A 58-year-old male with a significant smoking history and long-standing hypertension presented to the emergency department after noticing severe spatial neglect and clumsiness upon waking. He reported repeatedly bumping into doorframes and furniture situated on his left side. On detailed history taking, he recalled an episode six months prior involving sudden, transient numbness and clumsy weakness in his left hand and arm that resolved spontaneously within fifteen minutes, for which he never sought medical care.
Physical examination demonstrated an elevated blood pressure of $172/88\text{ mmHg}$. Neurological testing revealed a left lower quadrantanopia alongside spatial extinction on the left side during double simultaneous cutaneous stimulation. Laboratory investigations revealed an elevated $\text{HbA}_{1\text{c}}$ of 7.2% and an LDL cholesterol level of $105\text{ mg/dL}$. Neuroimaging via brain MRI identified a prominent acute ischemic zone involving the right temporal-parietal cortex within the middle cerebral artery (MCA) vascular territory, along with two distinct, well-circumscribed chronic encephalomalacic lesions located in the right frontal lobe.
Pathophysiology & Diagnostics
The patient's clinical history and neuroimaging establish a clear pattern of recurrent vascular events restricted entirely to the right anterior cerebral circulation. Although cardiac embolic sources such as atrial fibrillation frequently cause hemispheric strokes, a cardiac source typically showers emboli into multiple distinct vascular distributions, often producing bilateral or combined anterior and posterior circulation lesions. Conversely, atherothromboembolic lesions originating from high-grade stenosis or an ulcerated plaque at the right internal carotid artery bifurcation consistently release micro-emboli into the same downstream vessel, explaining the recurrent unilateral presentation. Microvascular diseases related to chronic hypertension or diabetes typically cause small subcortical lacunar strokes rather than extensive wedge-shaped cortical lesions accompanied by spatial neglect.
Management Strategy
Vascular Workup: Order urgent non-invasive vascular imaging (CTA or Carotid Duplex) to evaluate the severity of right internal carotid artery stenosis.
Surgical Revascularization: Consider Carotid Endarterectomy (CEA) or Carotid Artery Stenting (CAS) if significant symptomatic stenosis ($70\%\text{--}99\%$) is identified.
Secondary Prevention: Implement short-term Dual Antiplatelet Therapy (DAPT), high-intensity statin therapy to target LDL $<55\text{ mg/dL}$, strict blood pressure management, and smoking cessation protocols.
| Diagnostic Tool | Clinical Purpose | Typical Imaging Findings |
| Diffusion MRI (DWI) | Detect acute cytotoxic edema | Hyperintensity in the right MCA cortex confirming acute ischemia. |
| Carotid Duplex Ultrasound | Non-invasive vascular assessment | Quantifies peak systolic velocity and estimates luminal narrowing at the carotid bulb. |
| CT / MR Angiography | Structural vascular mapping | Identifies vessel tortuosity, plaque vulnerability, and calcification prior to intervention. |