Cerebellum (Keim)

Question 1

General concepts about the cerebellum:

Answer 1

Receives input but does NOT interpret it
Rarely results in muscle paralysis
Has motor and procedural learning components
Talks to other tracts

Question 2

Functions of cerebellum

Answer 2

Coordination, posture (+ the motor and procedural learning)

Question 3

Layers of gray matter in the cerebellum and what do they contain?

Answer 3

Molecular (basket cells and stellate cell bodies)
Purkinje (has the purkinje cell bodies)
Granular (has granule cells and few Golgi cells)

Question 4

What are purkinje cells?

Answer 4

Output cells (efferents that take info from cerebellum to muscles
Inhibit the cerebellar and vestibular nuclei
GABA is NT(coz inhibitory)

Question 5

What are granule cells?

Answer 5

Excitatory, NT is glu

Question 6

What are other inhibitory cells in the cerebellar grey matter and what do they inhibit?
What is their NT?

Answer 6

Stellate (inhibits purkinje) - in molec layer
Golgi
Basket (inhibits Purkinje) - in molec layer

-GABA

Question 7

What are climbing fibers?

where they come from, what they excite, function

Answer 7

Arise from inferior olive. Afferents that excite the purkinje and deep cerebellar nuclei. Sends info about movement errors to cerebellum

Question 8

What are mossy fibers?

where they come from, what they excite, function

Answer 8

Arise from spinal cord, not the olive. Afferents excite granule cells and deep cerebellar nuclei
Sends info about somatosensory, arousal, equilibrium and cerebral cortex motor info to cerebellum so we can do the right movement

Question 9

Vestibulocerebellum
Receives input from?
Output to?
Overall general function?

Answer 9

Aka flocculonodular lobe.

• vestibular apparatus and vestibular nuclei
• back to vestibular nuclei which….
• influence eye movements and postural muscles of head and body (where am I at?)

Question 10

Spinocerebellum
Info from?
Overall general function?

Answer 10

Aka vermis and the surrounding paravermal region
Somatosensory from spinal interneurons and sensorimotor cortex
Influence medial and lateral UMNs which control ongoing movement. Important in gait

Question 11

Pontocerebellum/cerebrocerebellum
Input from?
Function?

Answer 11

Cerebral cortex (motor and sensory etc.) via the pontine nuclei
Coordination of voluntary movements, planning and timing of movements

Question 12

Draw the big pictures schematic of the cerebellar pathways

Answer 12

Ok

Question 13

What afferents send input to the cerebellum?

Via which fibers?

Answer 13

Vestibular system (vestibular nuclei, CN VIII)
Spinal Cord (anterior and posterior spino-, cuneo-)
Cerebral cortex (cortico ponto-,olivo-, reticulo-)

*all via mossy fibers, except cortico-olivo-cerebellar (climbing fibers since coming from olive)

Question 14

Afferents coming from the vestibular system and spinal cord enter via…
Afferents coming from the cortex enter via …

Answer 14

• internal cerebellar peduncle

- Middle cerebellar peduncle

Question 15

Draw the cerebellar tracts (posterior, cuneo and ventral)

Answer 15

ok

Question 16

What information does the posterior spinocerebellar tract carry?

Answer 16

Touch, proprioception and pressure sensation from lower limb

Question 17

What information does the cuneocerebellar tract carry?

Answer 17

Touch, proprioception and pressure sensation from upper limb

Question 18

Significance of the superior cerebellar peduncle

Answer 18

Efferents descending from the globose emboliform and dentate nuclei, as well as afferents from the ventral spinocerebellar tracts pass thorough here

Question 19

Significance of the middle cerebellar peduncle

Answer 19

Afferents from pontine nuclei pass here to cortex

Question 20

Significance of the inferior cerebellar peduncle

Answer 20

Afferents from spinal cord pass through here

Question 21

General functions of the vestibulocerebellum:

Answer 21

Eye, neck and trunk movements

Question 22

General functions of the spinocerebellum:

Answer 22

Axial and lower extremity movements, gait and station

Question 23

General functions of the cerebrocerebellum

Answer 23

Precise, coordinated movements of the extremities (mainly upper)

Question 24

Draw the efferent cerebellar tracts

Answer 24

Ok

Question 25

What is the Inferior olivary nucleus tract important for?

Answer 25

Sends fibers back to the cerebellum. Important for correction of motor errors

Question 26

Nature of cerebellar lesions.

Answer 26

Unilateral lesion affects the ipsilateral side

Question 27

Ataxia:

Answer 27

Specific to the cerebellum (problem with afferents and efferents)
Voluntary jerky, inaccurate movements, wide based gait

Question 28

Lesions of the vestibulocerebellum

Answer 28

Disrupts the integration of the vestibular system and flocculonodular lobe.
Nystagmus (beating of the eyes), truncal ataxia and truncal instability

Question 29

Truncal ataxia

Truncal instability

Answer 29

can’t maintain sitting or balance. wide spaced gait

Cannot stand still/rocking, can’t tandem walk

Question 30

Spinocerebellum lesions

Answer 30

Disrupts the connections between the cutaneous and proprioceptive tracts from the spinal cord to vermis region
Wide base gait and truncal ataxia

Question 31

Damage to vestibulocerebellum and spinocerebullum generally result in…

Answer 31

Midline ataxia

Question 32

Midline ataxia

Answer 32

Caused by vestibulo and spinocerebellar disease

Truncal instability. Tremor of trunk (titubation) and gait ataxia

Question 33

Lesions of the cerebrocerebellum

Answer 33

Dysarthria: slurred speech (difficulty articulating)

Gait ataxia - tend to fall toward side of lesion

Question 34

Limb ataxia due to cerebrocerebellar damage:
Dysdiadochokinesia
Dysmetria
Action tremor

Answer 34

• cannot rapidly alternate movements
• cannot move an intended distance
• shaking of limb during voluntary movement

Question 35

Appendicular ataxia

Answer 35

Cerebellar hemisphere dysfunction
Scanning dysarthria (speech ataxia), hypotonia, dysmetria, dysdiadochokinesia, decomposition of movement

Question 36

Cerebellar ataxia

Answer 36

Positive romberg test - Unable to stand with feet together (with or without eyes open)
Normal vibratory, proprioception and ankle reflex

Question 37

Sensory ataxia:

Answer 37

Positive Romberg test - Can stand with feet together and eyes open, but not when closed.
Abnormal vibratory, proprioception and ankle reflex

Question 38

How would you test vestibulo or spinocerebellum dysfunction?

Answer 38

Test station, walking and tandem gait

Question 39

How would you test cerebrocerebellum dysfunction?

Answer 39

Test rapid alternating movements, finger to nose/toe to finger/heel to shin, rebound and check reflex, speech