Dementia / alzheimers

Question 1

What is dementia

Answer 1

Dementia is an overarching term that refers to a range of symptoms affecting cognitive abilities, while Alzheimer’s disease is a specific type of dementia characterized by progressive memory loss and cognitive decline affecting 65+ years old.

Question 2

Causes of dementia

Answer 2

Risk factors:
* advanced age
* genetics: 3-5%, downsyndrome, presnilins
* cerebral prefusion
* head trauma
* enviromental
* female (1.4:1)

Question 3

Effect on brain structure in alzheimers

Answer 3

1. Cerebral cortex - concious thought/language
2. Basal forebrain - memory/learning
3. Hippocampus - memory storage

Question 4

how does dementia effect the brain

Answer 4

Alzheimer’s disease is associated with brain shrinkage and loss of neurons in many brain regions. Several areas of the brain are at risk causing wide range of symptoms. the loss of cholinergic neurons in the hippocampus and frontal cortex thought to underlie the cognitive defect and the loss of short term memory.

Question 5

physiology of alzheimers

Answer 5

‘plaques’ and ‘tangles’ form in the brain due to two proteins called amyloid (plaques) and tau (tangles).
malfunction of Amyloid results in B-Amyloid which is toxic to brain cells and leads to cell death.
Mutations of the ApoE4 enhance aggregation of β amyloid.
Tau protein helps brain cells communicate with each other but “clump together” leading to death of the brain cells affected.

Question 6

Diagnosis of dementia

Answer 6

Mini-mental state exam (MMSE)
* score 21-24 = mild dementia
* score 10-20 = moderate dementia
* score <9 = severe dementia

Lab test depending on history / clinical features (eg, to rule out delerium as being caused by infection)

Imaging - MRI to rule out vascular/frontotemporal
SPECT - to differentiate subtypes
PET scan - Loss of cholinergic neurones and acetylcholinesterase (AChE) activity within the cortex in is thought to underlie much of the short-term memory loss seen in AD.

Question 7

treatment of alzheimers

Answer 7

• Acetylcholinesterase inhibitors (AchE inhibitors)
• Memantine:
• Moderate dementia, used if intolerant to AchE inhibitors or have contraindications
• Severe dementia

Question 8

AchE inhibitors

Answer 8

• Donepazil, rivastigmine, galantamine
• MOA: These drugs compensate for the death of cholinergic neurons and offer symptomatic relief by inhibiting acetylcholine (ACh) turnover and restoring synaptic levels of this neurotransmitter.
• Adverse effects: Nausea, vomitting, breathlesness, bradychardia

Acetylcholinesterase inhibitors (AchE)

Question 9

Memantine

ICDD

Answer 9

• moderate, severe dementia
• MOA : Memantine blocks the effects of glutamate, a neurotransmitter in the brain that leads to neuronal excitability and excessive stimulation in Alzheimer’s Disease
• Adverse effects: Impaired balance, constipation, dizziness, drowsiness

Question 10

Managing non cognative symptoms in alzheimers

Answer 10

1. Antidepressents
2. antipsychotics
3. anxiolytics
   Only to be prescribed if the patient is at risk of causing harm to themselves or others or is seriously distressed.