Visual Agnosia Mimicking Memory Impairment: A Case Report of Posterior Cortical Atrophy

Vision specialists will benefit from increased awareness of posterior cortical atrophy (PCA) syndrome. Failure to adequately identify the chief complaint as a visual symptom may lead to incorrect diagnosis or diagnostic delay. A previously healthy, 59-year-old woman presented with a 5-year history of 'losing her stuff'. Upon psychiatric and neuro-ophthalmological evaluation, this symptom was better recognised as a feature of visual agnosia and simultanagnosia. She also presented with multiple previously unrecognised symptoms indicative of higher visual processing dysfunction, such as alexia without agraphia, ocular motor apraxia, optic ataxia, prosopagnosia, akinetopsia and topographagnosia, so further assessment to investigate for PCA was carried out. After a work-up including cognitive assessment, brain structural/functional imaging, and laboratory tests she was diagnosed with visual-variant Alzheimer's disease. Patients with PCA merit a detailed review of their symptoms, as well as the use of office tests such as cognitive evaluation tools, different types of perimetry, colour vision tests, and non-delayed psychiatric consultation for correct management and assessment. This report will emphasise five key aspects to be considered when evaluating patients with PCA.