Bilateral thalamic infarction with posterior cerebral artery variant (the arcade artery): A case report

Rationale: Bilateral thalamic infarction is a rare type of posterior circulation stroke, and it often presents with a reduced level of consciousness in the elderly. Arteriosclerosis is the primary etiology of bilateral thalamic infarction, including conditions such as native vessel stenosis or arterial-to-arterial embolism. Cardiogenic or paradoxical embolism can also lead to thrombosis of the perforator branches innervating the thalamus, and these emboli tend to disintegrate and lead to multiple lesions, even in elderly patients.

Patients concerns: A 69-year-old man presented to our emergency room with sudden onset of drowsiness lasting for 2 days. A computed tomography scan revealed bilateral hypodense thalamic lesions, which resembled artery of Percheron infarcts. Magnetic resonance imaging confirmed cerebral infarction in the posterior circulation. Magnetic resonance angiography and diagnostic digital subtraction angiography suggested a suspicious embolus obstructing the junction between the arcade artery and the left posterior cerebral artery, which had further migrated. Echocardiography, 24-hour Holter monitoring, and deep venous ultrasonography were all negative; however, transesophageal echocardiography revealed a patent foramen ovale.

Diagnosis: Paradoxical embolism is a rare occurrence in older adults. However, when considering the etiology of stroke in this patient, paradoxical embolism should remain a priority in the diagnostic process following a multifactorial risk assessment.

Intervention: The patient was treated with antiplatelet, statin therapy, and foramen ovale closure.

Outcome: He recovered well after the interventional closure surgery and is currently under follow-up.

Lessons: The elderly experiencing a sudden drop in consciousness should be evaluated for thalamic lesions, primarily cerebral infarction in the posterior circulation. Anatomical artery variations may be helpful in attributing multiple and bilateral lesions to a single source of embolism. Digital subtraction angiography and transesophageal echocardiography can help to clarify the etiological categorization and formulate a secondary prevention strategy for cerebral infarction. Paradoxical embolism is a diagnostic dilemma in the elderly population, and treatment principles must be integrated with guidelines, the prospectively validated patent foramen ovale-associated stroke causal likelihood risk stratification system, interdisciplinary collaboration and customized analysis.