Alzheimer’s disease (AD) represents between 50% and 75% of dementia cases worldwide. It is classified into two types: Late-onset (LOAD), which is common in individuals over 65 years old, and Early-onset (EOAD), which affects 5-10% of individuals before the age of 65. Its manifestations vary considerably, ranging from typical amnestic presentation in LOAD to atypical forms such as non-fluent aphasia, executive, and visuoperceptive alterations in EOAD, which makes timely diagnosis difficult.
Currently, the diagnostic model goes beyond conventional, proposing the use of biomarkers in cerebrospinal fluid for early detection and management.
In the case presented, we describe a 57-year-old woman with EOAD, characterized by a two-year history of progressive and insidious memory loss accompanied by logopenic aphasia and behavioral changes. In her family history, the patient had a history of dementia in three generations on the maternal side. To confirm the diagnosis, complementary studies were performed such as conventional brain magnetic resonance imaging with perfusion sequences and the measurement of Tau protein and Beta-amyloid peptide biomarkers in cerebrospinal fluid. These analyses confirmed the presence of early-onset Alzheimer’s disease.
In this study, we discuss the diagnostic process of Alzheimer’s disease, emphasizing in the use of biomarkers in cerebrospinal fluid.



