A 58-year-old man with uncontrolled hypertension presents to the emergency department with sudden-onset severe headache, vomiting, and right-sided weakness. On examination, he is alert but has right hemiparesis and a blood pressure of 180/110 mmHg. Which investigation is the gold standard for confirming the diagnosis and determining the type of stroke?

Explanation

## Investigation of Choice in Acute Stroke **Key Point:** Non-contrast CT head is the gold standard first-line imaging in acute stroke because it rapidly distinguishes hemorrhagic from ischemic stroke, which is critical for treatment decisions. ### Why Non-Contrast CT Head? 1. **Speed**: Performed within minutes of arrival — essential in the acute setting where thrombolysis window is 4.5 hours. 2. **Hemorrhage detection**: Hyperdense blood is immediately visible on CT; sensitivity ~95% for acute ICH. 3. **Rules out contraindications**: Identifies intracranial bleeding before thrombolytic therapy, preventing catastrophic complications. 4. **Widely available**: Present in all emergency departments and stroke centers. ### Comparison of Investigations | Investigation | Sensitivity for ICH | Speed | Detects Ischemia | Timing in Acute Stroke | |---|---|---|---|---| | Non-contrast CT | 95% (acute) | Immediate (5 min) | No | **First-line** | | MRI DWI | 90% | 20–30 min | Yes (hyperintense) | After CT rules out hemorrhage | | CT perfusion | Variable | 10–15 min | Yes (mismatch) | Supplementary; not first-line | | Transcranial Doppler | N/A | 15–20 min | Assesses flow | Adjunctive only | **Clinical Pearl:** In this case, the acute presentation with hypertension, headache, and focal deficit strongly suggests hypertensive intracerebral hemorrhage (ICH). Non-contrast CT will show hyperdense blood in the basal ganglia or thalamus, confirming ICH and guiding management (no thrombolysis, hemostasis, BP control). **High-Yield:** The "CT-first" approach is standard of care in all major stroke guidelines (AHA/ASA, ESC) because it is the fastest way to differentiate hemorrhagic from ischemic stroke and is 95% sensitive for acute ICH. **Warning:** Do NOT delay CT for any other investigation. Even a 30-minute delay in imaging can mean loss of the thrombolysis window in ischemic stroke or worsening hematoma expansion in hemorrhagic stroke.