Clinical literacy companion
Recognition, differentiation and liaison context
Dementia describes cognitive and behavioural symptoms caused by diseases affecting the brain. It is not one disease and is not an inevitable part of ageing.
It can affect memory, reasoning, communication, perception, mood, behaviour and the ability to manage everyday activities. Dementia is progressive, but its pattern and pace vary.
More than one disease process can be present. Alzheimer’s disease with vascular disease is a common mixed pattern.
Subtype patterns help recognition; they are not fixed diagnostic rules.
Sources: NICE NG97 — About this guideline; NHS — Symptoms of dementia; NHS — Causes of dementia.
| Presentation | Pattern that may be seen | What keeps the picture open |
|---|---|---|
| Ordinary ageing | Taking longer to learn something new, occasionally losing a word or misplacing an item and later retracing the steps. | A sustained change from previous ability that increasingly affects familiar daily tasks is more concerning than an isolated lapse. |
| Dementia | Progressive cognitive or behavioural change with functional effect; the particular pattern varies by disease and person. | Mood, anxiety, physical illness, medicines, sensory needs and social context may influence the presentation. |
| Delirium | Recent change over hours or days, fluctuation, altered attention or arousal, perceptual change, restlessness or unusual withdrawal. | Dementia and delirium can coexist. One cognitive score does not reliably separate delirium superimposed on dementia. |
| Resolving delirium | Confusion and cognitive difficulty may persist while the acute episode improves. | Persistence after the most obvious acute features settle does not by itself confirm dementia. Baseline and trajectory remain central. |
These are illustrative patterns, not diagnostic thresholds.
Sources: Alzheimer’s Society — Memory problems and dementia; NICE CG103 — Delirium; NICE NG97 — Recommendations.
Alzheimer’s disease is associated with abnormal amyloid protein forming plaques around brain cells and tau protein forming tangles within them. These changes disrupt communication between nerve cells and progressively damage brain tissue. The exact trigger is not known, and the process begins years before symptoms become obvious.
Source: NHS — Causes of Alzheimer’s disease.
The onset is usually insidious and the change develops gradually over years. Recent-event memory and difficulty learning new information are often prominent early features because memory-related brain regions are commonly affected first.
Possible presentation includes repeated questions, losing track of recent events, word-finding difficulty, difficulty organising familiar tasks, disorientation in unfamiliar places and increasing difficulty with numbers or money. Other presentations occur and the rate and sequence vary between people.
Compared with vascular dementia, decline is more often steadily progressive than abrupt or stepwise. Early recurrent visual hallucinations, marked fluctuations or Parkinsonian movement are more characteristic of dementia with Lewy bodies; early personality, behavioural or language change is more characteristic of frontotemporal dementia. Mixed Alzheimer’s and vascular disease is common.
Sources: NHS — Symptoms of Alzheimer’s disease; NHS — Symptoms of vascular dementia; NHS inform — Dementia with Lewy bodies.
There is currently no cure. Donepezil, galantamine and rivastigmine are acetylcholinesterase inhibitors used for mild to moderate Alzheimer’s disease. They slow the breakdown of acetylcholine, allowing this chemical messenger to remain available for longer and improving communication between surviving nerve cells. For some people this temporarily helps symptoms such as recent forgetfulness, confusion, slowed thinking, difficulty following familiar tasks or difficulty understanding more complicated information.
Memantine is used in specified moderate or severe Alzheimer’s disease circumstances. It blocks the effects of excessive glutamate, which can further damage vulnerable nerve cells. For some people it can help memory, confusion, thinking speed, anxiety or coping with daily activities. Response varies, and neither medicine type stops the underlying disease process.
Sources: NICE NG97 — Pharmacological management; NHS — Treatment of Alzheimer’s disease; NHS — How donepezil works; NHS — How memantine works.
Sources: NHS — Symptoms of vascular dementia; Stroke Association — Memory and thinking after stroke; NICE NG97 — Pharmacological management.
Sources: NHS inform — Dementia with Lewy bodies; Alzheimer’s Society — What is dementia with Lewy bodies?; NICE NG97 — Recommendations.
Sources: NHS — Symptoms of dementia; NHS — Frontotemporal dementia.
BPSD is an umbrella term for psychological experiences and observable behaviours that can occur in dementia. These include agitation, anxiety, low mood, apathy, disturbed sleep, wandering, calling out, aggression, hallucinations, delusions and changes in eating or sexual behaviour. The term describes a presentation; it does not identify its cause.
Distress or behavioural change can reflect the dementia itself, but can also be shaped by pain, delirium, medicine effects, communication difficulty, sensory impairment, fear, an unfamiliar environment, disrupted routine or an unmet physical or emotional need. The same outward behaviour can therefore have different meanings in different people.
Tom Kitwood’s account of personhood was influential in modern person-centred dementia care. Dementia does not remove the person’s identity, history, preferences, relationships, feelings or need for recognition and respect. Behaviour is understood in the context of the individual and their social world, rather than as a diagnosis speaking for itself.
Sources: PMC — Person-centred dementia care and Kitwood; NCBI Bookshelf — Person-centred dementia care.
Dementia educator Teepa Snow demonstrates how behaviour that appears challenging can be reconsidered by recognising distress, communication and unmet need from the person’s point of view.
Medication does not provide a general solution to BPSD. NICE reserves antipsychotic treatment in dementia for situations involving risk of harm or severe distress linked to agitation, hallucinations or delusions. Trial evidence shows modest benefit for some symptoms alongside increased risks, including stroke and death. People with dementia with Lewy bodies can have particularly severe sensitivity reactions to antipsychotics.
Sources: NICE NG97 — Antipsychotic medicines in dementia; NICE — Antipsychotic decision aid evidence.
Memory Assessment Services are specialist multidisciplinary services for people with cognitive concerns. Their role can include specialist assessment, diagnosis and subtype clarification, relevant investigations, access to treatment and post-diagnostic information or support.
NICE describes referral to a specialist dementia diagnostic service, which may be a memory clinic, community old age psychiatry service or another appropriately configured specialist service. Dementia specialists can include psychiatrists, geriatricians, neurologists and other clinicians with specialist expertise in dementia assessment and diagnosis, including appropriately skilled GPs, nurse consultants and advanced nurse practitioners. The central requirement is specialist dementia expertise, not the title “Memory Assessment Service”.
Source: NICE NG97 — Dementia diagnosis and specialist services.
Local teams vary, but commonly include:
Some services also include geriatric, neurological, speech and language, social-care or third-sector input.
Sources: NHS England — Dementia implementation guide; Birmingham and Solihull Mental Health NHS Foundation Trust — Memory Assessment Service; Humber Teaching NHS Foundation Trust — Memory Assessment Service team.