'I Can See Letters but Cannot Read Sentences': A Case of Pure Alexia Without Agraphia Due to Left Posterior Cerebral...

Pure alexia without agraphia is a rare neurological condition characterised by the sudden loss of reading ability, while writing and verbal communication remain unaffected. It is typically associated with infarcts in the territory of the left posterior cerebral artery (PCA). Early recognition is essential, particularly when symptoms are subtle or atypical. We present the case of a woman in her 60s with a history of poorly controlled hypertension, type 2 diabetes mellitus, and a previous transient ischemic attack, who presented to the same-day emergency care unit with sudden-onset difficulty reading full sentences, despite being able to recognise individual letters. She reported no other focal neurological symptoms. On examination, visual acuity, writing ability, and motor and sensory functions were preserved. A non-contrast CT brain scan showed hypoattenuation in the left occipitotemporal region, and CT angiography revealed partial thrombosis of the distal left PCA. Electrocardiography showed atrial fibrillation, suggesting a potential cardioembolic source for the infarct. This case highlights the diagnostic challenge of posterior circulation stroke presenting as isolated reading impairment. It emphasises the importance of considering cerebrovascular causes in patients with atypical cognitive or visual disturbances. Early neuroimaging, particularly non-contrast CT brain, and evaluation for cardiac arrhythmias are crucial. Clinicians should maintain a high index of suspicion for rare stroke presentations in older patients with vascular risk factors to ensure timely diagnosis and management.