A patient presented with right sided hemiplegia while on warfarin. Which of the following will be the initial investigation of choice?
**Core Concept**
Warfarin-induced hemiplegia is a rare but serious condition that can occur due to warfarin-induced cerebral sinus thrombosis or cerebral hemorrhage. The underlying principle being tested here is the need to investigate the cause of hemiplegia in a patient on anticoagulation therapy.
**Why the Correct Answer is Right**
The initial investigation of choice in this scenario is a non-contrast computed tomography (CT) scan of the brain. This is because CT scans are highly sensitive for detecting acute hemorrhage, which is a life-threatening complication of warfarin therapy. A CT scan can quickly identify a hemorrhage, which would necessitate immediate reversal of anticoagulation and surgical intervention if necessary. In contrast, magnetic resonance imaging (MRI) may be more sensitive for detecting cerebral sinus thrombosis but takes longer to perform and may not be as readily available.
**Why Each Wrong Option is Incorrect**
**Option A:** **CT angiography** may be useful in detecting cerebral sinus thrombosis but is not the initial investigation of choice in this scenario.
**Option B:** **Magnetic Resonance Angiography (MRA)** may be useful in detecting cerebral sinus thrombosis but is not as sensitive as CT for detecting acute hemorrhage.
**Option C:** **Carotid Doppler ultrasound** is not relevant to this scenario as it is used to evaluate carotid artery disease.
**Clinical Pearl / High-Yield Fact**
It's essential to remember that a patient on anticoagulation therapy presenting with new neurological symptoms requires immediate investigation with a non-contrast CT scan of the brain to rule out hemorrhage.
**Correct Answer: C. Non-contrast CT scan of the brain.**