A 58-year-old man with a 10-year history of hypertension presents to the emergency department with sudden-onset severe headache, neck stiffness, and photophobia. On examination, he is drowsy with a blood pressure of 180/110 mmHg. Non-contrast CT head performed within 2 hours of symptom onset shows hyperdense material in the basal ganglia extending into the lateral ventricles. What is the most likely location of the primary hemorrhage?

## Clinical Presentation & Imaging Correlation **Key Point:** Hypertensive intracerebral hemorrhage (ICH) has characteristic locations based on the affected small penetrating arteries. The basal ganglia (putamen and external capsule) is the most common site, accounting for 35–50% of hypertensive ICH cases. ## Pathophysiology of Hypertensive ICH Chronic hypertension damages the walls of small penetrating arteries (lipohyalinosis), leading to rupture. The distribution follows arterial anatomy: | Location | Artery | Frequency | Clinical Features | |----------|--------|-----------|-------------------| | **Basal ganglia / putamen** | Lenticulostriate arteries (lateral) | 35–50% | Contralateral hemiparesis, hemisensory loss, aphasia (if dominant) | | Thalamus | Thalamoperforating arteries | 15–25% | Vertical gaze palsy, sensory loss, altered consciousness | | Pons | Pontine perforating arteries | 5–12% | Pinpoint pupils, quadriplegia, coma | | Cerebellum | Superior cerebellar artery | 5–10% | Ataxia, headache, hydrocephalus risk | | Lobar (cortical) | Cortical branches | 10–20% | Often associated with amyloid angiopathy in elderly | **High-Yield:** The **putamen/external capsule** is the single most common site of hypertensive ICH. Ventricular extension (as seen in this case) indicates a larger hemorrhage and is associated with worse prognosis. ## CT Imaging Features **Clinical Pearl:** Non-contrast CT is the gold standard for acute ICH detection. Hyperdense material (>60 HU) represents acute blood. Ventricular extension is a poor prognostic sign and increases risk of obstructive hydrocephalus. **Mnemonic: CHANT** — Common sites of Hypertensive hemorrhage: - **C** — Cerebellum (5–10%) - **H** — Hyperthalamus (15–25%) - **A** — Anterior/basal ganglia (35–50%) - **N** — Nucleus (putamen) - **T** — Thalamus ## Why This Patient's Hemorrhage is in the Basal Ganglia 1. **Hypertension** — 10-year history is the primary risk factor 2. **Acute presentation** — sudden severe headache with meningeal signs (neck stiffness, photophobia) due to ventricular extension 3. **CT location** — hyperdensity in basal ganglia with intraventricular extension is pathognomonic for putaminal ICH 4. **Age and demographics** — 58-year-old with uncontrolled hypertension fits the typical profile [cite:Harrison 21e Ch 296]