Rare dementias

Abstract

Dementia is becoming a worldwide phenomenon. Alzheimer’s disease represents the first cause of cognitive impairment followed by vascular dementia and fronto-temporal dementia. However, in addition to these well-studied dementia causes there is a wide number of conditions that can cause dementia as infections, toxic-metabolic conditions, inflammatory-autoimmune disorders, or metabolic inborn errors. These uncommon dementia causes, due to the heterogeneous clinical presentation, lack of diagnostic criteria, and rare frequency are often misdiagnosed. Their prevalence has been only partially estimated among young patients (age at onset < 65 years), and their management is based only on some expert suggestions. However, a correct diagnosis is of a great importance, since some of them are treatable and reversible dementias. This chapter presents a comprehensive summary of etiologies, clinical presentation, typical features, diagnostic strategies, and treatments of known uncommon dementias.