A Rare Case of Artery of Percheron Infarction: Diagnostic Challenges and Management

The Artery of Percheron (AOP) is a rare anatomical variant in the posterior circulation, where a single arterial trunk supplies both the paramedian thalami and the rostral midbrain bilaterally. Infarction of the AOP can result in altered mental status, memory deficits and vertical gaze palsy. However, early diagnosis remains challenging, as initial Computed Tomography (CT) scans often fail to detect subtle ischaemic changes. This underscores the critical need for the early use of advanced imaging techniques, particularly Magnetic Resonance Imaging (MRI), to improve diagnostic accuracy and expedite management. In this case, a 66-year-old male presented with sudden-onset severe drowsiness and unresponsiveness. Initial CT imaging did not reveal abnormalities, delaying diagnosis and ruling out thrombolytic therapy, which is most effective within 4.5 hours of symptom onset. Subsequent MRI identified bilateral thalamic and left midbrain infarction consistent with AOP occlusion. Management focused on supportive care, secondary stroke prevention with antiplatelet therapy, and rehabilitation. Despite the delayed intervention, the patient demonstrated gradual neurological improvement, highlighting the importance of tailored care in rare ischaemic stroke subtypes. Early identification and treatment remain essential for optimising outcomes and minimising long-term deficits. This case emphasises the importance of advanced imaging for diagnosing AOP infarction, a condition often missed on early CT scans, and highlights the challenge of timely diagnosis in ischaemic stroke management.