Dementia

Overview

Dementia is defined by loss of cognitive functioning—thinking, remembering and reasoning—to a degree that interferes with daily life. The syndrome can also affect language, visual-spatial abilities, judgment, emotion and personality. Age is the strongest risk factor for many dementias, but dementia is not inevitable: many people live into their 90s without dementia. ^[1]

Alzheimer disease is the most common cause in older adults. Vascular dementia reflects cerebrovascular injury; Lewy body dementia can include visual hallucinations, cognitive fluctuations and parkinsonism; frontotemporal dementia often causes early behavior, personality or language change and may begin at a younger age. Multiple pathologies often coexist. ^{[1] [2]}

Symptoms and warning signs

Early symptoms can include repeated forgetting of recent information, difficulty managing bills or medicines, getting lost in familiar places, word-finding problems, impaired judgment, personality change or loss of initiative. Later stages can affect eating, mobility, continence, communication and basic self-care. Sudden confusion over hours or days is not the expected course of dementia and should prompt assessment for delirium, stroke, infection or another acute problem. ^{[1] [2]}

Diagnosis

Diagnosis starts with history from the person and someone who knows their daily function well. Clinicians assess which cognitive domains changed, when the change began, how it affects independence, mood and behavior, and whether medicines, alcohol, sleep or sensory problems could be contributing. Standardized cognitive testing helps quantify the pattern but a score alone does not diagnose the cause. ^{[1] [2]}

Physical and neurologic examination, blood tests and brain imaging are used to look for contributing or alternative conditions and for patterns that support a specific dementia type. Common laboratory evaluation may include blood count, electrolytes, kidney/liver function, thyroid tests and vitamin B12 depending on the setting. MRI or CT assesses vascular disease, mass lesions, hydrocephalus and atrophy patterns. Biomarker testing for Alzheimer disease is increasingly used in specialist care when it will change diagnosis or treatment. ^{[1] [2]}

Major types of dementia

Alzheimer disease commonly begins with episodic memory impairment. Vascular cognitive impairment reflects strokes or small-vessel injury and often affects processing speed and executive function. Lewy body dementia can cause cognitive fluctuations, detailed visual hallucinations, REM sleep behavior disorder and parkinsonism. Frontotemporal dementia often causes early behavioral, personality or language change. Mixed Alzheimer and vascular or Lewy-body pathology is common in older age. ^{[1] [2]}

Treatable contributors and mimics

Depression, medication effects, sleep apnea, hearing loss, thyroid disease, vitamin B12 deficiency, alcohol-related disease, normal-pressure hydrocephalus and other conditions can mimic or worsen cognitive symptoms. Finding one contributor does not always exclude underlying neurodegeneration; clinicians reassess cognition after reversible factors are treated. ^{[1] [2]}

Treatment and management

Treatment depends on the cause. Cholinesterase inhibitors are used for symptomatic treatment in Alzheimer disease and some Lewy-body dementias; memantine can be used in moderate-to-severe Alzheimer disease. Newer disease-modifying anti-amyloid therapies are available for selected patients with early Alzheimer disease and confirmed amyloid pathology, but they require specialist selection, MRI monitoring and discussion of risks such as amyloid-related imaging abnormalities. ^{[2] [3]}

Non-drug care is equally important: regular activity, vascular-risk control, treatment of hearing/vision problems, structured routines, sleep optimization, fall prevention and meaningful social engagement can preserve function and quality of life. Behavioral symptoms are managed first by looking for pain, infection, medication effects, overstimulation or unmet needs; sedating medicines are used cautiously because they can worsen falls and cognition. ^{[1] [2]}

Safety and future planning

Early planning gives the person with dementia more opportunity to express preferences about healthcare proxies, finances, living arrangements and future care. Driving, medication management, cooking, wandering risk and vulnerability to financial exploitation should be assessed practically rather than by diagnosis label alone. ^{[1] [2]}

Caregiver and family support

Dementia affects families as well as the person diagnosed. Caregivers benefit from education about behavior, respite options, community services and their own sleep and mental health. Sudden worsening in a person with dementia should still prompt a search for delirium or acute illness rather than being assumed to be “progression.” ^{[1] [2]}

Sources

1. National Institute on Aging — What Is Dementia? Symptoms, Types, and Diagnosis
2. National Institute on Aging — How Is Alzheimer’s Disease Treated?
3. FDA — FDA-approved Alzheimer disease treatments and safety communications
4. MedlinePlus — Dementia

This article is based on trusted medical sources and is awaiting clinician review. It is not a substitute for personalized medical advice.