objective: Upon CT scan, subdural hematoma, resulting from a rupture of bridging veins, appears as a crescent-shaped hemorrhage that crosses the suture lines but is unable to cross the falx cerebri. References: First Aid 2014 page 462]]
Approved	Approved::Yes
Keyword	WBRKeyword::subdural hematoma, WBRKeyword::subarachnoid hemorrhage, WBRKeyword::subarachnoid hemorrhage, WBRKeyword::epidural hematoma, WBRKeyword::bridging veins, WBRKeyword::communicating hydrocephalus, WBRKeyword::aneurysm, WBRKeyword::headache, WBRKeyword::trauma, WBRKeyword::CT scan, WBRKeyword::TIA, WBRKeyword::transient ischemic attack, WBRKeyword::neurology, WBRKeyword::head trauma, WBRKeyword::rupture
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