WBR0893
| Author | [[PageAuthor::Ayokunle Olubaniyi, M.B,B.S [1]]] |
|---|---|
| Exam Type | ExamType::USMLE Step 2 CK |
| Main Category | MainCategory::Internal medicine |
| Sub Category | SubCategory::Neurology |
| Prompt | [[Prompt::A 78-year-old man with a past medical history of hypertension, hypercholesterolemia and diabetes is brought to the ED with an acute onset of impaired speech, right-sided hemiplegia, and right-sided facial palsy. He suddenly noticed that he was unable to hold his cutlery immediately he sat down at his daughter’s wedding rehearsal dinner nearly 2 hours ago. No history of trauma. He is on hydrochlorothiazide, lisinopril and pravastatin. His vitals reveals a blood pressure of 138/89 mmHg, heart rate of 85 beats per minute, respiratory rate of 16 breaths per minute, and he is saturating at 98%, while breathing room air. Examination reveals an elderly man, conscious and alert, not in any obvious painful distress. Lungs and cardiac were auscultations are unremarkable. Abdomen was non-tender, non-distended and without any hepatosplenomegaly. Neurological examination confirms the presenting complaints above. You suspect a slowly evolving stroke.
What is the best next step to take to confirm your diagnosis in the patient?]] |
| Answer A | AnswerA::Magnetic resonance imaging |
| Answer A Explanation | [[AnswerAExp::The sensitivity of standard MRI to detect hemorrhage in the acute setting is comparable with CT, and it is also recommended, especially in patients in whom radiation exposure is contraindicated (e.g., pregnant women). Standard MRI is also relatively insensitive to acute changes observed in brain ischemia.]] |
| Answer B | AnswerB::Carotid duplex ultrasound |
| Answer B Explanation | AnswerBExp::This is usually used for evaluating extracranial and intracranial atherosclerotic disease. It is rarely used in the acute setting. |
| Answer C | AnswerC::CT angiography |
| Answer C Explanation | AnswerCExp::Helical CT angiography (CTA) provides a rapid evaluation of intracranial and extracranial vessels in acute, subacute, and chronic stroke settings. It is used to determine the presence of vessel occlusions or stenoses. |
| Answer D | AnswerD::Diffusion-weighted imaging |
| Answer D Explanation | AnswerDExp::This is the most sensitive and most specific modality for the detection of acute infarct, especially with its ability to detect small cortical and subcortical lesions, which is a major limitation with the use of non-contrast enhanced CT. |
| Answer E | AnswerE::Non-contrast enhanced CT |
| Answer E Explanation | AnswerEExp::This is the most preferred modality in settings of acute stroke. |
| Right Answer | RightAnswer::E |
| Explanation | [[Explanation::This patient is experiencing symptoms suggestive of stroke or cerebrovascular accident (CVA). The term 'stroke' is used to describe pathological conditions caused by brain ischemia or hemorrhage. Therefore, the etiology of the patient’s symptoms may either result from brain ischemia (embolus, thrombus or systemic hypoperfusion) or hemorrhage into the brain parenchyma (intracerebral hemorrhage) or cerebrospinal space (subarachnoid hemorrhage).
In the acute setting, an urgent confirmation of the etiology is required, especially in cases with an onset <3 hours, who may be eligible for intravenous thrombolytic administration (i.e., recombinant TPA). Based on this, non-contrast enhanced CT is usually preferred due to its ability to exclude or confirm hemorrhage, easy access, ease of interpretation, speed of acquisition, widespread availability and cost effectiveness. Educational Objective: Non-contrast enhanced CT is the preferred immediate brain imaging to rule out or confirm hemorrhage in cases of suspected stroke. It is also easily accessible, and the most cost-effective strategy, when compared with other modalities. |
| Approved | Approved::No |
| Keyword | WBRKeyword::Stroke |
| Linked Question | Linked:: |
| Order in Linked Questions | LinkedOrder:: |