Glow Therapeutics: Helping Families Manage Sundowning in Dementia and Alzheimer's
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Understanding
Dementia

A comprehensive guide to dementia and its major subtypes, helping understand the different forms of cognitive decline.

What is Dementia?

Dementia is a clinical syndrome characterised by a decline in cognitive function severe enough to interfere with daily living and independence. It is not a single disease but a group of conditions resulting from various underlying neuropathologies.

The cognitive domains most commonly affected include:

  • •Memory: especially recent events and new information
  • •Executive function: planning, decision-making, problem-solving
  • •Language: finding words, understanding speech
  • •Visuospatial ability: navigation, recognising objects and faces
  • •Social cognition: understanding social cues, emotional awareness

Behavioural and psychological symptoms such as agitation, depression, anxiety, and psychosis often accompany the cognitive decline.

Prevalence & Importance of Early Diagnosis

The prevalence of dementia increases sharply with age, doubling approximately every five years beyond the age of 65. Globally, over 60 million people live with dementia, with numbers projected to triple by 2050.

Early and accurate differentiation among dementia subtypes is critical for management, prognosis, and caregiver support.

Core Diagnostic Features

1

Significant Cognitive Decline

Evidence of decline from a previous level of performance in one or more cognitive domains

2

Functional Impairment

The deficits interfere with independence in everyday activities

3

Differential Diagnosis

The decline is not better explained by delirium or another major psychiatric disorder

Dementia Subtypes

Alzheimer's Disease (AD)

60-70% of cases

Pathology: Characterised by amyloid-β plaques, tau tangles, and progressive neuronal loss, particularly in the hippocampus and association cortices

Core Cognitive Symptoms:

  • •Memory impairment (especially recent events)
  • •Disorientation
  • •Language difficulties
  • •Visuospatial dysfunction
  • •Executive dysfunction

Behavioural Changes:

  • •Apathy, agitation, anxiety, or irritability
  • •Sleep disturbances
  • •Sundowning (late-afternoon confusion and anxiety)

Distinctive Features:

Sundowning, progressive language issues

Vascular Dementia (VaD)

2nd most common

Pathology: Results from cerebrovascular disease. Multiple infarcts, strategic single infarcts, or chronic ischemia leading to white matter damage. Commonly coexists with Alzheimer's pathology (mixed dementia)

Core Cognitive Symptoms:

  • •Stepwise cognitive decline
  • •Impaired attention and executive function
  • •Psychomotor slowing
  • •Focal neurological signs
  • •Emotional lability

Behavioural Changes:

  • •Depression common
  • •Apathy
  • •Emotional instability

Distinctive Features:

Focal neurological signs, stepwise progression

Dementia with Lewy Bodies (DLB)

5-10% of cases

Pathology: Caused by abnormal deposition of α-synuclein (Lewy bodies) within neurons of the cortex and brainstem. Shares features with both Parkinson's disease and Alzheimer's

Core Cognitive Symptoms:

  • •Fluctuating cognition and attention
  • •Recurrent visual hallucinations
  • •REM sleep behavior disorder
  • •Parkinsonism (tremor, rigidity, slow movement)

Behavioural Changes:

  • •Visual hallucinations (often well-formed, detailed)
  • •Acting out dreams during sleep
  • •Sensitivity to antipsychotic medications

Distinctive Features:

REM sleep disorder, visual hallucinations, antipsychotic sensitivity

Frontotemporal Dementia (FTD)

Younger onset (45-65)

Pathology: A group of disorders associated with degeneration of the frontal and/or temporal lobes. Subtypes include behavioral variant FTD and Primary Progressive Aphasia

Core Cognitive Symptoms:

  • •Changes in personality and social conduct
  • •Disinhibition
  • •Apathy or loss of motivation
  • •Compulsive or ritualistic behaviours
  • •Language difficulties (depending on variant)

Behavioural Changes:

  • •Loss of empathy and social awareness
  • •Inappropriate social behaviour
  • •Dietary changes, sweet cravings
  • •Memory often preserved early

Distinctive Features:

Disinhibition, loss of empathy, personality change before memory loss

Parkinson's Disease Dementia (PDD)

Develops after motor symptoms

Pathology: Develops in the context of established Parkinson's disease, typically after several years of motor symptoms. Pathology overlaps with Lewy body disease

Core Cognitive Symptoms:

  • •Executive dysfunction
  • •Visuospatial difficulties
  • •Attentional fluctuations
  • •Slowed thinking
  • •Memory retrieval problems

Behavioural Changes:

  • •Hallucinations (visual)
  • •Depression and anxiety
  • •Sleep disturbances
  • •Apathy

Distinctive Features:

Occurs after established Parkinson's motor symptoms, hallucinations common

Mixed Dementia

Increasingly recognised

Pathology: Combination of Alzheimer's and vascular or Lewy body pathology, increasingly recognised in older adults. Presents with a blended profile of cognitive and behavioural symptoms

Core Cognitive Symptoms:

  • •Combined features of multiple dementia types
  • •Memory loss
  • •Executive dysfunction
  • •Visual or motor symptoms may be present

Behavioural Changes:

  • •Variable presentation
  • •Often more rapid progression
  • •Complex symptom patterns

Distinctive Features:

Blended symptom profile, rapid progression, multiple pathologies

Behavioural and Psychological Symptoms of Dementia (BPSD)

Common across all dementia subtypes and often the most challenging aspect of care for families and caregivers.

Agitation and restlessness
Aggression (verbal or physical)
Sleep-wake disturbances
Repetitive behaviours
Anxiety and fear
Psychosis (delusions, hallucinations)
Sundowning (evening confusion)
Depression and apathy
Important: These symptoms often drive caregiver stress and the decision to transition to institutional care. Non-pharmacological interventions, including light therapy for circadian-driven symptoms like sundowning, can significantly improve quality of life.

Knowledge Empowers Better Care

Experiencing Sundowning?

Learn how Harmoni uses light therapy to address the circadian disruption that causes evening confusion and anxiety.

Learn About Sundowning

Need Support?

Connect with our team or access resources for families and caregivers navigating dementia care.

Get In Touch

This guide is for educational purposes. Always consult qualified healthcare professionals for diagnosis and treatment decisions.

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