A-117 Posterior Cortical Atrophy Case Study: Neuropsychological Assessment Remains Gold Standard Diagnostic Tool of Choice

Abstract

Abstract Objective: Posterior cortical atrophy (PCA) is a rare, early onset, neurodegenerative syndrome that is characterized by impaired visuospatial/visual-constructional skills. Patients describe vague visual symptoms; however, ocular assessments are usually normal. Alzheimer's disease is the most common underlying cause of PCA; however, brain MRI is often unrevealing early in the disease. As a result, accurate diagnosis is often delayed. Method: The patient was initially referred in 2016 for a concussion evaluation following a work-related head injury when she was 54. Initial MRI of the brain was unremarkable. Neuropsychological testing was repeated in 2019, which was the first diagnostic test to establish a diagnosis of PCA. Subsequently, MRI of the brain with volumetric analysis showed total hippocampal volume to be at the 99th percentile and no pattern of cerebral volume loss to suggest a specific diagnosis. However, CSF biomarker assays were consistent with a diagnosis of Alzheimer’s disease. Results: The patient’s initial cognitive profile in 2016 reflected mild cognitive impairment, multidomain type with severely impaired visual-constructional skills, which were unrelated to her concussion. Neuropsychological testing was repeated in 2019, which showed interval progressive cognitive and functional decline. Profound visual-constructional impairments were again noted (see image), and she met criteria for PCA. Neuropsychological testing was repeated in 2021 and showed progression to moderate dementia with features of Gerstmann's syndrome. Conclusions: In spite of sophisticated neuroimaging techniques and increasing access to CSF biomarker analysis, neuropsychological assessment remains the gold standard diagnostic tool of choice for neurologists faced with rare dementia syndromes, such as PCA. See patient video at: https://youtu.be/9HdAKSL5alg