Understanding Dementia: Types and Symptoms

Dementia

Umbrella term for cognitive decline symptoms (memory loss)

Dementia cause

Abnormal brain changes

What dementia does

Causes damage to brain cells which interferes with the ability of these to be able to communicate with each other

Symptoms and types of dementia vary based on

region of brain that has been damaged and what type of damage occurred there

Main characteristics of dementia

• memory loss

• confusion

• language and literacy difficulties

• changes in behaviour and personality

all progressive and gradually worsen over time

Alzheimer's Disease

• Most common dementia type (65%)

• Brain atrophy occurs spreading from hippocampus to temporal and parietal lobes leading to cortical atrophy and ventricular enlargement

• once neurons are lost, hippocampus is partially disconnected from the cortex

Lewy Body Dementia

• 20% of cases

  Characterized by:

• Lewy Bodies (unusual proteins)

• reduced metabolism

• reduced cerebral blood flow in occipital and posterior temporoparietal regions

• atrophy and enlargement of ventricles is common

Vascular Dementia

• 10% of cases

• Can be caused by small or large vessel disease (blood vessel damage and strokes)

• high blood pressure breaks down small and large blood vessel walls that are replaced by collagen (hyaline arteriosclerosis), leads to small strokes (lacunar infarcts)

• some patients develop dementia after multiple strokes or after losing brain tissue volume

Frontotemporal Dementia

• 5% of cases

• Group of conditions with selective degeneration in frontal and temporal lobes.

• atrophy of these lobes leads to behavioural disinhibition and language deficits

Neurological basis of dementia

Progressive degeneration which leads to cerebral atrophy and disruption of neurotransmitter signals

Types of damage

• protein misfolding

• synaptic dysfunction

• neuroinflammation

• vascular compromise

Damaged brain cells are unable to communicate with each other, leading to

• weakened behaviour and thinking

• brain shrinkage from neuronal loss

• gaps and deficits in memory and learning

• vascular damage from strokes and reduced blood flow damages brain areas which in turn affects functions

Progressive Neurodegeneration

Gradual loss of neurons affecting brain function.

Cerebral Atrophy

Shrinkage of brain due to neuron loss.

Protein Misfolding

Abnormal protein structure contributing to brain damage.

Synaptic Dysfunction

Impaired communication between brain cells.

Neuroinflammation

Inflammation affecting brain health and function.

Vascular Compromise

Reduced blood flow damaging brain areas.

Speech and language difficulties associated with dementia

Cognitive symptoms impact:

• pragmatics

• word finding

• sentence structure

• spelling

• writing

• comprehension

• picture naming

Motor symptoms result it:

• dysarthria - results in slurred, slow speech

Other characteristics of dementia

• aching muscles

• sleep disturbances

• unsteady or tremors

• hallucinations

• dizziness