A Case of Atypical Alzheimer's Disease With Clinical Manifestation That Straddled the Boundary Between Primary Progressive Aphasia and Posterior Cortical Atrophy

Introduction: In the context of Alzheimer's disease phenotypes, patients may present with symptoms and signs that do not exclusively fit into one of the existing phenotypic categories, which often delays timely diagnosis and initiation of services to optimize patient awareness and coping. Case Report: A 74-year-old woman presented with the complaint of progressive word-finding difficulty, raising our suspicion for primary progressive aphasia. Clinical evaluations, however, also revealed emerging cortical visual deficits consistent with posterior cortical atrophy. During evaluation 1 year later, Gerstmann syndrome was evident. Her in vivo neuroimaging was positive for beta-amyloid and tau biomarkers of Alzheimer's disease pathology. Conclusion: In addition to contributing to the literature on the heterogeneity of the clinical manifestations of Alzheimer's disease, this report highlights that a breakdown in the visual-lexical interface can account for anomia in posterior cortical atrophy at least in some cases. Other relevant clinical insights pertinent to this case are discussed.