Neurodegenerative Disease Flashcards Preview

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Flashcards in Neurodegenerative Disease Deck (97):
0

What does neurodegenerative disease affect

nerve cells and glial cells

1

What is neurodegenerative disease a loss of

Cells in the brain and spinal cord

2

List 4 diseases involving degeneration of CNS neurons

1. Dementia
2. Extrapyramidal disorders
3. Ataxic disorders
4. Motoneuron disorders

3

Give examples of dimentia

- Alzheimer's disease
- picks disease

4

What is the most common version of dementia

Alzheimer's disease

5

Give examples of extrapyramidal disorders

- Parkinson's disease
- Wilson's disease
- Huntington's chorea
- dystonia musculorum deformans
- hallervorden-Spatz syndrome

6

Give examples of ataxic disorders

- friedreich's ataxia
- cerebello-olivery atrophy
- cerebellar atrophy

7

Give and example of motoneuron disorders

Motoneuron disease

8

In which part of the brain does dementia cause degeneration of neurones

Cerebral cortex

9

Which is the most common version of extrapyramidal disorders

Parkinson's disease

10

Which sort of movements is involved in diseases from extrapyramidal disorders

Involuntary

11

Which sort of spinal disorder is linked with ataxic disorders

Cerebello spinal disorder

12

How many people does Parkinson's affect

1 out of 750 people (common)

13

How many cases are there of Parkinson's in the UK

100,000

14

Which other disease is Parkinson's more common than

Multiple sclerosis

15

What does the prevalence of Parkinson's increase with

Age
Reaching a max at about 70

16

Is Parkinson's an age related disease

Yes
But can get when young (40) but rare

17

How many new cases of Parkinson's are there each year in the UK

9000

18

List Parkinson's disease symptoms

- 4-8 Hz tremor of limbs
- rigidity of muscle tone
- difficulty initiating movement (akinesia)
- movements slow

19

When is tremor of limbs at its worst

When anxious and resting

20

When does tremor of limbs stop

When asleep

21

Why don't Parkinson's disease px blink much

Due to rigidity of muscle tone

22

How to Parkinson's patients appear due to difficulty initiating movement

Appear frozen

23

What do Parkinson's disease symptoms result in

- deadpan expression
- stooped shuffling gait (increased muscle tone in back)
- pill rolling (between fingers & forefingers)

24

What is the cause of Parkinson's disease

It is idiopathic (don't know what caused it)

25

Between which groups is Parkinson's disease equal

Male & female

26

What is Parkinson's disease characterised by a loss of

Dopamine producing cells in the substantia nigra of the basal ganglia

27

What is the substantia nigra

A black area visible on a cut section of the midbrain which produces dopamine

28

What does the substantia nigra produce

Dopamine

29

What is the basal ganglia

5 pairs of nuclei

30

Where is the basal ganglia located

In the thalamus

31

What region is involved in motor control

Substantia nigra of the basal ganglia

32

What is the appearance of the substantia nigra in Parkinson's disease

Diminished (dark patch is reduced)

33

what is the aim of pharmacological treatments of parkinson's disease

increase dopamine levels

34

what is L dopa

a smaller version of dopamine

35

what happens if you just try to inject more dopamine

it won't work as it can't go through the blood brain barrier

36

what is L dopa a precursor to

dopamine synthesis

37

what is the most common treatment for parkinson's

administration of a precursor (L dopa) for dopamine synthesis (in the presence of a substance blocking its depletion outside the CNS)

38

what advantage has injecting L dopa instead of dopamine

L dopa has transporters that can go through the blood brain barrier

39

what must you also give when giving L dopa to a px

an inhibitor of the AADC enzyme

40

why must you give an inhibitor of the AADC enzyme when giving a px L dopa

so that the L dopa can go through the blood brain barrier from the periphery so that it can produce dopamine inside the brain

41

what is the name of the inhibitor of the AADC enzyme

carbidopa

42

what does carbidopa inhibit

it inhibits the enzyme which converts L dopa in dopamine

43

what happens when you give L dopa & carbidopa at the same time

the dopamine isn't produced in the periphery

44

what ends up going through the blood brain barrier after L dopa & carbidopa are given at the same time

Ldopa
carbidopa stays behind

45

what is the result of L dopa going through the blood brain barrier and carbidopa staying behind

the substantia nigra can produce dopamine with that L dopa

46

what is the advantage of inhibiting the enzyme which produces dopamine in the periphery

you can use much smaller quantities of L dopa to relieve symptoms of parkinson's

47

does L dopa cure the symptoms of parkinson's

no it only alleviates

48

does L dopa have an ongoing effect

no it becomes less effective after 5-7 years

49

name some other pharmacological ways of increasing dopamine levels

- direct agonists of dopamine by latching onto dopamine receptors & stimulate the neurones can increase the release of dopamine
- stop the destruction of dopamine as it is a monoamine so it can be destructed by monoamineoxidase therefore will have more dopamine around or it can stop the re uptake of dopamine

50

what is the most powerful pharmacological way of increasing dopamine levels

increasing the availability of L dopa

51

what side effects can pharmacological treatments for parkinson's cause

ocular side effects

52

list some non-pharmacological (therapies) used to treat parkinson's

- implantation of foetal tissue
- implantation of modified fibroblasts
- xenotransplantation
- adult stem cell culture and implantation
- glial derived neurotrophic factor (GDNF)
- electrical stimulation of basal ganglia by implanted electrodes
- gene therapy

53

how does implantation of foetal tissue work as a therapy to treat parkinson's

take parkinson cells from a baby and put into an adult brain but hasn't worked well

54

how does the implantation of modified fibroblasts work as a therapy to treat parkinson's

can be genetically modified to produce dopamine and but into brain

55

how does xenotransplantation work as a therapy to treat parkinson's

transplantation from other species such as pigs

56

how does adult stem cell culture and implantation work as a therapy to treat parkinson's

re programme stem cells to produce dopamine and put into substantia nigra

57

how does glial derived neurotrophic factor (GDNF) work as a therapy to treat parkinson's

substances produced by glial cells which help neurones survive.
can implant a pump into the abdomen which have these glial derived neurotrophic factors and occasionally pump it into the brain and into the substantia nigra to keep dopamine producing cells going

58

how does electrical stimulation of basal ganglia by implanted electrodes work as a therapy to treat parkinson's

by implanting electrodes into basal ganglia and inject electricity through them to produce dopamine

59

how does gene therapy work as a therapy to treat parkinson's

genes are out into people to replace the defective gene by putting the gene into viruses which get into the dna to produce dopamine

60

why are the effects of parkinson's on vision likely to be retinal in origin

- the basal ganglia are primarily motor
- dopamine is a neurotransmitter/neuromodulator in retinal amacrine and interplexiform cells (so dopamine is found in retina)
- in parkinson's disease levels of retinal dopamine are decreased
- parkinson's disease is also associated with abnormal ERGs

61

what is the basal ganglia involved in instead of vision

involved in movement so it won't effect vision directly

62

why is retinal activity changed in parkinson

due to lack of dopamine in the retina with parkinson's disease

63

name some visual deficits in parkinson's disease

- possibly decreased (low contrast) acuity
- abnormal saccadic and smooth pursuit eye movements (increased latency & reduced speed)
- decreased blinking
- large light adapted pupil. possible anisocoria. speed and amplitude possibly decreased
- longer latency and altered waveform of ERG and VEP - reduced temporal resolution
- possible triton colour defect (in blue pathway so tritanopic, associated with Alzheimer's)

64

which sort of visual functions are unaffected in parkinson\s disease

visual fields

65

how can akinesia (difficulty of movement) be alleviated

- by placing visual stimuli infant of the feet so px has something to aim for when walking

67

what can lead to akinesia (frozen movement)

irrelevent peripheral visual stimuli eg door frames inhibits movement

68

at what age does Alzheimer's disease usually occur

>70 years old

69

how many % of people over age 60 does alzheimer's disease effect

2%

70

how many % of people over age of 80 does alzheimer's disease effect

20%

71

what is alzheimer's disease characterised by

- loss of memory
- severely impaired judgement
- loss of emotional control
- eventually complete breakdown of mental function

72

how many phases does the progression of alzheimer's have

three

73

describe phase 1 of alzheimer's

- characterised by a slow deteriorating memory
- a feeling of disorientation in time and space
- inability to perform more complex tasks
- may get mood swings
- depression
- restlessness
- inability to sleep well
- disease may not be obviously apparent
- can last 5 years on average
- lose memory from recent things but can remember old things
- is not a bad stage when doing regular things e.g. making tea

74

describe phase 2 of alzheimer's

- more rapid
- deterioration of intellect and competence become more obvious
- blunting of emotions and apathy
- may get visual agonises (can't recognise faces)
- and dysphasia (use wrong words which are not understandable)
- possibility of delusions and hallucinations

75

describe phase 3 of alzheimer's

- represents the terminal stage
- may get epileptic fits
- general increase in muscle tone resulting in unsteady gait
- eventually become bed ridden
- and incontinent
- complete loss of personality
- patient fades away

76

what can the total duration of alzheimer's be

6-8 years

77

what type of disease is alzheimer's

terminal disease
so can end up dyeing from it

78

which risk factor of alzheimer's has a strong genetic component

family history of alzheimer's disease 3.5%

79

list the risk factors of alzheimer's and state the relative risk in %

1. family history of alzheimer's 3.5
2. family history of down's syndrome 2.7
3. previous head trauma
males 2.67
females 0.85
4. family history of parkinson's disease 2.14
5. depression 1.82
6. maternal age 40+ 1.7
7. epilepsy 1.6
8. encephalitis/meningitis 1.6
9. herpes zoster/simplex 1.15
10. general anaesthesis 1.0
11. alcohol 1.0
12. immune diorders, oesteoarthiritis, poliomyelitis, thyroid disease, headaches, smoking, solvent exposure, head injury, blood transfusion <1.0

80

list the neuropathology of alzheimer's

- thinning of the cortex
- sulci have widened
- gyri have thinned
- loss of tissue may be most severe in frontal and temporal lobes
- brain has less bulk
- ventricles are enlarged
- deposition of amyloid beta-protein in the form of 'senile plaques' (5-200um)
- and formation of neurofibrillary tangles

81

what is the difference of brain mass from a normal individual to an individual with alzheimer's

1350gms - 1000gms

82

which levels of neurotransmitter are reduced in presynaptic in alzheimer's

acetylcholine

83

which neurotransmitter receptors are intact in postsynaptic region

acetylcholine receptors

84

is there a proven drug therapy for alzheimer's

no

85

how does alzheimer's affect the retina

reduction in retinal ganglion cells & thinning of nerve cell layer&lose magno cells

86

how does alzheimer's affect the optic disc

- disc pallor
- optic atrophy
- disc cupping in the absence of open angle glaucoma in some patients

87

how does alzheimer's affect the optic nerve

- decline in nerve axons
- preferentially affecting the large diameter axons (Magno cell pathway)

88

how does alzheimer's affect the lateral geniculate nucleus

- accumulation of lipofuscin
- resistant to tangle (NFT) formation

89

how does alzheimer's affect the suprachiasmatic nucleus

- degeneration reported in some patients
- has lot of tangles and plaques in alzheimer's px so affects sleep patterns

90

where is the suprachiasmatic nucleus found

just above the optic chiasm

91

how does alzheimer's affect the visual cortex

- rarely atrophic
- myelin reduced in outer laminae
- loss of pyramidal cells

92

how does alzheimer's affect the B17 region

numerous cored senile plaques but few tangles
(pre stiate cortex affected)

93

how does alzheimer's affect the B18 region

numerous neuritic senile plaques and tangles

94

what affect does the release of acetylcholine by the parasympathetic nervous system have on the iris sphincter muscle

constriction

95

how do alzheimer patients' pupils respond to light

it constricts less due to reduced levels of acetylcholine

96

how does tropicamide affect an alzheimer's px

they are more sensitive to it which can prove that they have less acetylcholine

97

what other visual test is possible for early alzheimer's identification

- evidence indicates that in the early development of alzheimer's, beta-amyloid protein gets deposited in the lens forming a cataract behind the iris
- the level of amyloid proteins in the brain is reflected by the size of the lens deposit
- the cataract is apparent a significant amount of times before dementia develops