Dementia

Question 1

Explain the differential diagnosis for dementia

Answer 1

“AVDEMENTIA”:

• Alzheimers
• Vascular
• Drugs, Depression, Delirium
• Ethanol
• Metabolic
• Endocrine
• Neurological
• Tumour, Toxins, Trauma
• Infection
• Auto-immune

Question 2

Describe the differences between delirium and dementia

Answer 2

Delirium - acute onset with fluctuating consciousness level. It is secondary to an underlying medical condition, presentign with visual/tactile hallucinations and illusion

Dementia - progressive course with no alteration in consciousness. It is a primary CNS disease, commonly unaware of illness. Present with memory and cognitive impairment

Question 3

Describe the different types of dementia

Answer 3

• Alzheimers - most common with degeneration of the brian and amyloid and tau protein build up
• Vascular - mini strokes which lead to decreased blood flow to memory centres of the brain
• Lewy body dementia - presents with parkinsonism
• Frontotemporal dementa
• Other very rare cases

Question 4

Explain the role of preselins in dementia development

Answer 4

These are components of gamma-secretase, which cleave amyloid precursor protein. A mutation in them will shift the position so that instead of cleaving at beta position, will cleave a gamma, causing elongated amyloid protein to be formed. This is more likely to aggregate and build up, causing problems

Question 5

Explain the distribution of amyloid and tau in dementia

Answer 5

Amyloid - aggregation builds up as an amloid plaque. This build up causes oxidative injury and harm to neurons, resulting in neurodegenerative path

Tau - hyperphosphrylation of Tau causes soluble tau aggregates to deposit in neuro-cytoplasm, forming neurofibrilliary tangles