Movement disorders Basal Ganglia

Question 1

basal ganglia reflect the embryologically determined migaration of

Answer 1

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

Question 2

putamen and caudate are collectively called

Answer 2

the striatum

Question 3

putamen and globus pallidus collectively from

Answer 3

the lentiform nucleus

Question 4

basal gangliar output inhibits

Answer 4

the thalamus suppressing an excitatory thalamo-cortical projections.

Question 5

the degree of thalamic inhibitions dictates

Answer 5

modulation of the cortex dependent motor activity

Question 6

lesions affecting the basal ganglia commonly disturb

Answer 6

basal ganliar output.

Question 7

corticostriatal fibers release

Answer 7

glutamate to excite striatal neurons(cells forming caudate and putamen

Question 8

striatal cells are either

Answer 8

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

Question 9

the substantia nigra receives

Answer 9

inhbitory GABAergic signals from the striatum

Question 10

GABAergic output from the internal(medial)Globus inhibits

Answer 10

cells of the ventral anterior and ventral lateral thalamic nuclei.

Question 11

Thalamic cells excite

Answer 11

he motor cortex via the release of glutamate.

Question 12

Direct basal gangliar motor loop

Answer 12

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

Question 13

Indirect basal gangliar motor loop

Answer 13

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.

Question 14

dopamine from substantia nigra

Answer 14

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

Question 15

normal basal gangliar activity regulates

Answer 15

motor cortices to optimize communication between upper and lower motor neurons

Question 16

optimization of communication depends on

Answer 16

activities of direct and indirect basal gangliar components.

Question 17

unbalanced direct and indirect pathways can cause

Answer 17

hypo or hyper kinesis

Question 18

hypokinesis in parkinsons reflects

Answer 18

diminished release of striatal dopamine secondary to degeneration of nigrostriatal tract

Question 19

diminished dopamine in direct pathway.

Answer 19

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

Question 20

diminished dopamine in indirect pathway

Answer 20

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

Question 21

phenothiazines block

Answer 21

D2 receptorsin forebrain.

Question 22

Phenothiazines may limit

Answer 22

dopamine mediated inhbition of striatal neurons contributing to indirect pathway.

Question 23

drugs that deplete stores within the nerve endings may

Answer 23

diminish striatal output that affect both direct and indirect pathway

Question 24

metabolite of MPTP can damage

Answer 24

the nigral mitochondria

Question 25

Dementia pugilistica

Answer 25

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.

Question 26

Postencephalitic parkinsonism

Answer 26

viral infection that causes parkinsonism

Question 27

neoplastic parkinsonism

Answer 27

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

Question 28

huntington disease

Answer 28

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.

Question 29

syndeham disease

Answer 29

inflammation in the basal ganglia from rheumatic fever

Question 30

Drug induced chorea

Answer 30

treatmetn with L-Dopa can alter transmission within basal ganglia

Question 31

Athetosis

Answer 31

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

Question 32

Hemiballismus

Answer 32

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

Question 33

increased cortical activity can produce

Answer 33

contralateral ballismus

Question 34

catecholaminergic cells are generally vunerable to

Answer 34

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

Question 35

L-Dopa

Answer 35

precursor to dopamine increases syntehsis in surviving neurons in SNc.

Question 36

Peripheral decarboxylase inhibitors.

Answer 36

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

Question 37

stratial dopamine receptor agonists

Answer 37

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

Question 38

dopamine release-potentiating antiviral drug may

Answer 38

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

Question 39

MAO-B inhibitors supress

Answer 39

breakdwon of dopamine

Question 40

COMT inhibitors

Answer 40

reduces breakdown of dopamine

Question 41

Acetylcholine excites striatal neurons that

Answer 41

express D2 receptors which muscarinc antagonists suppress.

Question 42

muscarinic antagonists

Answer 42

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

Question 43

surgical subthalamic damage reduces

Answer 43

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

Question 44

stereotaxic surgical lesions of the internal globus pallidus (GPi)

Answer 44

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

Question 45

high frequency stimulation of the thalamus

Answer 45

directly increases excitatory output to the cortex

Question 46

stimulation of GPI may activate

Answer 46

local inhibitory neurons to decrease inhibitory output to thalamus

Question 47

boxcar ventricles

Answer 47

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

Question 48

the thalamus excites broadmans's area

Answer 48

6

Question 49

Striatum will always receive stimulation from

Answer 49

area 4 broadman's area