Basal Ganglia and Cerebellum

Question 0

What does Direct Pathway do?

Answer 0

Facilitates target-oriented movement

Question 1

What does the Indirect Pathway do?

Answer 1

Inhibits competing/unwanted movements

Question 2

Which Dopamine receptors are associated with Direct/Indirect Pathways?

Answer 2

Direct: D1
Indirect:D2

Question 3

Which parts of the thalamus does Globus Pallidus internus communicate with?

Answer 3

VA or VL

Question 4

What NT does Globus pallidus internus release?

Answer 4

GABA

Question 5

What NT does Globus Pallidus externus release?

Answer 5

GABA

Question 6

What NT does the STN release?

Answer 6

Glutamate

Question 7

What NT does the thalamus release to the cerebral cortex?

Answer 7

glutamate

Question 8

Describe the Direct Pathway

Answer 8

Cortex/ SN–> Putamen/Caudate (striatum) (D1 receptors)–> GPi–> VA or VL of Thalamus–> Cortex

Question 9

Describe the Indirect Pathway

Answer 9

Cortex/SN–> Putamen/Caudate (D2 receptors)–> GPe–> STN–> GPi–> VL or VA of Thalamus–> Cortex

Question 10

The Caudate, Putamen, and Nucleus Accumbens together form the____________

Answer 10

Striatum

Question 11

Together, the Putamen and Globus Pallidus for the ______________

Answer 11

Lentiform Nucleus

Question 12

Branches of which artery supply the Basal Ganglia?

Answer 12

MCA (lenticulostriate branches)

Question 13

Which part of the brain is selectively destroyed in Huntington’s?

Answer 13

striatum

Question 14

Which part of the brain is damages in Hemibalismus?

Answer 14

STN

Question 15

Name 2 therapies for Parkinson’s

Answer 15

L-DOPA, Deep Brain Stimulation, Pallidotomy,

Question 16

BONUS: Which part of the brain does the Caudate associate with?

Answer 16

frontal cortex (organization of behavior and personality)

Question 17

BONUS: Which part of the brain does the Putamen associate with?

Answer 17

cortical motor areas

Question 18

BONUS: which part of the brain does the Nuc. Accumbens associate with?

Answer 18

cingulate gyrus (affect and motivation)

Question 19

What are the functions on the flocculonodular lobe of the cerebellum?

Answer 19

eye movements, head position in space, balance

Question 20

What is the function of the vermis of the cerebellum?

Answer 20

truncal coordination/posture

Question 21

What is the function of the intermediate hemispheres of the cerebellum?

Answer 21

limb coordination, gait

Question 22

What is the function of the lateral hemispheres of the cerebellum?

Answer 22

planning, cognitive functions, motor learning

Question 23

What do the 3 cerebellar peduncles connect to?

Answer 23

Superior: Midbrain
Middle: Pons
Inferior: medulla

Question 24

Which cerebellar peduncle(s) mainly carry incoming afferent information?

Answer 24

Middle and Inferior

Question 25

Which cerebellar peduncle(s) carry OUTput information from the cerebellum? Which parts of the brain does this output info go? (2)

Answer 25

Superior peduncle Red Nucleus (midbrain) and VL of Thalamus

Question 26

What is the primary nucleus in the cerebellar deep nuclei?

Answer 26

Dentate Nucelus

Question 27

Where is the information going through the Middle Peduncle coming from? (Ipsilateral or Contralateral?)

Answer 27

CONTRALATERAL (info crosses IN Sup. Cerebellar puduncle) cortex via Basis Pontis--> corticopontine tracts mostly from supplementary motor cortex

Question 28

Name the 4 deep cerebellar nuclei from medial to lateral

Answer 28

Fastigial--> Globose--> Emboliform--> Dentate "Fat Guys Eat Donuts"

Question 29

What do you expect to find on physical exam with CEREBELLAR dysfunction? (8)

Answer 29

1) dysmetria 2) dysdiadokinesis 3) scanning speech 4) NEGATIVE Romberg sign 4) nystagmus 5) truncal ataxia 6) "Wide-based" gait 7) tremor (Intention tremor) 8) lack of coordination

Question 30

Define: Clasp-knife rigidity, Cogwheel rigidity, and Leadpipe rigidity

Answer 30

Clasp-Knife: increased tone followed by sudden loss of rigidity at end of external flexion (UMN damage) Cogwheel: catch and release (Parkinson's) Leadpipe: increased tone throughout passive movement

Question 31

Cerebellar dysfunction results in Contralateral or Ipsilateral deficits? Why?

Answer 31

Ipsipateral Inputs into the Inferior Peduncle come from IPSILATERAL dorsal spinal cerebellar tracts and inferior olive.

Question 32

Where is the information going through the Inferior Peduncle coming from? (Ipsilateral or Contralateral information)

Answer 32

Inputs from IPSILATERAL dorsal spinocerebellar tract (proprioception from muscle spindles) and inferior olive, vestibular nuclei and eye muscles

Question 33

Which arteries supply the cerebellum?

Answer 33

SCA, PICA, AICA

Question 34

How many cellular layers are in the cerebellar cortex? What are they?

Answer 34

3- Molecular, Purkinje, and Granular

Question 35

Describe the major pathway of the cerebellum (starting with Climbing Fibers)

Answer 35

Climbing fibers from inferior olive--> Purkinje cells--> inhibit deep cerebellar nuclei (Dentate)--> Red Nuc. and VL of thalamus--> Primary motor cortex--> pons--> contralateral cerebellar cortex (Mossy fibers)

Question 36

Can damage to cerebellar inputs look like cerebellar lesion?

Answer 36

YES!

Question 37

What can happen cerebellum expands?

Answer 37

Upward herniation--> CSF outflow obstruction, sleepiness, or midbrain syndrome (upward gaze) Anterior dislocation--> CSF outflow obstruction Downward herniation--> compress essential medullary structures

Question 38

Define: Akathisia

Answer 38

motor restlessness

Question 39

Define: Athetosis

Answer 39

slow, writhing movements

Question 40

Define: Ballism

Answer 40

Proximal, large-amplitude chorea. Typically unilateral.

Question 41

Define: Chorea

Answer 41

Non-rhythmic, unpredictable movements. Involuntary, randomly flowing jerks of muscles

Question 42

Define: Dystonia

Answer 42

Abnormal posture, result of co-contraction of agonist/antagonist muscles. May also have twisting, repetitive movements

Question 43

Define: Myoclonus

Answer 43

Shock-like movements due to muscle contraction (positive myoclonus) or abrupt loss of muscle tone (negative myoclonus)

Question 44

Define: Stereotypy

Answer 44

Purposeless repetition of motor set of movements

Question 45

Define: Tic

Answer 45

Patterned simple or complex paroxysmal movements. Subjective sense of relief after movement

Question 46

Define: Tremor

Answer 46

Rhythmic movement, with amplitude and frequency in sine wave

Question 47

Define: Akinesia

Answer 47

lack of purposeful movement

Question 48

Define: Badykinesia

Answer 48

slowness of movement

Question 49

Define: Dysdiadochokinesia

Answer 49

Abnormal rapid-alternating movements

Question 50

Describe the different signs from Medial and Lateral cerebellar lesion

Answer 50

Medial (vermis, fastigial nucleus, flocculonodular lobe): truncal ataxia, nystagmus, head tilting, wide-based gait Lateral: propensity to fall TOWARD injured side (ipsilateral).