WBR0612
| Author | [[PageAuthor::Rim Halaby, M.D. [1]]] |
|---|---|
| Exam Type | ExamType::USMLE Step 1 |
| Main Category | MainCategory::Anatomy, MainCategory::Pathophysiology |
| Sub Category | SubCategory::Neurology |
| Prompt | [[Prompt::A 65-year-old right-handed male known to have poorly controlled hypertension and dyslipidemia is brought by his wife to the emergency department for sudden onset of right upper extremity paralysis and loss of sensation. MRI of the brain is shown below.
 Image courtesy of radiopaedia http://radiopaedia.org/cases/left-mca-infarction.]] |
| Answer A | AnswerA::Paralysis of the right lower extremity |
| Answer A Explanation | [[AnswerAExp::A stroke in the left MCA does not lead to paralysis of the right lower extremity, in fact, a stroke in the left anterior cerebral artery (ACA) may lead to paralysis of the right lower extremity.]] |
| Answer B | AnswerB::Loss of sensation on the left side of the face |
| Answer B Explanation | AnswerBExp::A stroke in the left MCA may lead to loss of sensation on the contralateral right side of the face and not the left side of the face. |
| Answer C | AnswerC::Hemineglect |
| Answer C Explanation | [[AnswerCExp::A stroke in the MCA in the non dominant right side of the brain may lead to hemineglect while a stroke in the MCA in the dominant left side of the brain may lead to aphasia.]] |
| Answer D | AnswerD::Abnormal gait |
| Answer D Explanation | AnswerDExp::Strokes in the posterior circulation and not in the MCA may lead to abnormal gait. |
| Answer E | AnswerE::Speech difficulty |
| Answer E Explanation | [[AnswerEExp::A stroke in the MCA in the dominant left side of the brain may lead to aphasia.]] |
| Right Answer | RightAnswer::E |
| Explanation | [[Explanation::The patient is presenting with right upper extremity hemiplegia and hemiparesis suggestive of a stroke in the middle cerebral artery (MCA). The MRI of the brain confirms a stroke in the MRA territory. A stroke in the dominant right lobe might lead to contralateral right sided hemiplegia and hemiparesis in the upper extremity and right side of the face as well as aphasia; hence, the patient is expected to have a speech difficulty. A stroke in the MCA territory of the non dominant right lobe might lead to hemineglect.
Shown below is an image depicting the vascular territories in the brain.  Educational objective:
A stroke in the dominant right lobe might lead to contralateral right sided hemiplegia and hemiparesis in the upper extremity and right side of the face as well as aphasia. |
| Approved | Approved::No |
| Keyword | WBRKeyword::Stroke, WBRKeyword::Aphasia, WBRKeyword::MCA |
| Linked Question | Linked:: |
| Order in Linked Questions | LinkedOrder:: |