WBR0289

Author	[[PageAuthor::Ogheneochuko Ajari, MB.BS, MS [1] (Reviewed by Yazan Daaboul, M.D.)]]
Exam Type	ExamType::USMLE Step 1
Main Category	MainCategory::Pathophysiology
Sub Category	SubCategory::Neurology
Prompt	[[Prompt::A 76-year-old man presents to the emergency department (ED) with complaints of headache, difficulty maintaining balance, and progressive memory loss. Ten days prior to presentation, he was involved in a motor vehicle accident. On physical examination in the ED, the man appears alert and oriented to persons, but not to either place or time. A CT scan of the head with no contrast demonstrates a crescent-shaped isodense lesion that crosses the suture lines but not the dural attachments. A rupture in which of the following structures is most likely responsible for this patient's symptoms?]]
Answer A	AnswerA::Rupture of the middle meningeal artery
Answer A Explanation	[[AnswerAExp::Rupture of the middle meningeal artery results in epidural hematoma.]]
Answer B	AnswerB::Rupture of an aneurysm
Answer B Explanation	[[AnswerBExp::Rupture of an aneurysm results in subarachnoid hemorrhage, which may occur as a complication of Marfan’s syndrome, Ehlers-Danlos syndrome, adult polycystic kidney disease, or arteriovenous malformation.]]
Answer C	AnswerC::Rupture of bridging veins
Answer C Explanation	AnswerCExp::Rupture of bridging veins results in subdural hematoma.
Answer D	AnswerD::Rupture of the anterior communicating artery
Answer D Explanation	[[AnswerDExp::Rupture of the anterior communicating artery is associated with visual field defects.]]
Answer E	AnswerE::Rupture of the posterior communicating artery
Answer E Explanation	[[AnswerEExp::Rupture of the posterior communicating artery is associated with CN III palsy.]]
Right Answer	RightAnswer::C
Explanation	[[Explanation::Subdural hematoma forms between the arachnoid membranes and the dura. It is commonly caused by rupture of the bridging veins that drain from the brain surface to the dural sinuses. Both epidural and subdural hematomas do not cross the dural lines. However, subdural hematoma can cross the suture lines whereas epidural hematoma cannot. On unenhanced CT scan, a subdural hematoma appears as a crescent-shaped lesion, whereas epidural hematoma appears as a lens-shaped lesion. The patient in this vignette is presenting with neurological symptoms that should raise subdural hematoma as a differential diagnosis. Subdural hematomas are often observed in patients with brain atrophy, such as elderly individuals or alcoholics, spontaneously or following blunt head trauma (eg. motor vehicle accident or falls). Following the acute phase injury, patients may experience neurological decline within 24-48 hours (acute), within 14 days of the initial injury (subacute), or even beyond 15 days (chronic). Symptoms may vary and often include: headache, vomiting, cranial nerve palsies, ataxia, somnolence, or cognitive impairment. In children, subdural hematomas mostly occur following abuse as a result of shaken baby syndrome. Educational Objective: Subdural hematoma usually results from the rupture of the bridging veins. References: Victor M, Ropper A. Craniocerebral trauma. In: Adams and Victor's Principles of Neurology, 7th ed, Victor M, Ropper A. (Eds), McGraw-Hill, New York 2001. p.925. First Aid 2014 page 462]]
Approved	Approved::Yes
Keyword	WBRKeyword::Subdural hematoma, WBRKeyword::Headache, WBRKeyword::Memory loss, WBRKeyword::Bridging veins
Linked Question	Linked::
Order in Linked Questions	LinkedOrder::