A rare cause of coma with favorable recovery following early MRI diagnosis and multidisciplinary Management: a case report

The artery of Percheron (AOP) is a rare anatomical variant in which a solitary arterial trunk arises from one posterior cerebral artery to supply the bilateral paramedian thalami and rostral midbrain. Infarction in this territory is an uncommon cause of ischemic stroke and frequently presents with non-localizing features such as altered sensorium, vertical gaze palsy, memory impairment, or coma. Diagnosis is often delayed due to nonspecific clinical signs and limitations of early neuroimaging. We present a case of a 62-year-old male who arrived with sudden-onset coma (Glasgow Coma Scale score of 7). Initial non-contrast CT and CT angiography were unremarkable. However, persistent altered consciousness and signs of third cranial nerve involvement prompted an MRI brain, which demonstrated bilateral paramedian thalamic and rostral midbrain infarctions, consistent with AOP occlusion. The patient was outside the thrombolysis window. He was managed with dual antiplatelet therapy as an initial management and then switched to oral anticoagulation for newly diagnosed atrial fibrillation, and supportive neurocritical care. Two weeks later, he experienced transient deterioration due to post-stroke seizures, confirmed by EEG and effectively managed with antiepileptic therapy. At 6 weeks post-event, he had achieved functional independence with minimal residual deficits, including mild dysphagia and ptosis. AOP infarction should be suspected in patients presenting with acute unexplained coma or bilateral thalamic involvement. MRI is the diagnostic modality of choice. Early recognition facilitates appropriate medical and rehabilitative strategies. Despite the initial severity, favorable outcomes are achievable with timely diagnosis and multidisciplinary care.