Young-Onset Dementia

Abstract

Young-onset dementia (YOD) is an neurological syndrome that affects behavior and cognition of patients younger than 65 years of age. Although frequently misdiagnosed, a systematic approach, reliant upon attainment of detailed medical history, collateral history from an informant, neuropsychological testing, laboratory studies, and neuroimaging, may facilitate earlier and more accurate diagnosis with subsequent intervention. The differential diagnosis of YOD is extensive and includes early-onset forms of adult neurodegenerative conditions including Alzheimer's disease, vascular dementia, frontotemporal dementia, Lewy body dementias, Huntington's disease, and prion disease. Late-onset forms of childhood neurodegenerative conditions may also present as YOD and include mitochondrial disorders, lysosomal storage disorders, and leukodystrophies. Potentially reversible etiologies including inflammatory disorders, infectious diseases, toxic/metabolic abnormalities, transient epileptic amnesia, obstructive sleep apnea, and normal pressure hydrocephalus also represent important differential diagnostic considerations in YOD. This review will present etiologies, diagnostic strategies, and options for management of YOD with comprehensive summary tables for clinical reference.