WBR0289
| Author | [[PageAuthor::Ogheneochuko Ajari, MB.BS, MS [1]]] |
|---|---|
| Exam Type | ExamType::USMLE Step 1 |
| Main Category | MainCategory::Pathology |
| Sub Category | SubCategory::Neurology |
| Prompt | [[Prompt::A 38-year old male presents to the emergency room with a history of headache, decreasing loss of consciousness, difficulty with maintaining balance and progressive memory loss. 3-weeks prior to presentation, he was involved in a motor vehicle accident. CT scan of the head was ordered which revealed a crescent-shaped hemorrhage that crosses the suture lines. Which of the following mechanisms is involved in this patient’s symptoms?]] |
| Answer A | AnswerA::Rupture of the middle meningeal artery |
| Answer A Explanation | [[AnswerAExp::Incorrect. Rupture of the middle meningeal artery occurs with epidural hematoma]] |
| Answer B | [[AnswerB::Rupture of an aneurysm]] |
| Answer B Explanation | [[AnswerBExp::Incorrect. Rupture of an aneurysm occurs in subarachnoid hemorrhage (usually berry aneurysm in Marfan’s syndrome, Ehlers-Danlos syndrome, Adult polycystic kidney disease) or an arteriovenous malformation]] |
| Answer C | AnswerC::Rupture of bridging veins |
| Answer C Explanation | AnswerCExp::Correct. See explanation |
| Answer D | AnswerD::Rupture of anterior communicating arteries |
| Answer D Explanation | AnswerDExp::Incorrect. Rupture of anterior communicating arteries cause visual field defects |
| Answer E | AnswerE::Rupture of posterior communicating arteries |
| Answer E Explanation | [[AnswerEExp::Incorrect. Rupture of posterior communicating arteries causes CN III palsy]] |
| Right Answer | RightAnswer::C |
| Explanation | [[Explanation::The patient in this vignette is presenting with subdural hematoma, which occurs as a result of the rupture of bridging veins (Choice C). It is seen in elderly persons, alcoholics, blunt trauma and shaken baby syndrome (predisposing factors include brain atrophy, shaking, whiplash injuries). CT scan of the head would show crescent-shaped hemorrhage that crosses the suture lines with the gyri preserved because pressure is equally distributed.
Educational Objective Subdural hematoma occurs as a result of rupture of bridging veins Reference: First AID for the USMLE Step 1 2011 Pgs 405-406 |
| Approved | Approved::Yes |
| Keyword | |
| Linked Question | Linked:: |
| Order in Linked Questions | LinkedOrder:: |