Dementia Flashcards
What is dementia?
- Is not a specific disease.
- It is the broad term for a group of diseases causing a progressive decline of neurological function.
- Presents with symptoms severe enough to interfere with normal daily life.
- Symptoms include memory loss, confusion, and personality and behavioural changes.
- More common in elderly but not part of normal aging
- Famous dementia sufferers include Ronald Regan, Margaret Thatcher, Robin Williams, Sugar Ray Robinson, and Malcolm Young.
Signs and symptoms for dementia
- Subtle short-term memory changes. Trouble with memory can be an early symptom of dementia.
- Difficulty finding the right words.
- Changes in mood.
- Apathy.
- Difficulty completing normal tasks.
- Confusion.
- Difficulty following storylines.
- A failing sense of direction.
- Being repetitive.
- Struggling to adapt to change.
Types of dementia
- Alzheimer’s disease (most common 60-80%) • Vascular dementia
- Dementia with Lewy bodies (DLB)
- Mixed dementia
- Parkinson’s disease
- Frontotemporal dementia
- Creutzfeldt-Jakob disease
- Normal pressure hydrocephalus • Huntington’s disease
- Wernicke-Korsakoff Syndrome
- Others
Alzheimers disease
- 1906, Alois Alzheimer documented first case Auguste Deter • Most common progressive, neurodegenerative disease
- Most common form of dementia in the elderly
- Complex aetiology > genetics, environment & lifestyle
- Classification based on heritability & age of onset:
- Late-onset AD; >65 YOA onset, classical disease
- Early-onset AD; <65 YOA onset, often inherited, rare, faster progression • High socioeconomic burden
- Need for early diagnosis
Alzheimers risk factors
- Age
- Sex
- Family history and genetics
- Down syndrome
- Mild cognitive impairment (MCI) • Head trauma
- Chronic stress
- Depression
- Diabetes
- Hypertension
- Vascular disease • Oxidative stress
- Vitamin D deficiency
- Obesity & inflammation
- Smoking or exposure to second-hand smoke
Plaques in alzheimers disease
• “Amyloid hypothesis”
• Amyloid precursor protein (AAP) severed beta & gamma secretase
(enzymes) > resultant beta-amyloid (sticky protein)
• A𝛽 accumulation = initial pathological event
• A𝛽 folds into insoluble clumps or fibrils that form plaques (surface of neuron) > may block signalling at synapses
• A𝛽 accumulation > A𝛽-induced neuroinflammation (activation/dysfunction of microglia - main brain immune cell) > neuronal death
Tangles in alzheimers disease
• Form inside the neuron
• Health neurons connect via branches called neurites that contain
microtubules (support, carry nutrients & neurotransmitters)
• Microtubules are reinforced by tau proteins (ladder rungs)
• Tau proteins loosen and form neurofibrillary tangles > microtubules breakdown > neuronal death
Loss of neutrons and synapse causes:
neurofibrillary tangles • Cognitive Symptoms: • Attention deficit • Language impairment • Short term memory loss • Impaired activities of daily living (apraxia) • Loss of orientation (time, space)
• Behavioural Symptoms: • Apathy • Depression • Anxiety • Aggressive behaviour • Hallucinations • Social withdrawal neuritic plaques
Morphological changes in Alzheimers disease include?
Narrowed gyro
Increased sylvan fissure
global shrinkage
widened sulcal margins
These effect the patients language and memory
Imaging Alzheimers disease
Structural: • MRI > CT • Exclude differentials • Not typically used to diagnose • Determine degree of atrophy – Hippocampus – Entorhinal cortex – Temporal parietal cortical • Diffusion Tensor Imaging
Functional: •MRI • BOLD • Hippocampal BBB breakdown •SPECT •PET • F-18 FDG; demonstrates hypometabolism • Amyloid; range of radiotracers that bind to A𝛽 fibrils demonstrating increased activity • Tau; range of agents that bind to tau proteins demonstrating increased activity in atrophic regions
CT for Alzheimers disease
- Similar appearance to normal aging brain in early stages • Atrophy
- Enlarged ventricles
- Prominent sulci
- Correlate with clinical symptoms
- Rule out other brain causes for symptoms • Impacts allocation for care funding
MRI for Alzheimers disease
- Similar appearance to normal aging brain in early stages • Atrophy
- Enlarged ventricles
- Prominent sulci
- High intensity periventricular region T2 / FLAIR • Correlate with clinical symptoms
NM for Alzheimers disease
- FDG-PET – decreased glucose metabolism in Alzheimer’s regions
- Measures synaptic activity
Treatment for Alzheimers disease
- No cure
- Can slow progression
- Diet
- Exercise
- Education
- Memory aids
- Medication
- Acetylcholinesterase inhibitors (Prevent destruction of neurotransmitter acetylcholine)
- Memantine (Prevents calcium moving into brain cells causing damage
- Other drugs that treat symptoms (Sleep and psychological issues)
What is Parkinson’s disease
- Complex
- Chronic, progressive, neurological degenerative movement disorder:
- Degeneration/death of dopaminergic neurons, resultant dopamine deficiency within basal ganglia > movement disorders
- Also involves other neurotransmitters and other regions • Manifests with a broad range of symptoms
- Complex cause; genetics & environment