Dementia in Under 65s—An Overview

Abstract

Dementia is a broad category used to describe a neurodegenerative syndrome characterized by multidomain cognitive impairment that shows progressive decline and is sufficient to impact activities of daily living and occupation. When the dementia becomes clinically manifest before age 65, it is called early onset dementia (EOD), whereas if the symptoms arise onset before age 45, it is called young onset dementia (YOD). These terms are often used interchangeably. In the UK, approximately 850,000 people have a diagnosis of dementia, of which about 42,500 have YOD. 4.4% of people with Alzheimer’s dementia are less than 65 years of age. Various epidemiological studies show that the prevalence rates of early onset dementia (EOD) in the 30–64 age group range between 54 and 260 cases per 100,000. The rise in numbers is an emerging concern and is attributed to medical advances leading to increased life expectancy. YODs have unique presentations, atypical features and an extensive list of differential diagnoses which often make for a challenging clinical situation. There are often non-cognitive symptoms such as apathy, personality changes and resistant depression that precede the cognitive symptoms of dementia leading to delayed diagnosis. Additionally, EOD patients are at a point in life in which they play an active role in society and often have young families or children. The disruption to these roles and responsibilities is, therefore, greater than in older people. They also have to deal with specific problems such as marital conflicts, setbacks in their profession and financial issues. This chapter aims to summarize the symptomatology, etiologies, diagnostic strategies and psychosocial challenges in dementia in under 65 year olds.