Week 6 - Alzheimer's and Dementias

Question 1

What is cortical dementia?

Answer 1

Preferential neuronal loss to cortical regions of the brain

Question 2

What is the strongest predictor of Alzheimers?

Answer 2

Increase of age

Question 3

What gender is more likely to develop Alzheimers?

Answer 3

Twice as many women as men

Question 4

What is the average duration of Alzheimers?

Answer 4

8-10yrs, rarely survive more than 15

Question 5

What stages precede the clinical symptomatic phases of Alzheimers?

Answer 5

Preclinical

Prodromal stages

Extend over two decades

Question 6

What is the most common type of alzheimers?

Answer 6

Sporadic with a mean age of onset of 80yrs

Question 7

What age is familial alzheimers onset?

Answer 7

<50yrs

Question 8

What are the two key features of alzheimers?

Answer 8

1. Targets specific regions of the brain

2. Targeted structures sustain massive cell loss

Question 9

Where does preferential cell loss occur?

Answer 9

In cortical grey matter of the brain and limbic structures (hippocampus, amygdala)

Question 10

Where is cortical atrophy most evident in the brain?

Answer 10

Frontal

Temporal

Parietal lobes

Question 11

Dendritic arborisation causes neuronal loss in the frontal, temporal and parietal lobes. How much loss is there in these areas?

Answer 11

50%

Question 12

What is a result of cortical thinning?

Answer 12

Ventricular enlargement

Question 13

What brain areas reveal massive cell loss?

Answer 13

Parietal

Temporal

Hippocampus and structures leading to it

Amygdala

Specific subthalamic nuclei

Specific subcortical frontal areas (basal forebrain, olfactory areas)

Question 14

What are the two primary findings by Alois Alzheimer which are still primary histological markers or DAT?

Answer 14

Amyloid/senile plaques

Neurofibrillary tangles

Question 15

What are amyloid/senile plaques?

Answer 15

Clump like deposits in the neuropil (areas where there are large numbers of synapses) round aggregates of cellular trash.

Plaques contain beta-amyloid protein, as well are apolipoprotein E (ApoE)

Question 16

What are neurofibrillary tangles?

Answer 16

Resemble entwined and twisted pairs of rope within cytoplasm of swollen cell bodies.

Tangles made of proteins (tau proteins)

Question 17

Where are neurofibrillary tangles disproportionately concentrated?

Answer 17

Temporal-parietal areas

Hippocampus complex

Question 18

Where are senile plaques concentrated?

Answer 18

Frontal and temporal regions of the brain

Hippocampal complex

Question 19

What are some signs and symptoms that are usually associated with the onset of AD?

Answer 19

Failing recent memory

Depression and irritability

Occasionally a seizure

One or more language problems

Disorientation and confusion when a sudden disruption to work or social life occurs

Question 20

In what stage of AD do primitive reflexes reemerge?

Answer 20

End stage AD

Question 21

Describe the neuropathology of frontal-lobe dementia

Answer 21

Significant atrophy in the frontal and temporal lobes

Some changes in the parietal lobes

Subcortical structures unaffected

Cerebellum and brainstem unaffected

Question 22

What are some characteristics of the initial stages of frontal-lobe dementia?

Answer 22

Silliness

Socially disinhibited behaviour

Poor judgement

Incontinence

Question 23

What are some characteristics of middle stage frontal lobe dementia?

Answer 23

progressive apathy

Blunted affect

significant cognitive dysfunction

Question 24

What are some characteristics of late stage frontal lobe dementia?

Answer 24

Mute

Display motor rigidity

Typically ends in terminal vegetative state

Question 25

What is the prevalence of frontal-lobe dementia?

Answer 25

12% of all dementia cases

Question 26

What is the duration of frontal-lobe dementia?

Answer 26

2-17 years

Question 27

What is huntington's disease?

Answer 27

Progressive subcortical dementia Rare Linked to gene ITI5 on chromosome 4

Question 28

When does onset of huntington's disease usually occur?

Answer 28

30-40yrs of age

Question 29

How many years can a person survive with huntington's disease?

Answer 29

10-2- years following onset Always fatal

Question 30

What is the primary neuropathalogical change in huntington's disease?

Answer 30

Bilateral deterioration of the caudate nucleus white matter structures cerebellum

Question 31

What is the caudate nucleus?

Answer 31

Component of the basal ganglia Involved in timing, ordering, and sequencing of movement patterns

Question 32

What is multi-infarct (vascular) dementia?

Answer 32

Second largest type of dementia Results from multiple infarction of brain tissue, from repeated strokes or blockages to blood vessels Can present with either subcortical features, cortical features or a combination of the two

Question 33

How does multi-infarct dementia differ from AD?

Answer 33

Onset it acute and rapid History of risk factors for stroke Focal neurological signs consistent with focal brain damage Better memory performance than with AD Reduced verbal production etc

Question 34

What are the 4 types of Creutzfeldt-Jakob disease (CJD)?

Answer 34

1. Sporatic 2. Variant 3. Familial 4. Iatrogenic

Question 35

What is the most common type of Creutzfeldt-Jakob disease?

Answer 35

Sporadic

Question 36

What type of Creutzfeldt-Jakob disease occurs due to cross species infection via consumption of tainted meat containing neural tissue?

Answer 36

Variant

Question 37

What is familial Creutzfeldt-Jakob disease?

Answer 37

Extremely rare familial variant of CJD only found in a handful or families, results in fatal insomnia

Question 38

What is Iatrogenic Creutzfeldt-Jakob disease?

Answer 38

Humans can transmit CJD to each other via transplants of affected neuronal tissue, corneal transplants or contamination via medical procedures

Question 39

What is a conseuqnce of Creutzfeldt-Jakob disease?

Answer 39

Astrogliosis appears as a result of glia filling areas following death of neurons