Dementia means an acquired decline in cognitive function that interferes with usual activities such as work, social interaction, and self-care. It is a clinical syndrome rather than a single disease: different causes produce a similar functional loss through different patterns, so recognising the pattern is what points toward the cause. The cause matters because it determines the treatment.
Mild cognitive impairment is the stage before dementia, when decline is measurable but daily activities are largely preserved.
Choose a route through the topic
The topic moves from cause to care: which disease is producing the decline, how it is established, what can be done, and how the course is followed.
- Classification compares the major causes and the framework for telling them apart. It is the place to start.
- Dementia with Lewy bodies follows the cause with early visual hallucinations, fluctuating cognition, and Parkinsonism.
- Frontotemporal dementia follows the cause where personality or language change comes before memory loss.
- Vascular and reversible dementias covers stepwise vascular decline alongside the treatable conditions that can resemble dementia.
- Diagnosis sets out what the bedside assessment establishes and how further testing is chosen.
- Treatment covers the general approach to care once a cause has been identified.
- Monitoring follows the course over time, including behavioural change and caregiver assessment.
- Mild cognitive impairment covers measurable decline before daily activities are affected and how prognosis is assessed.
A reader with a particular patient in mind can go from classification to the cause that fits, then to diagnosis, treatment, and monitoring in order; mild cognitive impairment covers the stage that precedes all of these. A companion cluster on Alzheimer disease covers the dominant cause in depth.