Beyond Words: A Case of Pure Alexia Following Posterior Cerebral Artery Occlusion

Abstract

Alexia is an acquired reading disorder known as pure alexia or alexia without agraphia when unaccompanied by other higher-level deficits. We present the case of a 40-year-old man experiencing a sudden-onset headache and blurred vision. Despite an absence of known medical history, the patient exhibited a distinctive difficulty in reading without impairing other language aspects accompanied by a right superior homonymous quadrantanopia. Through comprehensive ophthalmological and neurological evaluations, a diagnosis of pure alexia was established. An imaging scan uncovered a left posterior cerebral artery occlusion as the underlying cause. Meticulous assessments of visual acuity, perimetry, and non-visual functions played a pivotal role in decisively diagnosing this condition. This case emphasizes the indispensable role of ophthalmologists in recognizing urgent clinical conditions that extend beyond ophthalmic concerns.

Keywords: hemianopsia; homonymous quadrantanopia; ischemic stroke; posterior cerebral artery; pure alexia.

Figure 1. Standard 30-2 computerized perimetry of the left (A) and right (B) eyes showing a right superior homonymous quadrantanopia (“pie in the sky”).

Figure 2. Hypodense occipitotemporal cortical-subcortical lesion on the left side (green arrow) in the contrast-enhanced computed tomography of the brain.