Alzheimer's Disease

Question 1

What is Alzheimer’s Disease?

Answer 1

• The most common cause of Dementia
• A progressive neurodegenerative disorder that causes significant deterioration in mental performance

Question 2

What is the Pathophysiology of Alzheimer’s Disease?

Answer 2

• Histological features of Amyloid plaques (clumps of Beta-amyloid) and Neurofibrillary tangles (aggregations of hyperphosphorylated tau proteins)
• The accumulation leads to a reduction in information transmission and eventually to the death of brain cells

Question 3

What are the Clinical features of Alzheimer’s Disease?

Answer 3

• Early impairment of memory
• Short-term memory loss
• Difficulty learning new information

Question 4

What is the Pharmacological Therapy managment for Alzheimer’s disease?

Answer 4

• Mild to Moderate AD: Acetylcholinesterase inhibitors (donepezil, rivastigmine)
• Moderate to Severe AD: N-methyl-D-aspartic acid receptor antagonist (memantine) - used in combination with acetylcholinesterase inhibitors

Question 5

What are the Risk Factors for Alzheimer’s Disease?

Answer 5

• Increasing Age
• Family history of Alzheimer’s disease
• 5% are inherited as an autosomal dominant trait ( mutations in the amyloid precursor protein - chromosome 21, 14 and 1)
• Caucasian ethnicity
• Down’s Syndrome

Question 6

What are Pathological changes seen in Alzheimer’s disease?

Answer 6

Macroscopic:
- widespread cerebral atrophy, particularly involving the cortex and hippocampus
Microscopic:
- cortical plaques due to the deposition of Beta- amyloid protein
- intraneuronal neurofibrillary tangles caused by abnormal aggregation of the hyperphosphorylated tau protein. Tau interacts with tubulin and stabilizes microtubules
Biochemical:
- deficit of acetylcholine from damage to an ascending forebrain projection

Question 7

What are the 5 A’s of Alzheimer’s Disease?

Answer 7

• Amnesia = memory loss
• Apraxia = loss in voluntary motor skills such as cooking, shaving or walking
• Agnosia = unable to recognise faces, objects, voice and places
• Aphasia = impaired communication through speech
• Anomia = unable to identify names of everyday objects

Question 8

What does Alzheimer’s Disease typically first present with?

Answer 8

• acetylcholine pathway
• hippocampus affects the memory loss

Question 9

What is seen on the imaging for Alzheimer’s patients?

Answer 9

• disproportionate atrophy of the hippocampus compared to the rest of the brain