S9+10+11 Dementia

Question 1

Which causes of dementia are treatable (reversible) conditions? (8)

Answer 1

Depression. Iatrogenic. Hypothyroidism. B12 deficiency. Neurosyphilis. Normal pressure hydrocephalus. Subdural hepatoma. Encephalitis.

Question 2

Name four neurodegenerative dementias.

Answer 2

Alzheimer’s dementia.
Lewy body dementia.
Frontotemporal dementias.
Huntingdon disease.

Question 3

Differentiate between the symptoms and causes of anterior vs posterior dementias.

Answer 3

Anterior: behavioural changes. Normal pressure hydrocephalus, huntingdons, metabolic.
Posterior: cognition changes with normal behaviour. Alzheimers.

Question 4

Differentiate between the symptoms and causes of subcortical and cortical dementias.

Answer 4

Sub: apathetic, slow. Parkinson’s, AIDS.
Cortical: dysphasia, agnosia, apraxia. Alzheimer’s.

Question 5

What is the molecular classification of neurodegenerative dementias?

Answer 5

Tauopathies - frontobasal, alzheimers.
Ubiquinopathies - MND, semantic dementia.
Synucleinopathies - parkinson’s, MSA.

Question 6

What is normal pressure hydrocephalus? (triad).

What are the two types?

Answer 6

Triad of dementia, gait disturbance and urinary incontinence.
With preceding cause (trauma, SAH, meningitis). Idiopathic.

Question 7

What symptoms does hypoglycaemia lead to that mimics dementia?

Answer 7

Complex partial seizures. Myoclonic jerks. Slowed EEG.

But decline very rapid.

Question 8

What is CJD?

Answer 8

A transmissible spongiform encephalopathy (named after sponge appearance of affected brain tissue).

Question 9

What do EEG’s and MRI’s show in CJD?

Answer 9

EEG: triphasic waves.
MRI: non specific changes in basal ganglia. Variant CJD shows pulvinar sign in posterior thalamic region.

Question 10

What is corticobasal degeneration?

What is it caused by?

Answer 10

Severe apraxia- alien limb phenomenon.

Tauopathy.

Question 11

What are the genetic causes of Alzhiemers?

Answer 11

Increased APP - trisomy 21

Altered Aβ - Presnilin 1 and 2

Question 12

What are amyloid proteins?

How do they form?

Answer 12

Insoluble fibrous aggregates.
APP cleaved by β and γ secretases, forms which Aβ accumulates extracellularly. Induces tau tangle formation and inflammation, causing more Aβ release.

Question 13

What are tau proteins?

Which form of dementia are they seen in?

Answer 13

Usually stabilise microtubules in neurones. Defective means microtubules become unstable.
Alzheimer’s.

Question 14

What is the role of α-Synuclein in dementia?

Answer 14

Forms Lewy-Bodies.

Question 15

What is the function of ubiquitin?

Which form of dementia?

Answer 15

Small regulatory protein that directs other proteins to compartments and labels them for destruction.
Pick’s disease.

Question 16

What macroscopic neuropathology is found in a brain with dementia? (4)

Answer 16

Decreased brain weight (900-1100g).
Atrophy in cerebral gyri, white matter, brain stem and cerebellum.
Ventricular dilatation.
Pale substantial nigra and locus cerules.

Question 17

What microscopic neuropathology is found in a brain with dementia? (5)

Answer 17

Neuron loss from hippocampus, cerebral cortex, substantial nigra and locus ceruleus. 
Microvacualoation in cerebral cortex. 
Attenuation of white matter. 
Wide perivascular spaces. 
Accumulation of abnormal proteins.

Question 18

What pathological changes are found in dementia with Lewy body? (3)

Answer 18

Pale substantia nigra and locus cerules (less neuromelanin).
Atrophy and neural loss.
Accumulation of of α – Synuclein +ve bodies in substantial nigra and amygdala.

Question 19

Give three examples of vascular dementias.

Answer 19

Multi-Infarct dementia.
Binswanger’s disease.
Arteriolosclerosis.