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PY0547_Week 10_Alzheimer's disease and other dementias_ES_For BB

Alzheimer’s Disease and Dementias Overview

  • Course Information

    • Course: PYO547 Psychobiology

    • Instructor: Dr. Ellen Smith

    • Week 10

Lecture Objectives

  • Discuss the significance of dementias as a societal issue.

  • Overview of types, pathology, and symptoms of dementia.

  • Focus on Alzheimer’s disease and current biological models.

  • Examine risk factors for dementia, including both established and potential factors.

  • Address treatment and prevention strategies for dementia.

  • Engage with interactive online activities related to the lecture.

Global Ageing and Dementia

  • Ageing Population

    • The percentage of individuals aged 60 and over is projected to dramatically increase across various regions from 1980 to 2050.

Economic Impact of Dementia

  • Financial Overview

    • Estimated global cost of dementia was over $1.3 trillion in 2019.

    • Forecasted increase to $2.8 trillion by 2030, alongside a projected rise in the number of dementia cases to 78 million.

Definition and Types of Dementia

  • Understanding Dementia

    • Dementia: A collection of symptoms affecting brain function, rather than a singular disease.

    • Common types include:

      • Alzheimer's Disease (AD): Most prevalent form, accounting for 40-70% of cases.

      • Vascular Dementia (VaD): Second most common.

      • Lewy Body Dementia (DLB): Rare form associated with Parkinson's disease.

      • Frontotemporal Dementia (FTD): Less common form affecting personality and behaviour.

Pathologies and Symptoms of Dementia

  • Dementia Types

    • Alzheimer's Disease: Characterized by amyloidosis and tauopathy, leading to severe memory loss and disorientation.

    • Vascular Dementia: Associated with reduced blood flow, leading to confusing and cognitive difficulties.

    • Frontotemporal Dementia: Impacts executive functions and personality.

    • Dementia with Lewy Bodies: Includes hallucinations and parkinsonian symptoms.

Biological Models of Alzheimer's Disease

  • Genetics

    • Familial vs. Sporadic AD: Genetic variants influence pathogenic pathways.

Amyloid Hypothesis

  • Suggests that amyloid-beta accumulation leads to plaque formation, resulting in neuron damage and cognitive decline.

  • Significant alterations in amyloid processing during aging.

The Tau Hypothesis

  • Focuses on tau protein phosphorylation, possibly triggered by calcium dysregulation, leading to cognitive impairments.

Risk Factors for Dementia

  • Established Risks

    • Age: Most cases above 65.

    • Genetics: Presence of ApoE4 allele significantly increases risk.

  • Putative Risks

    • Female sex: Risk remains after accounting for age and other factors.

    • Sleep deprivation: Linked to increased amyloid levels and cognitive decline.

    • Chronic stress: May influence AD onset through neurobiological changes.

Treatment and Prevention Strategies

  • Treatment Approaches

    • Medications: Cholinesterase inhibitors (e.g., Donepezil) and NMDA receptor antagonists (e.g., Memantine).

    • Disease Modifying Therapies: Target amyloid-beta and tau pathology (e.g., Lecanemab).

  • Non-pharmacological Interventions: Cognitive rehabilitation, cognitive stimulation, and other supportive therapies.

  • Prevention Tactics

    • Lifestyle changes: Diet, exercise, and cognitive training.

    • Education and social engagement may reduce risks.

Key Takeaways

  • Importance of understanding dementia types and risk factors to tailor treatment and prevention strategies effectively.

  • Continuous research is essential to develop effective therapeutic interventions and understand the underlying biological mechanisms.