Neurodegenerative Disease

Question 1

What are neurodegenerative diseases?

Answer 1

These are progressive and irreversible conditions leading to neuronal loss. They commonly result from the accumulation of misfolded proteins which may be intra or extra-cellular.

Question 2

What is dementia? Briefly name the types.

Answer 2

This is a global impairment of function and personality without an impairment of consciousness. The impairment goes beyond what is expected for normal aging. It is memory impairment plus 1one of: apraxia, agnosia and aphasia.

Types:

• Alzheimer’s (tau and beta amyloid proteins)
• Lewy Body (alpha-synuclein and ubiquitin protein)
• Corticobasal degeneration (tau protein)
• Pick’s disease (tau protein)

Question 3

Describe Alzheimer’s dementia

Answer 3

This is the most common type of dementia and is a diagnosis that is made clinically, and confirmed in a post-mortem.

It usually affects those >50 and shows atrophy of the brain, widened sulci, narrowed gyri and enlarged ventricles, in a symmetrical pattern.

Treatment is majorly symptomatic, with anti-cholinesterases, nAChR agonists and glutamate antagonists.

It can be staged according to the Braak staging, which is done post-mortem. Stages are 1 through to 6, with symptoms beginning to present at stage 3 or 4.

Question 4

Describe Lewy Body dementia

Answer 4

This is a dementia that is characterised by early psychological disturbance and hallucinations. Histology shows lewy bodies (alpha synuclein protein).

Question 5

Describe idiopathic Parkinson’s disease

Answer 5

This is a movement disorder caused by decreased stimulation of the motor cortex due to the death of dopaminergic neurons in the substantia nigra. It causes:

• Tremor
• Rigidity
• Akinesia
• Postural instability

Some will later develop psychiatric illnesses also including depression, hallucinations and anxiety.

Differentials include:

• Multiple system atrophy (MSA)
• Corticobasal degeneration (CBD)
• Progressive supranuclear pals (PSP)

Question 6

Describe multiple system atrophy

Answer 6

This is degenerative disorder characterised by autonomic dysfunction, difficulty with movement and difficulty with balance. It is difficult to distinguish from Parkinson’s but it is usually resistant to Parkinsonian treatment.

Question 7

Describe Pick’s disease

Answer 7

This is a form of dementia that is characterised with frontotemporal degeneration, aggression and the presence of Pick’s bodies (tau protein)

Question 8

Describe multiple sclerosis

Answer 8

This is an autoimmune demyelinating condition presenting in those 20-40 with focal symptoms. 2 episodes will warrant a diagnosis. There are different types:

• Relapsing remitting
• Primary progressive

Pathology shows MS plaques of sharp myelin loss and myelin basic protein or proteo-lipid protein