Movement disorders Basal Ganglia Flashcards

1
Q

basal ganglia reflect the embryologically determined migaration of

A

neurons away from the cerebral parventrictular zone which embeds an island of gray matter in the white matter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

putamen and caudate are collectively called

A

the striatum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

putamen and globus pallidus collectively from

A

the lentiform nucleus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

basal gangliar output inhibits

A

the thalamus suppressing an excitatory thalamo-cortical projections.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

the degree of thalamic inhibitions dictates

A

modulation of the cortex dependent motor activity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

lesions affecting the basal ganglia commonly disturb

A

basal ganliar output.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

corticostriatal fibers release

A

glutamate to excite striatal neurons(cells forming caudate and putamen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

striatal cells are either

A

excited or inhibited by dopamine arising from the substantia nigra pars compacta (SNc)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

the substantia nigra receives

A

inhbitory GABAergic signals from the striatum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

GABAergic output from the internal(medial)Globus inhibits

A

cells of the ventral anterior and ventral lateral thalamic nuclei.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Thalamic cells excite

A

he motor cortex via the release of glutamate.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Direct basal gangliar motor loop

A

SNc via D1 receptors sends input to neostriatusm which sends inhibitory GABA to globus pallidus(internal) -decerased output form GPi increaseses thalamic activity which increases cortical acitivty to facilitate movement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Indirect basal gangliar motor loop

A

Striatal output suppreses GPe, decreases output from GPe increases output from Sth. increased output form Sth increases activity within GPi. increased activity of GPi inhibits thalamic acitivty which will decrease thalamic output and diminish movement.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

dopamine from substantia nigra

A

optimizes output of the two basal ganliar circuits to normalize movement.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

normal basal gangliar activity regulates

A

motor cortices to optimize communication between upper and lower motor neurons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

optimization of communication depends on

A

activities of direct and indirect basal gangliar components.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

unbalanced direct and indirect pathways can cause

A

hypo or hyper kinesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

hypokinesis in parkinsons reflects

A

diminished release of striatal dopamine secondary to degeneration of nigrostriatal tract

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

diminished dopamine in direct pathway.

A

diminished D1 reduces striatal putput, which diminishes the inhibition of GPi, this suppreses the thalamus and the thalamus activity decreases coritcal output suppressing movement.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

diminished dopamine in indirect pathway

A

decreased stimulation of D2 dis inhibits striatal cells, striatal cells are more active and that decreasesGPe, which increases Sth activity which increases GPi which suppreses thalamic activity which decreses cortical excitation and diminishes volutnary movement

21
Q

phenothiazines block

A

D2 receptorsin forebrain.

22
Q

Phenothiazines may limit

A

dopamine mediated inhbition of striatal neurons contributing to indirect pathway.

23
Q

drugs that deplete stores within the nerve endings may

A

diminish striatal output that affect both direct and indirect pathway

24
Q

metabolite of MPTP can damage

A

the nigral mitochondria

25
Q

Dementia pugilistica

A

midgrain flexes which can tear blood vessels and shear axons, dura can cause damage to to midbrain during excessive acceleration, cumulative blows to head can damage substantia nigra.

26
Q

Postencephalitic parkinsonism

A

viral infection that causes parkinsonism

27
Q

neoplastic parkinsonism

A

neoplasia impacting the substantia nigra or its output pathway to striatum.

28
Q

huntington disease

A

uncontrolled grimacing, choreatic activity assuming a piano playing posture. -bilateral degenration of striato-pallidal neurons expressing D2 receptors, changes IP -increased thalamic output leading to hyperkinesis.

29
Q

syndeham disease

A

inflammation in the basal ganglia from rheumatic fever

30
Q

Drug induced chorea

A

treatmetn with L-Dopa can alter transmission within basal ganglia

31
Q

Athetosis

A

slow continuous writing movements can reflect striatal or thalamic injury, these can overlap abnormal movements.

32
Q

Hemiballismus

A

unilateral stroke to subthalamus with contralateral limb affeted. decreased GPi causes increased thalamic output and inceasesd cortical activity

33
Q

increased cortical activity can produce

A

contralateral ballismus

34
Q

catecholaminergic cells are generally vunerable to

A

lesions that lead to parkinsons diseas(pontine coeruleu and peripheral noradrenergic cells.)

35
Q

L-Dopa

A

precursor to dopamine increases syntehsis in surviving neurons in SNc.

36
Q

Peripheral decarboxylase inhibitors.

A

reduces peripheral metabolism of L-dopa which increases levels needed in brain.

37
Q

stratial dopamine receptor agonists

A

D2 agonists interact with indirect basal gangliar circuit D2 and D1 combined agonists interact with both direct and indirect.

38
Q

dopamine release-potentiating antiviral drug may

A

reduce akinesia and rigidity. may release dopamine and block ACh receptors, there are pshychiatric side effects

39
Q

MAO-B inhibitors supress

A

breakdwon of dopamine

40
Q

COMT inhibitors

A

reduces breakdown of dopamine

41
Q

Acetylcholine excites striatal neurons that

A

express D2 receptors which muscarinc antagonists suppress.

42
Q

muscarinic antagonists

A

decrease output from striatum to GPe which decreases GPi and increases thalamus and cortical function normalizing motor function, good for resting tremors,

43
Q

surgical subthalamic damage reduces

A

the excitatory inputs to GPi which disnhibits the thalamus, can cause ballisums

44
Q

stereotaxic surgical lesions of the internal globus pallidus (GPi)

A

directly reduces inhibitory input to the thalamus which cuases thalamus to be free to restore cortical excitation to reverse hypokinesia

45
Q

high frequency stimulation of the thalamus

A

directly increases excitatory output to the cortex

46
Q

stimulation of GPI may activate

A

local inhibitory neurons to decrease inhibitory output to thalamus

47
Q

boxcar ventricles

A

degeneration fo the striatal cells and efferent trats along the frontal cortices, lateral ventricular enlargments.

48
Q

the thalamus excites broadmans’s area

A

6

49
Q

Striatum will always receive stimulation from

A

area 4 broadman’s area