CCC-dementia

Dementia

Dementia is a collection of symptoms involving impaired cognition and reduced ability to carry out daily activities.

Dementia is not ageing

Dementia is not a normal part of healthy ageing, though risk increases with age.

Alzheimer-type dementia

The most common cause of dementia, involving progressive neurodegeneration.

Core cognitive symptoms

Memory loss, attention difficulties, language problems, and disorientation.

Behavioural symptoms

Mood changes, hallucinations, delusions, and altered social behaviour.

Progressive nature

Dementia involves gradual and irreversible cognitive decline.

Brain atrophy

Loss of neurons and brain volume, progressing from medial temporal regions to wider cortex.

Hippocampal damage

Early damage to hippocampus explains prominent memory impairment.

Neurotransmitter disruption

Reduced acetylcholine signalling contributes to cognitive symptoms.

Current medications

Drugs improve symptoms by boosting neurotransmitter signalling but do not stop disease progression.

Protein abnormalities

Abnormal amyloid and tau proteins disrupt neuronal maintenance and repair.

Amyloid deposition

Amyloid accumulates early and widely, sometimes without symptoms.

Tau pathology

Tau accumulation closely tracks disease stage and memory loss.

Biomarkers

Measures of amyloid and tau can be obtained from blood, CSF, or brain imaging.

Preclinical stage

Pathology develops decades before noticeable cognitive decline.

Diagnosis challenges

No single test; diagnosis combines biomarkers, cognition, and functional assessment.

Memory systems affected

Episodic memory is most impaired, but working, semantic, and spatial memory also decline.

Everyday functioning

Simple tasks fail due to combined memory, attention, and planning demands.

Risk factors

Age and genetic risk are strongest, but lifestyle factors also contribute.

Prevention potential

Lifestyle and environmental changes may substantially reduce dementia risk.