Young-onset Alzheimer Disease

Young-onset AD refers to Alzheimer’s disease manifesting before age 65. Clinical features include progressive memory loss, executive dysfunction, language impairment, and behavioral changes. Etiology involves genetic predisposition (APP, PSEN1/2 mutations) and environmental factors. Pathophysiology includes amyloid-beta deposition, tau neurofibrillary tangles, and synaptic loss. Diagnosis relies on neuropsychological testing, imaging (MRI, PET), and CSF biomarkers. Management includes cholinesterase inhibitors, NMDA receptor antagonists, and supportive care; prognosis involves progressive cognitive decline, often with earlier functional impairment than late-onset AD.